Boost Question.

[Steevo]

I have a T25/T2 - a .48 with a .47 rear.

There is no boost coming in at all until around 3200-3500 revs which seems really high up the rev range.

Is this normal or what should I be looking for?

On WOT I am showing 9-10psi

Thanks:)

[mk5gtt]

Hi i have the same turbo mine starts boosting a little earlier than that but starts to make full boost about 3500 running 22psi. They do take a little bit to get going but pull really strong all the way through the rev range after that.

[Steevo]

Hi i have the same turbo mine starts boosting a little earlier than that but starts to make full boost about 3500 running 22psi. They do take a little bit to get going but pull really strong all the way through the rev range after that.

Cheers mate, definitely feels like I have a problem preventing it spooling

[Markey Mark (BD)]

Normally the T2 rear housings are abit more responsive but all depends on the size wheel you got in there too

Another issue could be cracks in the rear housing, wastegate penny not sealing correctly or the actuator has become very weak
Have you checked the preload of the actuator?

[Steevo]

I adjusted the actuator and wound it in, and took out for a drive.

Think I may have overdone it as it boosted off the scale.

What do you mean by setting preload? Sorry I'm not educated around actuators:ashamed:

[Markey Mark (BD)]

I adjusted the actuator and wound it in, and took out for a drive.

Think I may have overdone it as it boosted off the scale.

What do you mean by setting preload? Sorry I'm not educated around actuators:ashamed:

The preload is how much the actuator is adjusted, its fine tuning it so it produces the boost you want but not too much it over boosts (like you found out)

Does sound like the actuator does need adjusting if it boosted off the gauge, just adjust it up or down untill you get the boost you want but if you see it spiking of boost tailing off it means the actuator is weak and needs changing