TOV 2006 TSX review

[yfin]

article here (http://www.vtec.net/articles/view-article?page_number=1&article_id=493583)

Whilst the differences between the Euro and the TSX are now greater than ever - there are so many interesting points in this article it is a must read.

This paragraph is very interesting:

At the 2003 US media launch for the TSX, Mr. Sakuji Arai (the chief powertrain engineer for Honda 4-cylinder motors whose credits include the F20C and K20A masterpieces) was quite visibly proud of the TSX's K24A2. In fact, he asserted that the K24A2 was Honda's finest 4-cylinder ever - a claim which makes you think a little bit about what the engineering goals were.

You will also find some of the comments to ring true with the Euro (the issue of rotor warping is raised - TOV says it is not the rotors causing the problem - it is the pads). Also the people with hard starting problems (I am not one of them) - clear vindication that you are not hallucinating. :D Comments about lag in the DBW - all there.

Excellent article and credit to TOV for such a great piece of work.

So what do you guys think about the article?

[EuroDude]

Thats a good read :thumbsup:

Does that mean that the Aussie 06 Euro's (K24A3) have more power too?
somehow I doubt it :(


Come to think of it, my Euro takes 5 or 6 turns to get the engine running, where my Civic only took 2 to 4. Here's hoping it doesnt have that hard starting prob...

[yfin]

Does that mean that the Aussie 06 Euro's (K24A3) have more power too?
somehow I doubt it :(



Answer is no - we carried over the same power specs from 03-05 models.

ps. the Axxis Ultimates given a huge thumbs up by TOV are actually made in Australia by Bendix. They are the same as Bendix Ultimates. Think these are going to be the new pads on my euro.

[aaronng]

We get the K24A3 from the Accord 4WD Wagon. 03-05 in the US got the K24A2 from the Accord FWD Sedan. For 06, I think they got a US-specific engine as it has large intake valve openings as well as a larger throttle body.

[GYPO2C]

Answer is no - we carried over the same power specs from 03-05 models.

ps. the Axxis Ultimates given a huge thumbs up by TOV are actually made in Australia by Bendix. They are the same as Bendix Ultimates. Think these are going to be the new pads on my euro.

that makes a little more sense, because i was spun out a little by the fact that they had the 6MT cracking into the high 6 seconds for 0-100 km/h. Even still... could the claimed 10hp off make the TSX go that much quicker, considering hondas stats read somewhere round the 7.8-7.9 mark? It may be a combination of all of the little things they've fixed.

[EuroDude]

I think their TSX is heavier than our Euro, so the original K24A2 performed close to the Euro's 7.8sec. But the extra 10hp getting it into the high 6's? That doesnt sound logical.

K24A3 190ps
K24A2#1 200ps
K24A2#2 210ps

7.5 sounds more logical.

[aaronng]

Got to remember, TOV got the 6.9 by flat shifting.

Remember the Corolla Sportivo that was tested by that race driver? It did 8.5s when shifted normally. But when flat shifted, it went down to 7.8-7.9s. Of course, the owner of that car said that the gearbox never felt the same again.

[yfin]

We get the K24A3 from the Accord 4WD Wagon. 03-05 in the US got the K24A2 from the Accord FWD Sedan.

Are you aware of any JDM Honda accords runing the K24A2? I thought the K24A2 is solely for the TSX. The differences to the K24A3 is a bit of an unknown. The most popular view I have read is the engine is essentially the same as the K24A2 but there is a vastly different tune for the US. Then there is the different power measurement standards in the USA (I am a bit lost as to how that works as they keep changing the standards).

Eurodude - you are right about the TSX being heavier. The 06 TSX is 100kg more than the Euro standard in Aus. The 03-05 TSX mostly makes up the weight disadvantage by a shorter final gear ratio and of course the slightly extra power. The 06 has gone forward again in power.

As for the 0-60 times - Car and driver got 7.2 on the 03-05 model. Keep in mind that 0-60mph is not 0-100kph. It is not unrealistic for a mere mortal to get consistent 0-100kph in 7.5 (stock Euro Standard) - so not much difference.

[GYPO2C]

Keep in mind that 0-60mph is not 0-100kph.

hey thanks for that... i didnt actually know that...i was always under the impression that it was exactly 100kph to 60mph. In actual fact it equals the following:

60mph=96.56kph
62mph=99.78kph

[Ferrarista]

i have the hard starting problem, my service centre think im crazy :(

[GYPO2C]

i have the hard starting problem, my service centre think im crazy :(

ive got it as well... my 20k service is on friday and im going to mention it but i dont think ill get very far....

[aaronng]

Are you aware of any JDM Honda accords runing the K24A2? I thought the K24A2 is solely for the TSX. The differences to the K24A3 is a bit of an unknown. The most popular view I have read is the engine is essentially the same as the K24A2 but there is a vastly different tune for the US. Then there is the different power measurement standards in the USA (I am a bit lost as to how that works as they keep changing the standards).

Guaranteed that the JDM Accord FWD Sedan has 147kW, while the 4WD wagon has 140kW. It's stated on Honda Japan's website. All they give for the engine code is K24A. But you can guess it from the power and torque numbers.
Europe's Accord Sedan also runs the 140kW engine. I have no idea why Honda Australia got the 140kW version instead of 147kW since USA is already havnig that 147kW engine, so it is not an issue of keeping the best for themselves. Remember, USA is pretty much in the same boat as us. Their hottest Civic has a 119kW engine, and they never got the Integra Type R. t least we got the watered down version.

[yfin]

Honda Jap web site now shows both k24 wagon and saloon with 147kw. Maybe there has been a change.

The 06 JDM Accord did not receive the TSX power increase - so it isn't always the case of keeping the best for Japan and it might suggest JDM is a different engine (ie k24a3). Much of the specs for the JDM accord are the same as the Euro - eg 4.4 final drive vs TSX 4.7.

I need convincing the JDM accord is K24a2 - I think it was a special project for the US market in the form of the TSX. :D

You mention the US being in the same boat as us re not getting the best models - I think we are in a worse position. There are some really nice Acura models here - as well as the incredibly beautiful Civic Si (see this) (http://www.tsxclub.com/forums/showthread.php?t=11916&highlight=civic) with 197hp, LSD, etc. Looking at one on the roads recently in the US and I was impressed!

[aaronng]

Honda Jap web site now shows both k24 wagon and saloon with 147kw. Maybe there has been a change.

The 06 JDM Accord did not receive the TSX power increase - so it isn't always the case of keeping the best for Japan and it might suggest JDM is a different engine (ie k24a3). Much of the specs for the JDM accord are the same as the Euro - eg 4.4 final drive vs TSX 4.7.

I need convincing the JDM accord is K24a2 - I think it was a special project for the US market in the form of the TSX. :D

You mention the US being in the same boat as us re not getting the best models - I think we are in a worse position. There are some really nice Acura models here - as well as the incredibly beautiful Civic Si (see this) (http://www.tsxclub.com/forums/showthread.php?t=11916&highlight=civic) with 197hp, LSD, etc. Looking at one on the roads recently in the US and I was impressed!
Checked Honda japan's site. Seems that they have changed it. Now the specification data for the wagons is all in 1 table. It used to be in 2 tables, FWD and 4WD being separate. Guess they ended the 140kW model. I'll go home later and take out HyperRev Accord to get the info on hp and torque numbers.

The Civic Si coupe only started selling this year. Back in 2003, there was no 197kW Civic Si coupe. All they had was the weak Civic Si hatch.

[Spec83]

for all of those with teh hard starting problem - get the dealer to reset the ECU's starting program... This fixed my problem but as was said in the article 10.5:1 compression is high for a road car so i suppose you can think of it as a trait of the car and not and issue :)

Was a good article - I still dont understand how the US versions make ~20 more hp and they only run 91 octane fuel ???

Bendix Ultimates are great pads - used them on my old car and a mates 180 and recomend them highly - just got to get them up to temperature :)

[Omotesando]

My car's slight starting hesitation has practically gone. It was never that bad for me, it just didn't like to start when I had a 5 min break in between. Anyway now that its completely normal I think it might have to do with needing to run in engine? I mean, I rev it like hell. :)


In the Auto - where the Sports Shift Mode gets much better times than the normal Auto mode, it is kind of weird. Don't think that difference is so pronounced on the Aust Euro in Auto. In fact, not much difference between the TSX's Sports Shift mode in the Auto and the 6 speed Manual not being flat shifted at all.


Regarding flat shifting - I don't really think there is so much 'shock' that it will completely damage the drivetrain with the clutch or the transmission. There isn't that much torque in the engine. I wonder if people in Aust have driven their Euro down the 400m strip while flat shifting?

[Tobster]

I still dont understand how the US versions make ~20 more hp and they only run 91 octane fuel ???
US has different fuel rating standards to Australia -- their 91 is more like our 95+

[aaronng]

Regarding flat shifting - I don't really think there is so much 'shock' that it will completely damage the drivetrain with the clutch or the transmission. There isn't that much torque in the engine. I wonder if people in Aust have driven their Euro down the 400m strip while flat shifting?
Totally not true. It wears your clutch plenty, and since you are releasing the clutch so fast, the drive line shock is much higher. And it's not only your clutch and transmission. The driveline includes the driveshafts, CV joints, hub bearings too. Those undergo more wear from flat shifting.

[Omotesando]

Totally not true. It wears your clutch plenty, and since you are releasing the clutch so fast, the drive line shock is much higher. And it's not only your clutch and transmission. The driveline includes the driveshafts, CV joints, hub bearings too. Those undergo more wear from flat shifting.


Well obviously I said it in the context of the Euro Accord only. In other cars with a lot of torque you wouldn't want to do this.

You are speaking on relative terms, comparing flat shifting to normal shifting.

I'm speaking on the effect of flat shifting on a very linear but not that torquey engined vehicle.

Of course, what you said is true about more wear, it is common knowledge :)

[aaronng]

Well obviously I said it in the context of the Euro Accord only. In other cars with a lot of torque you wouldn't want to do this.

You are speaking on relative terms, comparing flat shifting to normal shifting.

I'm speaking on the effect of flat shifting on a very linear but not that torquey engined vehicle.

Of course, what you said is true about more wear, it is common knowledge :)
Well, flat shifting on a Corolla Sportivo that had only 180 Nm did cause some damage to the driveline. The owner said that it was "loose" and gritty after that. That engine has less torque than the Accord Euro.

It's not because of the torque being linear. It's because of the speed of the clutch being released while the revs is about 2000 RPM above the next gear. Imagine when you shift from 1st to 2nd flatshifting. When you release the clutch at 7000rpm, your transmission speed is only about 4500-5000rpm in 2nd gear. That's 2000-2500rpm different and at the speed you're releasing your clutch, everything after the clutch (transmission, driveshaft, bearings, CV joints) is going to have to speed up. While the car is moving at about 60km/h, 2nd gear at 7000rpm is 100km/h. So everything is going to try to speed up to 100km/h, which is not possible. So your driveline will take a shock and if the tyres don't lose grip, the engine is also forced to jump back down from 7000rpm to 4500rpm. Even when not flatshifting, releasing the clutch fast during a 1-2 shift and applying throttle quickly after that will cause a very loud bang sound. That's the shock through the driveline.

[h22a accord]

At this stage the euro is best in class for the power it makes.....when some other car brand even tries to come close, honda australia will bring out the big guns and up the ante with the 147kw donk.

Withthe 140kw engine they run at the moment leaves the window of opportunity to upgrade at a later date.

makes good business sense if you ask me.

[EuroDude]

Or maybe bump the K24A up to 180kw :D I mean the K20A can make 164kw, whats stopping the K24A from reaching 180kw+ ?

[Chris_F]

interesting read.

i was sure that the Jdm and european accords had the k24a3's perhaps the a2 relates mostly to the 4.7 final drive? I'm pretty sure that the euroR final drive is 4.4... wonder why it didnt get the 4.7.

ALSO, this has raised a very interesting point. The peak gains found in the hondata reflash... In the US there were little to no peak gains from their reflash but over here with the prelimary results we've seen some very signifcant increases. I have a strong feeling that the engines are nearly identical for the 03-05 euro's and tsx's jsut differences in the tune :p
obvioulsly this isn't true for the 06 models as their have been some big changes.

[driven]

interesting read.

i was sure that the Jdm and european accords had the k24a3's perhaps the a2 relates mostly to the 4.7 final drive? I'm pretty sure that the euroR final drive is 4.4... wonder why it didnt get the 4.7.


Euro R has a 4.764 final drive, same as the DC5R and EP3.

[Chris_F]

oh ok.. for some reason i thought it was the same as the euro, thanks for clearing it up

[aaronng]

Or maybe bump the K24A up to 180kw :D I mean the K20A can make 164kw, whats stopping the K24A from reaching 180kw+ ?
Because the K24A can't spin up to 8000rpm for extended periods. :)

[aaronng]

BTW, I have my HyperRev here. It was published in 2003. The Accord Wagon comes in FWD and 4WD. The FWD (LA-CM2) comes with the 2.4L 147kW engine. The 4WD (LA-CM3) comes with either the 2.4L 140kW engine or the 2.0L 118kW engine.

The Sedan on the other hand, FWD (LA-CL9) comes with the 2.4L 147kW engine, while the 4WD (LA-CL8) comes only with the 2.0L 112kW engine.

Imagine the possibilities of a 4WD Accord Euro with a K24A2 swap!

[aaronng]

i was sure that the Jdm and european accords had the k24a3's perhaps the a2 relates mostly to the 4.7 final drive? I'm pretty sure that the euroR final drive is 4.4... wonder why it didnt get the 4.7.

While the TSX's K24A2 comes with a 4.4 final drive, the gear ratios in the 6-speed is shorter to compensate.

Edit: OOOOOOPS super typo. I got it the other way around. Yes, TSX 4.7 final, longer ratios to compensate.

[Chris_F]

the TSX's final drive is 4.7

the AUDM accord euro final drive is 4.4

[driven]

Does someone who knows something about gear ratios care to interpret the differences in the TSX vs Euro gear ratios? :confused:

I suspect the TSX will have more aggressive gearing which raises the question as to whether a 2nd hand TSX gearbox will be a good mod for the Euro.

Euro
1st 3.533
2nd 1.88
3rd 1.354
4th 1.027
5th 0.825
6th 0.659
Reverse 3.583
Final 4.388

TSX
1st 3.267
2nd 1.880
3rd 1.355
4th 1.028
5th 0.825
6th 0.659
Reverse 3.583
Final 4.7

as chris says, 4.7!

[Chris_F]

can anyone provide some inormation as to how the Final Drive actually effects acceleration vs. reduction of speed in each gear and top-speed?

[twing]

K24A2 vs K24A3... According to this site:
http://www.theksource.com/news/04/k-series-vtec-breakdown
A3 intake has 3 cam lobes, while exhaust has 2 cam lobes. It's like 12v - 16v config.
A2 has 3 cam lobes booth on intake and exhaust.

Has anyone open up their Euro's rocker cover see the cam lobes?
Very interesting to find out.

[EuroDude]

K24A2 vs K24A3... According to this site:
http://www.theksource.com/news/04/k-series-vtec-breakdown
A3 intake has 3 cam lobes, while exhaust has 2 cam lobes. It's like 12v - 16v config.
A2 has 3 cam lobes booth on intake and exhaust.

Has anyone open up their Euro's rocker cover see the cam lobes?
Very interesting to find out.


Na Ive read thats wrong for our K24A3. Thats the U.S K24A3 (only 9.7:1 compression).
The Aussie/EU ones use 10.5 compression and are virtually the same as the TSX's K24A2 but slightly detuned to accomidate lower octane fuel.

Dunno why Honda must confuse everyone and make two different K24A3's :confused:
If anything, they should have stamped our engines as K24A2 or even K24A6

[Chris_F]

yep EuroDude is correct. the k24a3 mentioned in that article is not hte same k24a3 as in our cars. I'm sure the differences between the 03-05 tsx and 03-05 euros is predominantly in the tuning and differences in gearing.

[aaronng]

can anyone provide some inormation as to how the Final Drive actually effects acceleration vs. reduction of speed in each gear and top-speed?
A lower final drive (higher number) reduces the top speed in EACH gear. In compensation, you get more torque to the wheels and hence stronger acceleration. The top speed is reduced by doing multiplying your top speed in each gear with the old final drive ratio and then dividing with the new final drive.

new top speed = old top speed x old final drive / new final drive.

The actual amount of RPM drop when you change gears still stays the same as original. So for the Euro, RPM drops from 7200 to around 4800 when you shift 1st to 2nd. A shorter final drive won't change this. To change the RPM drop, you have to change the actual gear ratios.

Octane: The petrol required by the K24A2 is similar to the K24A3. K24A2 specifies 91 PON, while K24A3 specifies 95 RON. From a previous TSX thread, 91 PON is very very close to 95 RON.

[Omotesando]

Well, flat shifting on a Corolla Sportivo that had only 180 Nm did cause some damage to the driveline. The owner said that it was "loose" and gritty after that. That engine has less torque than the Accord Euro.

It's not because of the torque being linear. It's because of the speed of the clutch being released while the revs is about 2000 RPM above the next gear. Imagine when you shift from 1st to 2nd flatshifting. When you release the clutch at 7000rpm, your transmission speed is only about 4500-5000rpm in 2nd gear. That's 2000-2500rpm different and at the speed you're releasing your clutch, everything after the clutch (transmission, driveshaft, bearings, CV joints) is going to have to speed up. While the car is moving at about 60km/h, 2nd gear at 7000rpm is 100km/h. So everything is going to try to speed up to 100km/h, which is not possible. So your driveline will take a shock and if the tyres don't lose grip, the engine is also forced to jump back down from 7000rpm to 4500rpm. Even when not flatshifting, releasing the clutch fast during a 1-2 shift and applying throttle quickly after that will cause a very loud bang sound. That's the shock through the driveline.

Well as I already mentioned, you're purely speaking on relative terms here. You don't seem to be able to see the point I'm raising here and that is, on a linear torque delivery car with relatively lower torque figure, the damage you do to the drivetrain when you flatshift, isn't actually that damaging compared to other higher torque cars.

Your Corolla example with a lowish torque figure clearly shows this. It being subjected to numerous flat shifting sessions is certainly prone to be slightly damaged in the driveline somewhat and becoming loose - hell if you try hard enough you can break anything in the car. BUT IT IS STILL WORKING AND MOVING.. See my point?

The important point is that - if you try to do flat-shifting to a car with 350-400Nm of Torque, but more like closer to 400-500Nm of Torque such as the V8s or one with a massive turbo rush - the transmission and the drive shafts can just snap. You do it only ONCE, and it will already fail. On some cars, you can flat shift once in a while when you're trying hard to get some acceleration figures on the drag strip. On SOME cars with a high torque figure, you do not even want to try it once. :o


You said "It's not because of the torque being linear..."
In fact you're overlooking one things here by saying that, although slightly veering off into another topic:

1) If the torque delivery to the drivetrain ISN'T linear such as a massive turbo coming on boost hard or an All Wheel Drive launch going from zero torque to big torque in no time, the sudden torque difference is big enough to put a substantial load on the drivetrain components to be able to damage it permanently. It is similar to the V8 example above yet different, because in the V8's the torque delivery is very linear YET can still damage something when you put a shock thru the driveline.



But the biggest problem with your understanding of Flat Shifting is that you're over exaggerating it.


When you drive a car normally but to the redline, your foot will be coming off the 7000RPM or 7300rpm or so ANYWAY. At this time, you release the clutch and change gears but the engine in fact DOESN'T drop right back down to 4500-5000rpm as you said that is suitable for say 60km/h in 2nd gear. It is still hovering around the 7000rpm mark just dropping down a bit at a time, since at this particular point of time, there is no drivetrain connection (or drivetrain energy) that is pulling a massive engine braking.

With normal shifting, the faster you can complete the gear change properly, the less the engine rev will drop. It will NOT change towards 4500-5000rpm ready for 2nd gear at 60km/h in anycase by itself.


The difference between a really fast shift and a flat shift isn't that much. If you can complete flat shifting FAST enough without lifting off accelerator then good on you (that is maximum damage btw!) but the fastest drag time. But for most people who flat shift, in fact they cannot put their foot 100% down on the accelerator because if they can't shift fast enough and then to release clutch in the 0.2-0.3s time, your foot being flat on the pedal means the engine is going to hit the rev limiter which slows down everything.


The truth is, flat-shifting and 'normal but fast shifting' might only have 500rpm difference. The damage that can be done isn't just from flat shifting and at high rpm as you said because that is wrong. A very similar thing happens when you shift fast anyway.

[aaronng]

Uh... you can crack your driveshaft and still be able to drive your car. But I consider that as damage eventhough your car still moves.

I don't get what's your beef? My point is that flat shifting can damage drivetrain components. That's it. I'm not making a distinction between a bearing being damaged, a driveshaft cracking or the whole transmission turning into mush. I'm just saying, flat shifting can damage the drivetrain. My example was the Corolla Sportive that after 3 passes with flatshiting, the car had sustained some damage to the drivetrain. I'm not saying that some part of the drivetrain would fail catastrophically if you flatshifted.

The technical difference between a normal shift and a flatshift is that when you flatshift, the flywheel is exerting torque because your foot is on the accelerator. When you release the clutch fast, all that torque is transmitted through the transmission and into the drivetrain. That quick transfer of torque is what causes the damage/wear. That's it. If you want to nitpick, the torque at the flywheel at that instant is the amount of torque at 7200rpm. So it doesn't matter if you have a car with a linear (example) 200Nm @ 7200rpm or a non-linear (turbo) 200Nm @ 7200rpm. It's still that same 200Nm going through the transmission and to the drive train.

If you are not flatshifting and changing at redline normally, when you release the clutch fast the engine speed is reduced instead as there is an instant where your foot is not yet on the accelerator. Even if you shift so fast that your RPM is still at that 7000rpm that you stated, the moment you release the clutch, the revs will drop because your foot is not on the accelerator.

And if you involve high torque V8s, the difference is in the component that is damaged. V8's higher torque damage the transmission first, while lower torque vehicles like the Euro and Corolla will damage the drivetrain after the transmission.

[Omotesando]

If you are not flatshifting and changing at redline normally, when you release the clutch fast the engine speed is reduced instead as there is an instant where your foot is not yet on the accelerator. Even if you shift so fast that your RPM is still at that 7000rpm that you stated, the moment you release the clutch, the revs will drop because your foot is not on the accelerator.


You are making a very big and may I say slightly false assumption there.

1stly whether you flatshift or normal shift, 'the revs will drop' back into the correct rpm (say 5000rpm) at that vehicle speed (say 65kph) for that gear (say 2nd) anyway > EITHER METHOD OF SHIFTING. I hope you agree with me on that.

I put 'the revs will drop' in brackets because it is not due to the foot NOT being on the accelerator, but due to the whole drivetrain being connected to the engine again at that vehicle speed, bringing back everything into reality... so to speak. The shaft(s) in the transmission/drivetrain are still spinning at the same vehicle speed, but due to the higher gear and lesser torque multiplier effect, the engine is ALLOWED to fall back into a lower rpm.
It has little to do with the foot being on the accelerator as you said.

But the important thing to realise is that when you are normal shifting but fast at say 7000pm, and when you let go of the depressed clutch, you WILL step on the accelerator because that is how everyone driving a manual car accelerates, no matter whether it is shifting at 2000rpm or 5000 or 7300rpm. Otherwise the whole damn thing will be shaking like a horse and DECELERATING quickly.

A person trying to shift 'fast' to accelerate up the gears will naturally have this overlap happening, not only that but they will put their accelerator down all the way again during this 'overlapping period'.





And if you involve high torque V8s, the difference is in the component that is damaged. V8's higher torque damage the transmission first, while lower torque vehicles like the Euro and Corolla will damage the drivetrain after the transmission.

I don't understand how you came into that conclusion at all. I completely disagree. The Engine's Flywheel is separated from the Transmission by the clutch. If there is any shock to the drivetrain after clutch is release again, the first component which bears it first is the clutch. That is the reason why the clutch is the weak link in most powerful cars, because it is suppose to be that way, to save other more expensive parts. If the clutch did bite properly, then it is whichever weaker part (either the transmission or part of the drive shaft or other drivetrain components) which will fail first.

What does this have to do with higher torque or lower torque vehicles? The weak part fails first in both cases.



The thing I'm trying to put across is that - you keep saying you think a flatshift 'relative' to a normal shift will damage the drivetrain somewhat. But that was never my point, as everyone in the world already knows that.


The thing being mentioned by me is that the 'sudden difference of torque' and also 'peak torque figure' are what damages a drivetrain, and on a car with a Linear Torque delivery (less likelyhood of sudden difference of torque during accelerating) and also a Lowish Peak Torque figure, would mean the damage by flat-shifting in such a configurated car isn't as great as one might think. Compared to an All Wheel Drive launch, or the torque of a V8 car flat shifting. Also the fact that Flat shifting isn't even as exaggerated as you think it is, because a fast shift that we all do has nearly equally damaging effects.

The most important thing is that since torque change is what damages the drivetrain, but with a lowish peak torque figure even when one is flat shifting the torque change during that action isn't that big an issue. A 223Nm peark torque figure isn't that high at all and usually drivetrains and transmissions can handle that, even if flat shifting.

[EuroDude]

1stly whether you flatshift or normal shift, 'the revs will drop' back into the correct rpm (say 5000rpm) at that vehicle speed (say 65kph) for that gear (say 2nd) anyway

Unless the wheels are able to spin freely due to crappy tires or a poor road, or because the engine has heaps of torque :cool:

Well at least thats what ive done in my Civic once, the car nearly kept its flat-shift rpm but the wheels spun and the car jolted forward.

[aaronng]

Edit: I realised this thread is going way off topic. I've removed my reply and I'll PM it to you, omotesando. :)

[Spec83]

I think you will find that in flat shifting the syncro's and to lesser extent gearsets will bear the brunt of the damage - as was said the clutch is designed to be the weak point and if the speeds are not equal there is a high chance the clutch will slip before the gearbox gets its turn if the clutch is used... (Always a good idea to slip the clutch in a new car for this reason)

Flat shifting causes hardly any wear on the clutch, but causes gearbox wear as the syncros get a pounding trying to even up the speed between gears... this shock is also transfer to gears.... helical gears are especially suseptable to breaking due to shock since the initial contact between gears is concentrated at a point.. on racing gearboxes the teeth are straight cut so the load is distributed along the entire width of the gear tooth... this design however is very noisy and not OEM friendly

Bearings and whatnot also undergo stresses which are generated through shafts into their respective housings... The sportivo gearbox would probably feel new agin with a new set of synchro's :)

Driveshafts will not get too damaged - spinning the wheels and whatnot will kill these