Boost control/setup [Archive]

Spooky

22-10-2009, 10:06

Ive got a t28 fitted, with a -31 actuator, yet I can't get anything above 9-10psi above manifold pressure with the rod completely wound in.

If I slip a bleed valve on, its fine, boost to where I want.

I dont want the bleed valve in place, so how can I increase the boost further ? :ashamed: :D

And Scoff, in that other thread I forgot to mention that the actuator is wound all the way in :)

Bigfoot

22-10-2009, 10:20

Dodgy actuator, how stiff is it if you try and move it by yourself?

James5

22-10-2009, 10:24

Dodgy actuator, how stiff is it if you try and move it by yourself?

Have to agree sounds like the act spring is not wanting to hold any more boost I take it you have the rod as small as you can get it. Nothing wrong with using a bleed valve to get the extra psi matey (It's only a prob when peeps turn it up without the fueling to match).

r5 rich

22-10-2009, 10:26

I have a gt tuning spider valve and adjustable boost controller in the car, Mark linked it up to his LM1 to get the afr to match for the time being until I get it on the rollers to wind the boost up a bit more at a later date

Spooky

22-10-2009, 10:31

I dont want to have to use the bleed valve, I trust my right foot :wasntme:

Fuelling is spot on for 20-21psi :cooter:

I'll get a bike pump and boost guage and test that actuator today as I'm bored of 9psi :p

Spooky

22-10-2009, 10:31

Dodgy actuator, how stiff is it if you try and move it by yourself?

As its fully wound in, impossible, almost :)

Mart

22-10-2009, 10:35

Actuator, boost leak, heavily leaking wastegate.

Spooky

22-10-2009, 10:45

Actuator, boost leak, heavily leaking wastegate.

Could be all of the above but why would the bleed valve make such a huge difference ?

I've got a -34 actuator kicking about so I'll see if it improves with that in situ.

Spooky

22-10-2009, 10:48

I may even try the -31 with no actuator pipe in place... :burnrubber:...followed by :cry:...:laugh:

As long as I can get 20lbs, Ill be happy :)

Brigsy

22-10-2009, 12:45

I can only get my -31 up to 24ish psi at the turbo, have to bleed off for more boost. If theres no boost leaks dont worry too much.

Spooky

22-10-2009, 13:10

Brigsy, if I can hold 20lbs with no actuator pipe, I'll be more than happy :)

Andrew Cooke

22-10-2009, 13:18

lockwire it shut and see what happens, you'll be able to control the boost with your trusty right foot :laugh:

Spooky

22-10-2009, 13:59

What are you implying andy?! :laugh:

Just went out, boosts very steadily upto 20lbs with no actuator pipe connected, mind you, I wasn't accelerating hard.

Just having a cup of tea, then I'll adjust the arm length so that I can achieve no more than 20lbs with no pipe in place :D

stu21t

22-10-2009, 14:21

You shouldn't run more than 6mm preload on a turbo. Half a hole in the actuator rod over the wastegate is just right. Any more and you overspeed the turbo, this chokes and will damage it.
You are supposed to bleed air to the wastegate. That's all any boost controller does, limits the pressure going to the wastegate.
Wind the actuator to 6mm pre load and bleed the rest off to what you want.

Slim

22-10-2009, 14:28

sorry to sound dumb... but what is preload?? is it the amount turned on the actuator?? how does this affect anything?? (other than the boost needed to open wastegate)

Spooky

22-10-2009, 14:46

Stu, I've just done exactly that :agree:

For me, the bleed valve felt too aggressive coming into boost, I was aiming for a more progressive build up that doesn't dive off.

I've just been out again, boosting to just over 20lbs at full throttle, I'll wind the arm back in some more to keep it in check :)

No actuator pipe ftw :D:agree:

Mart

22-10-2009, 16:04

Is that 20psi map? Not wise to run without the acutator working as such, as if there is a boost leak somewhere your turbo could be over-speeding something crazy just to make that boost level.

Measure boost at the turbo outlet if you can. If it reads substantially higher than map, that'll indicate there's a leak between turbo & inlet manifold.

Spooky

22-10-2009, 17:30

Manifold pressure is 20lbs Martin.

I'll shove a boost guage into the comp housing take off and see what I am doing. It'd be better jus after the housing but I don't have a take off to stick in my ally boost pipe.

Infact, I'll stuff a boost guage where ever I can take a reading for boost.

I've plugged it all back up for now, back down to a lowly 9lbs lol

It's way too wet for full throttle antics at the moment :wasntme:

stuTHC

22-10-2009, 17:34

And you saw at ND what happens to a turbo when a turbo it over speeds didn't you spooky........

Mart

22-10-2009, 17:42

I'll shove a boost guage into the comp housing take off and see what I am doing. It'd be better jus after the housing but I don't have a take off to stick in my ally boost pipe.

Infact, I'll stuff a boost guage where ever I can take a reading for boost.

Most comp' housings have a removeable blanking plug/grub-screw, where you can then screw a nozzle in, and connect your boost gauge piping onto that. Course, if it was plumbed the 'correct' way, you'd already have the actuator fed off the compressor housing ;)

Measuring boost off the housing is more ideal as that covers the boost pipe to intercooler, intercooler itself and so on downstream to the inlet manifold.

Spooky

22-10-2009, 18:07

And you saw at ND what happens to a turbo when a turbo it over speeds didn't you spooky........

No that was just a botched job :laugh:

Spooky

22-10-2009, 18:12

Martin, the original plan was to feed the actuator via that comp housing take off.

Couldn't find the damn adapter though, so I'll be nipping to Pirtek tomorrow.

I'll have a play again tomorrow and post up how I get on :)

I will have 20lbs of da boost :smokin: