knever3 Posted June 10, 2012 Share Posted June 10, 2012 I want 2.5" mandrel bent exhaust for my Jeep Comanche, short box. I already have the header with the stock flange. What options do I have? Dual would be cool but I have never seen anyone sell a kit. I am not going to run a cat unless it's absolutely necessary, in my state it's overlooked since we don't have to pass any emissions tests. Link to comment Share on other sites More sharing options...
Alexia Posted June 10, 2012 Share Posted June 10, 2012 I have not found any full exhaust systems, but you can get an exhaust manifold with the cross over pipe to catalytic converter. Then the rest back is straight except for a hump over the the rear axle. Link to comment Share on other sites More sharing options...
deziped Posted June 11, 2012 Share Posted June 11, 2012 Get some Pacesetter dual headers (ebay) and run your dual exhaust alongside the original ehaust. But I'd use 2" or smaller pipes. And if I wanted a cool sound out of it I'd run 1" exhaust. M2C. Orig is 2 1/4" on my 89. Link to comment Share on other sites More sharing options...
Eagle Posted June 11, 2012 Share Posted June 11, 2012 The stock exhaust for the 4.0L is 2-1/2 inches from the manifold to the catalytic converter. The cat has a 2-1/2" inlet and outlet, and the connector to the muffler necks down to 2-1/4" between them. The muffler and tailpipe are 2-1/4". If you're not going to run the cat (or even if you are), just use a 2-1/2" muffler instead of 2-1/4" and have a tailpipe custom bent. However, I don't think you'll like it. Back in "the day," my brother managed a Speedy muffler shop. The first replacement exhaust for my '88 XJ was a birthday gift from my bro' -- a 2-1/2" turbo muffler and a custom-bent 2-1/2" tailpipe. The sound was marginally "throatier" than a stock muffler, I had noticeably LESS low-end torque, and I lost 2 miles per gallon from my fuel economy. In short -- it sucked. That's the only time in my 68 years on this planet when I was actually looking forward to needing a new exhaust system, so I'd have an excuse to get back to stock parts. Link to comment Share on other sites More sharing options...
HOrnbrod Posted June 11, 2012 Share Posted June 11, 2012 Agree. If your engine is stock, use stock parts and specs for sure. If you don't most times performance and/or mileage will suffer. :cheers: On the other hand, stock suck and blow parts, i.e. intake and exhaust system parts, literally do not suck and blow well on a modified engine like a stroker. Unless your engine is modified to some degree, don't waste $$ on stuff like larger or dual exhaust pipes, bigger injectors, bored throttle bodies, throttle body spacers, etc. Link to comment Share on other sites More sharing options...
knever3 Posted June 11, 2012 Author Share Posted June 11, 2012 Oops, I guess I missed some valuable information to share. It's a 4.7L stroker with a bored throttle body, '99 intake, aFe stainless header, and 24lb/hr injectors. I don't know if just any exhaust shop can mandrel bend tubing? I need them to install a bung in the downpipe for a wideband O2 sensor anyway. Link to comment Share on other sites More sharing options...
buffalob Posted June 11, 2012 Share Posted June 11, 2012 If you are cool with welding up the pipes yourself...you can get all the bends you need (yes even in stainless) off the shelf at Woolf aircraft in Romulus MI. This bending house stocks more bends than any other company I know. Best suggestion...get a handle on the tube O.D. wall thickness and centerline radius of the bends you need that you feel will best do the job, and give them a call to see what they have available. you will have to do the cutting and welding but will have exactly whatever you want. And yes you are correct, most muffler shops are not set up for mandrel bending. Too much outlay in equipment and more importantly tooling. onesy twosy jobs would take a lifetime to pay off the investment. I work for a Company (machine shop) that makes tooling for rotary draw (aka mandrel) benders. Woolf Aircraft is on the web...as is "Tools for Bending" in Denver. Bob in Denver Link to comment Share on other sites More sharing options...
HOrnbrod Posted June 11, 2012 Share Posted June 11, 2012 Oops, I guess I missed some valuable information to share. It's a 4.7L stroker with a bored throttle body, '99 intake, aFe stainless header, and 24lb/hr injectors. I don't know if just any exhaust shop can mandrel bend tubing? I need them to install a bung in the downpipe for a wideband O2 sensor anyway. My bad - forgot what you had. :cheers: In that case opening up the exhaust to 2.5" will only help. My setup: Mike Leach header -> Stainless Cherry Bomb (no cat) -> single 2.5" inlet/dual 2.5" outlet Walker performance muffler -> 2.5" dual pipes exiting out the back. Done by my buddies at the local muffler shop, not mandrel bent. Swapping to 2.5" semi-dual pipes netted about 20 HP on the Hesco dyno over the original 2.25" single pipe setup. Link to comment Share on other sites More sharing options...
knever3 Posted June 11, 2012 Author Share Posted June 11, 2012 Sweet :bowdown: That's great info guys!! Link to comment Share on other sites More sharing options...
LarryH88bt Posted June 12, 2012 Share Posted June 12, 2012 I've wanted a pipe out the driver side for a while now. What I was planning on doing is just a dual outlet muffler and flexy pipe. Seems the easiest route. And thankfully it's old enough to be emissions exempt so no more cat converter :D Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now