I have a '88 ERST with a problem.

Boost is fluctuating and drops off about 0.15/0.20 bar.

The AMAL valve is acting up again (replaced it once already about 2 years ago) but i don't want to replace it again as it costs about 70 euro/50 pounds.

I thought the actuator spring was a bit dodgy also.

I had a new -31 actuator lying about so I put that on.
I disconnected the AMAL valve (just straight on the turbo now)

It's running 0.45 bar constantly now but the factory setting is 0.45 to 0.55 bar so I need to adjust it some more.

HERE'S THE QUESTION!!

What is the boost limit on a standard ECU without it cutting out?

I want to dial in as much boost as possible now as I'm now running without overboost control

 

Limit is set at 8 psi, but you will find that you be able to run slightly more {peek boost} as long as it drops back to 8 psi as the revs climb above 4000 rpm

Cheers

Steve.

 

How much Bar is 8 psi? (roughly)

I don't really have peek boost anymore after changing the actuator and disconnecting the AMAL valve

After the turbo kicks in it drops by only 0.05 bar and then it settles(spelling?)

 

1 bar is about 14.7 psi so I reckon 8 psi to be about 0.55 bar.

Hope that helps mate.

 

My standard box (S1) had it's limit at around 0.7 bar.

 

You can set the boost higher than "factory spec" on a standard chip.

The normal boost is 0.45 to 0.55 bar.

This is because when the overboost control is working (the first few seconds of higher boost when you slam it to WOT before it settles to 0.5ish bar)
If you raise the boost it will be too high on overboost and the engine cuts out.

I don't run overboost control anymore because I disconnected the AMAL valve (which controls overboost and boost cut-off if the ACT is too high)