sharp76

Hi all, just a wee question, i have a 98 jap sti with full de-cat,panel filter, the car's picking up det at 6k plus and was wandering if its worth a walbro fuel pump and regulator, ive been told that the standard fuel pump wont cope with the de-cat up the revs, thing is will my ecu let any more fuel in or will it be a waste of time on a standard ecu?

Cheers
Graeme

CDR

A fuel pump upgrade is always a nice reliability mod but I wouldn't say essential. I am currently running a std pump with 1.4 bar boost with full decat exhaust, headers, intake mods etc, and aftermarket ECU. on a V6 STI RA and have dynoed it with no fuelling issues. Although that said, it is on my list of mods to do next along with a surge tank for track work.

At your level of mods, I wouldn't say it was essential. I cant see it fixing your det problems and it is unlikely the std ECU will let any more fuel in. Although I have seen cases where guys have fitted bigger pumps and have had to retune their aftermarket ECU's as the car had started running richer.

A reflash of the std ECU would be a more appropriate fix I would have thought. The higher rpm det would be more due to the lower octane UK fuel and the aggressive map of the jap spec car yeah??

sharp76

Yea mate it would, im running optimax plus booster and still det, what confuses me is that the car is mapped for 100 ron so optimax plus booster is 100 ron so why the problems of det??

keevster

iTrader: (1)

join the club mate. i've got a MY04 just fitted with full decat. i am running lean, with probable det. enquired about the fuel pump and regulator road, and have been told its a waist of time as the ECU will still not give enough fuel. so its a remap for me.

Paul

RLE

iTrader: (2)

uprated fuel pump managed to eliminate the majority of the activity on my UK97 after a few mods.

jonny gav

iTrader: (1)

first of all yes, an upgrade is a very good idea, also a fse 1:1 pressure reg when doing any mods at all if you value your engine!

second of all, what type of octane booster are you running?
the reason i ask is most don't work!
if its NF then its a good proven product with proven results.

how much boost is the car running?

after a de-cat the STI's seem to boost spike and the boost tends to creep up in the higher revs causing det.

fitting a boost guage to see if this is happening is a good idea, also a manual boost controller like a GBE valve or a dawes will return the boost to a more sensible pressure and prevent the spiking.

hope this helps.

sharp76

Im running millers octane booster but i dont really see any difference in the knock link with it!it has a boost guage and its boosting 1.2 1.3 , never hits boost cut, getting a mixed response on this thread, after i bought the downpipe i was told id get spikes.

jonny gav

iTrader: (1)

i have seen a lot of STI's with big spikes but 1.2/1.3 sound ok.

get hold of some NF and give that a try, its well worth it.

millers only raises the octane by 2 octane points, there are 10 octane points in 1 ron.

sharp76

maybe an obvious question but what is nf??
Im taking the car round to a guy tommorow ( bhp developments) so will see what he comes up with.

cheers for the advice mate

Delboy2

NF is Nitrous Formula Octane Booster shown HERE

Cheers