RACE FUEL

[e90m3_6MT]

I am looking for race fuel to mix in with the 91 octane. I was wondering what's the maximum octane possible for the S65 engine with stock software. would an average octane of 100 be overkill or does it produce some nice horses?

I don't know much about race fuels and their effect on the engine, hence the question.

[dcstep]

Originally Posted by e90m3_6MT

I am looking for race fuel to mix in with the 91 octane. I was wondering what's the maximum octane possible for the S65 engine with stock software. would an average octane of 100 be overkill or does it produce some nice horses?

You want unleaded 100-octane, IF you're at sea level. As the atmospheric pressure drops the engine can't advance enough and you can actually lose power. I live at 5400 above SL and lose power with 100-octane, so I blend 91/100 to shoot for around 96 octane, which gives me a small boost. PencilGeek and others reported around 30-hp gain from 100-octane at sea level.

Sunoco, Sinclair and Phillips are some of the brands in the US that offer high-octane gasoline. Unless someone posts here with a specific location near you, you'll need to do an internet search, since there's usually only one or two suppliers per major metro area. I'm not sure what brands you have in Canada, but going to the site of the brands will usually lead you to a Product page and from there you can find a Location page usually. Expect to pay 200 to 300% of what you pay for 91-octane.

Dave

[Kyoshi71]

On a stock S65, you're throwing your money away with 100 octane. Maybe, just maybe, on a cold day/night, the car will run a little better.

[dcstep]

Originally Posted by Kyoshi71

On a stock S65, you're throwing your money away with 100 octane. Maybe, just maybe, on a cold day/night, the car will run a little better.

How can you say that?

Look at PencilGeek's dyno database for documentation. 30-hp from a tank of gasonline is really cheap performance.

If he's at high altitude, then it's a different matter, but at sea level the performance gain is pretty dramatic.

Dave

[Kyoshi71]

Originally Posted by dcstep

How can you say that?

Look at PencilGeek's dyno database for documentation. 30-hp from a tank of gasonline is really cheap performance.

If he's at high altitude, then it's a different matter, but at sea level the performance gain is pretty dramatic.

Dave

Did you know that PG also has a stroker motor and who knows what else? No offense to PG because he is a great dude but, he also ran leaded fuel through his car at one point.

You don't really think the you can acheive a 30hp gain on a stock S65? I certainly dont.

[dcstep]

Originally Posted by Kyoshi71

Did you know that PG also has a stroker motor and who knows what else? No offense to PG because he is a great dude but, he also ran leaded fuel through his car at one point.

You don't really think the you can acheive a 30hp gain on a stock S65? I certainly dont.

Perhaps I've known PG way longer than you. Look way back in his archive and you'll see 30hp gain in a stock, pre-stroker engine.

It's been a long time since I looked, but there were one or two other confirmations of the sea level gains. If you look through my dyno runs you'll see experimentation with various octanes at 5400-feet. My gains are only single-digit and only if I blend.

It'd be neat to see some others experimenting with octane. It's very real.

Dave

[turbo8765]

IIRC, PG gained not 30, but 35 hp AT THE WHEELS on an otherwise stock vehichle (baseline was 91 octane).

[e90m3_6MT]

I live close to sea level, montreal canada. I saw a few shops around that carry sonoco racing fuels. I would like more power for the race track and thought fuel was a cheap way to acheive this.

what would be the ratio ie how much race gas for every litre of pump gas? Is it 1:1? 1:2? etc...

thanks

[B-52Gunner]

Sunoco 260GT is what you probably want it's street legal 100 octane

[dcstep]

Originally Posted by e90m3_6MT

I live close to sea level, montreal canada. I saw a few shops around that carry sonoco racing fuels. I would like more power for the race track and thought fuel was a cheap way to acheive this.

what would be the ratio ie how much race gas for every litre of pump gas? Is it 1:1? 1:2? etc...

At or near sea level you want 100% 100-octane.

[e90m3_6MT]

Originally Posted by B-52Gunner

Sunoco 260GT is what you probably want it's street legal 100 octane

what's the difference with a offroad use only fuel like the 260 gt plus

[dcstep]

Originally Posted by e90m3_6MT

what's the difference with a offroad use only fuel like the 260 gt plus

It'll probably tell you at their site. It may have lead, so you need to be certain that you get unleaded. Don't be tempted by the higher octane, like 110, because the M3 actually starts losing power beyond the optimal octane, which somewhere around 100-octane.