rallycross PUG

I have a lovely original un-modified 1993 WRX and its going in for a headgasket change next week.

While its getting this work done what are the obvious things to upgrade to give it a bit more power?

And how much more boost can it run with its standard ECU?

jaytc2003

iTrader: (1)

decat downpipe as you can get away with it for the emmissions test, it will also help spool up the turbo and will generally make the car feel slightly more responsive, you will possibly get overboost situations with this though so fit a manual or electronic boost controller to settle this.

A new panel filter (sti/green), maybe 4 x new coil packs as a car that year they will probably be near breaking point.

Whilst the heads are off you could change the pistons to uprated items, however if its on standard rods then it wouldnt really be worth the effort.

You could also change to a z4 ecu as you may have a U8 in yours, the Z4 will give a different boost level and is generally a better/safer map

Of course everything depends on budget and generally once you start its hard to stop!

myblackwrx

iTrader: (1)

You are entitled to decat the car (pre 95 imports are allowed).
A better exhaust system to go with the decat.
Uprated fuel pump and fuel pressure regulator (if you are going to run more boost or go for a change of ecu specs).

Power wise it's either a replacement ecu such as Sigma,Power Fc etc or try looking at PolarPerformance (loads of people have used these on here and there have been virtually no complaints as far as i know)

slipstream_uk

iTrader: (1)

1. New cam belt
2. Performance air filter
3. De-cat downpipe
4. Performance exhaust
5. STI front 4 pot brakes
6. Polar performance chip
7. Uprated suspension & droplinks & antiroll bars
8. Uprated fuel pump

scoobyhep

Sorry to hi-jack this thread but is this correct about the pre95 allowed to be de-catted?
Only I've got a 3" straight through and am coming up to MOT time

P.S I had all the mods done above to my 94 WRX and it made a huge difference.

slipstream_uk

iTrader: (1)

pre import 95 are allowed de-cated

scoobyhep

Thank you, but how come they came with cats in the first place?

myblackwrx

iTrader: (1)

For Japanese rules as far as i know

Here's the regs for the UK

killerscoob

Mines registerd early 95 but I guess it's to late eh?

myblackwrx

iTrader: (1)

If it's pre July95 then you ,according to the rules, can remove the cat.

debbiesonic

iTrader: (7)

I agree, this always used to be the case. But in my experience, you will have a hard job persuading any mot tester that you do not need a cat emmission test.
It seems as it is all dats logged in the computer when they put you're reg number in, that it is not stated.

myblackwrx

iTrader: (1)

Never had a problem so far as my car, a WRX, isn't on the database (only the new ones obviously) therefore there isn't a match so the MOT tester should go by the allowed test.
Admittedly i take mine to where i bought the car so they know the rules and go by them.

rossyboy

iTrader: (8)

I wouldnt bother with Z4 Ecu. I hardly noticed any difference when I put one in.

FWIW my MY93 was run on its last emmissions test as a 2.5 Impreza newage Happily it passed, though the cat was back in.

WRXtra power

Has anyone had this confirmed by an MOT testing garage? would like to go cat free.

As a reference, I have just looked at my last MOT test certificate and under vehicle model it shows "(NEW) Impreza Model Year Code" does this mean that they could not find a match on their database and therefore used a generic one? I would hardly call a "March 1995 WRX" a "(New) Impreza". If this is true and according to what was mentioned above, does this mean I shouldn't of even had a CAT test at all?

myblackwrx

iTrader: (1)

My last Mot in June was tested as a Non Cat test model was WRX.
If they cannot find an exact match they are supposed to use the procedure i posted in post 8 but as debbiesonic mot testers can be hard to convince.
as i said i get mine tested by the people i bought the car off.

WRXtrapower if your car is registered befor July 95 then,as far as i know, it should be a non cat test.

jaytc2003

iTrader: (1)

a lot of mot stations arent fully sure of the rules, or are too lazy to check up on them. Your best bet is to take your log book which will have the year of first registration (if import model then this is the year its first registered here) it will also have the year of manufacture. My log book tells me it was first registered in 2000 but the vehicle manufacture date was I think Nov 1992 (I know it was 1992), with this information to hand the garages should then run the basic emmissions tests (BET) test.

WRXtra power

I can see a low cost mod with big gains coming

myblackwrx

iTrader: (1)

Wouldn't say big gains but i did find quicker spool up and a throatier exhaust note

scooby-power

mine passed with no cat i have a 93 jap wrx

WRXtra power

and flames?
Should be looking at up to 30hp extra on an unrestricted system. May take a remap to get it but removing the cats would be highly beneficial.

myblackwrx

iTrader: (1)

As you say a remap will get the best out it, i occansionally get a few pop and bangs when changing down a gear.

20withascooby

i got a 94 wrx import full 3 inch decat sounds great spools up at bout 2000-2500 revs a pops flames and bangs all the tym great fun had a years mot on it when i got it so assume it went thru ok without one

20withascooby

i just re read it all and im confused i have a 94 wrx import but think it was bought over in 2004-2005 not sure of top of ma head does this mean no cat for mot ????

myblackwrx

iTrader: (1)

doesn't matter when it was bought over just when the car was first registered and ,yes, a non cat test for your car.

20withascooby

IS THERE A OFFICAL WEBSITE ANYWHERE THAT HAS THAT IN WRITING INCASE THE MOT PLACE ASKS FOR IT LIKE THE DVLA OR SUMTHING LIKE THAT ?????

myblackwrx

iTrader: (1)

DVLA won't ask for it.

as discussed in this thread most MOT testers will have to be convinced i'm lucky as my car is tested from where i bought it.

the written proof is in the garages handbook i asked my garage to see it and thery were happy to show me