what size pipe?

I have a 90 camaro with a 3.1 in it. I was going to build a custom exhaust for it. I read the sticky about 2.2 cfm per horespower. I don't really understand how you figure out the flow amounts. Could someone guide me into the right direction? I am looking at either 2 1/4" pipe, or
2 1/2". With a flowmaster 80 series. My car is prolly making 120horsepower to the wheels. What size pipe would be best for torque and horsepower? The pipe will be mandrel bent if that makes any difference. Thanks

I would think something to the tune of 3/4 garden hose?

Well I'm going to tell you something you may not like.

I dought you are making 100h.p. to the wheels. You can dyno it and find out.

I would just buy an aftermarket cat-back system....it will be plenty big. You only need about a 2.5" or so if you want to do it yourself. The carbed 3rd gen LG4 engine and the TBI cars would use the sam cat-back system they all have the same converter. 2 bolts

I honestly don't think you will see any power gains worth anything, just make more noise.

Good luck either way with it, just don't get your hopes up with the "gain xx h.p." stuff out there.

Well its rated at 140 hp, and 180 torque. I figured after its only putting about 120 to the ground. It is a fresh rebuilt engine. .040 overbore. I ported, and polished the heads myself. Had them milled down a bit for more compression, and a 5 angle valve job done. I am going to build a set of headers myself. Prolly 1 5/8 stepped down to 1 1/2, and then to a 2 1/4 , or 2 1/2" collector. I'm sure the exhaust will have to help some. Plus I want it to look good, and sound nice. Eventually I'm either turboing it, or supercharging it. Which would be best all around performance for torque and horespower? 2 1/4" or 2 1/2"?

you would have been better off to put a small block in there than to go forced induction with it

but putting some of that information in a basic sig may make it easier for people to better help you in the future

Well its rated at 140 hp, and 180 torque. I figured after its only putting about 120 to the ground. It is a fresh rebuilt engine. .040 overbore. I ported, and polished the heads myself. Had them milled down a bit for more compression, and a 5 angle valve job done. I am going to build a set of headers myself. Prolly 1 5/8 stepped down to 1 1/2, and then to a 2 1/4 , or 2 1/2" collector. I'm sure the exhaust will have to help some. Plus I want it to look good, and sound nice. Eventually I'm either turboing it, or supercharging it. Which would be best all around performance for torque and horespower? 2 1/4" or 2 1/2"?

your looking at bigger loss than that from the engine to rwhp.

I would just buy the headers, pacesetter makes headers and Y-pipe.

You don't step the headers down like that.....backwards.

Really sit down and think about what your doing b/c you could swap in a 350 or something cheap and that 3.1 will never touch it even stock

Well I am just playing with this car. Gonna see what this engine will do. I've seen these 3.1's turbo'd putting out 340 horsepower. I think they used like 3400 heads, and manifolds on them. I'm doing everything on a budget. I was reading about the headers, and somewhere I read stepping down actually builds velocity, and makes the low end torque higher.

Well I am just playing with this car. Gonna see what this engine will do. I've seen these 3.1's turbo'd putting out 340 horsepower. I think they used like 3400 heads, and manifolds on them. I'm doing everything on a budget. I was reading about the headers, and somewhere I read stepping down actually builds velocity, and makes the low end torque higher.

Nothing wrong with that, I think people are just pointing out that the work you want to do and the associated gains are not going to be spectacular. With the money you start spending buying 3400 parts and exhaust parts, you may be pushing into the territory of picking up a decent TPI motor that you can put in there.

question still stands, what would be better pipe size for the setup im looking at? It won't be forced induction for awhile. So I want to find the best median between hp, and torque. I'm not sure what pipe I should go with. Someone help a dummy!;)

i don't know if anyone else agrees with me on this one, but i happen to think that the 3.1 has to be the worst sounding engine on this planet...All i can imagine is a 91 lumina driving around with the muffler hanging off...Like that gurgling goofy sound that emulates from that thing is just....awful :(

i'm sorry Gene, have fun with your Turbo 3.1 AWD Camarrow

And i truly think you're beyond help...:p

Thats weird? Usually everyone likes the sound of the 3.1 v6's. They are the best sounding small displacement v6 for sure. Type it in on youtube. They sound pretty good. Maybe a luminia with a crappy muffler or something, but I think they sound pretty good.


Here is a clip of a 3.1 in a cavalier, I've even heard some better then this.

http://www.youtube.com/watch?v=9yZ76kzT0SQ

Cancel fat...

With proper exhaust they sound good...

I retract my previous statement...

www.youtube.com/watch?v=46FlrzPZiLw

www.youtube.com/watch?v=kmkBc5MKMsk

Cancel fat...

With proper exhaust they sound good...

I retract my previous statement...

www.youtube.com/watch?v=46FlrzPZiLw (http://www.youtube.com/watch?v=46FlrzPZiLw)

www.youtube.com/watch?v=kmkBc5MKMsk (http://www.youtube.com/watch?v=kmkBc5MKMsk)

:think:

but this on the other hand

http://www.youtube.com/watch?v=9yZ76kzT0SQ&feature=related

LOL...don't show that to freddy...He'll get jealous...