My 99 Camaro has around 12.5:1 compression and is strictly for off-road use so no cats. It's currently tuned for VP MS109 but am considering AVGAS 100LL as an alternative fuel due to the cost savings and availablity. If anyone has been using or tuning for this fuel then share your thoughts. My plans are to spray this car with up to a 200 shot through a plate system.

Engine: LS370 with LS3 intake and a NW 92mm.

 

Avgas burns slow, probably not a bad thing with a 200 shot but with MS109 the car would be faster.

 

MS109 is one of the worst fuel we ever used. It also eats up nitrous solenoids.

 

Yeah it's got MTBE in it or something like that, but I think they have 2 versions of it so if you are running anything with rubber seals like nitrous solenoids I would run the version without that.

 

Plug fouling can be a real issue with airplanes using 100LL, due to lead buildup on the electrodes.

Just something to watch out for if you go that direction.

 

Don't be deceived by the "LL" Low Lead in the name. It has a lot of lead in it. Very toxic lead and I'm not speaking of any tree hugging, environmental concern here. I'm concerned enough to say you really don't want to get it on your skin - wear some good gloves. Breathing it should also be avoided. OTOH, it does have a pleasing blue color to it.

Rick

 

Here is a data point:
I have run UP TO 5% 100LL AvGas blended into Unleaded pump gasoline for a long time and NOT destroyed O2 sensors.
I have been advised against running more 100LL, at risk of wideband O2 destruction.

IF you are using O2 sensors, you may achieve higher octane Gasoline blends with Acetone and Toluene.

 

The car does have front O2's and a dual wide band AFR gauge but once the car has a final tune it will run in open loop and the widenand will get disconnected. I was able to get some 100LL yesterday and it's roughly a 50/50 mix MS109. I let it run for about 10 mins and it's idling just fine with no issues starting. So MS109 will make the car faster..How much faster?

 

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You say you are running OPEN LOOP, the Car ain't going any faster than the FUEL it's TUNED for.....

 

NicD said that MS109 would be faster so I asked the question..I spoke with a tuner who said AVGAS would be okay with the current MS109 tune but it will wipe out the O2's in short time. Once the car is tuned for the fuel it would be set to run in OPEN LOOP.

 

Why would you mix the two fuels? MS109 burns relatively quickly compared to avgas, how much faster isn't really something that can be answered. You could certainly do a test though on the dyno and see what kind of power gains can be had tuning for either fuel though and that might translate into something.

 

It wasn't that I was wanting to mix them together it's just that I had some MS109 still left in the tank when I added the AVGAS. I value your opinion so when you mentioned the car would be faster on the MS109 I was curios as to how much? The only way to know for sure would be to run the car on a dyno with the two different fuels to find out and just figured that was something you had already learned from your experiences.

 

"and a dual wide band AFR gauge but once the car has a final tune it will run in open loop and the widen and will get disconnected."
Unplugging will kill the heater & the sensor will then die.
Putting the tune in OL will leave the heater on but still kill the sensor.
For the sensor to "live to work another day", it has to come out of the pipe.

 

Yes, that was my plan. I hooked up my scanner and the startup tune I was given has the car running in OL already. Once the tune is set there will be no need to see AFR readings so the sensors for the dual wideband will be removed from the pipes. I have the plugs to insert in the pipes and will put the plastic caps that came on the sensors back on and zip tie them up and out of the way for future use, should I decide to move to a different fuel such as E85 or M1. As for the O2 sensors I'll remove them and plug those holes as well.