TheGmKiller331

That still doesnt make sense.The motor is turning the same rpm or there abouts with either setup.

Explain this to me it sounds like wishful thinking.

Jugador

no, it sounds like pulling something out of his *** trying to sound smart. to downshift to slow down why the **** would torque benefit you? it wouldnt!

2000GT4.6

Here is a good artical about backpressure. Basically what it says is that because of computers able to sense and adjust the fuel/air ratio, backpressure is no longer needed, but with old setups (carbs) there was no automatic adjustment of the air/fuel ratio. With no backpressure the engine would start to run lean, as more air was drawn into the cylender than before.

This is why often headers/exaust work, or intake work for that matter, will not seem to add much HP to an older car, but when the carberator is rejetted/sized/replaced it suddenly seems to wakeup. The A/F is thrown off untill you manually adjust it again.

Although I cant say running with no headers or anything would work well, I would say its safe to say run as little backpressure as you can stand to run (aka as loud as you want it)

roundman

I think he's talking about engine braking, you know how you can downshift to a lower gear on a steep grade to let the engine slow down the car and save your brakes? Ever heard of a jake brake on a diesel? by choking off the exhaust, you can slow the engine down cause it can't run as fast with the excess backpressure working against it. The exhaust gases don't get out of the cylinders as good, so the intake gases don't get in as good and they're diluted by the exhaust gas that didn't get out, yada, yada, yada...

VertStangGT86

YES! thank your roundman, everyone kept talking about getting more power as the reason for downshifting, like to take off when you're already running, I was just talking about coming up to a stoplight a ways off, hills, that sorta thing. If I'm coming up to a red light I'll go through the gears to slow me down gradually with just a little bit of break. That's the drivability I was talking about, if you use it in driving then you may not like an X as much cause it doesn't have as much of an effect.

roundman

yes, but I always looked at it the other way, that is it's easier to change brake pads than clutch disks. but to each his own!

VertStangGT86

My dad always used the engine a lot when he had his 85, that's what I learned to drive on so I kinda picked it up from him. It's real low stress when I use it.