Yesterday I put a bunch of miles on the car ….. over 40 minutes on the race track. The AFR's at WOT have risen from 11.8 to 12.4 so it's definitely getting more air. A retune seems to be in order not only for the AFR's but because the car doesn't like part throttle. More specifically, it's jumpy and wants to surge forward on all but the most gently applications of the pedal. A prior symptom from before my E/C tune but now it's pronounced. I have the feeling that I've found some pony's from the increased throttle body bore. Perhaps having long tube headers helps. Don't know. A dyno pull or two is in order, don't you think?

Les

 

for a standard 1psi drop across the TB...I'm guessing opening it up will give you a 3-5whp advantage, but the rough idle and tune required afterwards - others have experienced it. I got a stack of links/notes that I could go through, but you've probably already been there....you're welcome to them if you want.
Butt Dyno is excellent for the big gain (>10hp) mods - but when it comes to a few combined mods that yield...2+1+3+4 = 10hp....not so much ....

 

Since you track the car,every HP you can find is good. In my case, I'm looking for a very tractable GT car and don't want it to be touchy to throttle inputs, so I will skip this mod. Still, it's interesting, I'd like to see what the dyno says. I hope it all works to your advantage.

 

so i am curious , how can i figure out my cars AFR without a dyno, any ideas? i need to to finish my eurocharged tune after i did this mod

 

well if you have an android phone and download torquepro you might be able to decipher something, well at least "an indication" from that....
see thread here...
but I'd stress untested/unconfirmed and "indication only" at best.

 

Zietronix wideband sensor along with a dashdaq.

Les

 

vel - you forgot to mention the price (and PITA) differential....