I've been running 91oct All we get in CA. and tuned on 91. Found locally 100oct.
91 off the line lugging the engine, will ping a little 1000-1100 rpm
I had 3/4 of 91 and added 3.2 gallons of 100 sunoco to the top of the filler. Runs AWESOME
next time I add fuel how do I get a consistent ratio?

next time I add fuel I'll have a mix of 91 and 100. I usually fuel up at a 1/2 tank about 6 gallons
I have a couple gas cans (8 Gallons) full of 100


How much could I run of mix or straight 100??

I tried a couple cans of oct boost, bunch of crap $10 for a can B.S.

found this link....
http://www.gnttype.org/techarea/misc/Octanemix.html

 

9 gallons of 91 and one gallon of 100 would be 91.9
9 gallons of 91 and two gallons of 100 would be 92.6
9 gallons of 91 and three gallons of 100 would be 93.25
9 gallons of 91 and four gallons of 100 would be 93.77

Two gallons of 91 to each gallon of 100 gets 94 octane.

Just multiply the number of gallons times octane, add together and divide by the total gallons.

Just add a couple gallons to each fill up and you will be fine. If you tune it to that higher octane you can get into trouble when you run out.

If you have no cat, just get a 5 gallon can of C16 (117 octane) One gallon of 117 added to nine gallons of 91 gives 93.6 octane.

 

so if I take a weekend trip i need to travel with a RED can with 3 gallons and know where 100oct is for sale.

Just found 100oct have not found 117oct, that crap must combust in sunlight

if I ran out maybe I could run 151 rum???

 

There's no reason you should be lugging at low RPMs, especially when boost is barley building up. I would seek a retune, or verify your plugs and other items are up to snuff.

 

^^ Agreed.

 

I think running 91oct only was causing a couple pings off the line. Mixing the gas has resolved.

Trying to save the clutch and flywheel I've always driven with low rpm of the line. Plus I don't want to jack up the diff or trans. My very first car 1984 was a manual and I smoked the clutch the first month. running 1500-2000 and riding the clutch out. Since then its a game to see how low I could get rpm and off the line.

My stock ap2 22lb was easy barely had to touch the gas. This 11.0 lb SOS flywheel want to spin with little gas, then the clutch want to grab. I've stalled more the past 5 month than 8 years stock.

 

I know its counter intuitive but higher octane is less volatile, which is why it controls detonation better then a low octane which combust more. If the laws of physics didn’t apply and your motor would never detonate, the lowest octane you can get would make the most power.

 

That car must feel like a freaking turd driving around at such a low rpm. I don't think driving it normally will hurt your trans/diff. If its pinging at that rpm where there is no boost then it needs retuned. You are wasting money on race gas for no reason.