100 octane leaded fuel????
 

I've been wondering, will that work in my LS6 motor? The car doesn't have catalytic converters and is for track only.

100 octane aviation fuel is leaded/low lead and is a lot cheaper than 100 unleaded, so I was considering trying it if there is no ill effect.

Thoughts?

I fear the lead in the 100LL would do a number on your O2 sensors; I think that's one of the reasons they haven't had much success with closed loop systems in GA engines.

If that's not an issue then I see no other problems.

HTH, and have a good one,
Mike

Yeah, the amount you save in gas cost you will likely spend in replacing fouled O2 sensors.

Why don't you just run 93? I do.

Same here, when I got the car it was tuned for race gas that was the first thing I changed

We've used the 100LL and it seems to work fine with used 02 sensors but if you install a new 02 sensor it will foul it out right away.

Also you won't make the extra hp with 100LL, if you are going to run race gas you're better off running the premium oxygenated racing fuels and they are over $7 per gallon. I know Sunoco has some unleaded fuels that are as high as 109 octane! For ST2 it really doesn't make sense to use race gas, since you can always find ways to make it to 8.7.

Not sure what you're saying about closed loop in GA engines. When I started building and tuning the DP engines, we were running 100 UNLEADED, ran and raced in closed loop all the time with the ability to turn off the lambda control if we saw a sensor fail on the telemetry. During my time there, we switched to the 98 UNLEADED (again, not low lead, unleaded) and continued to run closed loop all the time.

We changed out O2 sensors with every engine replacement (~3k race miles) but that was more due to the heat issue than contamination (and the sensors were only $150 each).

That being said, running low lead or leaded WILL wipe out lambda sensors in a hurry. When we ran sensors on the NASCAR motors on the dyno during R&D, we'd go through a set of O2s every day (and those were the lab grade $750/ea sensors, one per cylinder).

Like someone said, running the higher octane LL fuel won't give you anything over the 98. When we stepped from 100 down to 98, we lost 0 power.

I'm pretty sure he meant General Aviation, not Grand-Am.

Like the others said it will wipe out the O2 sensors but even if you tuned for open loop I would not run aviation fuel. It is meant for higher altitude performance not for running on the ground.

The name 100 Low Lead came as a comparison with the previous 100/110 octane aviation fuel that had tons of lead in it. 100LL avgas still has about twice the amount of lead as was ever in automotive gas so it will wipe out oxygen sensors in a hurry. Better to use unleaded race gas since the cost of sensors will add up faster than fuel.

I wonder what NASCAR is going to do now that they are going to use fuel injection. I'm guessing that they will use an unleaded race gas so that they can use oxygen sensors and run closed loop too.

NASCAR has been running unleaded since the middle of 2006.

Correct. Sorry, I didn't think about the general audience when I made my reply.

Have a good one,
Mike

Now they are running E15!