Pace Setter headers?

[mendelmax]

Hi guys.

I'm in the process of headers choice/ headers build (not decided yet). Since I want to achieve very good scavenging, I'm searching for some pretty long stuff. I've found these online
.

Now the thing is- these are listed for YJ and TJ. Has anyone tried fitting it into ZJ? If so, what was the effect?

From my calculations it appears, that to achieve maximum scavenging at around 3500 rpm I would have to use 50" primaries. That's pretty long...

[1bolt]

yeah Pete's land speed record engine wanted 48" primaries, had to compromise a bit I think he's got custom 36" headers being built.

If custom built is an option you can go with smaller inside diameter, it will cost a tiny bit of horsepower at peak but it will efectively act like longer tubes... so if you could only fit 28" tubes you step down a size on the tubing and they will act like a longer tube.

Interestingly this is one reason why the factory iron manifold does better than the factory tube header, the iron manifold has small inside diemeter that is a good match to the 0331 heads exhaust ports, and the primaries are longer... so it acts like a longer tube header.

That pacesetter might be the longest tube header you'll find off the shelf... I'd like to get measurments from one to calculate the average length... I've done this for the Borla medium and long tube headers and the Borla comes out to only 16" average. That's not very long, but it's a lot longer than the factory tubular headers that avarage about 6-7 inches which then just T junction horribly into the log collector.

[mendelmax]

Thanks for answer. I also thought about cutting the length in half to use the 4th wave deflection instead of 2nd, but I still hope I'll figure out how to fit this 50" there. 36" doesn't seem to be good for my needs, because it will work at way higher revs than I intend to use- I'm not passing 4500 mark.
I like the idea of routing the pipes below the oil pan, this permit them to be much longer, and with 4" lift and elongated bumpstops I think I will not have problems with clearance.
For now I'm contemplating routing front 3 cylinders below pan in a row (for clearance), and rear 3 as they are now, but 3 tubes gathered in triangular shape (these will be routed just like 3" tube would)

My calculations say that 1.5" pipe would be ok. I'd love to get a little smaller one, but I'm stuck to what I can find ready on the market- this is a budget build.

BTW, I fully agree that the stock exhaust is simply sick design- how the hell can engine that big breathe through 1.7" pipe, while high-velocity gases from 2-5 cylinder smash on the exhaust wall at nearly 90*... My stroker on stock exhaust, with snorkel and cheap paper filter made 150HP only Now we're replacing the exhaust with 2.5" one, and fixing the intake restrictions (K&N cone filter, not much to do with the snorkel though...), and during the summer I'd like to weld this header...

[ajmorell]

I've heard not-so-great things about pace-setter's quality myself. I can't comment on performance though.

[1bolt]

I haven't heard much about pacesetter but even Borla's get cracks. With Headers cracking is just part of the deal. That said the Borla on my XJ is still going strong after 60k miles.

[mendelmax]

Well, crack can happen to any header, especially since these rigs are used offroad. Water splash, vibes etc- not too friendly environment for very hot metal.

I'm leaning towards my own build though. Here in Poland these parts are pricey as hell. Does anyone know, if any special metal kind has to be used? I haven't yet explored the subject, so I'm a totally newb when it comes to exhaust making, therefore any advice is appreciated

[ajmorell]

I haven't heard much about pacesetter but even Borla's get cracks. With Headers cracking is just part of the deal. That said the Borla on my XJ is still going strong after 60k miles.

I've got about 40k on my Banks with no cracks yet. Still looked to be in great condition when I pulled the motor.

[the_wrench116]

stainless steel is the material of choice because of its thermal properties and resistance to corrosion. if you cant afford stainless use mild steel and get it coated at the very least.
as far as the exhaust pipe size i wouldn't go smaller then 2.5 especially for a stroker.