Boost fluctuating

[lewiswm]

Hi guys.

I'm running a standard turbo on my E6.

It was mapped by RG Motorsport before I bought it to run at 1.5 bar.

For some reason, it doesn't ever go up that high, but has done when spooling up slowly on the motorway in 5th @70mph.

Generally it only goes up to 1 bar and sometimes the gauge can be seen to be fluctuating when on full boost when driving hard and it can be felt when driving.

I have got a greddy profec e-01 spec II installed, which is set at 100%

Could this be a faulty actuator or something else?

Thanks

Posted over the road too...

 

[Skytm]

Try doing some pulls in third gear at wide open throttle and see what your boost guage reads. You may have a boost leak.

 

[fq-craigus]

As already said try do a few runs so you get a good idea of what it's doing and see if the fluctuating is happening all the time, if it is un pipe the controller and just plumb a pipe straight from turbo to actuator and see if the boost is holding stable if not it's your actuator if yes then it's your solenoid

 

[lewiswm]

Try doing some pulls in third gear at wide open throttle and see what your boost guage reads. You may have a boost leak.

Gave it a couple of goes today like you said.

Boosted up to 14psi then slowly fell to about 10 before changing gear.

Sounds like a leak???

 

[lewiswm]

As already said try do a few runs so you get a good idea of what it's doing and see if the fluctuating is happening all the time, if it is un pipe the controller and just plumb a pipe straight from turbo to actuator and see if the boost is holding stable if not it's your actuator if yes then it's your solenoid

I will give that a go thanks

 

[Evo-Si]

def sounds like boost leak...

 

[Mickyyy]

X2 boost leak or vacuum pipe has come off

 

[lewiswm]

Sounds like a leak doesn't it. What is the best way of testing for it?

 

[DDS789]

Leak or waste gate issues

Had to replace my turbo a few months back due to the waste gate being worn on the hot side. This depends on what turbo you have though mine was a TDO5 16G 10.5T with the double flap waste gate.

My boost would fluctuate up and down, not enough to feel but you could see it on the dyno screens.

Your boost controller is making it fluctuate as it will be trying to achieve peak boost, but then something leaks it away, then the controller tries to reach peak boost again and so on.

I'd boost leak test first

 

[DDS789]

Sounds like a leak doesn't it. What is the best way of testing for it?

Youtube boost leak test and you'll see plenty of ways. It's a good idea to get some bits to make your own tester, they're always useful

 

[lewiswm]

Leak or waste gate issues

Had to replace my turbo a few months back due to the waste gate being worn on the hot side. This depends on what turbo you have though mine was a TDO5 16G 10.5T with the double flap waste gate.

My boost would fluctuate up and down, not enough to feel but you could see it on the dyno screens.

Your boost controller is making it fluctuate as it will be trying to achieve peak boost, but then something leaks it away, then the controller tries to reach peak boost again and so on.

I'd boost leak test first

Thanks a lot for your very useful response.

Mine is the standard E6 turbo whatever it is.

I will have a look and let you know how I get on.

Could this leak also be the reason that it stalls when coming off load?

 

[lewiswm]

Turns out it was the boost controller set up wrong or had been fiddled with. Also my boost gauge was not reading correctly. Had it set up and will be after a new gauge. Pulls much better now. Thanks for your help