too much boost

[frankthetank091]

my 91' rb20 is waaay over boosting. shoots to over 20psi. i removed my shitty boost controller and it was the same. ive never had to work on turbo yet, im wondering how do i start working on the wastgate on this thing? lol

[Skym]

Sometimes it can be the internal wastegate actuator arm is bent or holes on mount for internal wastegate actuator have been drilled out and internal wastegate actuator moved forward which means wastegate doesn't open enough on back of turbo and boost spikes. Or you have an upgraded adjustable (arm is adjustable length) HKS or Garrett internal wastegate actuator that you don't know about. Or vacuum hose to internal wastegate actuator bulb has a restrictor inside or is not connected to internal wastegate actuator bulb.

[Fiorante]

20psi is nothing, you will be fine

[Voodoo_ChildR32]

20psi is nothing, you will be fine

Considering 14psi is max safe boost for an RB20 turbo. My RB25 turbo blew a bearing at 18psi, due to a bad boost controller.


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[elmosteve]

20psi is nothing, you will be fine

haha have fun picking turbo pieces up off the ground if they make it threw the cylinders

[Goodlucks7even]

Me boosta -.-"

Unplugged vacuum or none fonctionnal wastegate.

[BongRips]

haha have fun picking turbo pieces up off the ground if they make it threw the cylinders

Usually the stock turbos lose the exhaust wheel, not the intake wheel due to being made of ceramic in which case it ends up in your cat, or past it. If the intake wheel breaks, I don't think the pieces would make it through the intercooler, but I could be mistaken. But when my rb20 turbo went, there was tiny pieces on the hot side of my intercooler and some bigger pieces by the cat

[Skym]

On intake side of turbo it creates a whining noise (compressor wheel touching compressor housing and bearings have failed, oil seal breaks) around 0 on boost gauge, then wacking noise when it gets really bad. I think it was due to oiltemp / coking problems which made the bearings fail.

Exhaust side is the same, wheel goes off balance and hits housing, shatters and goes down exhaust. Bits of ceramic can go back into engine if your backing off throttle to change gear when it fails (dragracing) and score the bores.

With higher boost levels the rpm of turbo is higher and combine that with off balance compressor or exhaust wheel due to bearings failing (high oiltemps can create coking which blocks oilways to bearings hence bearings fail due to lack of oil). Lack of oil is the quickest way to damage a turbo. That's why you need to prime a new turbo with oil before starting engine.

One thing I've learnt is always fit an engine oilcooler before you thrash car on racetrack, etc and when boost level is turned up.

[frankthetank091]

ok i'll check the internal wastgate arm and see if it moves correctly and is not mod'd or bent. it always has had some wierd boost spikes so ya that would make sense. i can tell someone has been messing with the turbo it has new hardware, im not to sure what to expect