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V205
07-10-2005, 09:20 PM
Can we permanently turn off the VSA somehow? Remove the VSA fuse or something like that?

I much prefer driving my euro without VSA.. sick of turning it off everytime I start the car....

stephen8512
07-10-2005, 09:37 PM
hmm not sure
this is sorta off topic but if u have VSA on, does it use more petrol?
becoming a petrol nazi nowadays cuz of the damn prices........cant hit VTEC too many times

coladuna
07-10-2005, 10:04 PM
hmm not sure
this is sorta off topic but if u have VSA on, does it use more petrol?
becoming a petrol nazi nowadays cuz of the damn prices........cant hit VTEC too many times

I doub it affects fuel consumption.
It doesn't even do anything unless you push the car really hard.
The only times I can get it to become active on dry road is when I launch suddenly in 1st gear on an uneven road.
I never turn it off even when the road is slightly wet.

yfin
07-10-2005, 10:41 PM
Look out - hard core Euro driver! http://www.acurazine.com/forums/images/smilies/gheywave.gif

Check the fuses above the intake lid. There is a diagram under the lid - I think there is one for VSA. Just check ABS is not affected.

Omotesando
08-10-2005, 12:53 AM
one push of a button lol!

wouldnt turn it off on a FWD car at all, no point, especially when aust spec doesnt have rear wheels VSA traction sensors.

Can still get throttle off oversteer or mid-turn braking oversteer if you want it, but without sacrificing the traction control when u need it most - when it goes to understeer!

aaronng
08-10-2005, 03:00 AM
It's like to start your car, you have to put the key in and twist. Pressing a button that is only 10cm from your ignition shouldn't take much effort. Treat it as finger exercise!

Omotesando: It is interesting that we don't have rear sensors. It makes the car more willing to do lift-oversteer and power understeer, which is a nice way of controlling the car at the limit. I think they purposely did this so that the driving aggressiveness was preserved in the European models (they also get the 140kW model). Only Australia and Europe get the 140kW FWD model. In the US, it's 147kW and in Japan, the 147kW is FWD while 140kW is the 4WD wagon. So the odd combo of 140kW + FWD could have a good advantage.

wynode
08-10-2005, 03:06 AM
VSA will help your tyres last longer :)

Omotesando
08-10-2005, 03:48 AM
The Euro Accord handles really well for a FWD... seriously :)

Honda cards are unbelievable... I still remember my POS lancer two cars ago, it was absolutely rubbish! So was the recent magna rental car I drove!


By the way, Aaronng, do u know if the Euro Spec in Japan uses the K20A exclusively because I have seen some that uses the Type-R engine, with 8400RPM redline, when I was working in Japan - although didnt bother to see if they use the K24s in other models!

aaronng
08-10-2005, 03:57 AM
There is the regular K20A Euro that only has 118kW and comes in FWD and 4WD sedans. These have only 6000rpm+ redline

The EuroR is the one with the Type-R K20A. It has 220ps, which is about 160kW, same as the JDM DC5R. You can tell them from the Recaro seats, EuroR badge and of course, the 8400rpm redline.

There are K24A models too. And there are 147kW FWD-only models (sedan and wagon), and 140kW 4WD Wagon. 7100rpm redline on these.

K24A2 (TSX, JDM Euro): FWD sedan and wagon
K20A4 (JDM Euro): FWD and 4WD, sedan and wagon
K24A3 (JDM Euro wagon): 4WD wagon. And of course, the Aussie spec Euro in FWD Sedan.

Weird eh?

tknova
08-10-2005, 09:26 AM
I would personally leave VSA on & only turn it off when needed.

What happens if something happens out of the blue while your driving on the freeway at 100km/h VSA just may save your life & somebody elses in another car or even your car.

I'm sure you don't boot your euro everywhere you drive. VSA will save wear on your tires from spinning aswell! :)

I only turn it off if i need it too be off, which is very rarely.

Bit off topic but i'm sure if you really need to turn it off you can locate the fuse under the dash. Make sure it doesn't send any error codes by having it unplugged. I don't think it will effect your ABS as there should be a different fuse for that.

Can i ask why you want it off all the time?

yfin
08-10-2005, 11:50 AM
wouldnt turn it off on a FWD car at all, no point, especially when aust spec doesnt have rear wheels VSA traction sensors.

Can still get throttle off oversteer or mid-turn braking oversteer if you want it, but without sacrificing the traction control when u need it most - when it goes to understeer!

VSA will cut engine power going around hard corners so there is a point to turn it off. Sometimes it does it mid corner which can unsettle the car. You really only need it in the wet.

Not sure what you are saying re rear VSA traction sensors. Even if that is true - the car must (should) have G sensors at the rear - otherwise how does it know the car is oversteering? :confused: It must have something to tell it the position of the rear and front of the car along with steering position, etc. I have seen the VSA correct oversteer in the euro. My old tyres weren't very good in the wet once they started to wear. I could get traction control to activate even in 4th gear.

tknova
08-10-2005, 02:51 PM
Ofcource it cuts power when understeer is present to control wheel spin

But, when your going in city traffic or on the freeway is there really a need to have it off if your not trying to go as quick as you car around a corner?

yfin
08-10-2005, 04:04 PM
Ofcource it cuts power when understeer is present to control wheel spin


When my car was stock it sometimes cut power around corners if there was lots of body roll. No wheel spin. No understeer. It still did it.



But, when your going in city traffic or on the freeway is there really a need to have it off if your not trying to go as quick as you car around a corner?


No need to have it off.

Omotesando
08-10-2005, 06:06 PM
Well this is starting to get interesting haha! Apparently VSA is two components , so hence it is not just just called Traction Control...


Usually the Traction Control part will cut the power when detecting there is a wheel spinning, and on a car without a helical LSD such as Euro this is usually the inside wheel during cornering, or may be both wheels when accelerating uphill, etc?? I dont know the technical details of the Traction Control on our Euro but usually they cut off Spark Plugs but keeps the fuel flowing so engine wouldnt run lean.


The other part of the VSA which controlled the oversteer or understeer is the brakes, which is applied individually when it senses one corner is losing it. I would say yfin is correct that there should be g-sensors in front and back!



But when you said that it cut power where there was lots of body roll, it was probably not the traction control but the VSA activating the brakes automatically to stabilise vehicle (I assume this latter technology is linked to the EBD system somehow) ....


Anyway with VSA on you can still get the oversteer going, trust me ! lol!!

aaronng
08-10-2005, 06:26 PM
Euro's Traction control: If 1 wheel spins, it brakes the other wheel so up to 50% torque is transferred (cheap man's LSD). If both wheels spin, then it cuts the throttle. By spark plug or by fuel, I'm not sure about that.

wynode
08-10-2005, 06:52 PM
The other part of the VSA which controlled the oversteer or understeer is the brakes, which is applied individually when it senses one corner is losing it.



That's not all. VSA will activate the brakes individually if you have to make any evasive manouveres. Say you have to make a sudden turn of the wheel to avoid a dog crossing the road, VSA will give you more control by applying the inside rear brake to help you turn.

I believe under/over steer is detected by a accelerometer (usually placed in the centre of the car) and the position of the steering wheel (depending on the speed). It will then apply the brakes individually if rqd.

tknova
08-10-2005, 07:47 PM
That's not all. VSA will activate the brakes individually if you have to make any evasive manouveres. Say you have to make a sudden turn of the wheel to avoid a dog crossing the road, VSA will give you more control by applying the inside rear brake to help you turn.

I believe under/over steer is detected by a accelerometer (usually placed in the centre of the car) and the position of the steering wheel (depending on the speed). It will then apply the brakes individually if rqd.

Spot on! That's why i think VSA should always be on until you flick the switch turning it off.

Omotesando
08-10-2005, 11:37 PM
Euro's Traction control: If 1 wheel spins, it brakes the other wheel so up to 50% torque is transferred (cheap man's LSD). If both wheels spin, then it cuts the throttle. By spark plug or by fuel, I'm not sure about that.



I think for a really good driver all this technology might not be so good afterall lol!! :D


Are you pretty sure about how our VSA Traction control works, by braking the individual wheel if only 1 wheels loses traction? Because even a Race Logic Traction control unit doesnt do this it just plains cuts off power, even though it allows a certain amount of slip such as 5%, 10%, etc,..

And if it does I thought it will brake the wheel that is spinning? :confused: Why does it brake the other wheel? Getting confused!!

aaronng
09-10-2005, 12:52 AM
LOL, my mistake. You are right. It brakes the spinning wheel. You won't be able to feel it when it brakes the spinning wheel. But the onset of both wheels spinning is slightly delayed. Try turning from a stop with more throttle, with traction control on and off. There should be a difference.

It depends on how ABS is implemented. On older cars with ABS, the ABS system is 2 channel. One for the front left and rear right, and the 2nd for the front right and rear left. The Euro has a 4 channel system, one for each wheel. This is how it makes VSA work.

The VSA software is able to utilise the ABS channel to brake each wheel. And since traction control and VSA are PROBABLY tied to the same system (same software, deactivated by the one button), then the traction control system is not similar to a Race Logic traction control system, but more of an "option" in VSA. VSA detects wheel spin when you are turning to determine understeer or oversteer and brake the proper wheel to counter it. When you are turning and you end up spinning the inner wheel and thus end up understeering, the VSA just brakes the inner wheel so you can turn. Basically it is an LSD effect, just not as good as a real mechanical LSD. And traction control is a situation in VSA where both wheels spin when the car is going straight.. I SPECULATE that the Euro does not have a separate traction control software module, but rather it is built into the VSA system as a pre-programmed scenario.

wynode
09-10-2005, 01:44 AM
On older cars with ABS, the ABS system is 2 channel. One for the front left and rear right, and the 2nd for the front right and rear left.

I'm not sure how true that is given the front does upto 75 percent of braking. With cars like the integra Vti-r (somewhat 'older' than the euro), they run a 3 channel ABS system. 2 Channels for each of the front two wheels and 1 channel for the rear wheels.

In regards to the Euro it is true to say that traction control and VSA are both disabled by the one switch however they are both seperate systems IMO. Traction control is primarily there to cut the throttle when wheel spin is detected at the front wheels.

VSA is there to increase vehicle stability and keep the driver in control of the car. From what I have read about other manufacturers, the stability program detects under/over steer and brakes the wheels individually in order to give the driver maximum control.

Aarong, I'm not sure you if you could call VSA a 'cheap' implementation of a LSD as an LSD actively transfers power from one wheel to another depending on the level of grip. VSA can't do this.

This looks like a good thread :thumbsup:

Anyone got some links to the EUROs stability program?

aaronng
09-10-2005, 02:39 AM
I thought that since the traction control uses the same wheel spin sensors as the VSA that hardware is the same as the VSA. My argument is that traction control is not a separate unit, but one that is part of the VSA. Like a tiny software module in the VSA that has the logic "if both wheels spin and no g-sensor activity, THEN cut throttle"

Honda Japan's website for model data shows "VSA (ABS+TCS+Sideslip control), translated of course. So I tend to see the ABS, TCS and stability control as one unit.

With an open diff, if the spinning wheel is braked so that there is more resistance than the non-spinning wheel, then torque will transfer to the non-spinning wheel. It's inducing a outer wheel spin instead of an inner wheel spin.

aaronng
09-10-2005, 02:52 AM
There is a description of what VSA does in situations of understeer, oversteer and wheelspin. But a babelfish of the page is difficult to understand:


The function of VSA
- At the time of oversteer control (revolution, behavior stabilization) when the involvement of the vehicle occurs
- At the time of understeer control (revolution acceleration, with respect to) road surface trace propensity when locus of the driving wheel is filled
- With respect to takeoff propensity when road surface circumstance of the takeoff control (left and right wheel is different)
- Stability improvement > at time of control < braking of braking

* As for VSA it is the system which to the last assists the brakes operation and accelerator operation etc. of the driver. Therefore, same as the vehicle which is not VSA, foreward the corner and the like sufficient deceleration is necessary, it cannot control to unreasonable driving. We request careful driving.

What I think it says:
The function of VSA:
- At the time of oversteer, the system tries to control the vehicle turn rate and stabilise the vehicle behaviour.
- At the time of understeer, the system tries to control the acceleration, (with respect to the difference in the direction of the vehicle movement on the road and the direction the tyres are pointing.
- Controls acceleration force when the road surface is different for the left and right wheels. (I think different wheel speeds)
- Stability improvement by brake control

* VSA is a system that assists in brake and accelerator operation for the driver. Therefore vehicles that are not equipped with VSA should anticipate the corners and decelerate sufficiently. It cannot control irresponsible driving (Hooning! lol). Please drive carefully.

aaronng
09-10-2005, 03:12 AM
More info... Yum yum. Got this from tsx.acurazine.com where they got info from Acura about the TSX's VSA.

Originally Posted by Acura Website
Vehicle Stability Assist (VSA) adds side-slip control to the ABS and traction control. It works by controlling brake pressure, engine power or both to help maintain traction. Even if you take no action, VSA will reduce engine power and/or apply the brakes to reduce front or rear side-slip. The traction control component of VSAŽ uses sensors that monitor the front wheels and computer-controlled modulation of engine power and front brakes to help prevent wheel spin when starting out or accelerating. If the sensors detect excessive front-wheel spin during acceleration, the traction control function automatically closes a secondary throttle valve until wheel spin stops. This helps the TSX maintain traction during acceleration and helps the driver retain steering control, even when accelerating on slippery surfaces.

And stuff I found from www.acura.com

The traction control component of VSAŽ uses sensors that monitor the front wheels and computer-controlled modulation of engine power and front brakes to help prevent wheel spin when starting out or accelerating. If the sensors detect excessive front-wheel spin during acceleration, the traction control function automatically closes a secondary throttle valve until wheel spin stops. This helps the TSX maintain traction during acceleration and helps the driver retain steering control, even when accelerating on slippery surfaces.
So traction control does use the front brakes. And the only thing I can think of to use the front brakes in a situation needing traction control is when 1 wheel is spinning. If both wheels were spinning excessively, then it would be better to cut the throttle instead.

wynode
09-10-2005, 02:03 PM
Interesting read that and I think you make a valid point about using the brake if one wheel is spining and cutting the throttle if both wheels are spining :thumbsup:

aaronng
09-10-2005, 07:07 PM
Yeah. I first read about it in one of Porsche's old "fake" LSD software. Usually the inner wheel spins because there is less resistance than the outer wheel during turning. By braking the inner wheel, it creates a situation where the outer wheel would have less resistance and so the torque goes there. But being only an open diff, at max 50% of torque can be sent to the outer wheel, no way close to a real LSD. But I guess for the heavy Euro, with no LSD and robbed of 1000rpm hi-cam range, we have to take what we get. :)

Omotesando
10-10-2005, 10:27 PM
That's some great information there.... I think most VSA systems work pretty much the same on newer cars these days, although probably what matters most is how much the reaction time is!


ABS is not actually part of the VSA however, because ABS is purely and can only be activated by your foot. It is not an automatical function.


However, they are separate but RELATED in a way, as I have already mentioned earlier on regarding E.B.D. (electronic brake distribution), because VSA uses the ABS/EBD computer to work out how to brake each wheel individually when VSA is automatically activated due to various reasons, and it is required to steady the car.


E.B.D. itself is an extension to A.B.S. but it too isn't automatically activated because it only comes into action when you are braking yourself, and that's braking very hard on slippery surface or crappy tyres.

V.S.A utilizes this as well as power-cut-off traction control. It is on top of everything, but if you turn V.S.A. off the car will still have E.B.D. and A.B.S. readily available when you brake hard enough!




Also, braking one individual wheel when there is one wheel spinning - might seem to have similar effect as a helical LSD or AYC system, but it doesn't. It is not an LSD equivalent because it did not TRANSFER torque to the outside, less-spinning wheel.


In fact, it reduces the torque on the wheel in concern, which doesn't give the car more traction going through the corner like a proper LSD would, on say a Civic or Integra Type-R, but barely reduces the car's speed so it is still within traction limits and isnt sliding around any longer!

It won't increase the cornering speed or ability of a car like an LSD would. :)

wynode
10-10-2005, 11:50 PM
EBD and VSA utilise the underlying ABS system. That's the primary link between them guys.

aaronng
11-10-2005, 12:12 AM
Also, braking one individual wheel when there is one wheel spinning - might seem to have similar effect as a helical LSD or AYC system, but it doesn't. It is not an LSD equivalent because it did not TRANSFER torque to the outside, less-spinning wheel.


In fact, it reduces the torque on the wheel in concern, which doesn't give the car more traction going through the corner like a proper LSD would, on say a Civic or Integra Type-R, but barely reduces the car's speed so it is still within traction limits and isnt sliding around any longer!

It won't increase the cornering speed or ability of a car like an LSD would. :)
AYC works like the VSA braking, but instead uses clutches to transfer torque between the left and right. It's similar to the VSA one but it works without needing to wait for slip to occur. Edit: I just found out, AYC is very similar to the ATTS that was in the Prelude VTi-R ATTS. Any members with experience on the ATTS?

The braking of one wheel does transfer torque to the outer wheel, so you do get an LSD effect. The difference is that Helical LSDs like the one used in the Type R can PREVENT inner wheel spin since the outer wheel is balanced in torque as the inner wheel BEGINS to want to spin. VSA on the other hand has to DETECT the wheelspin first before braking. So VSA is slower in reaction compared to LSD.

The 2nd thing is that the Euro still has an open diff, so with the VSA braking the inner wheel, the maximum torque that can be transferred to the outer wheel is 50%. You're right that it won't corner as fast as compared to when you are not spinning your inner wheel, but in situations where you are spinning the inner wheel, it tries to improve it as much as possibe.

Omotesando
11-10-2005, 06:39 AM
The original invention of a Differential was so that the car can actually turn into a corner as the two driving force tyres would have to trace a different radius of a circle, as the outer wheel needs to rotate slightly faster. Impossible on a solid front axle of course.


The problem on an Open Diff vehicle is that the diff actually wants to transfer more torque to the more freely spinning wheel. When you turn in, the car's loading, thereby grip advantage, is actually all on the outer wheel, making the inner wheel wanting to Slip (or spin).... eventually the open diff will act counter-actively by transferring even more torque to this wheel..... making the car understeer.



On a Limited Slip Differential this is the opposite.

Through a limited slip device such as a Viscous Diff, Helical Diff or a Clutch Type Diff, what happens is as soon as the inner wheel sense a slip, it does the right thing by instantly transferring greater torque to the wheel which has more grip, the outside wheel.



With a VSA system intervening, you are basically trying to apply a single brake on the slipping inner wheel when it is receiving the maximum torque, trying to slow this wheel down forcefully and externally. Unfortunately unlike an internal LSD device which has Diff Oil to cope with the frictions involved, you are attempting to exert a large effort on a wheel receiving the bulk of the torque using only your 'brake pad', in order to try slow down the wheel enough so that it won't receive more torque as it slips further. The idea is not to transfer more torque to the outside wheel because your brake pad isn't designed to handle torque for torque and this is while you still have your foot on the accelerator!! You are losing a lot of energy anyway, plus wearing out parts. During the whole transition, the brake pad is still biting hard on the wheel which is constantly receiving some torque.


Whilst this could potentially make the car turn in better, though reaction time a bit slower than LSD, this still doesn't give it a normal LSD effect because VSA is a passive system that's only activated over the limit. On a longish, high speed corner where the inside wheel doesn't have anywhere near enough torque to break traction even if car is already understeering, the VSA simply wouldn't turn on. On an LSD equipped car the more active system will be much more sensitive, starting to transfer the correct amount of torque to the outside loaded wheel 'linearly' and 'gradually', pulling/pushing the car into the corner better.



Secondly and very importantly when launching the car in a 'straight line', a proper LSD will ensure that you can get the best tyre traction, no torque steer due to diff torque between the wheels and the ability to still spin both tyres just a tad to get the best acceleration. This is especially true launching in the wet.


On the Euro Accord the VSA system is linked with a power-off or braking-power traction control system, so whether you turn it on or off, you won't get the launching effect of a proper LSD equipped car... LSD isn't just for cornering afterall!





As for the Prelude's ATTS system, it isn't a very sensitively incremental system, certainly nowhere near the reaction time of the Mitsu Evo's active-yaw and acd system. Although it is definitely better than a VSA system that is only mean to work PASSIVELY!

aaronng
11-10-2005, 01:06 PM
With a VSA system intervening, you are basically trying to apply a single brake on the slipping inner wheel when it is receiving the maximum torque, trying to slow this wheel down forcefully and externally. Unfortunately unlike an internal LSD device which has Diff Oil to cope with the frictions involved, you are attempting to exert a large effort on a wheel receiving the bulk of the torque using only your 'brake pad', in order to try slow down the wheel enough so that it won't receive more torque as it slips further. The idea is not to transfer more torque to the outside wheel because your brake pad isn't designed to handle torque for torque and this is while you still have your foot on the accelerator!! You are losing a lot of energy anyway, plus wearing out parts. During the whole transition, the brake pad is still biting hard on the wheel which is constantly receiving some torque.
Yes, the brake pads and discs take a beating. However the VSA system still tries to do that and do a half-hearted emulation of an LSD. I'm not arguing that the VSA is even 1/2 as effective as a torsen diff. Instead I am arguing that the VSA system does brake the inner wheel if it loses traction. Look at all the enthusiastic TSX drivers in the US who have warped rotors after just 30,000 miles without ever going on a race track. I suspect that the warpage is caused by the VSA braking the inner wheel when it loses traction. Those US guys do like to gun their cars on the freeway on-ramp after all.



Whilst this could potentially make the car turn in better, though reaction time a bit slower than LSD, this still doesn't give it a normal LSD effect because VSA is a passive system that's only activated over the limit. On a longish, high speed corner where the inside wheel doesn't have anywhere near enough torque to break traction even if car is already understeering, the VSA simply wouldn't turn on. On an LSD equipped car the more active system will be much more sensitive, starting to transfer the correct amount of torque to the outside loaded wheel 'linearly' and 'gradually', pulling/pushing the car into the corner better.
Yup, the VSA system does not increase the turning limit like an LSD. As I said, the LSD is superior. VSA is a poor man's LSD.



Secondly and very importantly when launching the car in a 'straight line', a proper LSD will ensure that you can get the best tyre traction, no torque steer due to diff torque between the wheels and the ability to still spin both tyres just a tad to get the best acceleration. This is especially true launching in the wet.
But then, LSD will tend to put more torque on the wheel with traction, so you will get MORE torque steer since one wheel has more tractive force than the other. I think suspension design is a better way to deal with torque steer.



On the Euro Accord the VSA system is linked with a power-off or braking-power traction control system, so whether you turn it on or off, you won't get the launching effect of a proper LSD equipped car... LSD isn't just for cornering afterall!
As I said, the VSA tries to do its best with 4 ABS channels and throttle control via drive-by-wire. I never said that the VSA could ever match an LSD. So why are we arguing over this? :)

To recap, I said that the VSA has an LSD-like effect, but it is a poor man's equivalent of the LSD, in other words, it's not as effective. The message I am getting from you is that the VSA doesn't carry out the action of braking the inner spinning wheel to transfer torque to the outer wheel. And that is the part that I disagree with. All your other information and comments about LSD vs VSA, I agree with 100%.



As for the Prelude's ATTS system, it isn't a very sensitively incremental system, certainly nowhere near the reaction time of the Mitsu Evo's active-yaw and acd system. Although it is definitely better than a VSA system that is only mean to work PASSIVELY!
Of course it is no where near the performance of the AYC, because it was developed almost 10 years ago and not used in any car other than the old Prelude ATTS. Of course if you compared the modern version of the ATTS, the SH-AWD, then I'm sure even SH-AWD is better than AYC due to its torque split control.

chop_sticks
12-10-2005, 05:09 PM
My VSA light is on constantly. Im guessing its not working since i fitted the merc wheel hubs and brakes. But i dont even know what its for. Is it the traction control system?

PERTH_EURO
12-10-2005, 07:36 PM
You're asking for a whole world of issues with different brand hubs and brakes on your car.

Do a search on insurance or something on this site and you'll see the risks your exposing yourself to.

Have you checked to see if your ABS works??

Who fitted them for you... they deserve to be shot.

Sorry man but i cant help but shake my head

YouRow
27-05-2006, 10:24 PM
Large familiar roundabout, diesel/oil on the road, reasonable speed (circa 60kph).
Car further sideways than I ever wish to experience again (unintentionally anyway)
Forget arguable shortcomings or alternatives (eg lsd).
I am OK and the car is still showroom perfect.
Had there been no vsa the car would not have got itself out of the situation. I probably would have got us out of the situation, but what if I was a bit more tired or distracted?
I have read about how it works and I have tried to test how it works, and now I have seen it live and unrehearsed.
For me, end of discussion. Every new car sold should be fitted with this type of system.

PS no-one was around but if they were, the system worked so well that they would have assumed i did it on purpose!

EuroDude
27-05-2006, 11:38 PM
hehe my EG civic now feels like a death trap with no ABS/VSA compared to my Euro.


In a sideways situation...

If the car is fishtailing sideways (arse is sliding left), does VSA brake the left wheel and accelerate the right wheel to neutralize the fishtailing?

Omotesando
28-05-2006, 12:59 AM
If VSA equivalent is installed on all cars - it will help avoid many accidents especially when road is wet (or has oil) for certain. It is a passive system and as such it usually activates and only required when you're not expecting something!! A good LSD is more of a different primary device - it makes the car corner much better in a neutral manner, especially when power is applied.


If car is fishtailling left on a right hand turn corner/roundabout, the VSA should brake automatically the right rear wheel? and if you're on the throttle cut fuel a little bit? When I tested it deliberately I think that is what it does? Although I find that as the tyres are more worn, the VSA doesn't work as well as it should. I still slide way too much into the other lanes to the point of dangerous (understeer majorly) and it still doesn't activate sometimes. :(

EDIT: Not really sure how the brakes work... just guessing.

timmy_12
28-05-2006, 08:45 AM
here is an easy way for you to test the VSA system take the car on a dirt road (hopefully fairly wide if your not confident on dirt) and try to get the car sideways and see what happens.

i have done this a few times and it is soo much fun it's as if there is an invisible rubberband attached to the car that flings you back straight again

the only way this system effectively works if is you DO NOT TOUCH THE BRAKES as this will apply brake pressure to all wheels and over ride the system i do quite a few mountain runs and some of the surfaces are sub standard and the best way to get full use of the system is is use or don't use the accellarator and definately don't use the brakes ( obveously there are situations where they are needed but most of the time being a front wheel drive car you can pull your self out)

yfin
28-05-2006, 10:26 PM
This is from the TSX technical manual - I can see if I can find it online if people want it - it is over 90 meg. There is a lot more info on VSA there.

"For example, if the driver enters a corner too quickly and the vehicle’s front wheels begin to slip (understeer), VSA almost instantly detects the situation and interprets it as understeer. VSA then reduces engine torque and selectively applies the brake on the inner front and rear wheels to help counter the understeer and enhance the driver’s control. The correction happens so quickly and so seamlessly that the situation is often resolved before the driver is even aware of it.

Another potential scenario involves a traction loss at the rear wheels, such as might be encountered when cornering on a dirty road or when encountering black ice. VSA detects the rear tires beginning to slip and quickly applies the outer front and rear brakes to counter the unwanted yawing motion and help restore control to the driver."

EuroDude
28-05-2006, 10:47 PM
Although sometimes these systems can put you in a worse condition unfortunately.

Today I took a roundabout (going straight through) a little quick but safe nevertheless. I braked before entering the roundabout so I can safely manouver around it, BUT...

When entering the roundabout, I braked, the road was a bit bumpy and the ABS engaged when I was braking! But since ABS engaged, the brakes vibrated and I lost alot of brake pressure, and as a result I could not brake normally and almost lost control going around the roundabout due to excess speed. I even lifted off the brakes after ABS to regain brake control, but I already lost so much braking that it didnt help much. Luckily I managed to steer around the roundabout without hitting anything... Damn ABS is too sensitive IMO :(


If I didnt have ABS, the wheel would have just done a mini-skid at worst and I would have still had full braking capability.


Does ABS get disabled when you turn off the VSA button?

yfin
28-05-2006, 10:50 PM
Do you have any mods on your car Eurodude (eg rims)? You seem to get ABS to activate more easily than me and I wonder whether something is right. When my ABS activates over some pot holes etc it is only for a split second - no where near enough time for me to lose total braking pressure.

You don't lose abs with VSA off.

Maybe honda updated the ABS module on the 06 model? There are always improvements to these electronic systems - do we have Bosch ABS?

EuroDude
28-05-2006, 11:00 PM
No its totally stock, 16" rims. The only mods done are the Audio system and a K&N filter.

The bump was short but rigid and I was braking kind of heavily, so maybe thats why ABS was so furious.

[edit] Come to think of it, there may of been some stones on the road, but not 100% sure - that what it feeled like anyway.

From memory, ABS was engaged for about ~750ms.

yfin
28-05-2006, 11:05 PM
No its totally stock, 16" rims. The only mods done are the Audio system and a K&N filter.

The bump was a short but high and I was braking kind of heavily, so maybe thats why ABS was so furious.

From memory, ABS was engaged for about ~750ms.

Ok - maybe the supplier of the ABS module to Honda improved the system with your model. Mine does kick in from time to time on potholes but certainly haven't lost as much braking pressure as you when it does.

EuroDude
28-05-2006, 11:14 PM
Yeah thats definetely a possibility - it really scares me sometimes.

Maybe its because I drive the 1400kg Euro like a 1000kg Civic LOL :p

timmy_12
29-05-2006, 03:31 PM
i have an 04 and abs is fine in mine

i think you need to get used to how the brakes work Brake assist is an electronic brake booster (someone correct me if i am wrong) what it does is magnifies the amount of pressure you put on the pedal which if your not used to this you can over apply the brakes

and understand where the point of maximum braking and when they lock up and you should only use abs in an emergency situation

and don't push the car beyond it's and your capabilities and you should be fine with the brakes

ok2
29-05-2006, 10:46 PM
A number of reviews I read as I did research on the Euro before I bought mine commented on the ABS being "easily fooled" or "tripped" by bumps and I can confirm it has done it to me several times. It’s even happened when I have not been breaking hard.

It’s quite disconcerting and have thought that if it happened when you are doing an emergency stop for real or breaking late and hard for a corner it could get really ugly real quick :-(. Then again maybe the breaking performance will not be effected and just that ABS feels wierd throught the pedal. Has anyone "tested" this ?

P.S. I would like that VSA video. When I searched for it it had been removed.

EuroDude
29-05-2006, 11:04 PM
The braking performance can degrade quite alot - this has happened twice now. But usually ABS isnt too harsh and brake pressure is near normal.

Its not just the feeling, the brake pressure actually disappears after ABS.
And the comment "ABS being easily fooled or tripped by bumps" is spot on in my experience.

In my sticky roundabout situation I was pushing down on the brakes pretty hard and the brake pressure was like if you were just gently touching the brakes (The brake pedal itself was quite low too).
It could have gotten ugly very quick but luckily I lifted off the brake and repressed them just in time. If I didnt, I'm quite sure I would have lost control :(

EuroDude
29-05-2006, 11:11 PM
By the way, do you guys feel subtle brake feedback when going over a rough surface?

I'm not refering to when ABS/VSA is engaging. Sometimes when I go over a small bump or something, the brake pedal nudges a little bit. It kind of feels like ABS is about to engage but it doesnt.
(no ABS/VSA light comes on and braking is 100% normal).

Its quite disconcerting sometimes.


[edited]

yfin
29-05-2006, 11:18 PM
By the way, do you guys feel excessive brake feedback when going over a rough surface?

I'm not refering to when ABS/VSA is engaging. Sometimes when I go over a small bump or something, the brake pedal vibrates or pulsates a little bit. It kind of feels like ABS is about to engage but it doesnt.
(no ABS/VSA light comes on and braking is 100% normal).

Its quite disconcerting sometimes.

That is the ABS - the light doesn't always come on in my experience. I can also hear my VSA trigger when cornering if I hit a pothole mid corner. The VSA light doesn't always come on either. When you have a big understeer moment in the wet you get the "flash flash flash" - that is definately VSA.

The thing is none of these experiences are disconcerting to me. I never feel like the car is going out of control or ost control of the car just because ABS activates. Does anyone else feel like Eurodude? I totally agree you can trigger ABS easily, etc but it is another thing to say you feel like you have lost control of the car when it happens.

EuroDude
30-05-2006, 12:01 AM
yfin,

I shouldn't have said 'vibrates or pulsates', the feedback is rather more like a single nudge in the brake pedal when I hit those plastic lane seperator things.

Almost as if the force from the bump on the road gets directly fed into the brake pedal. It really doesnt feel like ABS kicks in.


...maybe ABS senses the bump and is initializating and feeding a bit of hydrolic pressure into the brake pedal or something, which I find disconcerting.

Omotesando
30-05-2006, 01:12 AM
Ok - I have always said the ABS kicks in way too early on the Euro Accord but the main problem is similar to what EuroDude has described but probably I don't find it to the extent he experienced it (although still pretty disconcerting!) - when the ABS is working whether over potholes OR if I was braking too hard, the car is not actually braking very well at all and as such the braking distance is too 'long'.

To me the problem is very obvious - and that is because the braking pulsation on the Euro (and most Honda's I've driven unfortunately) isn't controlled that well, so in between the ABS letting go and gripping cycles, the distance being travelled is far too great - compared to other cars of similar weight.

One giveaway is when you brake pretty hard (brake booster working hard!) the G-force isn't that great before the ABS kicks in. 2ndly like I said the ABS doesn't pulse that well and the expected stopping distances on some occasions was to me was much longer than I anticipate.

Anyway, since you can't really change this brake characteristic, the only changes u can make is via using greater gripping tyres as the tyres won't 'skip' as easily to trigger the ultra sensitive ABS sensor.

The brake pads - well, I don't know to be honest. The very simple 1 piece brake caliper design means human modulation of the Euro's brakes manually can never be achieved to the +/- % accuracy of more sporty cars with 4-6 pot calipers. This is exaggerated by the very large caliper which tends to brake-grab more suddenly. I don't know whether putting harder biting brake pads would help at all due to this reason :(

Tobster
01-06-2006, 02:25 PM
People might like to have a look at this article:

http://autospeed.drive.com.au/cms/A_2927/article.html

Whiteline are developing an adjustable electronic stability adapter -- kind of like a piggy-back ECU.

EuroDude
01-06-2006, 02:57 PM
But does the Euro use the Bosch stability system?

Tobster
28-06-2006, 10:22 AM
Well, it happened to me last night: stopping in an 80 zone when traffic lights changed, not braking what I'd call hard, but not just gently slowing down either. While braking I went over what you could call a step in the road (it goes from bichumen to pavers, not the smoothest road!) which resulted in quite a thump through the suspension, the ABS triggered (first time it noticably has), and I found myself rolling considerably faster towards the car that was stopped in front of me.

I just pressed harder on the brake and stopped OK (then braking hard in the distance left) -- but it is VERY disconcerting when it happens.

Has anybody actually contacted Honda about the issue?

(Incidentally, I have to say that the ABS pulses in the Euro are very gentle -- barely noticeable compared to my TF Magna which you really knew about when the ABS triggered with no noticeable loss in braking speed.)

EuroDude
28-06-2006, 10:44 AM
I pressed harder in that situation too but the car didnt slow down, had to repress the brake. Honda should definetely look into this ABS issue.

Cranial
28-06-2006, 11:02 AM
I agree with you all. Many 'panic' stops I've made (mainly because of other careless drivers) has made me notice that the ABS kicks in way too early - making it very hard to modulate the braking pressure. My old Honda Legend, I could brake much harder before ABS kicks in. And while I'm at it, the VSA is also overly sensitive - there is a section of road that has some irregularities in it, and everytime I accelerate over that patch, the VSA kicks in and causes the car to jerk quite alot - I'm sure alot of bystanders must be wondering what's wrong with that Euro (hah!).

And oh yes, the VSA/ABS system used in the Accord Euro (and practically all braking systems too for Honda cars) are made by Nissin Japan - a subsidiary of Honda Motor Co.

ZYL11A
28-06-2006, 02:06 PM
Ive had this issue before with both the VSA and the ABS. I have made it standard practice so that when I start the car I turn off VSA. The car jerks bigtime which is very annoying.

And as for the ABS, pretty pathetic if you ask me. Im not sure if the 19" wheels or lowering it as much as I have could be a contributing factor however if I hit a pot hole when braking hard, the car shudders and the brake pedal pulses almost to the point that my foot is flat to the floor. My legend brakes better than the Euro which is a bit concerning considering it age.

Omotesando
28-06-2006, 02:55 PM
I agree with you all. Many 'panic' stops I've made (mainly because of other careless drivers) has made me notice that the ABS kicks in way too early - making it very hard to modulate the braking pressure. My old Honda Legend, I could brake much harder before ABS kicks in. And while I'm at it, the VSA is also overly sensitive - there is a section of road that has some irregularities in it, and everytime I accelerate over that patch, the VSA kicks in and causes the car to jerk quite alot - I'm sure alot of bystanders must be wondering what's wrong with that Euro (hah!).

And oh yes, the VSA/ABS system used in the Accord Euro (and practically all braking systems too for Honda cars) are made by Nissin Japan - a subsidiary of Honda Motor Co.


If you have VSA on and then you accelerate during a corner with irregularities, its detecting your inner wheel spinning most likely and the jerk comes from shutting down the injectors?

Well, a good LSD can solve the problem as the open diff system really doesn't complement the really well balanced Euro Accord :(


The brakes - seriously..... everyone we should complain to Honda :(

Personally my next mod will be better tyres though. Sensitive ABS really gets much better with better front tyres. :o Can't afford it yet :(

Tobster
29-06-2006, 10:20 AM
This is the first bad experience I've had with it -- and I have emailed Honda about it and pointed them to this web thread.

Tobster
06-07-2006, 11:33 AM
I've been away for work, but this email (read: brush-off) was sent to me:

****

Thank you for your recent email.

The Anti Lock Braking system is a complexed safety unit which has been
inbuilt into the normal braking system in your vehicle. Under normal
braking, brake fluid is being passed through the ABS modulator and is
continually operating to allow the ABS system to be activated when
required.

Unfortunately i am unable to comment on your recent encounter as i did not experience it first hand, i do however strongly recommend you to contact an Authorized Honda Dealership if you feel unsafe within your vehicles performance at any stage.

We appreciate you taking the time to contact us.

****

I would suggest that anyone who has had any real issues with braking (I don't just mean complaints that maybe the VSA kicks in too early) should email Honda to let them know: if enough issues are registered, then they may actually look into the matter...

timmy_12
12-07-2006, 07:12 PM
i personally think your complaints are related to Brake Assist which acts like a magnifying glass you apply pressure and it magnify's the pressure that actually goes to the brakes which in your panic situation you are hitting the pedal harder than you think which is why the abs is applying too easily

my 2 cents as i have had no issues with mine but if i do get it to come on i am aware of how and why it did

BiLL|z0r
12-07-2006, 07:22 PM
Mine comes on when I hit bad pot holes all the time, it's annoys the crap outa me, it's a pot hole ffs not a cliff (although some roads are almost as bad). I'd turn VSA off but you never know when it might help you + it's mainly ABS kicking in in my situation and that's always on.

aaronng
12-07-2006, 07:43 PM
i personally think your complaints are related to Brake Assist which acts like a magnifying glass you apply pressure and it magnify's the pressure that actually goes to the brakes which in your panic situation you are hitting the pedal harder than you think which is why the abs is applying too easily

my 2 cents as i have had no issues with mine but if i do get it to come on i am aware of how and why it did
Brake Assist is only used when you hit the brakes fast and hard in an emergency but not hard enough to engage ABS. It does not turn on when you brake gradually harder.

timmy_12
12-07-2006, 08:09 PM
Brake Assist is only used when you hit the brakes fast and hard in an emergency but not hard enough to engage ABS. It does not turn on when you brake gradually harder.

sorry my bad

but i must have been in the right area as he says abs engages when he hits the brakes in a panic situationand that is probably the reason

What is brake assist?

the following link will explain

http://www.brakeassist.com/

Omotesando
12-07-2006, 10:27 PM
Brake assist has already been considered as a separate issue earlier on in this thread :)

Brake assist 'might' be the catalyst which made the ABS come on.

However, most of us who have already had the foot on the Brakes but without Brake Assist kicking in in the first place, either find that the ABS will suddenly come on when there's a shxthole on the ground, or if ABS is already on, its pulsations aren't calibrated so well - it makes the final braking distance too much longer than required...

Turning off the VSA wouldn't help either, because ABS and Electronic Brake Distribution are still on :(

Tobster
13-07-2006, 10:40 AM
It's not the fact that the ABS comes on that is the great issue. Personally, I think ABS is a good thing (it's helped me in a couple of situations in other cars) and should be standard on all cars.

For me, the concern in the situation that I experienced was the loss of braking pressure that seemed to come with this ABS application. My foot didn't move on the brake pedal, the amount of pressure I was applying didn't change -- but after hitting the bump and the ABS kicked in, the car started rolling MUCH faster than it had been. It was almost as if I had completely removed my foot from the brake pedal.

I've never had an ABS braking experience like it before.

aaronng
13-07-2006, 11:21 AM
Tobster, you seem to be misunderstanding the use of ABS. You said you didn't change the amount of pressure applied. ABS does not help you increase your braking pressure in your situation that you described. That's because brake assist did not activate. Let's say you had "X" braking force while slowing down. You go over a bump, the wheels lock and ABS activates. Now you have "X divided by Y" braking force where Y is the ratio of the amount of time where ABS tries to "unlock" your stopped wheel. If you want a similar stopping force to what you had before ABS engaged, you have to press the brake pedal HARDER.

Omotesando
13-07-2006, 03:31 PM
Although pressing the pedal harder might give you slightly more braking pressure, provided your foot pressure wasn't already on the max threshold before (when possibly Brake Assist already kicked in) - if ABS is already engaged in this case - I don't believe it would really help much putting on more pressure because the ABS is already doing its very mis-calculated pulses for the next 1 sec or 2... :(

Even though ABS is suppose to increase braking distances in emergency braking in normal dry weather braking (perhaps even in the wet in the Euro Accord hmmmm unfortunately..) - its doing so as a sacrifice for the ability to manouver the car and steer clear of obstacles. But in most cases we don't need to manouver the car so for every metre that braking distance is increased, its putting us closer to grave danger.

When I drove non-ABS cars before, I think my own braking pressure adjustability was more suitable and safer at least I know what to expect!

EuroDude
13-07-2006, 03:36 PM
It's not the fact that the ABS comes on that is the great issue. Personally, I think ABS is a good thing (it's helped me in a couple of situations in other cars) and should be standard on all cars.

For me, the concern in the situation that I experienced was the loss of braking pressure that seemed to come with this ABS application. My foot didn't move on the brake pedal, the amount of pressure I was applying didn't change -- but after hitting the bump and the ABS kicked in, the car started rolling MUCH faster than it had been. It was almost as if I had completely removed my foot from the brake pedal.

I've never had an ABS braking experience like it before.


Yep thats what happens to me to :o
During/after ABS, you need to push harder to recover braking power, or sometimes even re-press the brakes if ABS activated alot... otherwise the car will keep on going and fly off a cliff

aaronng
14-07-2006, 02:10 AM
Just remember that ABS stands for antilock braking system and not some brake force booster system. ABS tries to unlock a locked wheel and does so by "releasing" the brake caliper for that microsecond and then re-engaging. ABS doesn't apply full force and then release if locking is detected. Full force can only be applied by your foot consciously or if brake assist is engaged.

EuroDude
14-07-2006, 08:58 AM
Yeah but the brake sinking issue is whats most concerning. I wander if other ABS systems do the same thing.

Tobster
14-07-2006, 10:30 AM
Aaronng I think you're possibly misunderstanding what I mean. I know perfectly well how ABS works and what it feels like.

EuroDude knows what this situation feels like. I didn't quite know what he meant when he first described it and I was trying to think about what was going on -- but when I experienced it myself it was unlike any other braking experience I've ever had (and I'm about to turn 35 and have been driving for good while). Unless you've experienced it, you just have to take our word for it.

In this situation it was like the brakes were no longer being applied.

In other emergency braking situations (not that this was an emergency) in other cars where ABS has kicked in, I have not experienced a loss of braking pressure: you're braking, slowing, the ABS pulses to prevent wheels locking up, and you stop pretty damn quickly. The ABS activation does not change the rate at which you're stopping.

In this situation, I was braking, slowing, hit the bump, the ABS activated but the rate at which the car was slowing drastically changed, i.e., the car started accelerating again -- which shouldn't happen -- and that's what's alarming because you then have to reapply the brakes, recalculate your stopping distance and it DOES become an emergency stop.

I don't know if I'm explaining this very well...

EuroDude
14-07-2006, 10:50 AM
Crystal clear Tobster.

We both have an MY06 model, so maybe the 03-05 ones behave differenty?
Either way, Honda should really look into this potential safety hazard.

aaronng
14-07-2006, 01:02 PM
Hmm... That's worrying if you are accelerating when ABS is activated. Seriously, I've been through the bump on the road situation, straight line and corner ABS activation and in all situations, the car continued to slow down while ABS was on. I made sure that my foot was pressed hard against the pedal in all cases. I'd say get your ABS checked by the dealer.

EuroDude
14-07-2006, 01:39 PM
The car doesnt "accelerate" per say, rather it just keeps on rolling with minimal brake force.

aaronng
14-07-2006, 02:27 PM
Minimal braking force is just as bad. In my 04, the car still slows down pretty hard. I'd say stopping distance increases by only about 10-20% (guessing)?