Bane

Hey guys,

I have an NA 13B in a Formula Mazda and would like some input on air/fuel ratios and EGTs as well.

The car is equipped with EGT sensor in each exhaust runner about 4" from the head. It has a wideband oxygen sensor in the collector after the runners come together.

It's running a a Weber DCOE carb. and I have a wide selection of jets to choose from. Right now it's PIG rich but my team won't listen to me and lean it out because they are scared of the 18.0:1 air/fuel ratio when the driver lifted off the gas (they won't believe me that it's normal to spike under no load...).

I'm trying to gather as much data as I can... I'm used to turbo Toyotas but the rules in the rotary game are slightly different... I heard "through the grapevine" that rotaries can run as much as 200-300 degrees (F) hotter than a piston engine for EGTs.

Max performance is key. Reliability and longevity are secondary (it is a racecar after all...)

My team is real conservative and thinks I'm too aggressive... I tried to tune for 13:1 air/fuel and 1700 degrees EGT and EVERYONE else balked at that. Noone has experience tuning rotaries on the team so I'd appreciate all the info I can get!! Next race is tomorrow morning at 7:30 am so quick replies are appreciated I'll check it later tonight and tomorrow morning before 7:30! (that's a practice session).

Thanks guys.

-Greg

P.S. Any additional info like "it's hard to run an NA rotary overly lean" is also appreciated!

rwatson5651

iTrader: (5)

visit thisweb site, lots of good information on mixtures, and proper egt for rotories
http://www.yawpower.com/

RETed

Your numbers are reasonable.
But, to prove you are right, get that thing on a dyno.
Dyno doesn't lie if you're making power or not.


-Ted