i've read lots of previous threads on this and am now more confused than ever...

Thinking of buying a 97 Sti Type R. The current owner was the 1st to have it in the uk and has done about 20k miles using only optimax. I understand this is 98 ron compared to the Japanese 100 ron.

Therefore if i continue to use optimax should i expect any problems? Will this be OK?

Should i use an octane booster in addition? If so which should I use?

What about getting it remapped to run on normal uk fuel? Is this a good idea and if so how much money would i be looking at.

Lots of questions I know, so any advice would be gratefully received.

cheers

 

I've been wondering the same thing mate as I have an STI Type-R V5 which I will be taking home to the UK soon. Apparently from what I've been told my members on here that if you continue to just run on Optimax (98RON) you will get Det and eventually a f*cked engine. You can run it on Optimax and Octane Boosters to increase the RON but this adds £3 onto everytime you fill her up. It seems to be cheaper in the long run, and safer to get it re-mapped. It is advisable to get a knocklink fitted to, so you can monitor the Det.

 

Its not JUST fuel (or lack of proper fuel) that can knacker an engine...
Their are other factors also such as: Oil Starvation, Not allowing the car to warm up/cool down properly, Hammering it i.e. redLining it, High Revs/Motorway Speeds for a long distance..etc etc...

Just some of the reasons i have read here on Soobynet... End of the day just keep a couple of grand saved incase you have to get a rebuild done.

Raf.

 

cheers guys,

having done 20k then on just optimax, is this car best avioded? Don't want to but something that i'm shortly gonna have to spend a couple of grand on!

 

I'm running a '98 V4 Type R on Optimax and it's fine. Get the car checked at a rolling road and see if it's detonating. If it is get it remapped, mine runs quite rich so I don't use any octane booster.
As long as the car runs fine then I see no need for any octane booster - but it's your car and your choice.

 

Does anyone re-map a 97?

I've been searching but can only find places that re-map 99's onwards.

 

you answered the question yourself - it HAS done 20k on just Optimax and obviously has not suffered a major failure.

 

It depends how its driven doesnt it; pootling to the shops itll be fine; but you could kill it within 20 miles if you really thrap it: high load, high revs, high speed, huge inlet temperatures..... BANG !

 

sorry to sound dumb but where do i get octane booster also what is it (an additive to your fuel or a thing you put in fuel line), its just i have recently bought an import wrx and am worried as i do drive it pretty hard, i always run on 98 *confused

 

WRX version does not seem to have half the problems of the Sti`s, I ran a WRX 96 for 3.5 years and fuelled it with 3 tanks of 95 ul to 1 tank of Optimax - not a glitch never, but this was my choice and Im not proclaiming gospel.

 

I personally wouldnt run a JDM STi on anything but optimax/octane booster, especially the classics.
If the car hasnt had a knocklink or the likes fitted then the owner wouldnt necessarily know if the car had been suffering det, as you dont actually hear it all the time.
The biggest cause of failures due to running incorrect fuel are:-

Pistons getting holed
Big end failure caused due to stress

IMHO, if the car hasnt been run on 100+ ron fuel or mapped for uk fuel i wouldnt touch it.

Tony(MY03 JDM STi owner)

 

xvw, i would also fit a knocklink, check out here>> (they also do octane booster )

www.jap-innovations.co.uk

Tony

 

has anyone seen them "fuel cats" 95 - 99 ron? theyre in jap performance ysually an add in the back. supposed to change 95 fuel to 99!!!!

 

You can get Broquets (think thats how its spelt) which last for 100k, this increases the octane in your fuel.

Tony

 

How do these work Tony?

 

hi team,

imho, the only way is get a ecu mapped for uk fuel.......i use a gems, a bit lump when cold, but well mapped by steve simpson and safe as houses!!!!

cheers robin.

 

Get it remapped for UK fuel. Less hassle, safer etc... Moreover, a proper solution to the problem rather than a temporary "fudge" Knocklink is also a very good idea: better safe than sorry.

Let's also not get too paranoid about det etc... after a remap, providing you look after the car properly and drive with mechanical sympathy: warm up and cool down etc... you shouldn't have any problems: these are tough engines designed to be used with a bit of vim! They just need treating with a bit of care and respect is all!

At the end of the day, if you're going to drive the thing like a Micra for fear of hurting it, you may as well have the Micra and save yourself a small fortune on bills etc... :-)

Enjoy it, just be enthusiastic rather than abusive to the car!! There is a big difference.

Best.

 

cheers people , but what actually is an 'octane booster' and how easily are they to fit

 

Chris,
The Broquets slowly release into the fuel, i believe they are fitted into the P1's due to the STi mapping (its a JDM map) to bring the car down so it can use 97 ron fuel.

Tony

 

cheers but i heard you cant remap a 93 wrx?

 

Technically you can't re-map a MY93 WRX...but you can change the map/chip to allow it to run on UK grade fuel.(the scooby ecu was one of the ways to do it).
Have a chat with Jon aka customscoobyIOM as he is now doing mapped chips for the early cars.

steve

 

holly crap, proper confused now.

ok, mine is a non-turbo impreza 97 2.0 awd (It's a GL) should i be using optimax instead of the regular 95 ron, or is mine considered a non-high-performance motor when it comes to fuel?

you might notice i dont have a scooby doo when it comes the correct fuel to run (bad joke? )

 

You dont have to use anything above 95 ron on your car, optimax would be wasteful really.

Tony

 

you dont have to run optimax and booster its a myth and load of cobblers i know people that run jdms on 95ron for the last 4 yrs not a problem, its a cop out for blowing your engine up!

 

Great, so now all of us can now just stick to safeway fuel!!!

 

Have run my wrx sti V5 type R on Optimax +silkolene Octane booster for the past 34,000 miles ! done one Dyno run no det it also has a label in the fuel tank flap which says 98ron only ! Most engines blow up due to neglect not warming them up first and not running them down after a bit of a thrash have had the car for the past five years and the only thing to let me down is the MAF sensor