Ive herd that there are headers for My Eagle Vision TSi 3.5l 24v if this is true where could i get them. And will they make a differance in performance for this car. Ive herd that headers sometimes dont really help that much so if anyone has info i would appreciate it.
Originally posted by jfsram A header will significantly improve the breathing of a 3.5L and you will need to add fuel to the air/fuel mixture to take full advantage of extra breathing.
The PCM won't adjust to the free(er) flowing exhaust?
So ideally, we should increase air flow to the engine (at the intake) and we should increase the air flow out of the engine (but still provide back pressure)
A CAI will help the intake.
Headers and 2-7/8" pipes for the exhaust and high flow cats? I don't like messing around with my emissions too much because of strict laws.... Am I making the right assumptions? What else can be done.
PS. I watched Monster Garage, Jessie Jame weldeds his own headers... I can do it too! (anyone want to show me how to use a Mig welder?) hehehe
The Chrysler PCM is limited on how much it can adjust for.
It gets it's mixture parameters from tables. In very simplified terms it gets mixture from fixed parameters. On a given throttle angle, rpm and minor data from O2, map sensors etc will supply the mixture written. This is call speed/density. Speed/density assumes a given amount of air is entering the engine according to throttle position.
Mustang guru's understand this and that's why when they start modifying 5.0L they will start with a Mass Air Metered car. If it's a speed/density car they will convert to a Mass Air car.
A Mass Air car actually measures the air entering an engine, not assume from a given throttle angle.
I'm not saying one system is better than the other, just stating the differences, they both have their advantages.
Originally posted by jfsram I'm not saying one system is better than the other, just stating the differences, they both have their advantages.
I bet one difference is cost. I've seen prices for mass air sensors, I forget the exact prices, but they are not cheap at all. It is probably very cheap just to assume air flow from a sensor that is basically a varible resister, then let the computer programming take care of the rest.
Cost and reliability.
A speed/density system will recognize a gross difference and continue to provide somewhat of a correct mixture.
The Mass Air system can respond to upgrades since it doesn't care what it's supposed to see, it cares about what it is actually sensing.