Alright my current setup on my 95 Prelude vtec is

Ebay Replica 4-2-1 header
Stock cat
2.25" Crush bent custom exhaust
2.36(i think) Rsr Exmag Muffler

i know this is a fairly shitty setup and id like to change that. Is going 2.5" really worth it? my mods are as follows
Apexi Intake
Exhaust listed above
Exedy cluthc
Jun Flywheel
Zex 50 shot (yet to be intsalled)
Vafc2

This is my daily driver, but take to the track on weekends

If i were to get a SMSP prototype header (as listed in classifieds ) A high flow cat (or test pipe??) and 2.5" catback (apexi n1, skunk 2, or any other mandrel bent) Would i see a bigger gain on teh dyno?

 

Yes you would see much better results. Although crush bent exhausts restrict only a little bit, its enough to interupt flow throughout the entire system. Remeber, the faster you can get exhaust out, the more you can put in

 

well then why wouldn't a 3" exhaust be good?


My bro does have a HKS fully titanium muffler that has 3" inlet.... would that be decent?

 

the bigger the piping the less back pressure which means decrease in torque. IF you have a turbo then 3" would be good, but if it's NA then you'll just lose power.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pointmann1029 &raquo;</TD></TR><TR><TD CLASS="quote">the bigger the piping the less back pressure which means decrease in torque. IF you have a turbo then 3" would be good, but if it's NA then you'll just lose power.</TD></TR></TABLE>

Almost there.

It's not backpressure; backpressure is bad. It's VELOCITY. You want the the exhaust to have no backpressure at the RPM you'll be making your peak power at, with the highest velocity possible. That's why n/a exhausts are tuned to a smaller pipe that produces a higher velocity. Turbo's, on the other hand, spool by a pressure differential across the turbine, so there really is no exhaust that's "too big".

You should treat the exhaust as a system: use the same size piping all the way through. For example, use a 2.5" cat or test pipe, 2.5" full mandrel exhaust, and 2.5" free-flow muffler; mismatching sizes between the parts will disrupt the velocity and flow, reducing power.

 

alright welli gues i understand now, but for comparison could u compare my current exhaust with the one i listed above

just wondering if its worth the time and $$$$

 

I can't imagine the 2.25" crush bent exhaust being too much better than the stock piping, but it probably won't be worth it to swap it to full 2.5" mandrel piping b/c there's not too much power to be gained.

IMO, you should put the money elsewhere.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LudeyKrus &raquo;</TD></TR><TR><TD CLASS="quote">I can't imagine the 2.25" crush bent exhaust being too much better than the stock piping, but it probably won't be worth it to swap it to full 2.5" mandrel piping b/c there's not too much power to be gained.

IMO, you should put the money elsewhere.</TD></TR></TABLE>

so when would you recommend to use a 2.5" exhaust system ? i dont know much about exhaust flow or velocity, but wouldnt a 2.5" system make the same power as a 2.25" system on a stock motor with bolt-ons ?

 

I would recomend Megan racing cat back stainless steel 2.5" pipe. It's a great bang for the buck system, and it will bolt right up, no welding or bending needed.

RoBear racing can hook you up, just tell them what car it's for and if you want a resonontor (I would recomend yes), and what type of muffler you want. Give them a call or E-mail for more info, they will help you out. If I remember right the set up is less than $300.

http://www.robearracing.com/customer_service3.cfm

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by redxalien &raquo;</TD></TR><TR><TD CLASS="quote">so when would you recommend to use a 2.5" exhaust system ? i dont know much about exhaust flow or velocity, but wouldnt a 2.5" system make the same power as a 2.25" system on a stock motor with bolt-ons ?</TD></TR></TABLE>

bump ... anyone ? i'd still like to know .