I've read that if you are going to run dual exhausts on the V6 that you should run 2 1/4" tubing unless you are going to be using a turbo/supercharger, in which case, you should use 2 1/2"...
Is there a reason that you shouldn't run 2 1/2" on the stock engine? Would you lose power? Why?
The 2 1/4" pipes will be fine for the V6. It's basic physics. It's a smaller engine, it doesn't rev as high as the V8. (assumig it's stock or close to it) it can't move as much air. No need for the 2 1/2" pipes. I would pay more attention to how the bends are made and the muffler design. Mufflers can make a huge difference as well has having mandrel bent pipes for smooth bends. Keep the pipes as straight as possible like what Ford did with the V8 exhaust. A good exhaust system will increase power as well as fuel economy on any engine.
Posts: 614
Joined: 3/19/2005 From: Boston, MA Status: offline
281GT: Good advice, thanks.
I was really considering getting the MAC Performance exhaust system available soon from v6mustangstuff.com , but I just found out you need to get the GT valance which will probably cost assloads after painting, installation, etc...
they only tell you to use the gt valance so you have the 2 cut outs for the pipes instead of one. I have the new duel exhaust on mine and they just hugged the pipes up to the bumper and if you look you can tell but it still looks good ( it is not real obvious but you can tell if you look for it.) The dealers also have a full ground effect kit that will allow duels to pass through the bumper and it looks great for around a grand fully installed. it gets rid of the cut out and replaces with two holes on be bumper made just big enough for the pipes, and mine sound just like a v-8.
Ok... well that really didn't answer my question...
Why SHOULDN'T I run 2 1/2 instead of 2 1/4...?
I'm planning an engine swap once I pay the car off, and it would be easier in the long run to have the 2 1/2 installed now, than to have the 2 1/4 installed and having to replace them once I change the engine...
Is there a reason I shouldn't get the dual 2 1/2 on the V6? Will it hurt my engine?
Posts: 614
Joined: 3/19/2005 From: Boston, MA Status: offline
I'm no expert on the matter, but you may lose a little torque due to less back pressure in the system. Another thing is, how long do you plan on waiting before you swap engines? I only ask this because if I had a dollar for everyone who said they'd swap engines later on down the road, I'd buy myself a GT!
I'm planning on swapping my 6 banger out for one of the Ford Racing crate engines once I pay the car off/the warranty runs out.
But I intentionally bought the V6 'vert instead of the GT for this purpose. I know I'll end up having to replace the transmission, rear end, etc in the process, and I'm already prepared for that. Oh, and, yes I know how hard it is to swap an engine in a car... I've dropped a 350 from a 79 skylark into a 85 regal... had to cut out a good portion of the firewall just to clear the valve covers/air intake...
I like the idea of being able to use this for my daily driving car until the warranty runs out, and then being able to turn it into my lil racecar...
I know a lot of people say and never do, but really, I've spent the last 3 1/2 years of my life getting ready to be able to do stuff like this. House now has 4 1/2 car garage with enough room in the driveway to park an additional 6 or 7 vehicles. I've acquired Welders / Tools / Ramps / Hydraulic Jacks / Pipe Benders / Metal Fab Equipment / etc (I'm a hydraulic lift and a CNC machine away from having ONE HELLOFA shop)
Thanks for the info about the loss of backpressure, I've read other forums that suggested that this might be a problem, but I always thought the idea was that you wanted LESS backpressure, not more... then again, what do I know?
Posts: 614
Joined: 3/19/2005 From: Boston, MA Status: offline
Well, less backpressure typically equals better HP at higher RPMs. But the backpressure actually helps the engine rev faster at lower RPMs, increasing torque (someone correct me if I'm wrong).
As far as the engine swap goes, it's ambitious.... I'll give you that much. Engine swaps are easier on older cars, but tougher on newer cars (obviously). I have a V8 in my 1975 Datsun 280Z. I didn't do the swap, but there was a lot of work involved.
My recommendation would be to go with a 2-1/4" system for now, if you've heard the 2-1/2" will hurt your torque. Most of your driving will be affected by a loss of torque before it'll be affected by a gain in HP in the upper RPM range... Plus, there will be so much expense associated with the engine swap (rear-end, tranny, etc...) that the cost of upgrading your exhaust then (at least 3 years later) will be insignificant.
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