Finally got round to fitting a Knock Link sensor in my Sti2 and have found that under major boost above around 5-6,000 rpm the top light illuminates for a fraction of a second before I ****** the next gear. Only noticed it in 1st and 2nd so far.

Under 'moderate acceleration' - full throttle 3500-5500 rpm (approx) all the lights stay out - its that last surge that lights everything up.

Does anybody know if the top light should always be out nomatter how savage the acceleration? The car's fully decated with an induction kit.

Thanks in advance for any info

Colin

 

Top light (RED) shouldn't be on..

If it is a spike then sounds like det.

usually you get a slow build up if it is engine noise and not usually higher than first Orange..

On my uk car on standard ecu I was seeing 1 green lit and second green flickering above 4500rpm.. engine noise..

The occasional spike to red in the summer when the TMIC was too small for the job.

Sounds like you might be detting..

JGM

 

What fuel you using?

 

I'm using optimax with 50ml of Nitrous Formula per tank. Being an STi I need to get to 100 RON.

Any ideas on how to stop the det? As I say it's only happening at max revs, max acceleration in 1st and 2nd so far. Sounds like others don't get this problem.

Colin

 

Remap, uprated fuel pump and fuel pressure regulator.

Speak to Mark at Lateral for a fuel pump and pressure reg..
www.lateralperformance.co.uk

Being an STi 2 you need to speak either to David Wallis via www.scoobyecu.co.uk for a new ecu map / chip which would map it to UK fuel rather than Jap 100RON or speak to Pavlo who posts on here about a custom remap.

None of which should break the bank too much.

JGM

 

Thanks JGM

I'll make some calls

Colin

 

how much approx is an uprated fuel pump and regulator?
how necessary is this?
I have sti2 type ra limited with scoobyecu type remap for 97 - do you recommend the same before i even know if its detting?

 

Hi JGM

Do Scoobs run too lean at max power when the've been modded because fuel can't get through in time to match the rapid spool up of the turbo - is that the reason for the uprated pump and regulator?

Colin

 

You both have Jap cars which have an ecu in for 100RON Jap fuel..

So the ignition is then retarded to stop it detting on uk fuel and you have then added an induction kit, requiring more fuel to make up, plus a decat again requiring more fuel.. ecu just cannot keep up.. hence the need for the scoobyecu which is mapped to uk fuel.

I have just fitted a pump and fpr to mine and it made a huge difference to throttle response and this was on a scooby ecu on my uk car and I was not running lean before hand.

You might get away with just the scoobyecu but it would be wise seeing as you know you have a fueling issue to do the pump and reg to make sure.

JGM

 

You've made it JGM, a Sage at last! hehe..

Good advice mate.


Blue Haze - Detting shouldn't occur if the scoobyECU remaps to UK fuel and you don't have many engine mods. The fuel pump and pressure reg will help stop lean running ( = melted bits! ).
But if you are putting more air into the engine ( induction kit, silicone hoses, inlet plenum, better intercooler, bigger turbo etc. ) you can exceed the injectors fuel flow capacity, and then run lean. I don't know what a STi2 RA has for injectors, guess 500's, so using 5.5 cc per HP ( and 4 injectors )the max hp you are making shows how close to the limit you are. ( 500 x 4 / 5.5 = 363 bhp) at 100 % duty cycle of injector ( i.e. open all time ! ) not good - better 85% duty = approx 310 bhp.

If you change the fuel pump to one that can supply more fuel / higher pressure fuel than the OEM pump ( e.g. Walbro at 255 l/hour ) and use an adjustable fuel pressure regulator say the FSE 1:1 fuel regulator, then you can increase the fuel pressure on the injector and make it put more fuel in on each open cycle, and artificially increase the injector flow. Some calcs some where on here on this!
Pump and reg about £100 - £130 each, search a bit for best price ( got mine on the group buy! ).

Neil

 

Silver wings - see above, think I answeredthat one too!