Proper exhaust size for stroker

[gonridnu]

I swiped this off the flowmaster website for informational purposes only. My thinking is that in my driver 2.5" will be sufficient but obviously there are guys here that will need more. Years ago I put a borla header and rear section on so that's what I'm gonna have to use....

Exhaust size for street car applications:

Tubing Size.......Dual Exhaust........Single Exhaust
2.00”..............up to 200 HP.........up to 100 HP
2.25”..............up to 325 HP.........up to 160 HP
2.50”..............up to 500 HP.........up to 250 HP
3.00”..............up to 600 HP.........up to 300 HP

[Don H Jr]

I BET MOST OF YOU MISSED a Post just recently here reference one of the most solid stroker MJs on the planet, engine by Hesco, dynoed regularly with upgrades. Runs dual 2 and a quarter inch all the way back.

don jr

[Don H Jr]

Duals, especially on a I6 designed like ours are a great idea. First of all, the ridiculous amout of engineered heat near the block/water jackets and especially the intake manifold and cracking exhaust manifold would be lessened with dual manifolds. Less weight stress on factory spread out, overheated header with no brackets to hold the weight toward the rear of block/tranny. But the heat going into the exhaust itself is enough for a recipe for disaster, which we all know about first hand.
Split the heat, let the engine compartment and hood stay cool. My paint on the hood for years has been cracked in small patterns like small chicken wire from exactly this heat on the driver's side.
Besides, WHERE HAVE YOU BEEN CHER MANIAC? I guess you weren't born yet in the mid, early sixties when we split our Chevy and Jimmy six exhaust manifolds, put in Muncie 4 speeds in young 50s Chev coupes and ran 4.11 posi rears with Glass Packs. What a nice sound it was, so sweet with 3 carbs sitting on the intake and a 3/4 cam.
I always remember the sweet sound of a 6cyl with duals. My BMW dual overhead cam six, with variable speed cam timing sounds even sweeter, with two of everything running full length side by side and cast iron stock dual headers.

Don Jr

[Don H Jr]

PS: My BMW engine is only 2.5 liters, which, if memory serves me correctly is around 152 cubic inches and the duals are right about 2 inches ID, just under.

Jr

[Plechtan]

I BET MOST OF YOU MISSED a Post just recently here reference one of the most solid stroker MJs on the planet, engine by Hesco, dynoed regularly with upgrades. Runs dual 2 and a quarter inch all the way back.

don jr

How about a link to the post?

[SilverXJ]

I think he talking about Comanche91 http://www.jeepstrokers.com/forum/viewt ... ?f=5&t=387

IIRC he doesn't have duals all the way back. I think uses a single in/dual out muffler and 2.5" pipe.

[Cheromaniac]

Besides, WHERE HAVE YOU BEEN CHEROMANIAC? I guess you weren't born yet in the mid, early sixties when we split our Chevy and Jimmy six exhaust manifolds, put in Muncie 4 speeds in young 50s Chev coupes and ran 4.11 posi rears with Glass Packs. What a nice sound it was, so sweet with 3 carbs sitting on the intake and a 3/4 cam.

I was born in 1963 so I was still wearing diapers when you were having fun running duals on Chevy sixes. I'll bet they sounded badass.

[Don H Jr]

I'm not savvy enough on computers to put on a link, lol. Srry bout that. It was on a post by Don Horn....on this site.

Jr

[Greenneck]

I know this is an old thread but seems to be the best on exhaust

I built a mild stroker with mopar performance cam to be a DD. I have a gibson header on it and a flowmaster super 40 or 44 (forgotten which). I have a 87 body and block with a 96 head, that being said obviously I have no exhaust for it except the header. I see my options being: Bolt in a stock 96 system and have my flowmaster welded in or have a custom down pipe, cat eliminator pipe and tail pipe. I am leaning to the second option and was not sure if 2.5 in pipe up to the muffler would be good and then 2.25 after. One site I was reading a person claimed flow masters like having 2.25 pipes after and this makes it easier for me to find a tail pipe for it dynomax 55014. I looked at Dinos set up but I think he built a beefier motor than I did .

[the_wrench116]

go with a min of 2.5. I had a custom header and 3 inch but I had it on there for cool factor. still had wicked low end.

[Greenneck]

go with a min of 2.5. I had a custom header and 3 inch but I had it on there for cool factor. still had wicked low end.

Would 2.25 from the muffler back be alright or would it ruin the point of having a 2.5 system? Im pretty sure my flowmaster I wanted to use was a 2.25 muffler.
When I talked to the muffler shop guy he said that the over the axle bending would be too hard to do in a 2.5 mendrel so I would be best off finding a tail pipe aftermarket and they would do the rest. The best I can find with out getting a catback system is that dynomax 2.25 tail pipe.

[Radioactivexj]

Exhaust size for street car applications:

Tubing Size.......Dual Exhaust........Single Exhaust
2.00”..............up to 200 HP.........up to 100 HP
2.25”..............up to 325 HP.........up to 160 HP
2.50”..............up to 500 HP.........up to 250 HP
3.00”..............up to 600 HP.........up to 300 HP

I'll have to redo my whole exhaust anyways so is the decrease in manifold temperature itself (and the BA factor) worth running the dual exhaust? If so what manifold would one recommend? I kinda like the idea of the dual with the pipes running right out in front of the rear tires. I would assume that 2.25" tube would be what most people would run seeing as the 2" is undersized.

[the_wrench116]

2.25 is good for a stock 4.0L and mine isn't stock and im running a 3 with this header that started life as a borla. I would go look around for another shop. where are you located?

[Greenneck]

lynnwood washington. There are a couple other shops I might be able to look at in town

[the_wrench116]

im no master fab guy but I got 3inch mandrel bends to fit with out to much trouble. and I used the cut and paste method then tacked it after a test fit I TIGed it all up. just a simple turn down at the factory rear bumper. also used flanges at the cat and muffler for ease of replacement. so a good shop should be able to get you where you need to be with a 2.50 system.