Additive

[Chevyss]

Boy, I found some great stuff. Lucas 3X booster. Really great for the fuel. Surely made a big difference in the Monte. Little pricy, but still worth it. Has anyone else used it??

[wallaby]

What difference have you observed?

Personally, I don't need any high-octane in my combo; maybe I'm lucky but she runs fine on regular grade unless the weather is really hot outside. If I'm going to the dragstrip I get some premium just to be safe.

Do you really need the additive? I always lean towards using the lowest octane I can safely get away with. Adding octane slows the burn rate of gasoline...my limited knoledge on the subject leads me to believe that it also lowers the BTUs. If you use high octane and don't really need it to control detonation, then you are actually reducing power output.

Maybe I'm completely wrong about this. I am open to enlightenment.

[502ci]

In simple terms Mark that's dead on accurate...

 

I'm curious too Royce, what improvement have you seen? Your motor with 9:6:1 compression should need no more than 92 octane, any more and you can actually decrease power like Mark stated.

[Chevyss]

I filled the tank, put the additive in. It starts better now and it really seems to pull better WOT. Maybe it's just psychological. I run 91 in it all the time. No 92 in Washington.

[CrazyDavey]

best I can get down here is 91 and on a warm day it will still "run-on" when shutting down. The booster helped some but not always completely (unless you want to back the timing off). As I understand there are 2 common issues, burn duration and burn control when it comes to octane. Octane will affect the start and length of the burn as well as control it by reducing uncontrolled burn (pre-ignition). The latter is the primary cause of "knocking" when lower octane numbers are used.

 

As both Mark and Bill have indicated matching the octane to the needs of the engine is optimal but there are too many varibles to be totally accurate. Personally I don't think the dilution of burn rate caused by a higher octane will hurt performance much if at all until you get over maybe a 110 number. You can actually go higher with oxygenated blends and get performance.

 

If anything error on the high side to protect the motor, if Royce can get 93 it should work good, 98/100 would be better yet during the summer or in competition.......JMO....Davey

 

Crazy Davey Racing

Yucaipa, Ca.....

[Heckeng]

I agree with everybody, but what we don't know is what timing Royce is running. If you are running too much timing, the added octane will bring it back down to the right burn timing. Royce, if you are noticing a big improvement with the booster, you may be running too much overall timing. If it is easier to start, you may have too much initial timing, and if you are feeling more at WOT, you may also have too much overall timing once the mechanical advance kicks in. Do you know your initial and total timing? What distributor do you run?

[Chevyss]

Scott;

 

I'm using the HEI that came with the engine right now. Initial is 12 and the total is 34. Seems to do good with those settings. Thanks for the replys. Next comes the MSD Billet, 8551, Control box 6240, coil 8202 and who knows what will happen after that gets in.

[Heckeng]

Well, I would not think you are running too much timing then, I would actually think you should upp it some, especially your initial timing. You have a lot of "umph" to pick up with that. I would agree with everybody else then and think maybe it was in your head! Or, if you had bad gas, the additive could just be bringing it up to par. Not sure. Sounds like a track test to me!

[CrazyDavey]

it won't like more initial if you still have the vacuum hooked up. On the street mine liked about 16 initial with about 36-38 total....manual advance...FWIW....

[Jared Richey]

I would be interested to see if my car would pick up much ET on all out race gas vs. 93 octane.

My Big Block is only around 9.5 compression ratio, and runs 93 just fine, which is good considering race gas is $7.50+ a gallon.

 

I really haven't had it at the track enough to play with anything, just can't afford to run it that much. It'll probably be a ....while before I get max ET from my car.

 

You retired people have it made...Davey!!!

 

 

 

[Kevin Wiles]

You retired people have it made

 

Please tell us what YOUR average day is comprised of. And then I'll tell you who has it made.

[wallaby]

If you are running too much timing, the added octane will bring it back down to the right burn timing.

That was the way I understood it. If you add high-octane fuel it slows the burn rate and stops the pinging, so then you add some ignition timing (because you can), and now with the slow fuel and quick timing you are right back where you started...except your wallet is lighter.

If you have an engine with high compression and detonation issues, that is a different story. You might not be able to retard the timing enough to to control the detonation. In that situation, high-octane is good stuff.

[Heckeng]

Yup, octane is kind of confusing stuff when you think about timing too. The only thing worse than that is spark plug heat ranges mixed with air/fuel mixtures!

[680HPStroker]

At 10:1 compression with aluminum heads even on the hottest day of the year anything higher than 93 octane doesn't make my engine perform any better. Having said that once in a blue moon on a really hot day I'll ad a couple gallons of Cam 2 and the only thing that changes is my engine starts easy on a hot re-start and idles smoother, but that's it. If I had a smaller hydraulic roller vise big solid roller cam with a 850 carb instead of a dominator the re-start/idle thing wouldn't matter.