best fuel for stock gsxr600 motor?

[carsick]

NHMS has 4% ethanol,

My testing says otherwise. Do you have proof?

[MaRce1o]

To get any gain out of a higher octane fuel you need to do one or more of the following:

- Raise compression to take advantage of increased knock resistance
- Advance ignition timing to account for higher octane's typically slower burn rate
- Increase VE via porting/cam timing/etc or boost (turbo/supercharging) to raise combustion pressures
- Adjust fueling to match

To get any gain out of an oxygenated fuel, you need to adjust fueling to match otherwise you'll be running way lean and loose power.

You haven't done any of those, or anything to improve the bike's breathing overall significantly. Your bike will make the most power on the lowest octane pump gas it'll run on without knocking. If racing with LRRS that means pump 93 from the track. Anything else is pissing money and HP away.

+1

[Kurlon]

My testing says otherwise. Do you have proof?

You tested? Results?

[carsick]

Last year Round 5 or 6, I put 100ml of 93 octane from NHMS pumps in a graduated cylinder, add 10ml water, shake and let settle, get 92ml gas up top and 18ml alcohol/water mix on bottom. Perhaps my procedure is flawed, but that seems to indicate 8% ethanol. I say my accuracy of measuring by eye has roughly a 2% variance, and there is likely some ethanol still in suspension in the gas. Pump gas in VT seemed to test about the same. If anybody can shed light on whether this is an accurate test, please do.

[makct04]

Diesel would be best for a gixxer...

^This. Make sure you plenty of this in your gixxah tank.

[cdovego]

^This. Make sure you plenty of this in your gixxah tank.

rocket fuel for racing you

[MattR302]

best fuel for stock gsxr600 motor?

This guy ran NOS in his gixxer's tank
http://www.gixxer.com/forums/showthread.php?t=226570

[tsorfas]

This guy ran NOS in his gixxer's tank
http://www.gixxer.com/forums/showthread.php?t=226570

Awesome thread.

"You should have put red bull to give you wings" LOL

[cdovego]

I remember that one, up there with the Kawasaki build by that kid with the big hair. I can't think of his name...

[makct04]

The one that cut the frame for better airflow or the one that drilled the ECU? Can't remember if that was the same guy.

[cdovego]

Yes, him.

[makct04]

I think you should make the same mods to your aforementioned GSXR, clearly there is power to be gained. Also, the weight savings will be incredible.

[Jim]

i've got a pale of 110 leaded fuel, if you wanted to give that a shot.
i was planning on trying it on the dyno to see readings & possibly use it for non-LRRS rounds.

[The Snowman]

I remember that one, up there with the Kawasaki build by that kid with the big hair. I can't think of his name...

The one that cut the frame for better airflow or the one that drilled the ECU? Can't remember if that was the same guy.

Yes, him.

Shervin.

[cdovego]

I love Shervin, talented kid.

[The Snowman]

This was always my favorite, painting the rotors...

[Ductard]

Your bike will make the most power on the lowest octane pump gas it'll run on without knocking.

That's always been my philosophy. Lots of uninformed people think that higher octane = more power but ironically it means "harder to ignite / slow burning"

But if I take that to it's logical conclusion does that mean if my bike doesn't knock on 87 octane gas from the street pump, I should run that?

I'm setting aside the ethanol content for now. I know it's higher on the street pumps and that's bad, but if I'm riding somewhere other than Loudon, it's hard to get my hands on anything else.

Also, I'm under the impression that doesn't necessarily hold for modern, computerized car engines or bikes - because doesn't the computer adjust the engine so that it doesn't knock, but runs less efficiently?

[Ductard]

Last year Round 5 or 6, I put 100ml of 93 octane from NHMS pumps in a graduated cylinder, add 10ml water, shake and let settle, get 92ml gas up top and 18ml alcohol/water mix on bottom. Perhaps my procedure is flawed, but that seems to indicate 8% ethanol. I say my accuracy of measuring by eye has roughly a 2% variance, and there is likely some ethanol still in suspension in the gas. Pump gas in VT seemed to test about the same. If anybody can shed light on whether this is an accurate test, please do.

It's been over a decade since I took organic chemistry, but it seems like that would work. Not sure if the water would extract 100% of the ethanol, but it seems like adding an acid or base to the solution would help increase the extraction rate. Either that or melt your face off...I'm not sure - I slept through class that day.

[CBR929RE]

ethanol makes more power but the problem is it has to be used before it bonds with water and separates from the mixture.

[Kurlon]

ethanol makes more power but the problem is it has to be used before it bonds with water and separates from the mixture.

Ethanol makes less power in a motor built for pump gas. To make power with ethanol you need to up the compression and advance the ignition as well as jet way fatter. (Assuming you're building for E85 or E100. You're not going to make up for the lower BTU per volume in E10 as you can't bump the compression/etc, there just isn't enough octane / knock resistance to do it.)

And yes, if your bike runs clean on 87, no knocking, run it as that'll net you the most HP.

[OreoGaborio]

10w40, but only semi synthetic.

[Degsy]

Kerosene

[CEO]

Wave at sportbikes, but not scooters or harleys

[CBR929RE]

Ethanol makes less power in a motor built for pump gas. To make power with ethanol you need to up the compression and advance the ignition as well as jet way fatter. (Assuming you're building for E85 or E100. You're not going to make up for the lower BTU per volume in E10 as you can't bump the compression/etc, there just isn't enough octane / knock resistance to do it.)

And yes, if your bike runs clean on 87, no knocking, run it as that'll net you the most HP.

wow next post and I caught the fishy

[makct04]

10w40, but only semi synthetic.

Kerosene

Wave at sportbikes, but not scooters or harleys

This is all solid advice Dove. Run all of these at once and wave to everyone while ON the track.