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Octane boost?

malc350

Well-known member
Joined
Jul 6, 2002
Messages
337
Location
Essex, UK
Corvette
1996 LT-4 Z51 CE
Hi has anyone tried and can recommend a worthwhile octane boost product? I run my twin turbo on 95 octane unleaded but am going to run it at the dragstrip soon so I've started filling it up with 97 octane fuel. Is the difference between 95 and 97 of any benefit?

A shop near me sells 104+ octane boost. 90 Callaway tells me he mixes 114 octane fuel with his regular fuel but I can't get anything like that.

For the record my Twin Turbo has no cats but (obviously) still has an oxygen sensor. I have never experienced any pinging under any circumstances. I just want an extra margin of safety for my car.

Regards, Malc.
 
1

1DOWN6TOGO

Guest
if you are convinced you want an octane booster (i say that because a good deal of people here don't use it), then only go with the highest octane possible.
if you can't get higher octane fuel to mix, then use a booster. if you have to use a booster don't buy an octane booster for street performance. buy one that's off-road only- stated right on the label. (note: you should look into the local transportation laws, because use of off-road only octane booster is illegal in most areas) that aside. why do you think it's illegal? because it's too much. and that's the only way to go in my opinion. i even use it in higher concentration than recommend. the higher concentration the higher performance of the booster. off-road use only boosters can be found at most auto parts centers i assume. i have always gotten them at AutoZone. they are usually found in metal containers that look just like the plastic containers of their street performance counterparts.

in my experience, this is the best route to take when you are going with octane booster. a good off-road booster can boost up to 10 octane rating points when used in the concentration recommended and some of them show charts representative of the boost as a function of concentration based on a 20 gallon tank.

if you try it, let us know what you think

sam
 
T

TurboLuigi

Guest
Malc,

The cans of octane boosters sold at Auto Stores are generally enough to raise the octane level by .2 for a tank of gas, per bottle. Here in the states these bottles sell for about $3.50. So you would have to spend a tremendous amount of money to raise the octane to 96 or greater.

In addition to my Callaway TT, I also own a Buick GNX and the guys at the Grand National clubs have done tremendous amounts of research in this topic and successfully make 96-104 octane fuel.

The principal additives they use are Toulene and or Xylene which we are able to purchase at Home Repair or Home Paint stores here in the US for about $8.00 per gallon.

I personally use 1 gallon of Toulene, 1 gallon of Xylene, and 6 ounces of Marvel Mystery Oil per 8 gallons of premium 93 octane gasoline in my Buick. I have also tried it in the Corvette on many occassions. However, many people have warned me that continuous use of additives will eventually loosen the bladder of the Corvette Gas Tank (the Buick's tank does not have a liner) and then I will have to replace it. The Callaway runs great with the boosted fuel.

For more info go to http://www.gnttype.org/techarea/fuelsystem/fuelpage.html and scroll to information. They even have a spreadsheet to calculate the new boosted octane rating.

Good luck,

Luigi
 
9

90Callaway

Guest
What Luigi said...

Malc - That is very good information. The octane boosters in the bottles like 104+ are basically junk. The benefits are negligable at best. I only mix race gas because I can't find unleaded higher than 94 octane around me. I'm probably only raising my octane number to around 98-100 overall. I'm too nervous about Toulene/Xylene cocktail to try it.

If your gas is 97 octane (and rated the same as ours) you should be fine. In answer to the question of is the benefit over 95 octane worth it, that depends. If you reduce knock counts and the computer does not have to pull timing, then yes. You will probably never hear engine knock in your car unless it is severe. That does not mean you are not experiencing knock because the computer may be retarding the timing. I have dyno graphs where I was starting to get knock and you can see where the computer pulls timing because it looks like someone turned off a power switch. We're talking 75hp and 100lb/ft at the wheels going away in the blink of eye. At no time did I ever hear any audible knock.

If you are not experiencing knock on 95 octane now you will see no difference. The only way you would know for sure is to hook up a laptop computer with data logger software to the data port under the dash.
 

malc350

Well-known member
Joined
Jul 6, 2002
Messages
337
Location
Essex, UK
Corvette
1996 LT-4 Z51 CE
Octane Boost

Thanks for the advice about 104+ & similar products. I had heard mixed reports about these but I thought they might be of benefit to a TT. Maybe not!

I'll try running on 97 for a while and see if I notice any difference. If not I'll go back to 95. I keep telling myself I'd better get a laptop and Diacom software. Then I'll be able to see what the car's really doing.

As for mixing my own gas I'm impressed by what you guys are doing! Not sure if I can get that mix over here.

Regards, Malc.
 
S

SurfnSun

Guest
From what Ive read the NOS product is the only one thats really any good, but again, it doesn't raise the level high enough to make a good cost/benefit ratio.
 
S

Stan A

Guest
Been said before!

Using straight line octane additives in C4 will creat a problem with the tank bladder in time. Experiencing this myself and the cost to replace a tank is not worth the gain.

Using higher octane gas is safer and less costly in the long run.

Stan
 

malc350

Well-known member
Joined
Jul 6, 2002
Messages
337
Location
Essex, UK
Corvette
1996 LT-4 Z51 CE
Octane

Sounds like the opinion is almost universal - I'll use the best fuel available. Thanks folks. Malc.

www.mm-2000.co.uk/corvette/
 

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