maf and throttle body diameter

[jaykay]

Alright a high noon drag race duel at Gimli! With any luck we won't get disturbed by any dead stick 767s

I was actually driving through Radium down into Nelson BC just a while ago...phew what drive still did get me primed enough for the out right speed of track driving the following week

Originally Posted by The Radium King

you're right; with a plenum that exits straight out from the intake i'll have to put in a larger radius curve further upstream as the intake runners themselves are canted to the left a bit. i'm just thinking that the further i put that from the 90 degree bend that happens at the actual plenum the better. the thought of the cayman plenum is attractive, however, as the resonsnace flap used on that plenum is now used on the dfi 911's also, so it must work (i think it is a low end/top end compromise, l however). further, as you note, it should be plug and play with a 987 airbox (which is a way better unit that the 986). i have a line on a cayman plenum if you are interested; pm me for details.

regarding the dme adapting to the larger maf housing i agree, BR has gobs more experence than most of the rest of us combined and says it works. he said in a different thread that he's going to try it on one of his cars and see if the air/fuel ratios adapt. i know i have read of people doing 3.4 swaps and not having the maf appropriate to their dme and having problems, so definitive results would be nice. it may be an issue of cumulative change, also; the dme can adapt to the maf change, and the dme can adapt to a higher flow intake, but both a higher flow intake (and exhaust, etc.) combined with the maf change change may exceed the learning capacity of the dme.

i'll tell you what: you do the cayman change, i'll do the 997 change, and we'll meet in the middle and compare (manitoba - geographic centre of canada - gimli motorsports park)!

[Johnny Danger]

So what's the final verdict ? Is it the cayman or 997 plenum that should be mated to the 76mm throttle body ?

[jaykay]

Mr. Danger

The face off has not gone down yet! We would need an air lift and snow ploughs!

Hmmm delving into this a bit. It seems the "tune" can be upset with addition/deletion of a distributor flap. The resonance flap us tuned to work with or without. I believe I would need a Caymanesque tune to make use of the sophisticated intake system.
I am not sure about the worth of this and can't do this myself. I think the distributor flap would certainly mitigate any low end losses associated with the larger TB.....just a guess. The engine experts might better answer this

It may be just spy vs spy at Gimli...as I will be likely running a big 3.8 diverter tee.
Shhhh don't tell Trk