All right folks my man Russ linked me to a pic of his oem headers side by side with the new OBX headers. Russ has a 2002 Acuara CL-S..
Now as most of you know CL-S's gain a cool 25 WHP from OBX and comptech headers. Now heres a pic of a side by side comparison of OBX headers and Cl-S headers.

CL-S oem headers on the right, OBX headers on the left.
http://us.f1.yahoofs.com/users/73d60...uZ_z9ASGD5i0cW

Now when I saw this pic I realised maxima headers look even worse!

For example here are some maxima headers I have hanging around the house, lol.. 95 maxima header is on the left and a 2002 header(and pre-cat) is on the right.





Now with everything I just said in mind it's painfully obviuos that a maxima will get good gains from "good flowing" headers! As some of you know I tested headers from NZ and let me tell you the gains sucked because the headers sucked. OBX is suppose to have headers out for the 95-2000 maxima soon(02's just need a little custom work). Alright, my case rests.. But I bet you all good headers will give a maxima a atleast 10+ WHP. 250 WHP is still in the works..

 

Didn't a company a long time ago in Holland produce a set of headers for a 95-99 Maxima and only gained 1 HP? I searched and couldn't find it.

 

I want in on this as well, need this crap for my s/c

Dixit

 

Dude it was from New zealand and my *** was the one who tested them and spent $1200 doing so.. Let's not talk about that and please DONT try to inform me about them.. I already proved those headers where no good and jsut said those "headers sucked".

 

those headers sucked lol

but i don't think these will do much better.

 

What about Don's custom headers that gained like 1hp?

 

Don's "custom headers" where nothing more then gutted out oem headers. All his did was increase the width of the oem headers. This is simaler to boring out a intake. A better flowing designe is the only way to go. As soon as OBX get's headers out I will test them out

 

Looks promising

I definitely think there's room for gains, but the real question is how much. I also believe that the CL-S OBX headers run all the way to the cat.

-hype

 

Ya, the acura headers include a down pipe. The piece being replaced after the headers on a CL-S does not look restrctive though. I beleive atleast half there gains are from the manifolds alone.

 

Any idea when these headers will be out for 4th gens?

sounds promising

 

There is absolutely no reason to believe a well engineered set of headers would not make 20 hp on this car. Having the precats bolted that for upstream of the exhuast is a big restriction. I bet over 6k rpm there is 10 hp just by removing the precats and replacing them with a pipe. Another big gain would be from equal length tubes so the exhuast pulses don't collide, thus maximum scavenging is achieved at low RPM and max flow at high rpm.

Jesse

 

Could it be that a VTEC head takes advantage of headers better than the Maxima's DOHC head?

DW

 

How would that happen? Exhaust gas is exhaust gas. The ability to move it away from the engine quickly and without restriction would seem to be the key. I don't know what VTEC would have to do with the exhaust.

Stereodude

 

Because on a VTEC (GSR Motor) the Exhause side has a CAM as well. Thus providing a greater flow of exhaust at higher RPMs. Headers is one of the best, actually THE best bolt -on you can do with a DOHC VTEC motor.

I think the Max motor should benefit from a fully engineered header, but let's face it, we will never have the full following of DC sports, or Greddy, Tanabe, etc.

Even OBX is low grade when it comes to this market.

 

Ethan, When are the new Headers going to be out for you to try?

When can we expect them?


-ChRi§

 

HP is what dictates the amount of exhaust flow. The CL-S cannot flow substantially more exhaust gas than the 3.5L VQ, otherwise it would make more power. (More air is needed to creat more HP, which in turn creates more exhaust gas.)

That having been said, the properties of the exhaust gas will change depending on the engine. Since the CL-S makes equivalent power with less less displacement due to increased compression, the CL-S will likely have higher combustion chamber pressures after detonation, thus the requirement for a better flowing exhaust is more critical on that motor. Additionally, since the cam timing on the CL-S is more aggressive than the 3.5L VQ due to VTEC and has far more exhaust/intake timing overlap, the CL-S will undoubtedly have some unburnt intake charge exiting the exhaust valve during the intial stages of intake. That's in addition to the exhaust gases, so the CL-S system must be sized to expend that as well. Also, the exhaust gases will flow out of the CL-S motor in a more steady manner due to the extended exhaust valve opening event, ie the pulsing will be steadier and more drawn-out.

In a nutshell, it's difficult to say whether the 3.5L VQ will see the same gains from headers as the CL-S due to the engine differences, but it is fair to say that the sheer volume of exhaust gases expelled from both engines is similar. The CL-S should benefit more from an exhaust system than a 3.5L due to the design differences, so yes I would say that "a VTEC head takes advantage of headers better than the Maxima's DOHC head."

I would venture to say that Ethan is in the ballpark in terms of estimated gains, on the order of 10-up HP at the wheels.

 

Yea, I don't know much but that's how I thought of it at 1st.. although it is amazing how Hondas and Acuras seem to react to mods so much better in terms of gains..

I'd like to see something happen.. but i can imagine how hard this would be

 

I won't even try to pretend I know all that. But from my basic undertstanding of VTEC, as you have sort of said, in high rpm operation, a VTEC head allows a longer duration on the intake and exhaust valves, and that's basically why I thought the VTEC would work better with headers. Now, a CL-S with headers, doesn't it lose a bit more low end torque?? Therefore, around town it's even more sleepy than stock?? That's where the VQ shines. It's the better all around motor, for street and track.

VTEC is better for out and out power, but it must cost Honda/Acura ALOT in terms of R&D and production, especially on a mutli-bank motor like a V6. Look at their production line, if it's a 4 banger, DOHC VTEC, if it's a V6, SOHC VTEC V6. When you do get a DOHC VTEC V6, it's in the $80,000 NSX. The RL has a 3.5 L V6 with no VTEC. If it had, our Maxima would be Done, but the RL would probably cost way more, too.

Anyways, I think the DOHC V6 system is better because of the cost/power ratio. Oh, and the low end torque. Best bang for the buck

Go ahead acura boys, enjoy your headers. I'm still loving my VQ.

DW

 

CL-S Dyno auto with obx headers, 3 hrs later after installed.

http://www.flwse.com/images/nashua/O...ersDyno003.jpg

 

Nice! Looks like you guys run way rich in the upper RPM range, but with the headers your just right. Maybe a little gain is possible at 6000rpms with an AFC.

So how much cheaper is the OBX than the Comptech($1300ish?)?

 

yes but your talking about a FI motor. I understand the thought process but seeing a 35 HP gain on a N/A motor I think is a little much.

But your point is well taken.

and the 3.0 cl guys say about 18-22 HP so this sounds good

 

The CL-S is NA, and this dyno was even on an automatic. I'm just interested to see how much the headers gain over just a ypipe. The 35fwhp would be like headers + ypipe for us since the OBX headers go all the way to the cat.
-hype

 

[QUOTE]Originally posted by xHypex

Quote:

[i]
The CL-S is NA, and this dyno was even on an automatic. I'm just interested to see how much the headers gain over just a ypipe. The 35fwhp would be like headers + ypipe for us since the OBX headers go all the way to the cat.
-hype

CL-S is the type S correct???

Now I am confused.. I thought the cl-s was the SC version ??

But a better point the headers are a combo for them... and I just thought about it as I read your post

bags

So, with that in mind I am thinking 7-10 HP tops on a 3.0L maxima motor N/A.. Since we already have the y-pipe at about 10-15 HP

Or am I missing something

 

 

$350 compared to $1000

 

There are about 20 other dynos I can pull that show a 30 hp increase with headers.

Btw that dyno is a stock CL-S auto then headers were added.

3.0 cl and Accord guys do not gain near as much as the 3.2 type-s guys do.

 

Now that's BANG-FOR-YOUR-BUCK!!!

 

I don't think that's quite correct. I think displacement and RPM are the only things that govern the amount of exhaust on a NA engine.

Stereodude

 

That's like saying if the exhaust valves stay completely closed from a broken cam belt or chain, rpm and and displacement will still determine the amount of exhaust on that NA motor. The way the valves work do have a significant influence. That's the whole point behind VTEC.

DW

 

Those gains are awesome Russ!



Bags, I guess we will have to wait and see what the gains are on a VQ, I personaly expect atleast 10 WHP with good headers. My gut feeling tells me more like 15 HP though



As for the release of teh OBX maxima headers.. OBX has been saying they will be out soon for a while now. They have a part # listed on there web site, hmm. I'm going to have to give them a call tomarrow and see what they say.

 

i think the acura will respond way better to the Headers for a couple reason, a high compression ratio, a better breathing motor and a high redline. those three things all call for a little more exhaust flow then a maxima then add them all up and it amounts to a decent need for better exhaust flow. with the apexi fitler and these i'm saying 240whp tops. good luck though i hope it's more but i don't think it will be.

 

245 Engines are just giant air pumps, the amount of air it pumps determines the power the motor creates. With that in mind both the CL-S motor and the VQ pump about the same amout of air, so IMO our VQ's should see simaler gains with a better exhaust. After all the more you can pump out the more you can pump in. Of course I'm sure like you and otehr said theres more factors involved We do have a very nice compression ratio at 10:3:1 though(VS 10:5:1) and we have VTC.

 

Any word back from OBX? I'd really like a header/Y-pipe combo for $350!!!!!!!!!!!!!!

Man, I'm going to have to talk to Cattman about that, but it would be $1000+ if he made it.

 

I'm gonna see if I can find OBX's number right now and I will give them a ring.

 

It appears they no longer have a phone # I emailed them instead, hopefuly I recieve a reply

 

PLEASE do!

I think IF we get enough of us together and offer to send them stock manifolds, they might be willing.

 

In typical Dave B fashion, I have to sour this post No one seems to be paying attention to the fact that the CL-S motor makes power FAR longer than the 3.5 VQ. Nearly every 3.5VQ, modded or not, has peak power occuring at 5800-6000rpms and the power slowly drops as it approaches 6500. The CL-S on the otherhand is making peak power at 6800rpms with power slowly falling off at 7300rpms. What I'm getting at is the VTEC system allows the CL-S to continue to make power longer. It's simply a better air pump than the 3.5VQ ever will be which leads me to say you will not see the same gains with headers on the 3.5VQ vs the CL-S. Air flow restrictions increase as velocity increases. The CL-S winds a lot higher than the 3.5VQ ever will. Don has already proven that the stock manifolds flow very well on the Maxima. Just because their ugly doesn't mean their restrictive. The restriction on the 4th/5th gen has always been the y-pipe. Ethan proved this when he got the New Zealand headers installed and made 1hp more than a y-pipe. The design of the headers was not bad at all. The truth was that the manifolds aren't restrictive.


Dave

 

This may be true, but the VI adds considerably to the top end air velocity. When your VI kicks in you can hear the difference in intake resonance, and you know that the velocity has increased.

Quote:

The CL-S winds a lot higher than the 3.5VQ ever will. Don has already proven that the stock manifolds flow very well on the Maxima. [snip]design of the headers was not bad at all. The truth was that the manifolds aren't restrictive.
Dave

The extra rpms definitely help, but that's not to say we won't gain the same during our shorter rpm band. I also disagree that boring out is the same as redesigning the headers. Finally, everyone compares headers to the bored out 4th gen headers, when the VI really adds to the equation. 5th gens always had VIs, so who knows what boring out their headers would have done. Now that 4th gens have a VI we should be on par and see gains similiar to 5th gens with the new headers (except maybe the 2k2 because of the extra displacement).
-hype

 

Does the same hold for the VQ30DE with MEVI and the VQ30DE-K?

I'm not that convinced by one or two "attempts" at making a header. Sometimes it can take some ingenuity and lots of R&D to extract more power over OEMs design. Don's was a bored out stock manifold and I doubt the New Zealand headers had any type of R&D. They just copied the flanges and threw the piping inbetween, which I doubt would gain much over OEM. The design MUST be optimized for flow and without trying several different tubing sizes and lengths, I doubt you would gain anything.

Also, were Don's headers tested with N20 or just NA?

If OBX made a similar header/y-pipe as the CL-S, we would still be spending the same amount of money as a Cattman or Stillen Y-pipe but with "1hp" extra. Same if not better, right?

 

If OBX uses different size tubing for the front/rear bank they could correct the unequal length of aftermarket Y-pipe arms which would help with exhaust pulse timing and balance the exhaust backpressure on both banks.

The long term effects still haven't been proven, but theoretically it is possible that unequal exhaust backpressure from unequal length Y-pipe arms could cause long term engine damage.