DiddyWRX

Hi guys, new guy here so HELLO!

I've just got my hands on a 93 Classic WRX import, it has the red and black seats, factory rollcage and everything seems very very light on it.

It has a full decat S/S exhaust system (unknown brand), forge d/v, mushroom style air filter and boost gauge that I fitted.

Right now you're up to speed with my specs I have a few queries and if they could be answered, fantastic!

1. Sometimes when on full boost the car is hesitating ever so slightly, it only ever does this on the odd occasion but lately has been doing it on and off more frequently and I haven't got a clue what's causing it, any ideas? The car boosts to 11 psi on full chat with a tiny spike to 12 when you initially boot it which I assume is ok?

2. What BHP should I be running when the car is at full power, I beleive stock it's 240?

3. What turbo would I be running, a TD04 or TD05? Either so can the boost be turned up at all from stock setting once hesitation issues sorted or is there a better way to go about it, ie. change ecu, injectors etc?

That's pretty much all I can think of for now but look forward to some answers on these especially no.1!

Thank you once again ladies and gents!

myblackwrx

iTrader: (1)

1:Check spark plugs and coil packs to start with

2:236bhp (240PS)

3:TD05 (but mine has a VF12) have a look at the turbo housing for ident marks.
There a lot of ways of giving you more power in no particular order
1:Z4 ecu from later WRX
2:Remappable ecu (Motec,Hydra,Apexi Power Fc only avaliable from authorised apexi dealers etc)
3:ESL/Scoobyecu which gets soldered into the spare socket on youe ecu (www.enduringsolutions.com and www.polarperfromance.co.uk)

DiddyWRX

Would the plugs cause an intermittent fault and also if plugged into a diagnostic machine would it flag up the fault or not neccesarily?

Where can I get a Z4 ecu and what does it do (up boost and fuel etc) and where can I find marks on the turbo housing?

timmyajmy93wrx

iTrader: (27)

The fault sounds like the coil packs, as they are getting older they become more & more useless, hence the 'hesitation' when more & more power is required/more current is put through & if they are on their last legs they are unable to keep up.

I would also get some new plugs just to be sure, plugs is always the first & cheapest way to see about this problem.

As for the Z4, i had this in my old 93 wrx, someone on japan before i owned had already put this in, basically its a slightly better map for the early impreza & instead of being 240ps it is 260ps. Also if you get the scoobyecu (great bit of kit) on the z4 the power gains are fantastic. Worth every penny (along with induction kit & full decat system) they car pulls so much better & is far more responsive. well mine was

tim

myblackwrx

iTrader: (1)

if you put a scoobyecu chip in a z4 it makes no difference than sticking it in an early ecu as the chip bypasses the standard map (snipping the J1 resistor)


This is where the id for my mates td05 was.
Looking at the front of the turbo at the bottom of the housing cos you have an induction kit it's easier to find (but still abugger to see it though)

DiddyWRX

Oh right cool so what year was the Z4 ecu in and is it a straight swap?

Ill take a look for the turbo later on and have a look at changing plugs/coilpacks but surely not EVERY coilpack would break down?

timmyajmy93wrx

iTrader: (27)

argh! did not know that! well i thort it worked better as the z4 is a better ecu to start with & more power then the scoobyecu made it better on top of that? or did it used to? i got mine done by scott.t about 31/2 or 4 years ago. From memory i just know that i was lucky having the z4 already there as it had a better map in it & that the ecu would just improve it even more & allow me to run optimax. Did not know that the ordinery ecu with 240ps would get the same advantages from the chip as it was not as well mapped & had 20ps less?!?

tim

jaytc2003

iTrader: (1)

shouldnt have a rollcage as standard. those crazy japs!!

But like mentioned, coil packs and plugs would be the first things to check, when checking the coil packs, there is like a cap on the end, be careful when removing this, as underneath it can be very brittle and this is what can cause hesitation due to cracks appearing and even whole pieces missing!!

Also worthwhile, is choose a fuel type and stick to it, when you have filled up, (and changed plugs/checked coilpacks) do an ecu reset and that will give max power

timmyajmy93wrx

iTrader: (27)

yeh the z4 is a straight swap think they are from 95 ish models sure someone will know which ones for sure.

jaytc2003

iTrader: (1)

think the Z4 is from a 95

myblackwrx

iTrader: (1)

post september 94 wrx was when the 260ps wrx came out.
Timmy the reason is that the scoobyecu has the map on it so by snipping the J1 resistor the scoobyecu ran the car.

timmyajmy93wrx

iTrader: (27)

right so if i get any sort of wrx sti/ra on a 95 96 plate, regardless of power i.e 260 or 280ps, the scoobyecu will replace that ecu that is in the car & run whatever i get the scoobyecu to be running at? is it 15.5 or 16.5 psi, raised fuel cut & they get it to run on 98ron fuel?

tim

myblackwrx

iTrader: (1)

Basically yes the map on whatever chip is put onto the pcb in the spare slot will run the car (www.enduringsolutions.com shows what the basic chip would do).
Now with the coming of PolarPerformance the new chips are basically remappble.

DiddyWRX

And back to my topic lol, Will the z4 chip increase boost, does it change the overall mapping? I would assume so with 20bhp increase!

DiddyWRX

https://www.scoobynet.com/private-sa...t-93-97-a.html

Is this the chip that will fit and increase power etc? If so ill be having it lol!

Scott.T

iTrader: (2)

Wouldn't advise fitting it unless you know what's in it.
If it came from an early STI, it's a No....No....

myblackwrx

iTrader: (1)

sorry for the thread hijack
Z4 isn't a chip it's an ecu you just take out your old one and it's a direct replacement.
The Z4 has a better fuel map (prodrive used the base map for their ecus except with higher boost).
If you do buy 1 i wouldn't pay more than about £75 (that's what i paid for mine off here but the chips you can buy (although more expensive) may be better for you.

DiddyWRX

I've just had a long chat with Matt (guy selling the chip) and he informs me the chip would be perfect for getting the car to 280bhp at around 1.1 bar and it will run that safely with the map and then I can stage2 that chip to get me to around 330bhp with a front mount and 440cc injectors!

Scott.T

iTrader: (2)

Sorry, I thought the link was to a Chip from and STi not a Z4 ECU that for some reason came out of an STi.
If it's a Z4 ECU it will be fine and give you 12.7psi of boost (260ps) rather then 11.47psi (240ps)

DiddyWRX

After having a long chat with Matt who rebuilds them I know this chip will put the car up to 270+ bhp with supporting boost so bring on the chip!

Scott.T

iTrader: (2)

Z4 isn't a chip, It's an ECU to replace your U8, W6 or 2C ECU

DiddyWRX

Sorry yes that's what I meant but the map on the Z4 chip is better!

DiddyWRX

Right well I found the problem after speaking with Matt about my weird hesitating issue (at least I hope this is the problem solved)

This is what a coilpack should not look like...



and what a spark plug should NOT look like....



So new plugs and new coilpack on the way as well as my Z4 chip, we should be cooking come Thursday afternoon, fingers crossed!