scoobydoo123

Hi im new to this forum and i understand you all have more knowledge about scoobys then me... i have a 1993 wrx it has a w6 ecu 260ps, tdo5 turbo with a straight through exhaust and decat. and apexi air induction kit. when i drive the car it in lower revs its fine and when the boost kicks in it shows 1.3 on the boost gauge i dont know if this is healthy?...

also when i get into later revs it starts to cut out like the boost comes in spurts and it starts juddering what is this? it drives fine in the lower revs but when it gets around 5500rpm onwards it starts doing this.

also i would like to know if a 7k or 6k ecu would fit straight into my car? would i have to do any mods such as front mount, bigger injectors etc?

i would appreciate some help as im new to all this your feedback would be much appreciated.

thank you

J20BUT

not sure i'm best person to answer your question but i'll have a go.

1.3 is fine, think i'm running about 1.5

does it hold the boost after 5500rpm?

think it could be your MAF (mass air flow)?

or possibly turbo actuator ?

i'm sure someone will correct me if im wrong! however ring john at TSL

TSL MOTORSPORT | Subaru Mitsubishi | performance tuning | parts | repair | servicing | UK

he'll definately know. where abouts do you live?

Glowplug

iTrader: (8)

Hi,
This is 'overboost' caused mainly by the de-cat exhaust. The standard MAP sensor has a limit of c.1.09 bar, anything past this causes the ECU to cut the fuel and boost to prevent any damage to the engine.

Two or three ways to get around the problem, in order of expence;

1. Aftermarket ECU and remap (the most expensive but the surest way)

2. Polar Performance chip (do a search on here for vastly varying opinions)

3. Dawes Device, manual boost controller (cheap and safe)

Re the 6k/7k ecu, this will not solve the probem.

On a side note i would get the boost gauge checked as 1.3bar (18psi) should not be seen really on more or less standard cars.

scoobydoo123

thanks for the replies guys. no it does not hold boost after 5500rpm it starts to cut out and judder after that. my mechanic did say it may be the actuator what would be the best actuator to go for?

i rang tsl they tell me john has moved to australia however the guy did say the 2 main causes are spark plugs and coil pack. i live in slough near london is there any good subaru specialists around here?

will the polar perfomance chip solve this problem? also will it go straight into my w6 ecu? as i have heard that z4 ecu's r alot better if i get the performance chip will it solve my problem?

thanks

Glowplug

iTrader: (8)

If you take it past 5500rpm using less than 1 bar boost, say 0.5 bar max does it still cut??

Which ever ecu you choose to install the PP chip in(z4 w6 k6/7 ect ect) is irrelivent as once the J1 resistor is cut the ecu will run the map on the chip anyway.

The PP chip will not solve your problem if like you say you are hitting 1.3bar, the cut will just come in at a raised c.1.2bar.

I run a PP chip, full de-cat KnN panel and a Dawes and if my boost gauge sees 18psi (1.241054 bar) then i hit cut, however it will hit and hold 17psi (1.172107 bar) all day.

J20BUT

Think you should listen to "b13 bat" sounds like he knows what he's talking about. however i have used TSL myself and would highly recommend them, maybe change the plugs and coil pack anyway as this would be relativley cheap and would rule that out.

I live in lincolnshire so can't recommend anywhere near you but i'm sure someone can??

If you can get hold of Andy Forrest (sure everyone will agree he is one of the best) he will have the answers, however he's in Scotland!

AndyForrestPerformance

Hope you sort it.

J20BUT

Just looked on "Andy Forrest's" web side and below is what he recommends as an upgrade-

Level 1 290-300bhp

Full Decat or Sportscat exhaust from turbo back 2.5 or 3” bore
Walbro 255 l/hr uprated fuel pump
Apexi Induction system with resonator delete
ESL custom live mapping of original ECU
Fuel Lab turbo specification fuel pressure regulator with fitting kit & gauge
NGK PFR 7B uprated spark plugs
Uprated dump valve such as Sard or Forge motorsport

decat exhaust but no mention of a aftermarket ECU? mapping of "original ECU"?

and thats a quote for your model " 92-96 UK/WRX/STI/RA"

sorry maybe helped, maybe confused!!

Glowplug

iTrader: (8)

The z4 and other early ecu's cannot be remapped, hence the PP chip, you would need at least a ESL daughter board:

Products

www.jollygreenmonster.co.uk

Coil packs and plugs can checked before renewing, plugs NGK 7's £30-£40 a set, not a big hit and well worth it at any time. Coil packs will come in at c.£250 from JGM, slightly more of a hit but if needed are a must. Hence my questioning about getting upto/past 5500rpm by keeping the boost down.