I am interested in gradually cranking up the boost on my TO4S to 20lbs on aviation fuel (100 octane low lead) and was wondering what to look out for as far as tuning. I should have the fuel setup to pull it off. I am setup to run a conservative 10 deg timing for that range. I am wondering what my AFR's should be on that type of fuel. On pump gas I am tuned for low 10's for 17lbs in the upper rpms and when I put in AV fuel my plugs foul out quickly, so it seems to not like such a rich mixture.

 

I tuned for 20lbs yesterday with a mix of 93 and 110. Timing was around 13 advance and A/F's were in the 11's. I would say my tune was conservative. My EGT's were still low and I could run a leaner mixture but the car runs good.

Jason

 

Could it be the lead in the mixture that is fouling out your plugs or do all mixtures that go up that high in octane have lead in them?

Seams like an obvious culprit but I still think that with 100 octane you should have adequate protection against detonation for running 20psi. As Jason pointed out, you probably want to stay within' conventional AFR ranges even if your fuel is better.

Garrett

 

most races gas has lead above 100

 

Do you guys make a seperate map for running high boost levels? I'm assuming you just switch to that map when running race gas, or can it be incorperated in the same map as pump gas?

 

typically there will be a seperate race gas map, because with the race gas you can run leaner, more advance and higher boost...

all the things in a map