Thread: upgrading turbo-need help

hey guys im upgrading from my t25 to a gt28rs and i have a few questions due to the fact im upgrading alot of stuff. im going with subie 520cc injectors, z32 maf, 4bar, and jwt ecu to match all that stuff. i went on to solder the injector clips and maf yesturday when i ran into a problem. i think i possibly did the injector clips on backwards on the harness, will this be a problem? also is there a write-up or anything to help me to make sure i wired up the maf correctly? the maf has 4 wires and the b13 harness only has 3. what should my fuel pressure be at 4bar? and lastly what are the capabilities of the gt28rs, what daily psi should i run it at and what could be the highest i should run it at? thanks alot for the help guys.

i also have a full 3in mandrel bend exhaust and am planning on replacing it with a greddy sp style muffler but it is 2.5in. will this create a backpressure issue?

Your first problem is that you're soldering wires in the engine bay. This is a no go. Crimps are preferred.

Yes. They are in essence a DC solenoid. If you wire them backwards the solenoid moves the opposite direction. I don't think the injectors will work at all this way, but I've been wrong before.

I can't help you there.

It should be around 4 bar at idle. Unit Conversions and Calculations from MegaConverter megaCalculator megaKidstuff

325 WHP max is a good bet.

Whatever you feel like. 10-15 psi would be great.

If I remember it's compressor map well enough, I'm pretty sure it gives up quickly past 20 psi.

English please. What are you replacing? Your 3" exhaust? With what are you replacing it with?

you need to redo the injector harness. Do not solder use butt connectors due to vibration. You can find the proper wiring diagram for a z32 maf on jwt website. I would not switch my exhaust for anything smaller than a 3". The gt28rs can make 350-370whp with cams and 300-325whp with out cams. 15-18psi is the place you want to be for max power.

injectors do not matter what terminal you put the positive wire to, they will work either way, When i did my suby 520's i didnt even bother wiring in the new clips, i removed the pins from the stock connector clips and pined them into the subaru clips, The wire pins are the same size for those connectors and our connectors. This saves any fustration of having to do crimping of wires and crap like that.

But yeah dont solder wires in the bay, use the nicer crimp connectors that have a heat shrink coating on them already. Crimp them good and heat them up to make a long lasting connection.

Again repinning the injector clips are way easier to do than doing cutting and splicing of wires. Sorry i would have told you this before

Genius. So obvious now that you say it...

yeah and when you do this make sure you unplug the battery or you will send sparks flying if you touch the constant positive to a ground when doing the pins. So yeah make sure you definetly unplug the battery.

ya i should of thought about unpinning them..

is it 4bar-58psi at idle with vac source disconnected?

thanks alot guys

English please. What are you replacing? Your 3" exhaust? With what are you replacing it with?[/QUOTE]

I am replacing my 3inch muffler to a 2.5in muffler. the exhaust is 3in mandrel bend

It won't hurt things too much to do just a 2.5" muffler. May I ask why though?

i like the way the greddy sp looks and sounds and cant find one in 3in