AutoRacing Technik CL9 Project Teaser *Updated With Sound Clip On Post 1*

*UPDATE*

SOUND CLIP : http://download.yousendit.com/A0234BF96F6C9D93
Recorded using my mobile phone, windows up.

Well, couple of us guys set down in the office, and discussed over the RBC Manifold testing being performed on the Euro...

NOTE: All tests were done in 4th gear (Closest Ratio to 1) with a real World ramp rate of 5km/h. Average ramp time was 27 seconds with ambient temp around 30 degress +

--------------------------------------------------------------------------
DYNOGRAPH 1

http://img.photobucket.com/albums/v1...ynograph1w.jpg


In dynograph1, the comparison is the baseline RBC manifold and RBB manifold only. The secondary y-axis is in MAP (Manifold absoulte pressure). As part of the induction system, this test was logged to evaluate the respective manifolds ability to provide air to the cylinder head. The graph shows that the RBC manifold maintains more vacuum in the plenum chamber than when compared to the RBB manifold. This difference although small, reduces over the rev band and indicates that a larger intake aperture and/or plenum chamber would improve air quantity to the cylinder head for both manifolds. If higher performing cams were to be installed, cylinder head porting etc, it would most probably increase the vacuum in the plenum chamber in both RBC and RBB manifolds.


A log of the factory MAP sensor mounted on the intake manifold was also taken. It shows a start voltage of 2.96v falling to 2.89v at the end of the run. Throttle position was also logged and it showed that the butterfly remained open full-throttle throughout the run at 4.74v +/- 0.02v. Injector duty was also logged and reflected the cars ability to support more horsepower without issue.

A further note is that this shows also that a longer intake upstream of the throttle body will not help as the system static pressure will increase, thus reducing the total air quantity for combustion. Will confirm how the MAP is affected by this on the road at a later date.

The other item is the power band comparison between the RBC and RBB manifolds across the rev band. The power and torque difference up to 4000rpm is pretty much the same which is a little unexpected, however, it clearly shows that the RBB's longer intake runners produce better torque from around 4000rpm to 5500rpm. From around 6200rpm, the RBC manifold is by far superior with its shorter runners. Note that acceleration enrichment and engaging a different gear may alter the results, this will be tested next.

DYNOGRAPH 2

http://img.photobucket.com/albums/v1...ynograph3w.jpg

Dynograph3, has the A/F (Air/Fuel) ratio in the secondary y-axis, note that this is taken from the exhaust tailpipe. This partially explains why the RBB and RBC manifolds produce similar power up to the 4000rpm region. The leaner A/F ratios of the RBC manifold contribute to better torque as it is closer to the stoichiometric ideal 14.7:1 (approx). Between the 4000rpm and 5500rpm the RBB manifold shows more complete combustion as anticipated. Finally, from 6200rpm the mixtures start to lean off to around A/F 11.75:1 thus supporting the power advantage of the RBC manifold in that range.

DYNOGRAPH 3

http://img.photobucket.com/albums/v1...L9170/1336.jpg


Dynograph 4, is the comparison of the RBC manifold alone, and the other with A/F correction and ignition control using the PROTOTYPE interceptor ECU. Obviously showing a gain throughout the rev band after tuning. Not much but still significant at 133.6Kws


More testing to come in conjunction with more parts that have already been ordered and in transit. :)

HAPPY READING!


http://img.photobucket.com/albums/v1...L9170/RBC1.jpg

http://img.photobucket.com/albums/v1...L9170/RBC2.jpg


More to come :)

hehehehehe

im loving it!! ill have to change my avatar message from,
"only RBC euro in AUS"

to

"1st RBC euro in AUS"

lol!!

did you tap into the plenum for the idle control solenoid? ill have to hurry up and finish my DIY on it... got like 100pics! lol

im just so happy to see that u didnt loose bottom end power.... cause i felt that i did :( but i think my butt dyno is out... once i have my engine bay sorted, ill get her dyno'd... see how she goes :D

im still planning my secret ;) but as soon as yours is sorted.... we gotta talk business :P

what other mods are you running on the engine? is it still using the k24 head?

Sorry to be noob, but what does RBC stand for?

oo cant wait too see final results

wow!!! standard k24? revving pass 8000rpm??

Quote:

---

Originally Posted by SiReal

Sorry to be noob, but what does RBC stand for?

---

I'm not quite sure but... i think people talk about RBC and KBC. I think that RBC is k20 headers and KBC is euroR headers. maybe im making an ass of myself but i dunno ^^

Quote:

---

Originally Posted by hooyn

I'm not quite sure but... i think people talk about RBC and KBC. I think that RBC is k20 headers and KBC is euroR headers. maybe im making an ass of myself but i dunno ^^

---

RBC is EuroR intake manifold. RBB is 2.4L Euro. PRC is DC5R. PRB is DC5S.

Nice to see the progress is going well. :thumbsup:

O M G!!!

It's loud!!!!! As in SERIOUSLY LOUD!

Atjo went for a spin with me in the car, ask him how loud it was!!!!!

What's amazing is at the higher RPM range, I get a turbo spool whistle you hear in Turbocharged cars...

sorry... what's loud?

Quote:

---

Originally Posted by Chris_F

sorry... what's loud?

---

Sorry the intake :D

I like loud........sound clip anytime soon? :p

sounds like a turbo !!!! :O :O :O :O i was wondering around how much did this damage your pockets ?

Love that crazy VTEC induction noise like in the K20A's revving out :p really cool!

Quote:

---

Originally Posted by hooyn

sounds like a turbo !!!! :O :O :O :O i was wondering around how much did this damage your pockets ?

---

You'll be surprised, it's not much really....

Quote:

---

Originally Posted by EuroAccord13

Sorry the intake :D

---

love the induction roar on euro's :thumbsup:

Quote:

---

Originally Posted by EuroAccord13

You'll be surprised, it's not much really....

---

hahah not much for a salary employee or not much for a 2nd year uni student ^^

Quote:

---

Originally Posted by hooyn

hahah not much for a salary employee or not much for a 2nd year uni student ^^

---

Mmmmm...... Ok you got me....
But my advise to you is, don't spend on cars :) Save the money and reap the rewards by the time you finish uni :D

The thing is, this R&D takes into account maximising power using different branded parts. It's like hot swapping heeheeheehee...

looks really nice - question is how does it drive now?

At the 3rd graph it looks very lean up top after the prototype ecu was fitted and tune. you sure the that dude knows what he is doing?

Quote:

---

Originally Posted by jessica

At the 3rd graph it looks very lean up top after the prototype ecu was fitted and tune. you sure the that dude knows what he is doing?

---

Good question :)

First of all, it's measured post cat, not pre cat. This represents a slight variation in the actual mixture and this graph is the normal way of producing results where as the more accurate way of attaining the actual A/F ratio is to take the A/F ratio before the cat closer to the collection point of all four cylinders. In essence, what is measured post cat is more than likely to be leaner than what the actual A/F ratio value is.

The optimum A/F ratio for any car varies with balance of fuel and ignition advance available at the combustion chamber and this threshold varies with every tuner as each tuner employs their own techniques but at the same time, the graph shows pre-tune and post-tune and has a degree of ignition advance as well as a reduction in fuel delivery which is characteristic of a typical Honda engine tuned for maximum torque for road use.

:)

Sound Clip Posted...

sounds good :D
looks like it's all coming together :)

which is all understandable and i agree with what you are saying but 14:1 A/F ratio is lean at 6 grand

Mate, don't think you understand what he just tried to explain. What he said was that the graph readings were at the tailpipe and the real A/F ratio is richer than what was on the graph due to the function of the cat, ie its RICHER than 14:1 A/F.

holy crap vtec kick in sound is win. :D:thumbsup:

lol maybe i should get you eg carby to tune my car

Quote:

---

Originally Posted by EuroAccord13

*UPDATE*

SOUND CLIP : http://download.yousendit.com/A0234BF96F6C9D93
Recorded using my mobile phone, windows up.

Well, couple of us guys set down in the office, and discussed over the RBC Manifold testing being performed on the Euro...

NOTE: All tests were done in 4th gear (Closest Ratio to 1) with a real World ramp rate of 5km/h. Average ramp time was 27 seconds with ambient temp around 30 degress +

--------------------------------------------------------------------------
DYNOGRAPH 1

http://img.photobucket.com/albums/v1...ynograph1w.jpg


In dynograph1, the comparison is the baseline RBC manifold and RBB manifold only. The secondary y-axis is in MAP (Manifold absoulte pressure). As part of the induction system, this test was logged to evaluate the respective manifolds ability to provide air to the cylinder head. The graph shows that the RBC manifold maintains more vacuum in the plenum chamber than when compared to the RBB manifold. This difference although small, reduces over the rev band and indicates that a larger intake aperture and/or plenum chamber would improve air quantity to the cylinder head for both manifolds. If higher performing cams were to be installed, cylinder head porting etc, it would most probably increase the vacuum in the plenum chamber in both RBC and RBB manifolds.


A log of the factory MAP sensor mounted on the intake manifold was also taken. It shows a start voltage of 2.96v falling to 2.89v at the end of the run. Throttle position was also logged and it showed that the butterfly remained open full-throttle throughout the run at 4.74v +/- 0.02v. Injector duty was also logged and reflected the cars ability to support more horsepower without issue.

A further note is that this shows also that a longer intake upstream of the throttle body will not help as the system static pressure will increase, thus reducing the total air quantity for combustion. Will confirm how the MAP is affected by this on the road at a later date.

The other item is the power band comparison between the RBC and RBB manifolds across the rev band. The power and torque difference up to 4000rpm is pretty much the same which is a little unexpected, however, it clearly shows that the RBB's longer intake runners produce better torque from around 4000rpm to 5500rpm. From around 6200rpm, the RBC manifold is by far superior with its shorter runners. Note that acceleration enrichment and engaging a different gear may alter the results, this will be tested next.

DYNOGRAPH 2

http://img.photobucket.com/albums/v1...ynograph3w.jpg

Dynograph3, has the A/F (Air/Fuel) ratio in the secondary y-axis, note that this is taken from the exhaust tailpipe. This partially explains why the RBB and RBC manifolds produce similar power up to the 4000rpm region. The leaner A/F ratios of the RBC manifold contribute to better torque as it is closer to the stoichiometric ideal 14.7:1 (approx). Between the 4000rpm and 5500rpm the RBB manifold shows more complete combustion as anticipated. Finally, from 6200rpm the mixtures start to lean off to around A/F 11.75:1 thus supporting the power advantage of the RBC manifold in that range.

DYNOGRAPH 3

http://img.photobucket.com/albums/v1...L9170/1336.jpg


Dynograph 4, is the comparison of the RBC manifold alone, and the other with A/F correction and ignition control using the PROTOTYPE interceptor ECU. Obviously showing a gain throughout the rev band after tuning. Not much but still significant at 133.6Kws


More testing to come in conjunction with more parts that have already been ordered and in transit. :)

HAPPY READING!


http://img.photobucket.com/albums/v1...L9170/RBC1.jpg

http://img.photobucket.com/albums/v1...L9170/RBC2.jpg


More to come :)

---

Looks like someone been busy glad to hear of your successes

Quote:

---

Originally Posted by jessica

lol maybe i should get you eg carby to tune my car

---

Where's the queue ?

Quote:

---

Originally Posted by eg_carby

Mate, don't think you understand what he just tried to explain. What he said was that the graph readings were at the tailpipe and the real A/F ratio is richer than what was on the graph due to the function of the cat, ie its RICHER than 14:1 A/F.

---

:thumbsup::thumbsup::thumbsup:

Quote:

---

Originally Posted by yfin

looks really nice - question is how does it drive now?

---

It is actually quiet when you drive normally at 10%-15% throttle... Flat out, it screams...

have you had traction control kick in when vtec hits in second yet?

lol i laughed so loud the first time mine did it lol

Quote:

---

Originally Posted by EUR003act

have you had traction control kick in when vtec hits in second yet?

lol i laughed so loud the first time mine did it lol

---

SHHHHHHHHHHHHHHHHHHHHHHH!:D

Wait till I put the Video up heeheeheeheehee.... You gotta listen to that Turbo Spool and the BOV!

where is this Auto racing technik? i like to see what they can really do?

Quote:

---

Originally Posted by EuroAccord13

SHHHHHHHHHHHHHHHHHHHHHHH!:D

Wait till I put the Video up heeheeheeheehee.... You gotta listen to that Turbo Spool and the BOV!

---

lmao :p

my bad.... lol ill wait

ive still gotta make my DIY :( im sooo lazy

And then we have this....



http://img.photobucket.com/albums/v1...170/SK_Web.jpg



Anyways.... Wrong part was sent but replacement is on it's way!

your gonna have to let me know what springs/retainers you used..... james form jtune reckons that the k20 and k24a2 springs dont fit the euro.... :(

Quote:

---

Originally Posted by EUR003act

your gonna have to let me know what springs/retainers you used..... james form jtune reckons that the k20 and k24a2 springs dont fit the euro.... :(

---

Not sure about the 06+ k24a2, but the k20a2 should fit.

what program do i use to open the sound file?

Use Quicktime

I'll try to record with a proper recorder, my phone did no justice to the sound.

I'll try and record the metallic spooling noise as well as the BOV....

Quote:

---

Originally Posted by EUR003act

your gonna have to let me know what springs/retainers you used..... james form jtune reckons that the k20 and k24a2 springs dont fit the euro.... :(

---

Just check on the k20a.org forum there are alot of discussion of 03-05 k24a2/TSX. From what I gathered the k24a2 is most likely using k20a2 part from RSX type S, and it is done more than a dozen members,
My understanding probably the compatibility are not from the k20a3 non type S RSX or k24a1/k24a4 from CRV or accord.

Anyway Skunk2 or IPS cams so far is the highest produced power ,from dyno result taken from k20a forum, so it's gonna be fun project for Technik Tuning

hehe hey buddy! i got very very very similar figures to you today (133.3kw atw) with no ecu tuning. A/F ratio nearly perfect entire wat thru rev range! had all the toyota boys jealous of hondas ecu engineering! :D

still running an exposed pod? or not
and did you force feed a CAI pipe to it?

Exposed dry pod now, enclosed pod lost power due to restriction of air intake within the enclosure.
Got a ghetto CAI pipe running up to the pod as well.

Euro13,

What exhaust do you have on your car now and do you think bolton+RBC and a tune ( i have jtune) warrants a better than stock exhaust.

Im considering a custom 2.5 inch or 60mm single exhaust, resonator, mid-muffler then ending in twin loop muffler to free up my car with these mods. My cars making simiar power to yours.

Any comments on my expected single design?

You will probably experience the same issue as my previous single set up (currently on Skunk2 Twin system), that is not enough flow, same as why JTune has came up with such a nice twin outlet system, there simply isn't enough to flow the exhaust gases with my camshaft and RBC set up on top of all the other mods.

So you reckon single 2.6 inch wont do it? I dotn have cams thought. Maybe dual 60mm into 50mm splits on twin? Im not going 3 inch. That will piss me off as a daily.

A straight through single outlet 2.5" should flow better than a 60mm being split into two.

Some guys in the states are running 2.5" single systems and making over 230whp on the k24. The peak power of a single outlet 3" system is usually 5-10hp more than a 2.5" system. The only reason you'd run a 2.5" system on a k24 is if you're a bit worried about noise levels (trust me, even a 2.5" exhaust is pretty loud), or can't have the car tuned to take advantage of the extra flow. Generally speaking the k20/k24's do better with a 3" system (but it also helps if you have a header with a large collector that can take advantage of the 3" diamtere)

Euroaccord13, what was your previous setup? I'm suprised a skunk2 dual exhaust would outflow a single outlet exhaust? Isn't the function of a dual outlet exhaust to reduce noise (exhaust gasses pass through two end mufflers)

In relation to cams, with a k24a3/k24a2 you can use cams, valve springs and retainers that are designed for a k20a2 you just need to use some k20a2 spring seats.

Quote:

---

Originally Posted by EuroAccord13

You will probably experience the same issue as my previous single set up (currently on Skunk2 Twin system), that is not enough flow, same as why JTune has came up with such a nice twin outlet system, there simply isn't enough to flow the exhaust gases with my camshaft and RBC set up on top of all the other mods.

---

So basically your saying ( and chrisf is saying) that a 2.5 inch system is not big enough!??

I was actually thinking a 60mm or 2.38 inch single system would be good for my mods with RBC etc.

I might get a quote on 2.5 inch into dual in mild steel with 2 x twin loops. Might get expensive though.

Im sure i will get some gains from exhaust. Im definately making more power than the 06 tsx and they have a 57mm into a 47mm twin system ...up a fair bit from the stock 52mm system on our cars but only making a few more kw, so Honda justified the bigger exhaust some how....

the bigger exhaust on the 06 tsx is used because it has the more aggressive cams (the most aggressive OEM k-series cams you can buy). The 06 tsx also has a bigger throttle body (64mm i think).

2.5" into 2 x twin loops will flow less than a 2.5" single outlet with 2.5" straight through muffler. When it comes to having a custom exhaust made with Y joins you also have to be careful. The quality of the Y join is going to be really important to how the exhaust flows so the exhaust shop will need to know what they're doing.

Don't get me wrong though Suntzu, all I'm saying is that 3" is generally considered ideal for the k-series if you want to make as much power as possible (also assuming you have the supporting mods like a race header with a large diametre collector). Most of the guys in the states are running 3" setups on dedicated drag cars so they have different requirements and dont need to make as many compromises (such as comfort/sound levels). So of course a 2.5" system is big enough it's just not ideal when every last hp is critical. A single outlet 2.5" exhaust will still outflow the stock exhaust by a hell of a lot.

For reference, I made 125kw atw with my old j's racing exhaust and that came with 60mm piping and a ~50mm internal diametre rear muffler (on the same day a stockish DC5R made about 115kw atw).

With stock cams, stock VTC and stock throttle body you really won't realise the full potential of a 3" system anyway. You may still gain 5+ peak hp but you'll probably end up sacrificing 5 decibles at the same time.

I'd really like to hear more about euroaccord13's old exhaust setup. I'm suprised that a skunk2 dual outlet exhaust would outflow a single outlet exhaust??

I can't see any torque figures in the OP, am I missing something?

Quote:

---

Originally Posted by Chris_F

the bigger exhaust on the 06

2.5" into 2 x twin loops will flow less than a 2.5" single outlet with 2.5" straight through muffler.

---

Hmm. i dont want a single with a cannon though. That because it will be loud, and very ricey. Both things I have to avoid at all costs.

Do you reckon a 2.5 inch with quality mid muffler and resonator onto single Twinloop ( quality, quite brand?? suggestions) will flow a lot better than stock and not be too loud.

Thats my plan at the moemtn anyway 2.5 inch, resonator, muffler, twinloop mufller in mild steel.

Any ballparks on a cost for this you reckon?

Quote:

---

Originally Posted by Suntzu

Hmm. i dont want a single with a cannon though. That because it will be loud, and very ricey. Both things I have to avoid at all costs.

Do you reckon a 2.5 inch with quality mid muffler and resonator onto single Twinloop ( quality, quite brand?? suggestions) will flow a lot better than stock and not be too loud.

Thats my plan at the moemtn anyway 2.5 inch, resonator, muffler, twinloop mufller in mild steel.

Any ballparks on a cost for this you reckon?

---

A setup like that shouldn't cost you anymore than $900.

Supercat and Magnaflow are both respected brands, well priced in Australia and have 5 year warranties. I'd go with one of those. A good exhaust shop will be able to reccomend you a muffler, just tell them you don't want a canon and want it as quiet as possible.

First set up was only an axle back, then we found restrictions in the mid pipe, then a custom one was fabricated to help flow the exhaust gases better, it was ok with the RBC and intake modifications and base tune, then the camshafts went in, there wasn't enough flow and hence the Toda headers was purchased (processed very efficiently from Adrian @ Toda Australia) and then the Skunk2 Cat Back was installed as well.

What Chris F has mentioned is true, 3 inch is too much for NA applications if its is not going to be modified hardcore.


What we've found with the single vs. dual outlet system is the same as what JTune has found, in short, the flow is much more optimum for the application I am using.

Mind you, there is nothing wrong with the single outlet setup, but it does have a limit to it if you are going to push maximum gains.

My original plan was to push for HP but with all the power and no traction, it's useless hence my goal has been changed to having the car going for torque instead (Read my Dynograph) which would be good for track days. The one I went to a few weeks ago proved that the torque I have in the car helped as I was able to pull and match the end speed of RX8s, WRX STIs and Liberty GT, and even outrunning some of them them around the track, only losing out on corners due to the extremely wet track.

I might just get a local company to fab up a copy of the skunk2 dual setup with twin loops. That might be better then in terms of noise/power. I think its a 60mm to dual 50mm no mid muffler hen cannons..i think..

Id get the proper skunk2 but the exchange rate and shipping make it unviable.

Thanls for the advise.

EuroAccord13, sounds like your current mods and tuning have made a big difference to the real-world acceleration of the car :thumbsup:

Quote:

---

Originally Posted by EuroAccord13

What we've found with the single vs. dual outlet system is the same as what JTune has found, in short, the flow is much more optimum for the application I am using.

Mind you, there is nothing wrong with the single outlet setup, but it does have a limit to it if you are going to push maximum gains.

---

I'm still not sure why a dual outlet system would flow more than a well designed single outlet exhaust? Maybe the single outlet exhaust you initially tested had poor flow for a differnet reason (type of muffler used, workmanship etc.)

All of the high power k-series in Australia and in the US all use single outlet exhausts. The JDMYARD k24 is using a 3" single outlet exhaust and is making 178kw atw. I've also seen other cars in the states running single outlet 2.5" systems making 230whp or more. I still doubt a single outlet exhaust would be more restrictive. By adding a Y join all your doing is splitting the exhaust gasses, forcing them to travel through two mufflers and ultimately reducing the velocity of the exhaust gases/flow.

If I remember correctly, Jtune designed a dual outlet exhaust for cosmetic and noise reductions reasons. Since the product was "inteded for a mature market". I'm sure their design flows really well but I have a feeling it'd flow better if it was a single outlet 3" all the way through.

Quote:

---

Originally Posted by Chris_F

I'm still not sure why a dual outlet system would flow more than a well designed single outlet exhaust? Maybe the single outlet exhaust you initially tested had poor flow for a differnet reason (type of muffler used, workmanship etc.)

---

Just taking a stab here, but could it be to aid initial back pressure and then an easier release towards the end?

^ doubtful, if that was the case why would all the high power K-series in Australia and the states be using straight through 3" exhausts with a single outlet?

I'm talking about cars making anywhere from 200whp with simple bolt ons and tuning all the way up to cars with 340whp (All NA). They all run single outlet exhausts. There are no k-swapped cars making more power with a dual outlet exhaust. Surely if there was an advantage the workshops and private tuners in the states and Australia would have started using such a setup. Call me a skeptic but I'm just not convinced that a psuedo dual outlet exhuast can provide any benifit on a 4 cylinder car compared to a well designed single outlet. Why would companies like FEELS, J's Racing, Spoon, Amuse all offer a single outlet exhaust as their "high power" model. None of the dual exhausts on the market that I've seen tested have shown more than a 2-3whp gain.

I'll be having my car tuned with a standalone ecu soon, so it'll be interesting to see what sort of gains I can achieve with the single outlet setup.

Quote:

---

Originally Posted by Chris_F

^ doubtful, if that was the case why would all the high power K-series in Australia and the states be using straight through 3" exhausts with a single outlet?

I'm talking about cars making anywhere from 200whp with simple bolt ons and tuning all the way up to cars with 340whp (All NA). They all run single outlet exhausts. There are no k-swapped cars making more power with a dual outlet exhaust. Surely if there was an advantage the workshops and private tuners in the states and Australia would have started using such a setup. Call me a skeptic but I'm just not convinced that a psuedo dual outlet exhuast can provide any benifit on a 4 cylinder car compared to a well designed single outlet. Why would companies like FEELS, J's Racing, Spoon, Amuse all offer a single outlet exhaust as their "high power" model. None of the dual exhausts on the market that I've seen tested have shown more than a 2-3whp gain.

I'll be having my car tuned with a standalone ecu soon, so it'll be interesting to see what sort of gains I can achieve with the single outlet setup.

---

what about if you ran custom headers that went 4 -> 2 and then kept twin piping down to two seperate canons :p

lol

IMO twin exhaust is only for sound level and looks...

oh, this is also my 2cents...

system 1: (twin mufflers)
each muffler is say 80db, and flows 300CFM
thats a total of 600CFM flow...

system 2: (single muffler)
sound level of 90db, flows 500CFM...
total of 500CFM flow...

System two is quieter, and flows more...

(these numbers are made up, i have no idea what an exhaust flows at, im just trying to show the difference)

Quote:

---

Originally Posted by EUR003act

what about if you ran custom headers that went 4 -> 2 and then kept twin piping down to two seperate canons :p

lol

IMO twin exhaust is only for sound level and looks...

---

lol, then you'd loose power...

Quote:

---

Originally Posted by EUR003act

oh, this is also my 2cents...

system 1: (twin mufflers)
each muffler is say 80db, and flows 300CFM
thats a total of 600CFM flow...

system 2: (single muffler)
sound level of 90db, flows 500CFM...
total of 500CFM flow...

System two is quieter, and flows more...

(these numbers are made up, i have no idea what an exhaust flows at, im just trying to show the difference)

---

Do you mean system 1 is quieter and flows more?

But that's the problem. You can't just add up the individual flow of each muffler and say one flows better than the other. It's more complex than that. How about the increased turbulance created by the y-join? The reduction in velocity of exhaust gases caused by splitting the exhaust gasses and forcing them to twist and bend through the extra piping and the extra muffler?

Also, faster traveling exhaust gases will create a scavenging effect that pulls subsequent exhaust pulses through the exhaust.

My main point though: if there was a true performance benift to a dual outlet exhaust on a 4 cylinder car (not talking about noise reduction or looks) why don't all of the tuners who are obsessed with extracting every last HP out of the k-series go with a dual outlet design?

By the way, I'm not saying that a dual outlet exhaust can't flow just aswell as a single (depending on the design). I'm saying that a single outlet exhaust is all that's needed regardless of the power figure you are chasing. It's also more straight forward to design a single outlet exhaust that will give you the flow you need for your setup.

Quote:

---

Originally Posted by EUR003act

what about if you ran custom headers that went 4 -> 2 and then kept twin piping down to two seperate canons :p

---

Then your Euro would sound like it had a 2-cylinder engine. Hahaha.... Try it!

Quote:

---

Originally Posted by Chris_F

But that's the problem. You can't just add up the individual flow of each muffler and say one flows better than the other. It's more complex than that. How about the increased turbulance created by the y-join? The reduction in velocity of exhaust gases caused by splitting the exhaust gasses and forcing them to twist and bend through the extra piping and the extra muffler?

Also, faster traveling exhaust gases will create a scavenging effect that pulls subsequent exhaust pulses through the exhaust.

My main point though: if there was a true performance benift to a dual outlet exhaust on a 4 cylinder car (not talking about noise reduction or looks) why don't all of the tuners who are obsessed with extracting every last HP out of the k-series go with a dual outlet design?

By the way, I'm not saying that a dual outlet exhaust can't flow just aswell as a single (depending on the design). I'm saying that a single outlet exhaust is all that's needed regardless of the power figure you are chasing. It's also more straight forward to design a single outlet exhaust that will give you the flow you need for your setup.

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Ultimately up until the split a single and dual outlet catback run the exact same course and you're right when you say the main problem is in the split but you'd assume a good aftermarket exhaust would have a good-quality split that won't disrupt flow that much. But a single outlet exhaust still has to bend in the same place at roughly the same angle as one of the dual's. What's the say it's impossible for the gas to flow as well if it splits before the corner as if it just stayed all together around it?

Not saying you're right or wrong but just looking at it from another perspective

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Originally Posted by integral90

Ultimately up until the split a single and dual outlet catback run the exact same course and you're right when you say the main problem is in the split but you'd assume a good aftermarket exhaust would have a good-quality split that won't disrupt flow that much. But a single outlet exhaust still has to bend in the same place at roughly the same angle as one of the dual's. What's the say it's impossible for the gas to flow as well if it splits before the corner as if it just stayed all together around it?

Not saying you're right or wrong but just looking at it from another perspective

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Well if the gas splits after the Y wouldn't the energy/velocity of the gass travelling through the pipe is also split into two. It then has to travel through twice as many bends and mufflers before it exits the system. It adds complexity and that hinders flow for sure.

A well designed dual outlet should be able to flow very well, I'm just saying a single outlet exhaust shouldn't be a restriction by the simple fact that it is single outlet. (from the research I've done there should be no performance benifit of going to a dual exhaust if both systems are well designed)

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Originally Posted by Chris_F

lol, then you'd loose power...



Do you mean system 1 is quieter and flows more?

But that's the problem. You can't just add up the individual flow of each muffler and say one flows better than the other. It's more complex than that. How about the increased turbulance created by the y-join? The reduction in velocity of exhaust gases caused by splitting the exhaust gasses and forcing them to twist and bend through the extra piping and the extra muffler?

Also, faster traveling exhaust gases will create a scavenging effect that pulls subsequent exhaust pulses through the exhaust.

My main point though: if there was a true performance benift to a dual outlet exhaust on a 4 cylinder car (not talking about noise reduction or looks) why don't all of the tuners who are obsessed with extracting every last HP out of the k-series go with a dual outlet design?

By the way, I'm not saying that a dual outlet exhaust can't flow just aswell as a single (depending on the design). I'm saying that a single outlet exhaust is all that's needed regardless of the power figure you are chasing. It's also more straight forward to design a single outlet exhaust that will give you the flow you need for your setup.

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Quote:

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Originally Posted by Chris_F

Well if the gas splits after the Y wouldn't the energy/velocity of the gass travelling through the pipe is also split into two. It then has to travel through twice as many bends and mufflers before it exits the system. It adds complexity and that hinders flow for sure.

A well designed dual outlet should be able to flow very well, I'm just saying a single outlet exhaust shouldn't be a restriction by the simple fact that it is single outlet. (from the research I've done there should be no performance benifit of going to a dual exhaust if both systems are well designed)

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nah i was just saying that up until a certain point, a dual system can flow more than a single... where that point is i dont know, and its going to vary greatly depending on the quality and design of each system... i was merely trying to point out that two quiet/restrictive mufflers can flow better than a single loud/free flowing muffler... :thumbsup:

and yes it will get more complicated with pipe diameter and tuned lenghts and bends/joins etc. but unless someone needs maximum power, and can handle the noise, a straight thru 3" system prob isnt the best for street lol

Quote:

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Originally Posted by Chris_F

Well if the gas splits after the Y wouldn't the energy/velocity of the gass travelling through the pipe is also split into two. It then has to travel through twice as many bends and mufflers before it exits the system. It adds complexity and that hinders flow for sure.

A well designed dual outlet should be able to flow very well, I'm just saying a single outlet exhaust shouldn't be a restriction by the simple fact that it is single outlet. (from the research I've done there should be no performance benifit of going to a dual exhaust if both systems are well designed)

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But isn't the piping after the split thinner than before it? That could be tuned to keep the same velocity and back pressure as before the split but with the benefit of being able to run through 2 less restrictive mufflers than 1 huge one?

I just think the flow of single/dual outlet (if both are done properly) would be so similar it's pointless trying to argue which one is superior. From a performance aspect, rationally the single would have to have flow better (if they used the same exit mufflers) but the dual would look better and be more driveable and it's likely it would make almost identical power.

Overall, is this AutoRacing Technik CL9 a race car or a modified street car?

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Originally Posted by EUR003act

nah i was just saying that up until a certain point, a dual system can flow more than a single... where that point is i dont know, and its going to vary greatly depending on the quality and design of each system... i was merely trying to point out that two quiet/restrictive mufflers can flow better than a single loud/free flowing muffler... :thumbsup:

and yes it will get more complicated with pipe diameter and tuned lenghts and bends/joins etc. but unless someone needs maximum power, and can handle the noise, a straight thru 3" system prob isnt the best for street lol

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I see what you're saying. I guess at the end of the day, dual outlet or single outlet doesn't determine the flow but the type of mufflers your using and the piping diameter does. Maybe if you do a flow vs. noise comparison a dual outlet will come out on top. That would be a really interesting test! When it comes to exhaust gass velocity and scavenging the dual outlet will always be at a disadvantage.

You do get the weight savings with a single outlet exhaust though. My old J's racing exhaust was 17kg lighter than stock (that's like having a carbon fiber bonnet, carbon fiber boot lid, lightweight battery and lightweight race seat in the car lol).

That's true, a straight through 3" really isn't ideal for the street. 3" piping with dual outlet mufflers might be the best solution for a street driven euro if you're worried about noise. All the TSX race cars in the states use 3" single outlet systems aswell and I guess they'd be noisey haha.

Quote:

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Originally Posted by integral90

But isn't the piping after the split thinner than before it? That could be tuned to keep the same velocity and back pressure as before the split but with the benefit of being able to run through 2 less restrictive mufflers than 1 huge one?

I just think the flow of single/dual outlet (if both are done properly) would be so similar it's pointless trying to argue which one is superior. From a performance aspect, rationally the single would have to have flow better (if they used the same exit mufflers) but the dual would look better and be more driveable and it's likely it would make almost identical power.

Overall, is this AutoRacing Technik CL9 a race car or a modified street car?

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Yea usually the piping after the split is thinner but that doesn't neccesarily mean your going to maintain exhaust gas velocity, the energy is still being split into two at the Y join. With a good equal length header you're merging the exhaust pulses together achieve a high exhaust gas velocity (ultimately aiding flow and giving a scavenging affect). It's hard to see a benifit in splitting the merged exhaust gases after they have already been merged like this. You're just making the same amount of energy travel around more bends and go through more mufflers.

It's true though, in a real world scenario the two designs may flow similarly and it might not make much difference at all. I don't think a well designed dual outlet will hurt performance too much I just don't think it'll provide a performance benift (only a noise reduction benifit). If you're talking sound level vs. performance and don't care about weight... it might be a different story :)

revive much :p

so RBC will lose mid torque but gain in top end?

what about if it is tuned with emanage ultimate?

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Originally Posted by Kason

revive much :p

so RBC will lose mid torque but gain in top end?

what about if it is tuned with emanage ultimate?

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RBC will lose you power everywhere except probably the last 500rpm.

Emanage is still only piggyback, it's limited and can't advance cam timing which the RBC really needs to be good.

With full intake, TB, ,exhaust and RBC I think I'm only just matching a stock Euro for torque up until about 5000rpm

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Originally Posted by integral90

RBC will lose you power everywhere except probably the last 500rpm.

Emanage is still only piggyback, it's limited and can't advance cam timing which the RBC really needs to be good.

With full intake, TB, ,exhaust and RBC I think I'm only just matching a stock Euro for torque up until about 5000rpm

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So conclusion.RBC=waste of time and money unless your car is highly modified,I,H,E,cams etc.

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Originally Posted by tony1234

So conclusion.RBC=waste of time and money unless your car is highly modified,I,H,E,cams etc.

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Agreed, +higher redline

Yes, only beneficial with more serious mods and higher redline, if you read my first post, I explained most of the tests performed..

Here's more Dynographs...
This is the latest one from Havoc's Dyno Day last month..


http://img.photobucket.com/albums/v1...0/146Webii.jpg


Old graph... Showing stock output from many years ago...

http://img.photobucket.com/albums/v1...Dyno_Webii.jpg

nice nice Nick! that's almost 50% increase!
how did you find the teins? hehe

Is your dip from 4500rpm to 5500rpm just because you were limited to 25 VTC?

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Originally Posted by integral90

Is your dip from 4500rpm to 5500rpm just because you were limited to 25 VTC?

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might be because of the VTEC point aswell?

VTEC point at 4500rpm seems too early... The power/torque curve hasn't even started to drop at 4500rpm. Might be wise to try 5000rpm for drivability. Won't affect peak power though.

what cams are they again??

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Originally Posted by johnprocter

what cams are they again??

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Says all the mods on the dyno graph down the bottom. Skunk2 S2 :D

lol fxck i really need glasses lol.