Hi guys,

I own a 94/95 WRX wagon which I believe has about 220 bhp as standard, due in part to different ecu mapping.

Last week I had the chance to get a Z4 ecu from a friend who had binned his 95 WRX Salon.

I called scoobyclinic and they told me that the ecu's were interchangeable and that there would be no problems.... So I bought the Z4 from him and fitted it to my car. The difference was instantly noticable, the car drives way better on part throttle, and when you floor it the car pulles much stronger.


BUT....After fitting the Z4 I have since read on this forum that it can cause problems with the TD04 turbo which I believe my car had as standard.

The question is, can/should I keep running the car with the Z4 ecu and if so what possible problems can this cause.

cheers,
Ross

 

I'm suprised it's running OK. I would of expected you to be hitting fule cut sure to the different spool rate of the TD04 compared to the TD05 in a Z4 equipped car.

Do you have any other mods i.e decat and do you have a boost gauge. It would be interesting to see what boost it is hitting/holding.

 

The car has a magnex decat system, but retains the cat in the downpipe from the turbo. It also has a dump valve and I've removed the resonator box, but other than that it is standard.

And the car is not just running OK, its running fantastic.

On the way to work last night I gave it a little blast on some empty roads near my house, the first time I've really driven quickly since the ECU change.

The car pulls very well from low rev's and picks up very quickly with very little lag. Not that the car was laggy before but its noticably more responsive now. The difference at motorway speeds is dramatic, the car is very eager to accelerate pulling much stronger than before. -- This is what makes me concerned, nothing normally comes for free in life and this type of performance gain should not be so easy

I'm not sure if it is my imagination but the boost seems to come on earlier, even shortshifting from second to third, changing about 2700 rpm, gives a ptsssss (thats meant to be the dump valve noise btw ). But I have been driving the car with the stereo off to listen to the engine so I may just be more aware of it.

Anyone else performed this change, with good or bad results?

 

Do you have a knock link????

 

Im afraid not. I know, i'm planning on getting one to keep an eye on the engine but I have not managed to get one yet.

Just wondering though, would the car not be less likely to DET with this combination? I'm assuming that if the turbo is too small to flow enough air I would run rich and be less likely to DET (sorry if I'm being stupid, limited techinical knowledge )

 

it seems my thread has been moved to a different section in the forum.

Anyone here have any advice or suggestions for me?

 

Watching with interest here (I also read it shouldn't be done)

 

All I know is that when I put a TD05 style boost map in a wagon, it over-boosted/fuel-cut like a mad. It took quite a while to tone down the boost control to get it to behave.

This was with a full decat though which would make it spool even quicker.

The duty cycle levels were similar at high revs between TD04 and TD05, it was the mid-range that needed adjusting due to the quicker spool of the TD04 compared to a TD05.

Maybe a standard 12.7psi Z4 map still works within limits.

 

Turbo will spool up sooner as it is smaller.. the map will not be expecting boost at the lower rpm and therefore could be under fueling.. hopefully as it is a standard boost map and this being MAF based it will be compensating by adding more fuel due to the air being sucked in past the MAF etc..

..and as Scott says the catted downpipe will be saving the day also.

I suggest you get a knocklink to confirm though asap..

 

cheers guys, I was planning on getting a knocklink anyway. This just gives me an incentive to get a move on.

 

I would be worried with that set up, better off with a dawes/ebc and standard ecu.

 

If you like it now i think you will like it even more with the td05. I have a td05 and Z4 on my wagon. I dont think i could go back to a td04 again. The power delivery is nicer and it will pull up to the red line nicely. Loads more grunt. I think is wise to get a td05 if you are going to keep the car some time. The td04 is not really suitable. Expect to pay 175 - 275 for the td05unit an then theres the fitting.
Knock link is defo your next move though whatever your wallet.



Andy