Car won't boost over 0.8 bar, does the crack on the wastegate affect the boost?

Status
Not open for further replies.
P

Paul_JJ

Member +
Standard Turbo CT9b
All the supporting mods, the fueling is setup properly, but the car won't boost over 0.8 bar, no matter what the actuator setting is...

In 3rd it spikes to 0.9 bar for some time, but then goes back to 0.8 bar.

Also, it feels like it needs more time to build the boost, starts boosting (above 0 bar) at 2K RPM, but I don't feel the punch for some time...

Also now turbo whistle pretty loud almost all the time, since -0.3 to around 0.5 BAR. Is that normal?

My mechanic said that it won't boost more than 0.8 bar cause of the massive crack on the wastegate!

Thanks everyone to advise,
Reps given as usual.
 
weeJohn

weeJohn

Lifer
Pull the pipe off the actuator and try it see what happens, watch the boost does not go to high but.
 
P

Paul_JJ

Member +
I'll try that John, does anyone run 1 bar with cracked wastegate? As far as I know they're all cracked... unless it's a brand new!
 
weeJohn

weeJohn

Lifer
You dont have a leak in the intercooler system do you? Seen you posted its louder, could be air escaping.

Look for one off an auto, they always seem to be better I am told.
 
P

Paul_JJ

Member +
Actuator is very strong, front mount with all the T clips - but I will check everything.

The turbo indeed has a loud whistle, a lot louder then on many cars, louder than my stereo -)
 
Texx

Texx

Super Moderator
Have you checked the vacuum hose to the BOV, if its blocked or leaking the valve could be opening at full boost.
 
P

Paul_JJ

Member +
Right, got it running today! Checked all the clips, tightened them even more. Reset the ECU and twisted the actuator even more to see if it will make a difference this time.

And It goes to 1.1 bar with half throttle.... I was very careful and didn't push the car any further. Waiting now to cool it down and adjust it to just under 1 bar.

The whistle still very strong, but does NOT whistle at all if above 0.5 bar, so I reckon if it was a boost leak, when increasing boost it would increase the whistle???
 
P

Paul_JJ

Member +
Got to 0.9 bar today, pulls like a train, still has the whistle till 0.5 bar, I think it does whistle because of the cracked wastegate, apart from that no shaft play and the seals are good.
 
R

Rev

Member +
Glad to hear you've made your mark. Re some of your questions -
> My ct9a waste gate didn't crack at .6 and .8 bar but had a turbo timer to help it cool.
> 0 psi at 2000rpm is similar to what I get depending on temperature.
> I found off boost and early boost punch is helped by spark plugs , I have changed back to copper type ngk - bkr6e.
I have been thinking it probably helps the torque covertor to lock a little earleir as they don't hesitate like my previous spark plugs did.... ( torque lock being 2500rpm if I remember correctly )
 
S

Skalabala

Member +
Paul_JJ said:
Got to 0.9 bar today, pulls like a train, still has the whistle till 0.5 bar, I think it does whistle because of the cracked wastegate, apart from that no shaft play and the seals are good.
Click to expand...

If you have "no" shaft play then you have a problem bud.
The shaft needs to float on oil. As it turns 190000RPM+-
What can happen is that the exhaust housing can pull because of heat/cracking and then sort of wedge the shaft.
So be careful... There should actually be play that you can feel easily.
 
Texx

Texx

Super Moderator
Paul_JJ said:
Got to 0.9 bar today, pulls like a train, still has the whistle till 0.5 bar, I think it does whistle because of the cracked wastegate
Click to expand...

I'd doubt a crack in the wastegate would be much of a hindrance to a boost creep happy CT9. Sounds more like an actuator problem or a boost leak. If you've got a boost leak and keep driving it then it's likely your going to over rev the turbo and possibly kill it.
 
P

Paul_JJ

Member +
Texx said:
I'd doubt a crack in the wastegate would be much of a hindrance to a boost creep happy CT9. Sounds more like an actuator problem or a boost leak. If you've got a boost leak and keep driving it then it's likely your going to over rev the turbo and possibly kill it.
Click to expand...

Well, the actuator is very stiff, 2 year old HKS. It holds the boost once it's build up.
The FMIC is a cheap one, but just a few months old and with all the silicone/T clips - Blitz copy. I believe if it was leaking boost then the whistle would increase with the Boost, but once it gets to 0.5+ bar the whistle disappears.

I will put the pic of the crack!

Can the whistle be because of the BOV? It's an HKS but I need to check it.
 
P

Paul_JJ

Member +
crack1.jpg
 
P

Paul_JJ

Member +
Well, apparently it boosts to 1.1 bar -) and holds it no probs with no creep - like I mentioned before. I've managed to get 0.95 bar today and pretty happy. I know that turbo is on it's way, but will do me for a while. At the end of the day most of the CT9's are cracked.
 
Status
Not open for further replies.
Top