I am in the planning stages for my single conversion and was wondering what the guidelines are for boost vs octane. I know 17lbs is the recomended safest for pump gas, but 100 octane low lead is cheap and easy for me to obtain, so thats what I will most likely be running. Is there a rule of thumb you guys go by?

 

Ryan,

Sounds like we'll have some conservation at our next "beer, steak and tune!"

Tony

 

20psi depending on tunning. I use c16 when boosting over 20 becuase Its 5 bucks a gallon

 

What is c16?

 

Its 117 octane VP Racing leaded fuel, good ****! I call it go juice.

 

Where do you buy your gas? It cost me $11 a gallon for C16.

 

11 bucks?wtf, dude I think your paying way to much for your gas. Vp racing is about 7.50 per gallon. I know people
Its doesnt have to be Vp racing. There are other brands that have c-16 also. Vp is most common.

 

sorry I didnt see that you where from newyork things cost alot more in new york then they would here. Like our min wage is like $5.25 and hour. So that might give you idea

 

You can get 100 octane low lead from small airports for about $2.70 a gallon.

 

20 psi is the max I would run on 100 octane. I have run 18 psi before on 100, was scared to turn it up more though. I won't run more than 16 psi on 93.

 

$2.70 - Way TOO much. $1.75 to 1.95 in Kalifornia.

 

I have a small airport nearby that I use the 100 oct AVGAS from exclusively on my Sea-Doo.(highly modified)

However, Crispeed told me never to use that stuff on my Turbo car. Unfortunately, I forgot the "why" part.

 

Sorry, but I'm not driving to Cali to get gas. That's what they charge around here. I always thought it was a deal cause the tracks around here charge $7/gallon for 107 octane race gas. Do you get it from an airport?

 

Hmm, I would like to know why. I have never heard anyone say it was bad other than it kills o2 sensors.

 

under $2 for 100 octane in cali? Where did you buy it from? I bought 100 octane at special 76's stations (racing fuel or whatever they call it) for like $4-5 a gallon. Whats the diff between the 100 you get and the 100 at 76?

 

The 100 octane at airports is leaded.

 

With PROPER TUNING you should be able to run more than 20lbs, I have run 28psi on 103 plenty of times under tough conditions. Make sure you are running the appropriate plugs, and that you are tuned in the 10.5:1 range, and you should be fine. Tuning is the KEY. You can also run water injection, and push another 5-10 psi. Carl Byck

 

Final Compression Ratio (FCR) = [(Boost/ 14.7) +1] x CR

Good Vibrations Motorsports has a convenient chart for final compression. You can run higher with the usual tricks.

Quote
{
This chart shows the final compression ratio by combining the static compression ratio of an engine and the maximum blower boost from the blower system. It is to be used as a guideline in determining the proper maximum boost level for a specific application. Final compression ratios in excess of 12.4:1 are not recommended for use with "pump gas". The higher the final compression ratio, the higher the octane rating of the fuel must be in order to help prevent detonation and serious engine damage.
}

http://www.goodvibesracing.com/Compression%20Ratio.htm