Asked this before and got a mixed bag of responces, lets try again.

Is there any point or benefit from putting an octain booster in a uk-sti-8 or a sti mark 3 whatever you want to call them ?

cheers

Chris

 

Where is the tec-gods now???

 

If your car ECU is mapped for 100RON ie Un-modified WRX STI jap import then yes as optimax + octane will take your up to mapped octane level.

Anything less does not require octane booster...as mapped for UK fuel...

 

You may get a bit of divergence of opinion on this, but IMO there's no point running booster on top of Optimax or SUL on a standard UK car as the ECU won't advance the timing to take advantage of it.

If you've modified the car to the extent that it dets/knock corrects on Opti/SUL alone, that's a different matter though...

 

Basically, run it on normal SUL, and keep an eye/ear out for det (preferably an eye out unless you like driving everywhere with det cans on ). If you get det frequently, your car might like some booster. If you get it infrequently & only when driving hard then it's probably not worth it. However, always keep a bottle of booster in the boot just in case of a bad fuel tank - the car should adjust to it very quickly, but you can't be too careful

 

Chris

You have No need mate.

Uk car is fine on optimax.

Booster is not used as a performance enhancer

It is used by owners of JDM cars.(Self included )

To bring up octane levels of UK fuel .

Too allow them to obtain the levels of performance.Their cars were originaly Mapped for in Japan

You could use it. but Money down drain IMHO.

 

...unless you have a dodgy batch of fuel.

It's a good idea to have booster in the boot, just in case, but do keep an eye on knock - every car is different! But if all is ok, yup it's a waste of money, although you might want to try a single bottle, just to see if you like it

 

I have to say that if your car is modded even slightly then use an Octane booster.

My car is quite heavily modified and runs an Apexi power FC, i ran it using Methanol as a booster for about 6 weeks and only showed signs of knock on a couple of occasions. Ran out of Methanol and NF was rare so had to run the car for 2 weeks on Optimax alone and the car was knocking it's ***** off whenever I gave it any stick high in any of the last 3 gears. Also this was from Optimax from 3 different Shell stations.
Got some NF eventually and put in 50ml per fill up and the car hasn't knocked once This is over 3 fill ups, so my advice would be use NF as it is relatively cheap compared to a new engine and also gives peace of mind, also get a proper knocklink fitted so you know your car is knocking so you can prevent damage to the engine.

 

I think that comes down to the same thing - monitor knock, and if there is any, adjust the octane to suit.
My car's modified, but I've set it up to run on SUL; Optimax sometimes lets it run a little quieter (we're talking one green light on the knocklink rather than the odd flicker of number two here...), usually very similar though; sometimes I fill up with SUL/Optimax & the knocklink is noticeably brighter than usual so I chuck in some booster, which calms it down... I'd say that's one in fifteen tanks, and is probably the only occurence that most UK cars should need the stuff for, although every car is different even before you get to modding!