[Mk2] [Turbo] Boosting too high! Any advice?

[David21]

About 3 months ago i had an Apexi AVCR boost controller fitted. It was setup and running fine, for example my setting B was setup and running a perfect 0.8 bar boost.

Within the last month or two though it has been boosting way too high and any adjustment to the boost/duty does not seem to make a difference. I set setting B to 0.2 bar boost with a low duty think 30% or so and it still boosted/crept to around 0.9 bar at around 4.5k rev upwards!

When i set the boost controller to off it was still hitting 0.8 + bar at around 4.5k rev plus.

Just to note i have checked all the hoses coming from the solenoid and actuator, they all seem ok no splits etc and when it does boost it is hitting 0.9 bar i.e it isn't giving a false reading.

I'm wondering if it is the actuator as it does not look in top condition and is quite rusty

If anyone has any ideas would be much appreciated.

[Extubby]

My boost is higher than normal as will most peoples I guess. This is due to the drop in temp.

[Odin_S]

0.9 is rev 3+ normal isnt it? 0.85 is rev 1/2

Anyway you shud count yourself lucky, mine boosts to 1.2 when the running of just the actuator Having it changed very soon

In short i dont think you have a problem

[Peter Gidden]

Normal max. boost is 10psi for Rev1-2, 12psi Rev3-5. Turbo VSV will reduce by 3psi when cold etc.

Decat and free flowing exhaust can often result in 1-1.5psi increase.

A weak actuator can result in overboost.

So if any doubt, remove aftermarket solenoid so back to standard actuator. If all OK, then problem must lie with boost controller, solenoid or plumbing.

[David21]

Thanks for the replys everyone.

I know that my VSV is disabled but has been since the AVCR was fitted. I havn't had any modifications changed that could effect the boosting. I know an aftermarket/ more free flowing exhaust can increase the boost but i have had one on the car since.

I will try what you suggested Peter and see how it goes. It wasn't me that fitted the boost controller but i'm sure i can work out how to bypass the boost solenoid and run on standard actuator.

I will let you know the out outcome, thanks again

[splashnatz]

bear in mind, you can turn boost up with an AVCR ... you can't turn it down below actuator pressure though.