i'm looking for input on exhaust systems for my 71 sbc powered chevelle. i have the Hooker S/C's 1 3/4" headers with 3" collectors. right now i have a hacked up 2 1/2" system with Flow Tech mufflers, which i'm 99% sure is robbing me of some power. i'm leaning towards a 3" system and i'd like to have either an "X" or "H" pipe going back to 3" mufflers and possibly 3" tailpipes. just curious to know what you guys have and how you like it, how it fits, and so on. TIA.

It's hard to say without your combo info, but IMO unless you have a serious SB, the headers you have could be too big and hurting performance. 3" would be overkill too if your combo is mild.

I'd go with a 3" X pipe kit and 2.5" Flowmaster tailpipes..Ultraflow mufflers or whatever floats your boat

Yeah, unless you're making serious power 2 1/2 should be sufficient. I have a 2 1/4 system with flowtech terminators on mine.

Flowmaster is the way to go! I have 42 series Turbo mufflers dualed out with 2 1'2 piping and I wouldn't go any other way! Sounds way good too! I get more compliments on the way she sounds then anything! smile.gif

i wasn't really looking for what size exhaust i need, i already know what size i'm getting, my headers aren't too big, (i'm doing 1.66 60ft times @3700lbs) what info i was really hoping to get was what brand systems guys are running and how well they fit, etc. sounds like no one else is running 3" exhaust on a sb?

I installed the Jeg's 3" on my 69 with a 350 - price is $169 with mufflers plus shipping. There is another post about this.

Sounds good, maybe a little louder than expected but deep. At that price it is hard to go wrong, although I had some fit issues with the tailpipes that took extra time. Happy with the results, especially since the repro tips fit perfectly over the 3" pipes and look cool.

Ed

With a too large diameter of an exhaust you will lose lower RPM torque. You might gain some hp at very high RPM but, where does your engine spend most of its time? This is something to think about.

A good 2.5" system, with an H or X system and some free-flowing mufflers, is perfect for stock to mild small blocks. That's what I will be installing on my daily driver with sb400. I will be using the HEMI Super Turbo mufflers to reduce the noise (convertible). They flow as good as the Flowmasters too!

Theo.

Originally posted by m71:
...what info i was really hoping to get was what brand systems guys are running and how well they fit, etc. sounds like no one else is running 3" exhaust on a sb? We ran Super Comps with 3" Flowmasters, H pipe and exhaust when the engine was making about 550hp. They performed well, but getting the pipes out the back was impossible and we ended up running turn outs (in front of the back wheels).

Originally posted by Theo:
With a too large diameter of an exhaust you will lose lower RPM torque. You might gain some hp at very high RPM but, where does your engine spend most of its time? This is something to think about.

A good 2.5" system, with an H or X system and some free-flowing mufflers, is perfect for stock to mild small blocks. That's what I will be installing on my daily driver with sb400. I will be using the HEMI Super Turbo mufflers to reduce the noise (convertible). They flow as good as the Flowmasters too!

Theo. this isn't a daily driver. i'm definately not going to spend the bucks on a 2 1/2" system when it probably isn't big enough. it's an 11.5 to 1 406 with 215cc Pro 1 heads. i can tell you from past experiences with similar combos, 2 1/2" ain't big enough for a motor like this. i built a 406 for a buddy's 79 malibu and it was 10.5 to 1 with 200cc heads and a smaller cam and it picked up .3 uncapped vs 2 1/2" STRAIGHT pipes 2' long with the same mufflers i have. ;)

Originally posted by eduardo69chevelle:
I installed the Jeg's 3" on my 69 with a 350 - price is $169 with mufflers plus shipping. There is another post about this.

Sounds good, maybe a little louder than expected but deep. At that price it is hard to go wrong, although I had some fit issues with the tailpipes that took extra time. Happy with the results, especially since the repro tips fit perfectly over the 3" pipes and look cool.

Ed hey ED, which mufflers come with that? sorry i don't have a Jeg's catalog. :(
also, where do the tailpipes exit? straight out the rear or behind the rear tires under the 1/4's?

I agree that if you go too big of piping on a 350 you will begin to loose power. There's a required amount of backpressure needed for the proper power. If you find the right ones, a lot of the local guys do great exhaust jobs if you just tell them what you want as far as piping size and brand of turbo mufflers (Flowmaster <grin>) and the type of tips/tailpipes then they can order them in and do a really good job. Plus you can take it to them for any repairs or flaws down the road which can happen. It's also good to take to the local guys if you want a good performer car, becuase most of them can do what's called mandrel bending when they shape the pipes. This is better for looks and way better for precise flow. If you don't use mandrel bending techniques then you run into wrinkles and bends in the pipes and even weak spots where you might easily damage or break a pipe. Look around and ask what kind of machinery they use and get it done right. smile.gif

there aren't any good shops like that around here. last few times i've needed exhaust work done, i've taken it over to a buddy who has a good welder and just done it there. if i could get a nice fitting 3" system i could do the install myself. my buddy also has a hydraulic lift, which makes the job much easier when the car is at whatever height you want it to be.