Rev3 Turbo Overboosting help. *UPDATE* - DP off

[adam3442]

Gents,

Hoping for some help. Car was going for mapping and had a funny boost issue. Basically, the car was making actuator pressure (0.5 bar est) then it would pause making boost, then would shoot up to 1.6 bar. The mapper suggested that the actuator could be catching which seems plausible having a look around here.

Got the car back, have whipped the heat shield and turbo to intercooler pipe off. Hooked up my compressor and checked the movement of the actuator. I've taken a video below, whilst it looks ok to me I'm not really sure what it should look like.

Is there anything else I should be looking at? All the vac lines to and from the actuator, turbo and boost controller are fine.

Car is a rev3 turbo with Blitz K1-380V (CT20B with BW internals) and early Berk downpipe.

Is my compressor sending too much pressure to check properly? Is there a better way to check?

http://sendvid.com/oo0al4gr?secret=081e ... cc8f15f4a5

Thanks in advance!

[almeida1234]

Just make sure actuator is not catching the inner of decat.

[almeida1234]

This link will explain
https://youtu.be/ku1MwZZ3_Fw

[adam3442]

Thanks bud! Turbo off time or boroscope up the downpipe?

[simpson_eh]

nope just the turbo downpipe no need to take turbo off, you should be able to see if the wastegate catching downpipe

[rgb]

can you set your compressor to 10psi and see if it opens . if you put full pressure into the accuator it may still work even if the accuator is knackered .did it work before cause a wastegates not going to just
start catching

[adam3442]

So gents, whipped the downpipes off today, when I say whipped, I mean swore a lot, got cold and bruised.

But here she is, I can't see anything alarmingly obvious but has started to grind the flange back to the same diameter as the gasket to rule it out. Can anyone else spot anything obvious I have missed.

To remind you, the mapper said he attached a hand pump to the actuator, you could see it move, then stop then free up and move again. I don't have a hand pump and my compressor opens and closes it with ease.

It would be great if someone could take a look. I also notice the Berk DP (one of the first) has a crack on one of the welds so I have to tack that up tomorrow. Could the crack cause the over boost?











I have another video of the waste gate opening with the DP off if people want to see that to help?

Thanks in advanced for any help. [/img]

[rgb]

I cant see any mark where the wastegate is hitting the downpipe. I had similar issues and it was because the wastegate hinges in a metal bush and it was loose in the turbo making it stick it had to be spot welded. I recon it a boost controller issue . see what it does with the boost control turned off. id also get a regulator for your compressor so you can set it to 13psi and connect it to your air pipes then spray them with soapy water to look for leaks.

[adam3442]

It was the same with the boost controller disconnected and the actuator hoses blanked. As in running only actuator pressure.

The arm seems to move ok. It's a really odd one 😔

[almeida1234]

Two screws holding the actuator arm not loose or misaligned?

[androo007]

Did this behaviour happen before mapping? What rpm does it shoot up?

[adam3442]

Prior to mapping she was laid up for about two years and has been changed significantly since then. Last time I drove it, on actuator pressure it wasn't going beyond 0.5 bar. And mapping was literally getting her setup to run. She's had a COP conversion, water meth, bigger injectors etc etc etc. So she was in for mapping to be setup and sorted.

Turbo is a blitz k1-380v, and a profec b boost controller but even when that's disconnected she has the same behaviour.

[adam3442]

Two screws holding the actuator arm not loose or misaligned?

I will check.

I'm thinking about buying a new actuator just to rule it out.

[adam3442]

Ok, so update time, I have clearance the DP even though there were no signs of contact, IO have fitted a forge actuator and adjusted the preload correctly, it is still overboosting.

I am using a Jun intake, BERK DP and BERK exhaust, I also have a G4+ PnP. The stock boost control is disconnected and the car is set to run actuator pressure which should be around 1.2/1.3 bar of boost.

Does the Link PnP need the stock boost control connected, clutching at straws with that one.

It seems I can't bleed enough boost off when it gets on it, any suggestions, please!?

[rgb]

I still recon its a boost controller issue . accuator pressure with a 12 psi spring wont make 12psi boost pressure it just starts to work at 12psi and its too late by then. have a look at mr2 exhaust restrictor which I was going to do but I finally got my boost control set right . ive got a forge accuator and a greddy e01 and it boosts perfect but it took years to set. at least your turbos good.

[androo007]

You should be using a decent 3 port solenoid.

[SonicSW20]

What happens if you run it with the port on the turbo outlet connected directly to the actuator?

[adam3442]

What happens if you run it with the port on the turbo outlet connected directly to the actuator?

All tests have been done like that.

Currently the turbo is off, the waste gate is being ported to allow a bit more gas to flow, I've reduced the actuator spring so it bleeds boost quicker. If that doesn't work then we will try it with the boost controller to see if that makes a difference.

I don't see how it can as if the actuator can't bleed boost off and run actuator pressure, how does a solenoid help it can only open the actuator if there's enough pressure by which point there's too much... Genuine question, this is new territory for me!

I want to avoid a restrictor in the exhaust, it's counter productive, if it gets to that point the turbo will come off

[SonicSW20]

Adding the boost controller into the loop just introduces another variable, don't do that until you have it running at actuator pressure. As you say, all the boost controller can do is add boost over what it will run on actuator only, it cannot reduce boost below that point.

Wastegate porting will help, but it may just be compensating for an underlying issue.

What ECU are you running with this setup? You've mentioned mapper so I assume aftermarket? has it ever ran correctly with this turbo, and if it has, what has been changed since then?

[rgb]

you need a boost controller why don't you try it with the waste gate tied open and see what it does it will have massive lag and make full boost at about 6000 revs but will it over boost by the time you've sorted it youll be an expert