Thread: Yes,Another freaking exhaust thread(VE only)

Well I have searched ALOT on this,and I am looking for some input from you VE guys.

My sr20ve with stock cams,currently has the following on it...
SSAC with the smaller collector(not 2.5)
2.25 crushbent cheapo system
Fartcan of some sort,not sure what brand
Just recently,I had to fix major leaks on both ends of my gutted cat.I had a 2.5 highflow cat laying around that I had welded in its place....Holy crap,what a difference It is way quieter and runs alot smoother.I would swear that by sotp buttdyno it feels like it has more torque.So It got me wondering if the "freer flowing exhaust",haha,more like leaking system was robbing torque.

That stuff was on the car when I got it.
I am swapping the motor into a new shell soon.My plans are to change to a SSAC 2.5" at that time and redo the exhaust right.I will be going with N1 cams at some point as well.

I want to know how much of a difference there really is in power,and driveability there is between 2.5 to 3" exhaust.
By driveability,I mean I see the dynos say that the 3" makes more power (and noise).But what about torque on the low/midrange?
Do you sacrifice low end torque for HP with a 3" exhaust?How about fuel economy,any difference?


My car will be a DD and get driven alot of miles.I want it to be as quiet as possible,but I don't want to "choke" it as some would say here.Yeah I know the SSAC already chokes it a little,but I cant afford a REAL VE header for it for a while.

Maybe the dumbest question,but If I have a 2.5 downpipe,how does the 3" exhaust flow more than a 2.5?(mandrel bent,of course)Seems like only so much can come out the header collector,not more than a 2.5 hole will allow,thus going down a 2.5 exhaust should be just right....does this make sense??

a cat is the biggest restriction in the ex system, of course changing it will give a whole heap of power, especially since ve's really seem to like very little backpressure. Answers to your question should be interesting

if you are to try a gutted ited, run a pipe throught the middle, as the ex direction changes inside a gutted cat and can give less power than a true highflow item like metalcat.

SSAC is 2.5" and Cat is 2.75". No cat will flow better. With the VE I doubt you will lose anything going from a 2.5" to 3" exhaust, more like gain. 3" NA is definately loud.

2.5 header with 3" exhaust.

Peace

Stock cat is not restrictive. It only causes ~2.5psi. That's like a mouse fart.

I had fuji/megan racing exhaust on my VE when it made 182 at the wheels. Megan is advertised as 2.5 but its really not that big.

Now I have a full 3" system and 2.5 SSAC on a JDM DE. Its loud but I am used to it. On the dyno it actually showed good tq gains compared to other similar cars on the low end.

i just got mine on an i must say that i was very doubtful about the noise and ma son driving in the back...hes 1 yr.... and i still wents ahead with the knowledge of andreas mikos and i must say its soooooooo quiet out of vvl and in vvl she starts to scream. but as a daily driver my points are set to 5500 rpm so theres no need to pass that doing daily driving..... i gats a ssac 2.5" complete header into a 3" mandrel bended exhaust going into a 3" obx/ forza tunning oval pan.

I am thinking of trying that Megan OE style muffler (or possibly the flat black vibrant one like it)on a 3" VRS piping kit w/resonator,and hopefully another 3" resonator in place of the cat....off a 2.5 SSAC. If it is too loud,than I guess I will have a catback for sale..haha

What about clearance for 3" on a NX...did they ever correct early fitment issues on the NX?
anybody tried one recently?

3inch can be quite it's that simple. And on the ve it is the best option.

There are two choices.

Get a 3inch, resonate it properly with a good quality muffler and a magnaflow resonator/cat: Enjoy getting the most out of your exhaust with a deep exhaust note that is very drivable and quite.

Get a 2.25 or 2.50, and have a higher pitched, raspy tone, that if left un-resonated will most likely be louder, and more obnoxious then the 3inch ever will be. Oh, and expect a reduction in top end and mid range.

Personal experience: Having had my 3inch for over a year now, I find it very comfortable to drive with. Highway at 4grand, no problem. Nice deep tone. Cops have never bothered me. Been followed and pulled over and they never say a thing. I can listen to music, or talk with my friends with no problems. It is not a luxury car, but it is comfortable enough that my ears do not hurt, and the exhaust does not "resonate" in the cabin. I have multiple friends with 1.8L Honda's, and both their cars are much, much louder, with 2.25 and 2.5 exhausts. The TRICK is in the RESONATOR. It's that simple!

Towards your question about power. It is a common conception that using a larger exhaust can degrade low end torque output. While this is commonly true for most 4cyl engines. It is NOT with the ve. The ve suffers from lower then normal intake plenum air velocity. Therefore having back pressure simply degrades scavenging efforts from overlap and intake velocity. Using a larger exhaust will allow for the LEAST amount of back pressure possible, allowing the intake stroke to pull as much air into the cylinder as possible. Thus improving volumetric efficiency, even at low rpms.

This has been dyno proven multiple times (not by myself), and does not lower torque output AT ALL on the ve.

If you don't believe me. Search it. It has been covered many times by people who understand these motors MUCH better then myself. And have proof to back it up.

GL!

Dudeman

I wouldn't say that necessarily.

http://www.e30tech.com/forum/showpost.php?p=680504&postcount=5

Two decent resonators and a quality muffler and cat will definately be quiet. Don't run a straight through muffler.