Let’s talk exhaust

[OGdr]

So I got a great deal on a set of pacesetter headers today, I’ll be installing them soon when I pull my engine for some work. Question is, what exhaust should I run with them? What sounds really good with these engines? Should I run y pipe or duals with dual mufflers? I’m thinking duals with a dual in dual out muffler but I’m curious as to what other people have done.

 

[19Walt93]

A 2 1/2" single system will flow slightly more than a 2" dual and will be easier to fit. I have 2 1/2" single systems on my 13 second Mustang and my 351 Ranger. If you still have a 2.9 please buy a quiet muffler and not a fart can.

 

[OGdr]

I already have a flowmaster with 2 inch dual tail pipes. It’s nice and quiet at cruising speeds and that’s how I’d like it to stay

 

[ecgreen]

OGdr thanks for your service!

19walt93, the plea to not install a fart can is GOLD

 

[ecgreen]

Do the pacesetter headers usually come flat enough or do they need to be re-milled? I know they are on the cheaper end...

 

[OGdr]

The flanges look pretty flat to me, although I haven’t had a straight edge on them to check. The welds on the collectors look like crap, but if they leak I can reweld them.
All in all they seem decent for what I paid for them. I probably wouldn’t buy them new though

 

[19Walt93]

Get some copper gaskets and keep rechecking the bolts until the torque stays stabile, a light coat of red silicon wouldn't hurt if you want.

 

[gaz]

OGdr,

I would use the Flowmaster you have with a single 2¼" into it, though I don't know what size it's inlet has.

I recommend Stage8 locking header bolts; torque them once, FOREVER!!!

In regards to what sounds good with a (stock) 2.9L, a simple Borla turbo sounds nice, the XR1 sounds meaner @ WOT with a little better flow but I would use you dual outlet that you already have, if I had it just to be practical. It will probable sound pretty good with headers ..)

While you have things out, I suggest relocating your oil filter, it makes getting at the passenger side exhaust much better. Also, with your engine out, GREAT time to get rid of that crankshaft driven fan/clutch and install a 16" electric fan. The little 2.9 really responds well to the reduced load. You will see that at the gas pump; It's been a couple of days but no other change helped my 2.9's get more mpg that losing that fan.

With headers, exhaust and no fan, depending on you tire/diff setup, you chould be in 25mpg+ highway territory.

I am not sure which year your 2.9is but 86-88 had a true dual Y pipe stock. If the Pacsetter "Y" is a like replacement you can go duals from it but a single 2¼" systm for a stock 2.9L with headers is a good match-up.

I am interested to hear a sound clip of the finished setup with the dual 2" outlet muffler you have; despite my love if the Borla sound, I suspect that set-up will sound good enough to keep ..)

 

[mikkelstuff]

Be careful not to go too large on the exhaust. I don't know anything about the 2.9L but engines with much in the way of exhaust/intake valve overlap need some back pressure or unburned air/fuel spills out the exhaust killing performance as I learned once the hard way.

 

[OGdr]

Thanks @gaz for the insight. I honestly was thinking of exactly what you described, as it’ll be my cheapest option and I’m on a tight budget.

ive always liked borla too but this flowmaster was a takeoff of a customers car so it was free

 

[19Walt93]

Be careful not to go too large on the exhaust. I don't know anything about the 2.9L but engines with much in the way of exhaust/intake valve overlap need some back pressure or unburned air/fuel spills out the exhaust killing performance as I learned once the hard way.

I agree you don't want to go to big but it's not because the engine needs back pressure, what it need is for the exhaust to flow fast enough to evacuate the cylinders thoroughly. The bigger the pipe the slower the exhaust flow.

 

[ecgreen]

They gotta be better than most aftermarket manifolds. I have seen some crap "new". Ones