At those power levels, reducing the size of your is obviously (as you know) going to increase back pressure and reduce power. BUT, you are also going to run more rich as a result. To minimize the power loss, are you going to pull fuel out of the mixture or are you simply going to bolt up the 3 inch pipe?

Would you mind doing both so we can have 'tuned' and 'untuned' numbers? I bet it makes a big difference. I bet you'll still lose power but at least you can minimize the loss...right?

 

Threads like this are why I love this site, so much drama.

Thanks Momentum, Joe and anyone I missed for posting good info. My car is at Mase's getting his kit installed and hopefully tuned for 600WHP. I had the exact same question about 3" vs 4" exhaust. You've ansered my questions.

Thanks btstone and junky for the entertainment but you got served.

-Chris

 

My car wont go rich, I have EMAP sensors on both scrolls so it will compensate for the added back pressure and not only run the exact same AFR it will adjust timing to suit and data-log the drop in efficiency (map/emap) and increase in EGT's

Should be pretty hard to argue with those results

 

Ah...excellent. And you are running the Motec M800, correct? Sounds neat!

 

Is that what you think, they just found tid bits of info and cut and paste stuff. i do believe you lose power with smaller exhaust, i never disputed that. i said the losses were minmul and you would create back pressure and that would equal more TQ. I was told that back pressure = tq is not right and i didnt have proof to dispute it so i dropped it. but everything else i know i am right on. so re read th post young man. floyd the nut swinger has been dismissed several times

 

i was always under the impression, that with a turbo car, there was no such thing as too big. if you purposely put a smaller exhaust on a car, then it will take longer to spool, if it takes longer to spool, you make less power and less tq. its not like the car suddenly becomes more efficient and makes more power per pund of boost even thought the turbo is spooling slower.


this honestly makes no sense, if the turbo takes longer to reach peak boost, you will lose power at least up until that point, and then the turbo will prolly be working harder to reach/maintain that boost so its less efficient.

on a turbo car, backpressure creates inefficiency, which is not a turbo's friend, will increase the amount of time to spool, and reduce tq/hp in that area of the curve.

 

motec > anything else

cant wait to get the Mx00 to s2k plug and play harness from ya momentum. lots of people should be jumping on that. it takes a HUGE chunk out of the cost of getting into a motec system. a nice engine harness is big bucks.

probably going to put 30,000 miles on the car, just on the dyno now lol

 

Didnt realize I was being entertaining. Got served

 

[QUOTE=btstone84,Sep 23 2009, 08:33 AM] Is that what you think,