Been having a few issues with my new setup, namely lack of boost.
Having rectified a couple of other minor issues it still doesn't boost more than 19psi (That's indicated on the in car gauge and also the SECS monitor).

So last night I was pissed off and decided to have a look at it again to see what the issue was, so after connecting the actuator to the compressor, seeing when it opened, and then taking it off the wastgate, i screwed it up about 4-5 turns knowing that should change it significantly, on connecting the compressor back up, it still read the same, so I took the car out for a blast out and it still doesn't boost any higher.

My powers of deduction tell me it's the actuator (-34), but it's a brand new unit supplied with a new turbo (2 months ago with very little use), so I'd like to be sure before I seek a replacement. Any other way I can test it?

 

Quick test, put your mouth over the nipple of the actuator canister and suck, if you can stick your lip to the nipple with the vacuum then its an indication that the diaphragm inside is still intact - if you're just sucking gobfuls of funny tasting air in and creating no vacuum then there may be a hole in the diaphragm.

Personally i'm surprised you're using a -34 actuator on a T4, what boost control are you on? AMAL valve or air injector?

The other thing that may well be worth checking thoroughly before condemning the actuator is for boost leaks! Things like dump valves (Bailey ones in particular) can leak above certain boost pressures...

 

It's supposed to be runing 26psi, but doesnt get anywhere near there. Why are you surprised about the actuator choice? It's on amal valve control.
I will check what you have said, but it does have a bailey on it actually, but the actuator seems to move at the same pressure regardless of rod length.

 

Sounds likely to be an air leak but you can rule out amal control and pipework faults easily by just pulling the pipe off the actuator altogether. That should see you running 40psi+

Out of interest, is it quite easy to move? a -34 is a real bastard to move, its very very strong indeed and takes some moving, often needing bodyweight against a large screwdriver on the shaft nut if you dont have the luxury of a pressure rig like we use.

 

-34s are great for use with T34s etc. when you want to really ring their neck for as much boost as you can get out of them through the rev range!

T4 turbos however want to make boost for fun, normally you end up having so much going through the wastegate at high revs that you can encounter boost creep when the wastegate isn't big enough! As such, a -31 is better for helping to regulate the boost as you don't want to be trying to hold the wastegate shut so much, especially as you're not trying to run 30+ psi.

Just my take on things

 

Call the tuner of choice, the moaning one lol

Steve

 

If the diaphragm had split it would over boost, if you could rig up a foot pump or something along them lines to pressure the actuator then you can see when it opens, should be around 14 psi. If the turbo is quite new then the wastegate should be sealing properly, make sure the crank arm is not bent, a good adaption to check for boost leaks is make a bung up for the intake pipe with a Schrader valve in it, this way you can pressurise the system and listen for leaks without the noise of the engine.

 

where is your turbo from
sounds like you may have issue with the waste gate penny sealing and or the penny getting stuck in the whole and or the waste gate penny rod may be twisted and or the wrong bearing and waste gate penny rod materials
what size jets have you got in the amal valve ports
are you sure the amal valve works

 

Howdy!
Well after our last convo I checked the amal valve again and it appears to be working, but I'm going to swap it out for another one to confirm. As for the dump valve query, I swapped that last night for peace of mind and it made no difference, I also took the other one apart and it was ok.
Turbo was bought through MT, but it came from CR turbos it was fully rebuilt an un-run so I'd like to think it should be ok, but I guess you never know. The hoses, clips etc are all new, as is about 90% of the car
The issue or confusion I have is, if I have to run "X" psi when should the wastegate start moving to open? Does it move at that pressure or before, I realise it's a big turbo so would it have to open prematurely, and the fact i screwed the rod up and it made fuck all difference tells me the actuator is either wrong or defective.
To answer Stu's question, I can move it with mole grips on the shaft, thats the way I normally do all my adjustments on any cossie, it doesn't feel any different to normal.
As for the amal valve jets I don't know, i know it has been jetted but haven't got any idea i would like to clear up the actuator question first as it's bugging me that this is the problem. The car is very fast, and I've already destroyed 1 gearbox and the replacement doesn't sound too healthy now so although i want it to be running as intended I don't think it will last very long if I can get the box to last a few months I'll stick a more appropriate transmission in.

 

Rog, when you say adjusting with mole grips - are you taking the turnbuckle off the wastegate arm before turning the shaft, or just slackening the locknut and twisting the shaft in situ?

 

Hi, take it off the wastegate and slacken the lock nut and then turn it mate.

 

pop the c port pipe of the amal valve you should have a white restricter in there
this is std and is 2.5mm
check what is in the r port of the valve std is 2.5 mm
check the valve is piped correctly
if all is ok road test with the valve unplugged your boost should be lower if it is considerably lower the valve seems to be ok

 

Ok, I tried that already but I'll check again, everything is deffo plumbed in ok. As I said above about running 26psi, when should the rod on the actuator start to "actuate" at 26 or before?

 

coul;d you have dropped a jet/insert when removing the amal? also worth checking the amal is plumbed in properly.

failing that id suspect wastegate issue.

 

You really need to get the car set up, playing with boost without carefully monitoring fuelling and for det can be pretty dangerous as can driving the car hard with the boost turned down.

The actuator will only do so much, you shoulnt try to over load it. The rest will be done by increasing the jet size in the amal valve. You will get to a point where the boost wont go up because the valve cannot bleed any more air off.

 

So no one can answer my question then?