NateDogg wrote:Interesting stuff. Did you notice any decrease in driveability with the S14 intake manifold?
Not even a little bit. Its pulled closed by high vacuum, so the only time it would make a difference is under very light throttle and idle...my guess is 10-20% throttle and lower (if its even engaged then). The engine response isnt all that crisp anyway under those conditions, so nothing was felt. The biggest difference it makes is most likely at idle, it swirls the air better for fuel atomization. The effects of that are better gas consumption and emissions, thats about it.
When you remove them your not gonna feel a big jump... maybe a few hp up top, very minimal. Air flows fastest at the center of any tube, your exhaust, your intake runners, anywhere. So all this does is allow that center section of air an uninterupted path.
The strangest drivability related difference has been with the removal of the cat. Everyone's experienced that power dip around 2500rpm right? When i removed the cat theres still a dyno proven dip there, but its much smoother and cant be felt. Maybe my stock cat is just old and clogged? Ive had my exhaust worked on by meineke (yea yea yea ) twice, and they require that you have a cat on the car. Everytime i had work done the cat was on the car for the next day or so... and the dip is DEFINATELY more prevalent with the cat on. This is with the stock exhaust and also with the 3".
My EGR was properly working when removed and no difference was felt.