My turbo shit itself, the stock t28. japwestmods was local so went and got a hks gt ss turbo to get the car back on the road. put the stock actuator on and it keeps hitting 1.2 bar and fuel cut. borrowed a hks adjustable that's supposed t come with it and same problem, even with it adjust all the way out to keep the boost down. any ideas? I cant work it out, its plumbed from the intake pipe to actuator, holds half a bar to about 3k then just roars upto 1.2 ish
Maybe something is preventing the free movement of the wastegate then, you said you've tried a couple of different actuators already?
you will overboost with a turbo-back 3" system unless you port the wastegate out. Turbo off, and open out the wastegate with a drill/carbide burr as far as you feel safe on the gate seat area Or get it mapped properly at 1.2bar. That turbo should hold 1.4bar nicely IIRC if you're looking for more power? Assuming your fuel pump and injectors have enough breathing room, anyways.
I did read somewhere that the wastegate port could be to small. Strange thing now is I put my stock wastegate back on, and it holds half a bar from 2.5k to 4.5k and then it just hits over a bar and fuel cuts again.
how have you fitted your stock wastegate back to it without changing the rear housings? I thought these turbos were internally gated.
Put a standard elbow back on. I had boost creap when i had a stainless elbow on. Put a cast standard one back on and its fine
I am going to try my other exhaust its only a 2 inch so will create a bit of backprssure which I have read on sxoc that will stop the boost creep, won't fix it but will mask it till I can run the higher boost or go external gate.
Some proper shit advice here, but the people who aren't just blindly guessing are spot on. Basically, the internal wastegate hole on these are too small, same as it is on the GT2871, which is near as damnit a GTSS, so even if you unhooked the actuator totally, never mind fitted the stock one, it would still boost higher than you want it to at the moment without mapping. Only real way is restrict the shit out of it with a wanky exhaust/elbow or similar, or port the wastegate hole, or get it mapped so it can handle the boost it's trying to give.
Thanks bud, that was the conclusion I had come to last night, I'm glad someone has confirmed it, I should say that I didn't have this problem with the shifty 2 inch exhaust I had on before, and I fitted a three inch with this new turbo. I'm going to put my old one ack on and see if it creeps a bit less, and if so I'll either go external gate or just get the supporting mods to go with the higher boost pressures
Yep, it's pretty common on 2871s to go external gate to prevent the boost creep problems, and sounds like you'd maybe be in the same boat.
