wrxmad

hi, guys ,
good morning need to pick all your brains again
i now know a u8 ecu is a direct swap for a z4 ecu more boost and better fuelling but would a 6k ecu fit in place of the u8 ecu??
i have the 240hp wrx and if i fitted the 6k ecu what gains would i expect
from it ?is there any info on the web that gives u the figures of the ecus?
boost pressure,fuel cut off etc.the 6k ecu is out of a 96 wrx sti v3.
help would be excellent. or should i look for a z4 ecu?which is better?
praise the scooby

myblackwrx

iTrader: (1)

Boost Targets & Fuel-Cut Limits
WRX/STi Saloon ECU's 2C, U8, W6, W9 - As above, 11.47psi held to redline. Fuel-cut 14.57psi
WRX (1995/96) ECU Z4 - 12.71psi, dropping to 11.78psi @ 6600rpm. Fuel-cut 15.65psi.

Z4 is an easier replacement

Andy Stevens

The 6K is off a v2 STi and is the map Prodrive used for the PPP with a raised speed limiter (180mph instead of kph). It is similar to the Z4 with a touch more boost (0.94bar vs 0.87bar) and is the best straight ECU swap for a pre 96 td05 equipped car. You can view the two maps by downloading my demo software at www.enduringsolutions.co.uk/software.

Scott.T

iTrader: (2)

Just compared the 6K (after finally getting hold of a base map, thanks Andy). And can confirm it is the same as a UK PPP map.

I thought the Z4 base was v.close to the PPP, but the 6K from the STi 2 is nigh on an exact match.

that'll shock a few people, knowing that a UK is running an STi 2 map LOL !!!!!!!

Bit strange though how Prodrive rated the PPP at 250BHP and the STi 2 is supposed to be 275BHP. Must be down to mechanics rather then electrickary 1's and 0's.......

Andy Stevens

Not sure how different the heads are, redline is the same though. I suspect with a standard exhaust and airbox in place and running 97SUL 250bhp isnt far off for an STi2.

The difference between Z4 (wrx) and 6K (sti2) is pretty small, so if the internals are different, the engine management doesnt know about it

jayparot

heyi have a 6k ECU and it cut off boost i have a guy with a z4 with a chip on it so boost goes to 1.33 bar and no speed limiter about how much HP would i get ????

drischnie

iTrader: (5)

but whats with an Z4 or 6K ECU in a standard UK-Model? cause the jdms have a compression ratio of 8.5:1 and the UKs 8.0:1

dan83590

Interesting the 6K being a match to the PPP map. Strange how Prodrive were/are willing to push the UK engine so hard.

The mappers here have always said the STI map was a very extreme map to put into a UK or WRX due to the timing. Is this the case with the 6K now that you can see the map for yourselves Scott and Andy?

dj219957

this thread is well old. irony is that the 6k sti ecu doent work very well in the early wrxs sometimes (a few have tried) probably cos of the differet heads.

drischnie

iTrader: (5)

Is the 6K/PPP Map really so hard??? If so only the timing? Cause Boost-Pressure isnt really high.

But why did Prodrive this Map in early UKs? I am driving with the 6K, but till now only 1000 miles, till today it works fine. Or should i change it to a Z4? Is this the better choice? Are the heads from an original Z4-WRX identical to the early UK-ones?

dj219957

the map is fine so long as its run with 97 ron or more fuel.
if yours is working then leave it, it will be fine. Its all about the fuel.

drischnie

iTrader: (5)

@dj219957

Thanks for your answer.
I am driving 98RON. So you think its fine and i can drive with the 6K? No Problems cause i dont have the STi-Heads, Camshafts and Valves? These are 100% different on the UK-Modell to the STi V2 Model.
My Car runs fine till now with the 6K, only down-reving from 3000 and under, there i have missfires in my backbox since the 6K ECU is installed, is it why the outlet camshaft is not the same like the STi-one??

Sorry for my bad english, i am german

batmanwrx

iTrader: (1)

where about in germany are you driscnie im not far from hanover

drischnie

iTrader: (5)

i am living in Hamburg, so not far from hannover

dj219957

i cant tell you if the car will be ok but what i can tell you is that some people in the UK have run them with no problem, others have had boost problems or the engine management light has come on.
its upto you. your risk.
personally i see no problem if the car runs good. you are using 98 ron fuel which is the most important thing.
the popping in the exhaust will be un burnt fuel. mine does this with the u8 ecu sometimes so i would not worry about that.
i cant see any reason why you would damage your engine.