Octane Boost

[Machl]

I've heard about Octane boost, and I was wondering if anyone could give me insight as to how substantial the difference is..I mean how much of a boost does it provide in terms of octane, actually to think about it what is Octane exactly..and does octane booster have the same effect on 93 octane as it would with 100..in terms of the increase..like if the increase is 3 octane..then would 100 go to 103, and 93 go to 96..and can you feel the difference..
Cheers:beer:

 

[f4sfed]

Originally posted by Machl
I've heard about Octane boost, and I was wondering if anyone could give me insight as to how substantial the difference is..I mean how much of a boost does it provide in terms of octane, actually to think about it what is Octane exactly..and does octane booster have the same effect on 93 octane as it would with 100..in terms of the increase..like if the increase is 3 octane..then would 100 go to 103, and 93 go to 96..and can you feel the difference..
Cheers:beer:

If you can't change the timing, I don't THINK it'll make a difference. The only other reason to add it, would be cleaners and other additives, but do you really need that yet? Especially if you run a good grade of super all the time anyway.

Just my $0.02

 

[Friendchicken]

From my understanding, the cars A/F and timing is tuned for 91-92 octaine. Going to 87 or 100 octaine might drop your engines efficiency unless you got a chip tune to compensate.

 

[Machl]

Just a question, why would having a greater octane than 91-92 decrease the performance of your car, if that's what the car is rated at..I mean would that be an example of when people say a car is running too rich for say 100 octane, compared to running too lean with an 87 octane. I thought that delt more with the amount of A/F not the octane of the fuel itself..And what kind of tuning changes do you have to make when you're going with a greater octane then the prescribed level..
Thanks..

 

[f4sfed]

Originally posted by Machl
Just a question, why would having a greater octane than 91-92 decrease the performance of your car, if that's what the car is rated at..I mean would that be an example of when people say a car is running too rich for say 100 octane, compared to running too lean with an 87 octane. I thought that delt more with the amount of A/F not the octane of the fuel itself..And what kind of tuning changes do you have to make when you're going with a greater octane then the prescribed level..
Thanks..

I don't think a car can be running too rich or lean for any octane. All octane does is raise the flash point of the fuel, making it harder to ignite. Which allows you to advance the timing, etc.

I don't think you HAVE to make any tuning changes with higher octane, but the whole point of higher octane is TO make changes. Running higher octane alone (no tuning) will prolly not make a difference.

 

[Cobra'03]

I agree that boost will not help unless car is modded to the point where ping is an issue. Some octane boosters (cheapies) contain materials which can actually be harmful. Also, too much octane can cause some of the fuel to be unburned in the cylinder, which could drop power, and possibly damage exhaust valves/catalytic converters.

Plus, racing fuel for example does not contain the detergent ingredients street engines need to control intake valve, cylinder head, and piston dome deposits.

I snicker when I see posts that putting a few gallons of avgas or racing fuel leads to huge ET improvements - I think it is just the effect that expectation can have on reality - the driver is just more attentive and possibly drives/shifts better, attributing the big improvement to the fuel.

Same thing as those miracle improvements in MPG with the Snake Oil additives - it has been shown that drivers feather the throttle more, leading to MPG improvements, which they of course attribute to the oil additive - it is a human psych phenomenon exploited by the hucksters (just like exploiting get rich quick schemes for the greedy).

 

[cobra racing]

Originally posted by f4sfed
I don't think a car can be running too rich or lean for any octane. All octane does is raise the flash point of the fuel, making it harder to ignite. Which allows you to advance the timing, etc.

I thought these cars have a knock sensor that retards the timing and if octane boost is added then this will allow more timing, as long as the adaptive stratagies in the computer have been reset.

 

[Cobra'03]

I believe you are wrong on both counts. There is no knock sensor, and the spark/timing maps are reactive, not proactive: they will cut timing under ecrtain conditions, but I am not aware that they will advance it. I believe only a chip tune will do that, since it will actually change the spark lookup tables.

 

[Machl]

You guys are talking about advancing or regressing the timing..how on earth can the computer detect the octane level of the fuel you're adding..I could understand a sensor for decreasing timing to prevent engine damage, but I can't quite figure out how it could advance the timing..isn't that what a chip does?
Thanks for the input guys..:beer:

 

[a94cobra]

The SuperStallion that Ford built was supposed to switch timing when it detected the different fuels.

 

[Mojo03]

I'd say that CAM2, say one gallon to 13 gallons at 92/93, will give you a minor improvement, but if you have no knock, which is all octane measures, you'll be better served just keeping it tuned well. Mods may increase your ned for octane, but again, that depends on if it's knocking.

Drop $5 on a can of 104 octane and you'll feel the car running a little smoother, etc, but it's not THAT appreciable.