2.5 ore 3"exhaust

[paulv]

i''m building a 4.6 stroker for my yj wrangler . it's going to be my daily driver. 99% road use

i just bought an borla header, but it's for a wrangler TJ so i'm going to cut of the collector and turn it around so it wil fit my YJ .
should i weld 3" exhaust pipe's to it, ore should i leave it like it is (2.5")

i.m going to use a borla muffler and no cat. converter.

add. info. 3.55 gears, 31 bf goodridge, carb. and hei, offenhauser, lpg convertion 9.6 -1 compression . 210-218 comp cams camshaft

thanks for your help.

Paul
the netherlands

[paulv]

i just received my borla header.. what a disapointment!!

ok great design. but the primairies have the same diameter piping as original, the collector is 2.25" and the end pipe is 2.5"

why in gods name do they make a 2.25 "collector and then go to a 2.5" end pipe.??

i'm going to cut of the collector and weld a 3" exhaust on to it..

what size of exhaust are you guys using???

thanks,

Paul
the netherlands

[Muad'Dib]

I think it all depends on what your doing with the build. Even for most stroker builds 2.5" is plenty.

[SilverXJ]

I'm running a 2.5" exhaust. Most people are too considering most after market performance type systems are 2.5".

[paulv]

the plan is to make it a "fast" daily driver.

if the borla header had 2.5" collector i would keep it like it is . but it's only 2.25"

so i want to cut it off anyway.

should i step up to 3" ore keep it at 2.5 " i havent bought anything yet. think i'll go for 3 "
better to big than to small..

paul

the netherlands

[YJason]

I run the Borla 17202 header, like this:



I have it running into 2-2.25" pipes down in front of the oil sump where it goes into 1 3" pipe and then wraps around and runs parallel to the frame back to a 50 series flowmaster. It then steps down to a 2.5" pipe out the back. There isn't much room between the gas tank and the leaf spring for a 3" pipe, plus I figured it needed some back pressure for the FI and fuel mileage. It sounds really cool, I have people on the trails aask me all the time what kind of engine is in it.

There is a thread on here somewhere that discusses the optimal exhaust size, iirc it was 2.75"

[astjp2]

2.5 inch is all we need for a stroker, any larger is a waste of money. The exhaust cools and slows down as it gets to the tail, so a bigger pipe diameter is not necessary.