Fuel in Cali stinks, Octane Boost reccomendations?


Jun 22, 2003
I live in the California Bay Area, the fuel around here is crummy. The best I can get is 91 Octane unless I drive over an hour to Sears point/Infineon or whatever the heck they call it now! :) A few people have suggested going with propane. That's great but I'm not ready to do that yet. I'm getting my Cherry Gn this weekend. (22,000 miles, original owner no winters, etc). Do any of you reccomend any brand of octane boost or not? I'm guessing I will get some ping ping with such cummy fuels.

I will be installing an RJC power plate (already have it) and a Caspers knock gauge.

Thanks for any input you can offer.
The Power Plate will help reduce the knock immensely!

Get an alky kit, or a propane kit.
I have a lot of thing I want to do to the car before that. I am first taking care of some of the reliability things. Tranny cooler, biggie oil filter, turbo oil feed and return lines. I want to drive the car when I get it. I won't want to strap on the alky kit the second I get it! But I can't get anything over 91 octane. So which is a good octane booster to use until I can go alky or Propane?
Some of these guys are on a one track mind it seems like... Alcohol or propane will alleviate your problem greatly, but arent that economical if you dont want to have to buy alky all the time. Dont use octane boost either, like the Auto Zone kinds... When they say "boosts octane by 7-9 points" it means .7-.9 octane rating. So you will go from 91 to 91.7-91.9. Use tuolene. You can get it at Menards or any large retail hardware store. It boosts octane like all hell. It is a good, and cheaper way to get the octane numbers up in your gasoline. Always put it into the tank before you pump in gas. Otherwise its like adding cereal after the milk. Here is a point of reference. http://www.gnttype.org/techarea/misc/octanebooster.html

This is just my opinion, but has worked for me. I always use BP 93 gas, knock gauge never went once except when my vaccuum line blew off and I hit 28# of boost off the stocker.
toulene works but is more of a pain then an alcohol kit.
You'll have to buy ALOT more toulene than you'l ever have to buy alcohol. This past summer, I only went through 1 1/2 gallons of alcohol - that's track trips and street driving. It only switches on when needed....the toulene has to be added everytime you fuel up.

There's always the option of keeping your foot out of it until you do the alcohol injection but, who wants to do that.

Personally, I think alc injection should be one of the first mods to do to protect the engine (after reliability issues).

I waitied a few years to put on my alcohol injection and if I was to do it over, It's be one of the first things I did, not one of the last.
I've been running the SMC alky unit for 3 years and have been very impressed. 21PSI on 93 octane with no knock. I averaged about 2 gallons a season ($20) instead of running race gas ($6.00 or more a gallon) or hardware store cocktails every fill-up.
No more destroyed O2 sensors either... zam70 was right should of been my 2nd or 3rd mod not my 10th.....
Might consider working on developing a complete understanding of how to really tune, and then work on doing your own chips.

Don't let the Octane Numbers game get to you. A car properly tuned on 91 will run right up there with one just slightly out of tune on 95.

And water/alky injection is a valid option.

Better yet do both.
First mod is a scanmaster or other scantool to monitor knock. Then you have to support the extra fuel delivery requirment and install a better/bigger fuel pump and hot wire kit. Walbro 340 fits the ticket. get rid of the stock chip and get an aftermarket chip with reduced timing.. eventually getting a custom program as your tuning skills dictate.

At this point tune the vehicle for zero detonation.. if this is achievable, then you can proceed on the alky/propane/water/etc..

Alky rocks.. given the rite system, it can protect over boost, boost creep, detonation, fuel system irregularities, etc...

I've blown past the 30 PSI mark on many occassions.. not intentionally tho :D on 93 octane gas.

Its high on my list of too do's.. getting a one gallon reservoir will make the alcohol last a pretty good time. I use methanol which I get for 2.50 a gallon.

Razor - shoot me a price on just your controller (progressive). I'm using an SMC controller with a flo-jet pump and a 1 gallon fuel cell...thought your controller might be a good addition..


So basically everyone is saying forget the octane boost and go Alky. Ok two more questions. Who makes a good alky kit? Do you have to hack up the car badly to install it? How do the head gaskets hold up at high boost?
I'm in San Diego and the gas is crap. I don't have alky but I'm working on it. Do a search on DIY alchohol injection and you should get tons of info. Also, if you go with a cooler spark plug that should help. I run the ac delco 43's and a power plate and run about 12 psi on pump gas with no knock. Any more boost though and the scanmaster starts to get a workout. That's my experience with 91 socal fuel. Hope this helps.
Yes, that's good info thanks! I will be running an RJC power plate as well. I have a bad feeling the fuel here will be a problem despite what most have said. They all say they are running 93, that's great and all but the best I can do is 91!! The fuel here sucks for turbo cars. Maybe I should buy a barrel of Vp fuel! Ha! Does the caspers knock gauge respond quickly enough to knock signals or is the scanmaster faster?

Funny I have all these parts from Summt, Kirban, H&R, ATR and the car isn't even here yet! :)
Originally posted by Gnx6
So basically everyone is saying forget the octane boost and go Alky. Ok two more questions. Who makes a good alky kit? Do you have to hack up the car badly to install it? How do the head gaskets hold up at high boost?

I'm biased.. sig below :)

No hacking

HG's hold up really well. Detonation will do them in if your not on tune tho. Alky works tremendously in that dept..

Keep it on zero KR.. throw all the boost you want.. they dont pop or lift. Within reason.. I've run past 30 on occasion.. but typically ran 25-29.

You will need to spray a lot to sustain those boost levels.fwiw.