How much boost is safe with pump gas?

[chopperguy]

I am new to the boosted market and am getting ready to take out my new TNytro. The person I bought it from said that he was running 15-16# of boost and was running straight race fuel.

So my question, I would like to turn it down and run a less expensive fuel in it. I don't believe it has a head shim, so what would I be safe running for boost numbers with 91 octane at 9,000 to 11,000 feet? What about AV gas? Is that less expensive? Would I be safe on 10-12# of boost on 91?

Any thoughts would be greatly appreciated.

Thanks,

Tim

 

[chopperguy]

Oh, and sorry...if it makes any difference I believe the turbo is a kit from Boondockers.

 

[Wheel House Motorsports]

throw a shim in it and depending on the thickness you should be good to around 15# or so on pump at those elevations.

 

[JSCC]

12lbs on Av is fine.

 

[snocattin]

100 LL Av gas is $4.57/gal here right now, approx $1.47/gal more than 91 pump.
You can check local Av prices with this website:

http://www.airnav.com/fuel/local.html

Straight AV (100LL) would be fine at 15psi and 9+K feet.
I run straight Av with 15 psi at 4-7k sometimes when I run out of race, no problems. Just my $.02 worth.

 

[Midstates]

I run 11 psi. above 8k ft. on 91 octane. Ulmer Racing Kit. No shim. Add a little 104 Octane boost if worried. I run a mix of 110/92 at sea level. Brad

 

[chopperguy]

Thanks guys. I found a place that will sell me some 100LL (the airport about a mile away won't put it into anything other than an airplane) so I will try that and turn the boost down to 12-14#.

I am excited to see what all the hype is about!

 

[robertyoke]

Thanks guys. I found a place that will sell me some 100LL (the airport about a mile away won't put it into anything other than an airplane) so I will try that and turn the boost down to 12-14#.

I am excited to see what all the hype is about!

loveland/fort collins? they said the same to me airplane only. I've heard mead will sell it but i havent tried, I bought a 5 gal pail of torco instead. I've been running 15/16 lbs on pump with just 25% race from team petroleum. last year i ran just straight pump but I was concerned about getting some '85' instead of the '91'
mcx with shim.

 

[chopperguy]

FYI I bought 100LL at Greeley airport for $4.05 per gallon! Seems pretty good to me and they were cool with me putting it into gas cans.

Has anyone ever heard that 100LL is bad for high RPM motors?

 

[JSCC]

Yes and I heard its dry, and bad for everything but planes, and that if you use it you could get herpes and syphilis....

I just ignored all the he said she said........

 

[motojunkie101]

I talked to Boondocker a few weeks ago and they said 91 is okay over 4k feet @ 10lbs of boost. Just increase octane for the days you go big.

Sent from my Droid using Tapatalk

 

[relentless rider]

I run 14-16 on pump at 5000-7500 ft.Ive got a .063 shim with a gasket on each side,apex