I have a 94 LS with 2.5" piping. I have new piston rings, after market intake manifold, header, and fuel rail. Is the exause pipe too big? I feel like the car takes off pritty slowly, but once it gets goin... it performs great.

Another question... what can I do to improve acceleration? Does the MSD ignition really help? What else is out there? I dont want anything extream like supercharger, nos, or turbo.

 

That fuel rail is useless and the exhaust is too big, especially for an LS with minor bolt-ons. I would recommend either some larger cams and engine management or an ls vtec conversion.

 

listen to this man! him and the moderator of this forum(theotherdave) are freakin geniuses when it comes to integras! i haven't been on the forum in a long time due to school which equals no money for toys! I may be off my rocker so don't flame me for sounding like a tard, but don't integras depend on a certain bit of back pressure from the exhaust?(friend told me this not my words and he's been known to talk out of his ass regularly lol)

but if you're looking for good advice listen to the guys i've mentioned!

 

technically all cars require a certain amount of backpressure to perform right. without the right amount you will have both poor performance and also poor fuel mileage. point in case, when ur exhaust craps out u cant accelerate as well or go as fast as far.

 

i was j/w cuz i'm just now learning more and more about cars before i dive into working on my baby and as i mentioned my friend is known to speak out of his ass on a regular basis... i mean it made sense to me being an ex engineering major b/c a larger pipe equals less back pressure just trying to figure out how it actually applies to an engine

 

back pressure can be described as the amount of pressure it takes to keep the unburned exhaust gases inside the cylinder. the more unburned gasses that escape the less power you will make. when a valve opens it is pushing out exhaust gasses and with a smaller diameter piping your keeping the velocity up. with a larger exhaust the the velocity slows and it actually has a harder time expeling the gasses. because denser air is heavier. well colder air is denser. so now becasue of a larger diameter piping the velocity is slowed and it has to move a larger weight to expell the gasses. that is why bigger isnt always better

 

Back pressure doesn't mean jack.

Read and learn:
https://www.honda-acura.net/forums/s...03&postcount=2

 

very informative! i knew you'd chime in adventually with the truth Schmoo! good link it actually shed light on what i was trying to understand...

 

i can post view of other people too but the truth is i have experience in this field. bigger is not always better and back pressure is wanted in an exhaust system with out it youll have a bunch of unburnt gasses escaping causing a loss in power. what happens when you dont ignite all the gasses in the cylinder? you dont get the power the motor could have from the increased pressure on the down stroke from the larger combustion. for this application being an ls 2.5" piping is big especially since he wont be reving past k maybe 8k at very most with a mild build with cams. i read your post and in reality it says exactly what i said although they say back pressure isnt wanted that you have to find a happy medium or no back pressure but high velocity. with stock motors you do want to retain some of the back pressure. read my article as well


http://www.nsxprime.com/FAQ/Miscella...austtheory.htm

 

Would 2.25" be too big for this application as well?