should i go for a 6s ecu?

[subaru-mania]

okay well have been thinking about changing my ecu out in my v3 gf8 , mods done so far are, full 3inch exhaust from turbo back, ( 1 resonator in mid) external wastegate, yellow injectors , tdo4 , bigger sti top mount ,runs 12 psi daily , thinking on putting a 6s ecu in it, from what iv gathered this will raise boost to 18 psi? and has more of an aggressive tune? thoughts?

Cheers

[Kiwi_Fozze]

it will raise the boost, and the likelihood of your engine going pop... i'd get a boost controller and keep it down at about 14 psi...

[subaru-mania]

yeah i wouldn't keep it at 18 as like you said it would most likely end bad for my motor, is the factory tune on a v3 sti alot more agressive than a non sti tho? would it be safe to run on a non sti motor? with lower boost of course

[Kiwi_Fozze]

many have done it, you'll need an orange afm, yellows and the 6s.

a few have swapped in a vf22 for a bit of a kick too, as the tdo4 has a totally different boost curve.

you'll notice now that the td04 runs out of puff above about 4500 rpm, where as a vf 22/23/24 will generally keep a good amount of boost through till redline.

oh, be careful you don't over rev. the sti ecu has a higher rev limit, and being a shim over bucket head, you may spit a shim (not good)

[subaru-mania]

yeah the tdo4 defiantly runs out of puff after about 4k or so , have quite a bad miss at the moment when i get over 4.5k on boost in 4th/5th , last guy before me did not do much servicing , doing an oil change & plugs this weekend so will see if it makes a difference for the miss. otherwise im guessing the coil/leads could be breaking up under load,

[Kiwi_Fozze]

make sure you gap the plugs properly, 0.6mm from memory.

[Guest]

put iridiums or platinums in you don't need to gap them and they last longer 8)

[WRXONP]

0.8mm gap is fine - even an iridium at a 1.1mm gap will blow out the spark

and copper is a better conductor than iridium

bit of wack info on this thread here

first off are u runing yellow injectors and a green maf on a non sti ecu? or yellows and a orange on a 1s???

so many people (who havent even had experience with a 6s) are like a broken record saying stuff

I for the record have run a high compression wrx motor on a 6s - yellow injectors and orange maf without problems - had a walbro pump (which is a MUST for anything modified unless you wanna kill it)

and for the kick - it was a daily driver - same motor lasted over 2 years straight - running 20psi boost on a vf23 (previously had vf22)

had it on the dyno - solid 11.0 - 11.5 AFR and no detonation what so ever - this IS a unopened WRX motor with 6s - yellows and orange maf

afterwards even went to a modified 6s (mines 6s) and still had no detonation issues even with the more aggresive timing maps

[subaru-mania]

Im unsure what the deal with the motor thats in my v3 is, it has yellows, but the a/f is not a factoryu green or orange sticker 1 its some after market 1 by the looks il chuck up a pic

Next question is what a/f meter should i be on then? my ecu i s a A8

[WRXONP]

oh i just clicked u have the other thread running

your motor is a ver 5 non sti and the ecu is a ver 5 non sti - it will be running the insert type AFM - it doesnt have a coloured sticker as such as thats only on ver 1-4 (coloured labels)

[subaru-mania]

Haha yer mate

so motor has been swapped at some point then yeah? its also running a factor tdo4 , are they in the v5 non sti also? as the cars only a 96 v3

But yer iv never seen the type of afm it has like you said it has no sticker or nothing.. and its longer

[WRXONP]

all ver 5-6 run that style afm so dont be alarmed

for the car to run properly with a ver 5 motor it would have (and must have) ver 5 motor - ver 5 loom - ver 5 ecu - ver 5 afm and ver 5 injectors

i dont have much experience with the later ver 5-6 stuff but i think some other sensors are different aswell - i know the AICV is different (on the throttle body)

[subaru-mania]

so being a v5 there goes putting in a 6s ecu in out the window right? whats a v5 sti computer J2 ?

[Kiwi_Fozze]

j2 is correct, but, they don't swap around as easily... aparently you run in to detonation issues. i'm slowly getting to the point of swapping my v6 forester with a v6 sti ecu. will get there eventually lol.

[WRXONP]

yea 6s wont work -it would take alot of work for it to work

j2 is the sti ecu to use

theres alot of talk on here about j2s detonating on a wrx motor - but like most myths there are no results

i have honestly been waiting so long for someone to put a wrx motor with a j2 on the dyno to see what happens

[Kiwi_Fozze]

bubblz had audible det when he swapped his....

[subaru-mania]

 kwi_fozze said:

bubblz had audible det when he swapped his....

Just sent yu a Pm dude , interested into how to get around this as im pretty keen on getting a J2

[WRXONP]

1 must realise there is a lot of things that can cause detonation ahh

[subaru-mania]

whats the main reason for det issiues with the j2 in a non sti? higher fuel maps? couldn't i counter this with a external Fpr ?

[WRXONP]

lolol upping the fuel pressure is a very crude way of running a car richer

the main reason is that a sti ecu runs more aggressive timing maps - ie it advances the timing more on boost - advanced timing = more power

a higher compression motor is more prone to detonation therefore u would normally run less timing on a higher compression motor than a lower compression motor

a sti is lower compression than a wrx motor

but on a ver 3 i had run a sti ecu (and so have so many others) and had no detonation issues

ive seen ver 5-6 wrx stis on dyno before with stock fuel pump - they run pretty lean compared to a ver 3

[subaru-mania]

 WRXONP said:

lolol upping the fuel pressure is a very crude way of running a car richer

the main reason is that a sti ecu runs more aggressive timing maps - ie it advances the timing more on boost - advanced timing = more power

a higher compression motor is more prone to detonation therefore u would normally run less timing on a higher compression motor than a lower compression motor

a sti is lower compression than a wrx motor

but on a ver 3 i had run a sti ecu (and so have so many others) and had no detonation issues

ive seen ver 5-6 wrx stis on dyno before with stock fuel pump - they run pretty lean compared to a ver 3

Interesting, i have a walbro intake pump , yellows, tdo4 but changing to a a vf23, straight thru 3" from turbo back, external wastegate etc you think its safe chucking in the j2 with these mods?

Any idea what the boost would be set at on a J2? might pay to get a boost controller right?

[WRXONP]

you run an external gate - it should not be hooked upto the factory solenoid anyway - if it is u should plumb it up properly - the standard solenoid isnt setup to run an external wastegate

i would love to see one run up on the dyno with a knock link and a air fuel probe banged up its bum

[Kiwi_Fozze]

i personally wouldnt take the boost up over about 13-14 psi on a wrx motor with a j2, and you'd want it on a dyno when you do. i would do it but cant afford the dyno time just yet.

[subaru-mania]

 WRXONP said:

you run an external gate - it should not be hooked upto the factory solenoid anyway - if it is u should plumb it up properly - the standard solenoid isnt setup to run an external wastegate

i would love to see one run up on the dyno with a knock link and a air fuel probe banged up its bum

Yeep pretty sure the guy i brought the car off hooked the external into the factory solenoid ? whats the correct way to plumb it up? iv never run a external b4

[WRXONP]

dont have it plumbed to the factory solenoid at all - have the boost source go straight to the lower port of the gate - run either a hard spring or a boost controller to get desired boost