i havent seen many of the designs for this car, but i take it most arent like on a 4 cyl where a 4-1 style would be more for top end, where as a 4-2-1 would be more mid and top end, but a 4-1 or 4-2-1 LONG TUBE would enhance low end as well.

i take it pretty much for this engine most are 3 into 1 per side?

 

Not too hot man or you start to do damage to the exhaust valve. Look at a turbo system where heat is ideal and increases the efficiency of a turbo. You end up needing either Ti valves or good quality SS valves to not have them burn up. I agree heat is good, but it also kills parts.

 

IMO, longtubes or nothing when it comes to any header setup. I've done enough work on F-Bodies and Stangs to know that shorties headers do little on 4.6-5.7 liter motor so why should a 3.5 liter behave any differently? My buddy had shorties on his 00 Z28 auto. Those gained him about 5whp. We installed some long tubes (pain in the butt) and the car gained a whopping 25whp. The car went from 13.7s@103 to 13.3s@106mph. I think there is only one company that makes longtubes of the 3.5VQ and I can only imagine how much of a pain it is to squeeze them into the bay.

 

I hear you, I was just saying that normal operating temp is ideal. People tend to think that cold is better and it's really not the case unless you're talking about the intake manifold/air only. A hot combustion chamber and hot exhaust components help keep the exhaust velocity high. It's all a balancing act though because if you get the chamber too hot, detonation will occur.

 

Agreed, just once everyone starts tuning and adding more air and fuel temps will increase so I was just pointing out headers will help keep this down... I guess closer to normal.

 

Correct - 3 into 1...

 

Longer Tubes = Higher or lower RPM (the longer the easyer it is to + velocity)
- Long Tubes = Low/Mid powerband
- Short Tubes = High RPM Powerband
Equal/Different length headers = RPM Peak
- Equal = High Agressive Peak
- Different length = Lower peak but it'll streached the power band out
Diameter.. eh not sure what it really effects.. i THINK its RPM Range or TQ or iono xP lol i'll look it up later

You can figure all this out with the engine displacement, valve lift, and RPM

But one of the biggest reason why people loose power through headers is cause of an EXHAUST LEAK!!.. headers under go EXTREME temps and can easily "untorque" your header bolt.. thats why accessories such as locks were made to hold the bolt in place. you should install the header and torque from inside out (not using a torque but something more accurate.. i also forgot the name.. so tension on all the bolts are the same) then retorque it after about a month later..

also IMO the test pipes with the fattest resonator will provide the best scavaging effect for your exhaust.. and IMO the ideal exhaust design would be (example) 2" header.. and expands into 2.25" at the test pipes.. then 2.5 after the Y piple, X, H, whatever pipe.. (i believe an H pipe is the ideal pipe.. you have two dual pipes that are connected to even out the pulses) and 2.5 through the rest of the way.. with whatever tip you want.. keeping in mind that mufflers and resonators that uses restriction to cancel out sound will loose HP. the exhuast should expand because the exhaust gas travels like soundwaves and it'll expand as it gets closer to the exit.. but if we go by that i think we'll all be running like a 5" tip or something lol


just some food for thought.. i'm bored at work -_-

 

also 2.5" is more then enough for our exhaust system.. thats why ISM's exhaust is the **** lol .-.

but all that changes once you go FI...

 

Heh.... this is way more complicated than I thought. Hmmm...


Thanks everyone for great replies. I think I'm just gonna give it a try and see how much power I make. I was thinking about Strup headers... yay or nay?

 

can you get the specs of the headers? runner lengths and diameter

 

Forgot to check back on this thread... I could only find these specs: 1 5/8" tubing X .065 thickness.