Silvia Club of NSW

hey, just wondering what the stock wastegate rating is on a gt28rs, ive heard its 14.7 psi but that seems rather high

thanks guys

not knowing 100%, but i'd take a guess that it'd be around the 8psi mark. cant see them sticking anything above that on a turbo that is designed as a direct easy bolt on. not everyone wants to run 1 bar all day every day...

Mine came with 4.5PSI. I was told when it was installed that it is set low for safety, as it's a direct upgrade for the T25, so it's a larger turbocharger, therefore set lower.

B.

oh k, great info, thanks turbo_brian

the reason i want to know this is my car has no boost controller at all and its running 0.9bar of boost, i dont really understand how this can be so? does the wastegate open at 4.5 psi (or watever it is) and then cant flow enough gas so the rest of it flows through the turbo, causing boost the go higher than the wastegates 4.5.

ive just bought a power fc and im wondering what boost will do without any controller? and wether i should get an avcr to plug in to it or what?


what will my boost most likely get to?

mods:

gt28rs
3inch exhaust
555cc injectors
power fc
z32 metre
new manifold
front mount
gtr pump



thanks

cant really say what your boost will get to, but my mods are:

CA18DET
GT28RS ball bearing turbo
2.75"hi-flow muffler.

The rest is stock, from manifold to ECU and injectors, but if your able to flow more gas, you can get more boost (if the waaste gate stays closed).

usually, once the waste gate opens, you either hold boost, or start to loose boost, mine holds nice boost now at 10PSI with the help of a turbosmart T-boost controller.

The power FC should be able to control most of the engine's combustion, without the need for anything else to try and help, as it's a complete ECU, just needs some Dyno time, and some happy programming hands.

I would suggest getting soem sort of boost controller, but you shouldn't be seeing anything more than 4 - 6PSI from a totally stock gt28rs, unless the wastegate has been adjusted (pop off the gate lever, and twist it either in for more boost, or out for less boost). Always best to let the wastegate have less bost, and use a boost controller to fluctuate the boost required.

B.

joelman, your boost level sounds about normal for the mods you've got for that turbo.. i'd def recommend getting a proper boost controller tho..

the avcr doesn't plug into the power fc, you might be thinking of the optional power FC boost control solenoid - that plugs into the pfc.

This whole actuator topic seems to be going around in circles between this and your previous thread.

And i just thought of something else to confuse everyone. I've noticed that the gt2860rs (discopotato) has an adjustable actuator in all of garretts promotional pictures which would lead me to beleive that yours is the same. Funnily enough this makes a lot of sense as it can be adjusted to suit your application.

So one question. Does your actuator have a threaded shaft? If it does you can adjust it to whatever boost you want and not worry about an ebc.

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meh

yeh im fairly sure it has a threaded shaft, but that doesnt change the presure that it opens does it?, isnt the spring in the actuator the thing that determines that?

nope, there's pre load to consider as well. It's not an ideal solution but it works pretty well.

Basically by shortening the shaft, you can raise the boost (within reason obviously). My old hks actuator held a pretty steady 12psi and 14psi when i adjusted it up. It's a pain in the arse to adjust, and you have to wait for the car to cool down before you can make a second adjustment but once it's set, it's good.

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meh

dave with bad hair is right, generally it should be adjusted so the shaft has about 5mm or so of pre-load

alrite thanks guys

and listen 180sx, where does the avcr plug in? is it a bitch to wire up? i must have been thinking about the plug in solanoid