using avgas as a octane booster?

[Guest]

howdy, I can get ahold of some avgas quite easily, just wondering when I have to run 95 can I add a few liters of avgas to the tank to boost the octane to 98 or higher? obviously don't want too much lead in the fuel other wise i'll kill o2 sensors

[DRFVDR]

not exactly legal for road use though, but i guess it can be done

[Guest]

yeah not legal but the amount of it would be just enough to boost it up to 98 or past it so i'd say no one would ever know?

[madmike]

you would be surprised at how easy it is to smell in the exhaust gas.

[Guest]

alright putting the smell and legal issues a side would any one be able to come up with a mixture ratio?

[albaru]

I've heard that avgas is around 103 octanes. It's just a matter of straight proportion so if you add 30 litres of avgas to 30 litres of 95 then your tank will have (103-95)/2+95=99 octanes in it.

If you add just a few litres ie 5 litres to a tank of 55 litres of 95 (for example) then the octane rating of your tank goes up just .67 to 95.67 octanes.

So adding a few litres - not so useful.

[gotasuby]

Bp av gas. Not low lead stuff is 115 octane.

[Guest]

I guess avgas wont work then as the lead content will be to high with 30lt of avgas per 30lt of 95 . . .

[vorigan]

http://www.klotzlube.com/techsheet.asp?ID=87&submit2=View

[Guest]

have you used this?

[vorigan]

 cruiser40 said:

have you used this?

works good as does the NOS additive

[Guest]

where do you buy it?

[vorigan]

 cruiser40 said:

where do you buy it?

i brought it in for personal use youll need to google if anyone carries it here

[Guest]

okay fair enough thanks

[GC8E2DD]

Can you remember roughly how much that stuff was when you bought it Steve? Going by that product page it looks like the best part of a whole can would take a full Subby tank (~55 litres) of ~98 to around ~100. I see it for sale on Ebay for $100USD a can! Sadly a bit too expensive for me even for just event use.

[Kiwi_Fozze]

Speedfreak uses avgas in the rally car... It's about $3 a litre iirc

[gotasuby]

Av gas atm is around 2.12+gst

[Guest]

much the same is 95 then

[wrx_lou]

Learn to math dude.

$2.12+gst is around $2.45

[Guest]

 wrx_lou said:

Learn to math dude.

$2.12+gst is around $245

fuckin rofl

[wrx_lou]

LMAO sorry, forgot the decimal haha :

[Stoffa]

My car is tuned for 98, I went to queenstown and took 45 extra litres in gas cans but still didn't have enough, ended up trying a 50/50 mix of 98 and 95 and could feel a small amount of missing at low revs/load but didn't get any knock, ended up running 50/50 98 and 95 with a bottle of octane booster and it was mint.

FYI BP Cromwell sell octane booster off the shelf $20 a bottle

[Pappu1]

Hey fellas - digging up an old thread but....

 

Does anyone know whats involved in tuning an engine to run on a mix of avgas and 91 fuel (or even straight avgas - unsure how good that will be)

 

Note - its an overseas car (so nothing to do with legality of things in NZ) 

 

 

Questions:

 

any ideas on target AFR for avgas (for best power)

does it indeed take additional timing without hitting knock

possible to run higher boost with avgas mix

 

 

Wanting to heat form ppl who have used/tuned for this fuel

i know few people here run that (for race use) so would be good to get some comments on that

[gotasuby]

Can run more timing than unleaded. Only usefull if knock limited. The dilution of the oil and the residue left on spartan plugs, ports and exhaust are a pain though. Same lambda targets as unleaded. 

[Pappu1]

10 hours ago, gotasuby said:

Can run more timing than unleaded. Only usefull if knock limited. The dilution of the oil and the residue left on spartan plugs, ports and exhaust are a pain though. Same lambda targets as unleaded. 

thanks for that bro!

 

is it the same afr targets for straight avgas vs say 50/50 mixed with pump gas?