what ocatane do you run?

[2000v6bird]

i was told i can only run on premium 90 octane. then others have told me its ok to run regular unleaded. the kit im running is a 70 shot dry nos kit

[Dominic]

ONLY, and I mean ONLY run it on the highest you can get. 93 if its around in your area!

[John_D.]

With a 70-85 shot, I'd think you could get by with 91, maybe even 89.

For 100 shot and up, especially for a wet kit, I'd find some 93 octane.

Depends on how much lower octane gas is already in your tank too. If you have 4 gallons of 87, and add 4 gallons of 93, the net effect will be about 90 octane, overall.

I ran 93 on a 150 dry shot and got 10 degrees of knock retard for the duration of the run... But with an 85 shot I ran 89 octane and no knock retard at all.

[2000v6bird]

what is knock retard?? good bad?? how can you tell if you have it

[02PewterBird]

<blockquote>quote:</font><hr>Originally posted by 2000v6bird:
what is knock retard?? good bad?? how can you tell if you have it<hr></blockquote>

I don't think it's a good thing. The only way I know of to find out is to use Autotap. There might be another way that I don't know about.

[John_D.]

<blockquote>quote:</font><hr>Originally posted by 2000v6bird:
what is knock retard?? good bad?? how can you tell if you have it<hr></blockquote>

Knock retard, also known as kr.

I logged mine with autotap. The knock sensors on the motor detected knock just as it was starting, and pulled timing back to avoid it.

It's not good for performance.

It is good for your engine, if it is truly starting to "knock" (detonation, pre-ignition).

The best thing is to have enough octane, or to retard the timing enough, to avoid the kr in the first place.

I'm told that the pcm will pull more timing than necessary, in order to control the situation. So with my 10 degrees of kr, I probably only need to pull 4-6 degrees of timing. With kr doing it for me, I'm losing another 5 degrees or so of timing advance, that I should normally have working in my favor.

[viper98885]

Does anyone know the differences in power with running race gas (108 octane) with nitrous vs. running premium pump gas (93 octane) on nitrous. I plan on running 108 race gas while at the track in combination with my 200 shot, but I would like to know how much more the nitrous responds to higher octane ratings.

[95 3.4 Firebird22hp]

why not try some Octane boost on top of 93?

[viper98885]

I would end up spending more money on octane boost and still probably wouldn't get to 108 octane unless I dumped in about 4 bottles of the booster. In the long run, 108 is cheaper. I looked into the reaction of nitrous and higher octane and it will be even more powerful with the higher octane. I'll have some results when I get on the dyno.

[SixBanger]

4 bottles of octane boost will bring you up to 108 octane??? you do know that each point is only .1 octane right?

[OneQuickV6]

You really don't wanna run too high of octane...For or cars NA, 90 is overkill with the lower compression we run. Even on the bottle, I will only run 92 octane, and NO booster. As far as race gas, unless you have modified your heads and raised the compression ratio, you don't need more than 92 or so even on the bottle.

[viper98885]

<blockquote>quote:</font><hr>Originally posted by SixBanger:
4 bottles of octane boost will bring you up to 108 octane??? you do know that each point is only .1 octane right?<hr></blockquote>

Even more reason to stay away from the stuff,

[viper98885]

<blockquote>quote:</font><hr>Originally posted by OneQuickV6:
You really don't wanna run too high of octane...For or cars NA, 90 is overkill with the lower compression we run. Even on the bottle, I will only run 92 octane, and NO booster. As far as race gas, unless you have modified your heads and raised the compression ratio, you don't need more than 92 or so even on the bottle.<hr></blockquote>
I have ported and polished heads, Lunati cam, Ross flat-top pistons (10.0:1 compression), Manley forged aluminum rods. I think I will be fine with 108 race gas.

[Dominic]

The only issue I have with race fuels is that they usually don't have any kind of lubrication additives for the fuel injectors, nor do they have any cleaners in them. So if you run race gas, try to run it sparingly, or at least add some lucas fuel additive (which has lubricants and cleaners in it) to keep the injectors lubed.

[12secondv6]

I like to have minimum of 93 octane for my 100 wet shot.
Sometimes when I know it will be hot out I get 94 octane.
I have tried 100 octane cam 2 but I spin too much.
I don't have any proof of it's benifit.

I'd stick with 93-94 for nitroused passes