[Bennehboy]

Can somebody tell me if it's acceptable to increase the boost a bit by shortening the actuator rod one thread, without carrying out any other modifications?
And will this provide a noticeable increase in power?

It's acceptable, you _might_ feel a small increase and/or have a reduction in smoke, but tbh you normally don't really see any worthwhile increase without also chucking more fuel in (remap) and/or putting a bigger intercooler on. You may get slightly higher EGT by increasing the boost with just the stock intercooler.

 

[lightning]

On my old Renault 5GT Turbo it gave an extra 30bhp just by adjusting the wastegate actuator rod.
Any more and you had to alter the fuelling (difficult as there was no ECU) but 150bhp from 120bhp was safe, it was even approved by Renault.

 

[bankz5152]

Great?

 

[Bennehboy]

On my old Renault 5GT Turbo it gave an extra 30bhp just by adjusting the wastegate actuator rod.
Any more and you had to alter the fuelling (difficult as there was no ECU) but 150bhp from 120bhp was safe, it was even approved by Renault.

Mechanical fuel pump on that engine so it probably adapted fuelling to the boost (like the boost pin on a bosch pump?), higher power probably needed a bigger pump??

 

[lightning]

Probably. Things have changed since then though.
The car went like stink with 150bhp as it only weighed as much as a packet of crisps.
It handled well too. It would wipe the floor with other "hot hatches" of the day, until the new generation of Turbo cars started to appear, such as the Sierra Cosworth and Lancia Delta lntegrale.