Lead content Race fuel vs 100ll

007 · Dec 13, 2013

I know this has been hashed over, but I want real proof.

Is 110 race gas better for a turbo than 100ll?

I also want the 02 sensor to last as long as possible.

Here is what I found about lead content.

leaded fuel the amount was rarely over 2 grams per gallon, often 1 or so. B) his thought is that current low lead AV gas is a little under 2 grams per gallon C) 110 octane should be 4.5 grams / gallon D) 112 octane should be 5.2 grams / gallon E) the Nascar unlead is the Sunoco 260 GTX which would have no more than 0.05 grams.

av8er · Dec 13, 2013

sounds good

i got 1000 miles on my turbo running 100ll no issues with o2 sensor

backcountryislife · Dec 13, 2013

Who would you compare 110 to 100LL... they're HUGELY different fuels.

The sled tuned for one will run like crap on the other.

I thought we were WAY past this debate. Put 110 in a sled running enough boost for 100 and say goodbye to your bottom end performance, put 100 in a sled running enough boost for 110 and say goodbye to your pistons

Lead content is a non issue between the two, but "proof" is a unicorn puking rainbows riding a narwhal... you're not going to find it either way.

LONG TERM, as in running car/ truck type mileage, yes, leaded fuel will eventually kill your 02 sensors. When you put 200k on that M8T, I'll start worrying about it

Catman 42 · Dec 13, 2013

100LL is more forgiving than 110 race

I have run both in two turbo sleds the first a 98 mxz with an aerocharger at 9 lbs second an m7 with a Garrett 2871 at 13lbs. Riding at an average alt of 6000'.
the 100LL was more forgiving in two ways it was easier to tune and keep tuned and when it hit the wall the 100LL would usually let you get out of it before the damage was catastrophic.. Just what I have found and I have scorched a lot of pistons in both but a lot fewer with 100LL.:argue:

sledfvr · Dec 14, 2013

100ll tests out to be similar to 110 sonoco. They are within 1 or 2 points in octane.

007 · Dec 14, 2013

Bcl this is why I posted this everyone seems to have strong feeling about this topic, but I wanted facts.

I'm leaning towards running straight av at low elevation and mixed 50/50 up top. I also don't think I need 12lbs of boost.

Catman 42 · Dec 15, 2013

HA!HA!HA!

It's not a matter of need bro!!!
Just my opinion:face-icon-small-win

backcountryislife · Dec 15, 2013

007 said:
Bcl this is why I posted this everyone seems to have strong feeling about this topic, but I wanted facts.

I'm leaning towards running straight av at low elevation and mixed 50/50 up top. I also don't think I need 12lbs of boost.

I think the only thing with the question posed is that it's comparing two totally different things. If you were comparing the 100LL to 104, it would be a different situation you know what I mean?

When you compare 110 to 100 (more like 104) are you going to mix 91 with the 110 to bring it to 104?

IF you can get away with 100LL, IMO, run it... but the distinction between the two in how it would affect a sled is minimal to non-existent. Obviously though, if you're adding 91 to the 110, THAT fuel is the one most of us have good reason to avoid compared to any premium fuel

Uncle Bob · Dec 18, 2013

just my humble opinion. they are both good fuels. pick one and run it straight. its the mixing that i have realized gave me the fits for years. not having the 50/50 mix exactly the same and using the same brand 91 everytime will have you chasing your tail. straight 100ll is safer, cheaper, and more forgiving, and can take more boost then 50/50 can in my opinion. up in canada i puke a little everytime i think of running straight 110, nor do i need the 16lbs of boost it is capable of. set mine for 100ll at 10 lb. last year and have never looked back

av8er · Dec 18, 2013

Ditto

I'm running straight avgas at 10 psi riding from 4500-9000 feet, no det. I feel at 7000 and up I could safely run 11-12 psi with no det. but don't feel like messing with it, my TM8 with 2871, Kmod and 3"x162" at 10 psi easily puts me in places I don't want to be.
91 premium is $3.18, avgas $5.49, 110 is $7 per gallon around here

Sparx · Dec 31, 2013

007 said:
Bcl this is why I posted this everyone seems to have strong feeling about this topic, but I wanted facts.

I'm leaning towards running straight av at low elevation and mixed 50/50 up top. I also don't think I need 12lbs of boost.

Be careful and make sure you think things through before making any decisions. You want more octane down low and less up top in any situation in this application. At low elevation you should be on race no doubt, AV would be pushing it. By this I mean 0-3000ft refered to low elevation. Then I would run straight AV up to 10lbs boost taking it easy at 3000ft until at riding elevation at least over 5500+ft. At 3500ft in Revy on some deeper snow on the trail I managed to trip DET a few times on AV and on my recent Propane setup. Always use more octane and work your way down then the other way around...

I've abused AV gas pretty hard in my M8 pushing it to the limits on boost at different altitudes. I started with Race and worked my way down, rode at 800ft elevation on Race as well. It's great fuel but has it's limits still. 12-14lbs boost never really seemed attainable for me without an intercooler. Amazingly hot charge temps, not much different with the Propane so far WITH the intercooler and much cooler charge temps.

I have even tried higher Octane (118) without the intercooler and still the charge temps were killing me with no benefit in reduced DET at 8000+ft.

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Lead content Race fuel vs 100ll

007

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Catman 42

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sledfvr

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007

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