Straight Pipe Exhuast? Yes\No

I currently own a 1991 G20 and recently purchased a Exhuast bypass valve. The valve is "Y" shaped with a gate in the center of the "Y" that allows two exhuast paths. (The gate is controled inside the car) This valve allows you to have two exhuast systems in one. The first path allows you to run your stock or modified exhuast. The second can be used to run a straight pipe. (The bypass will be placed in front of the cat.)

My question is, will this produce a gain or a loss of HP and Torque?
It is recommended?

Also, has anyone used AeroSpeed wires?


:alien:

should gain because you would have no back pressure its basicaly like running dumps

Originally posted by str8maxn


My question is, will this produce a gain or a loss of HP and Torque?
It is recommended?

:alien:


It depends...if you have no other mods..then by taking out backpressure you will lose low-end torque, but you may gain some upper rpm horses...i wouldnt go too far with the exhaust...not till you do some other stuff first.

Here are my current mods:

PeaceSetter Header (I got the cheap)
Intake filter
AeroSpeed 9.2 mm wires
Intalling soon:
OBX twin muffler
2.25 Piping for the cat back
MAYBE:
Bypass exhuast


I plan to install the exhuast and the bypass some time next week but want to make sure the bypass will help. What do you think?

I don't thinkt he bypass will do too much, just make your car louder, but now good louder, ANNOYING louder. You also might feel a bad rough idle from the lack of back pressure. Just keep the exhaust you got now.

put it behind your cat gut your cat but leave the empty shell that will keep some of your back pressure.

it will be alot louder like a old truck i ran a few days with no exhuast get annyouing

I wouldnt even do that. The catalitic converters nowdays are almost un restrictive (very very little restriction) like maybe a half of a horsepower. Gutting it is just a waste of money, and dumps more unnessescary pollution into the air.

Free flowing pipes are good for high rpm horses, but kills your low end torque. It will also make it idle like crap (and probably sound like crap). The only time you really want a really free flowing exhaust is with a turbo or supercharger. Unless you are going to the salt flats, i would just keep the stock exhaust, maybe add a cat-back system or something.
-JP

Oh yeah, especially since you live in CA...
Dude, you shouldn't install that bypass, unless you are getting it smogged illegally or in another state (i dont even think it legal anywhere in the US).
The headers you installed probably already jacked you for CA smog tests.

Just my 2 cents, but I really dont believe in screwing up the air over a half a horsepower, especially for just street use. Granted the smog laws in CA are majorly jacked (installing a turbo will usally improve emissions and horsepower and everything good), it still is no excuse.

Originally posted by freaktroll
I wouldnt even do that. The catalitic converters nowdays are almost un restrictive (very very little restriction) like maybe a half of a horsepower. Gutting it is just a waste of money, and dumps more unnessescary pollution into the air.

Free flowing pipes are good for high rpm horses, but kills your low end torque. It will also make it idle like crap (and probably sound like crap). The only time you really want a really free flowing exhaust is with a turbo or supercharger. Unless you are going to the salt flats, i would just keep the stock exhaust, maybe add a cat-back system or something.
-JP

it makes a good amout of difference i did mine