3.5L 265HP. mods

[Stumpalump]

2008 Ford Edge.3.5L 265 HP V6. Put 16 miles on and tore into it yesterday. I removed the aibox and removed the 1" snorkle that it breathed thru. This left a perfect 4 inch oval port that dryer duct fit right on. I ran the duck down to a factory covered cutout in the air dam for direct cold air induction. It was like it was made for it! I'm wondering if pluging the throttle body inlet boot muffler ports and tubes will help much? It also has two huge resonator chambers in the rear plus a muffler. I wonder if just swaping muffler to a free flow type and leaving the resonators on will help. Whats in and whats up with the two huge resonators? Are they restrictive? I got nothing into it so whats a few bucks for a muffler if it will help it scream. I'll fool with a potentiometer on the air inlet temp sensor also but for now what do you think a muffler will add to such a new high HP car? Can you think of anything else to tweek it?

[Keros]

"The best exhaust is no exhaust"

Unfortunately we can't live by that mantra, mostly because we like our ear drums intact.

If you're willing to spend some coin, depending on the diameter of the exhaust already (2.5" N/A and 3.0" for turbo) a high flow catalytic converter and a good high-flow muffler will do quite nicely to round out the exhaust system, resonators as required.

Anything in the exhaust system creates backpressure, the minimum requirement is a cat and a muffler, depending on where you live. If it is too loud still, then you can add on resonators as required... otherwise, go with the minimum.

Good high-flow cats will leech about 2-5hp off your engine... which is about the error margin of a dyno, so technically it's immesurable. Might as well save the environment a smidge, eh?

I don't know enough about that particular motor to help anymore. It sounds like you know what you're talking about, so I hope the above helps

[jonmark1985]

Originally Posted by Keros

"The best exhaust is no exhaust"

Garbage...

Back pressure can be used to time the pulses on exhaust manifolds and headers. No back pressure or too large of tubes will cause exhaust to flow to fast, then at low RPM the exhaust pulses will just blow on past the collectors and no scavenging will take effect. On a street motor primary tubes should be an adequate but small size, this amount of restriction will keep pulses moving at a reasonable speed, and scavenging works great at lower and mid RPM.

Extensive dyno time will help a person tune their exhaust and headders to gain more tourqe under the power band.

[mark v]

It has been proven that exhaust and mufflers will help you gain HP, with out it you will loose HP, Jet or Rocket engines do not count.

[Keros]

I should have been more specific... in an ideal engine, no exhaust would be best. Ideal engines don't exist on the street.

All cars produced are designed to have an exhaust system to produce back pressure. Boyle's Law, pipe dia, exhaust velocity, and all that is very lengthy and complicated.

I agree, however I was pointing out that if the OP has gone through the trouble of getting air into the engine easier, he should go the next step and let air get out of the engine easier.

Alot of design features in engines require some form of backpressure to hold the exhaust back or share exhaust vacuum: Valve overlap, limits of the ECU, EGR, ect.

I apologize for the confusion and apparent misadvice.