1999 GTB legacy ECU - change to - G4 Link ECU for V5/V6 wrx

[Holsht]

Hi guys.

So i have a 1999 legacy GTB, it has the following mods, V7 sti block, J.E. pistons, con-rods and bearings, v7 sti crankshaft. spilt fuel rails, v8 highflow oil pump. v7 sti turbo. custom aftermarket modified downpipe and 3inch straight through exhaust system.

BUT i am running the stock heads so obviously the stock legacy ECU as well so needs a tune badly.

called up many dyno tune shops all across auckland, no one will touch it unless i buy a g4 link ecu. found one on trademe but i've been told to find out if it will fit my car, this g4 link description is said to fit a V6/V5 WRX or STI and Facelift Forrester. Any thing with a facelift dash and the coil pack for the engine on the LH side.

I have been told that my GTB and the v5/v6 ecu is the same, is this true? If it is this g4 technically should fit correct? What are your thoughts??

heres the link to the ECU: http://www.trademe.co.nz/Browse/Listing.aspx?id=482849507

Cheers guys!

[Drunkenmonkey]

Yes you plugs are the same as v5/6 but there is some wiring modification for the fuel pump that needs doing to bypass the controller

[pl0x]

as per your other thread, yes thats what your after. few simple wiring mods.

If your putting a G4 and waiting to make use of your mods, you will be wanting to install a walbro (or similar) fuel pump and wire in a better fuel pump relay to power it

[funkytown]

 pl0x said:

as per your other thread, yes thats what your after. few simple wiring mods.

If your putting a G4 and waiting to make use of your mods, you will be wanting to install a walbro (or similar) fuel pump and wire in a better fuel pump relay to power it

this man speaks the truth! If you wanted to go that wee bit more a split rail mod would also increase peace of mind.

[Holsht]

Thanks heaps for confirming that guys! Yea so I already got the split fuel rail set up already with the 550cc injectors that come stock, been told this would run it all good but you guys reckon a 500hp pump as well? Prob getting it tuned to about 230-250kw ATW, will a walbro be nesercary for this much power?

[funkytown]

yup i would definitely change it, its just safety and prudence.

the money you're paying to tune and dyno it:

a) you dont want to potential run out of fuel on the dyno (v unlikely but hey).

b) factory pumps gets tired and you dont want that to happen on WOT somewhere and you lean the motor and kill it.

[pl0x]

definitely change pump and wire in a relay in wanting that much power.

factory injectors will get you 220-230atw max

id say vf30 would be pushing to get 240atw

sitting at the top of factory level is quite good though, gearboxes can handle it, fuel eco isn't to bad, forged engine at that power would be very reliable etc

[Holsht]

So ultimately best way to go is 220kw and fit a walbro without getting too much more involved?

[funkytown]

walbro it the thing you should do for safety

either way you are going to be limited to around 220-230kw as your turbo wont flow any more than that.

fwiw.. 550s will outflow a factory vf turbo. mine back in the day did 235easily

[pl0x]

Funky - I think they are factory 440cc (which people rate as 550cc @ 100%dc) injectors, holsht can you confirm this?

Yup id fit the walbro, wire in a relay and send to tuner and say go hard

[funkytown]

sorry had assumed pinks as i saw lots of other v7 bits. which are 550 @ 80% idc??

yellows are as you say. and more likely as is a base gtb bh leggy

i run apexi side feds 550 @ 80% idc

[Holsht]

walbro it is then! ah im not entirely sure, all i was aware was that the GTB model comes stock with 550cc injectors, didn't think other models did. this is just what i've been told

[pl0x]

factory yellow tops are 550cc @ 100% idc & 440cc @ 80% idc