I have a 2002 C32 and I have a few mods on the car. I have recently done some exhaust work (100 Cell CATS, custom SS tubing, and Eisenmann Race Exhaust), and I have now lost 10Whp on the Dyno. The car is running lean (see graph) so I called Renntech to have them adjust the A/F ratio and I was told that the map they used for my car would not run that lean unless there was an air leak in the intake system. So, the only place that seems logical (thanks to other board members) is the Surge Tanks / Evosport Phenolic Spacers.

I personally feel that this is not the case, and that the ECU needs a new map that is designed around the 100 cell cats and exhaust system.

The car has a rough idle when in gear, and sometimes knocks at 6000+ RPM. Idle is fine in park / neutral.

The car also seems to Dyno better after multiple pulls. Normally, the first pull would be the best; however, my last pull is always my best. So, maybe if there is a leak at the surge tanks, it seems to diminish as the car warms up. This could mean that the metal is expanding and making a tighter seal.

Question 1: What should the Torx screws be torqued to?

Question 2: What do you think the issue could be?

Thanks for any help you provide.

Graphs

 

i recently installled a set of evo sports spacers, i was not impressed.
i torqued bolts down to 8nm. and installed shims for outer bolts to compensate for gap- i only snugged those bolts so as to prevent cracking
spacers or warping intake-simple check for leak with a can of parts wash
and you should be able to detect a leak- or any mb tech at shop could
observe lambda pattern while spraying area- good luck. just my opinion
trash those spacers