during idle the car runs really rich .. its idling at about 1.2k with an a/f of about 18 when i rev it to 4k it gets really lean to about 10. whats causing this?

 

You have it backward. 18 is extremely lean and 10 is rich. 10 would be normal under boost with the stock ecu or richly tuned ecu. I sincerely doubt the car would even run at 18. How are you measuring this?

 

Is lean ok for idle? What rpms is "too lean" safe for? I'm guessing anything under the boost threshold?

 

In traditional terms, "lean" means a higher AFR than the stoichiometric value of 14.7. An FD will not idle well that lean, it typically likes values around 13 (definitely a wide range of suitable values though). You can tune the car in cruise areas of the map to 14-15 AFRS, you will not make quite as much power and the engine will run a tad hotter at the higher AFRs, so some people like to keep cruise at 14 to 14.5. Once under boost, the AFRS should taper down from 12.5 or so to 11-11.5, depending on boost level and fuel octane.

 

Hmm... my primary concern was the smell of the exhaust from my M/P. For cruise... does that constitue high rpms? Like if you're cruising at 4000 on a highway, how can a map differentiate between WOT and "cruising"? I guess I'll try tuning my idle for high 13s to start, and work from there.

 

Boost/Vacuum is the main load indicator as well as the TPS, rpm, and VSS. Cruising down the highway, your map sensor isn't seeing 10lbs. of boost.

 

If you have an airpump, 17 to 18 AFRs are normal at idle. The airpump dilutes the exhaust.


I'd recommend you do some research on basic fuel injection, and then how it applys to a turbocharged rotary before you attempt any tuning.

Paul

 

Thanks for the suggestion, but when I said I was "going to tune it for XXX", I meant thats what I was going to have it tuned for. I'd rather not write out "I'm going to have my tuner, XXX from XXX, tune my car."

 

I'm a little embarassed that that completely slipped my mind.

 

im measuring it with my apexi turbo timer, not sure if the numbers are reliable but they seem to be pretty good

 

Your TT is only using your narrowband sensor, so it won't really give very accurate results. Any readings under boost are nearly worthless. NEVER tune off of a narrowband sensor.