who has a T4 turbo? help needed
06-12-2009, 09:57 PM
#46
Boost Builder
i always thought msd only sold genuine Garrett actuators, but looking at their site they are aftermarket, ebay is slightly confusing as says Garrett -31 RATED. Not heard of supplied parts from them being of poor quality
07-12-2009, 12:25 PM
#52
If Vince has already said that the spring pressure on your "-31" is not as good as a genuine one, then surely it won't be able to hold the wastegate closed and therefore you have already the answer to your problem......
You could easily check this on the rollers, as I had a similar problem with a standard actuator on our Lotus. I couldn't get it to hold any more than 0.8 bar at high rpm on APTs rolling road (where it should have held 1.25 bar (where it only peaked at that) and backed off at high rpm). I then got Gary to hold the wastegate shut with some pliers (to confirm what we thought was the issue) - instant 1.25 bar held at high rpm. New uprated actuator fitted - job jobbed.
You could easily check this on the rollers, as I had a similar problem with a standard actuator on our Lotus. I couldn't get it to hold any more than 0.8 bar at high rpm on APTs rolling road (where it should have held 1.25 bar (where it only peaked at that) and backed off at high rpm). I then got Gary to hold the wastegate shut with some pliers (to confirm what we thought was the issue) - instant 1.25 bar held at high rpm. New uprated actuator fitted - job jobbed.
07-12-2009, 12:52 PM
#54
If Vince has already said that the spring pressure on your "-31" is not as good as a genuine one, then surely it won't be able to hold the wastegate closed and therefore you have already the answer to your problem......
You could easily check this on the rollers, as I had a similar problem with a standard actuator on our Lotus. I couldn't get it to hold any more than 0.8 bar at high rpm on APTs rolling road (where it should have held 1.25 bar (where it only peaked at that) and backed off at high rpm). I then got Gary to hold the wastegate shut with some pliers (to confirm what we thought was the issue) - instant 1.25 bar held at high rpm. New uprated actuator fitted - job jobbed.
You could easily check this on the rollers, as I had a similar problem with a standard actuator on our Lotus. I couldn't get it to hold any more than 0.8 bar at high rpm on APTs rolling road (where it should have held 1.25 bar (where it only peaked at that) and backed off at high rpm). I then got Gary to hold the wastegate shut with some pliers (to confirm what we thought was the issue) - instant 1.25 bar held at high rpm. New uprated actuator fitted - job jobbed.
how much preload on the actuator show i have?
!
07-12-2009, 01:49 PM
#58
my turbo will only produce 30 psi with my brand new -31 actuator.it has a hole of preload. it does'nt matter what i do it won't produce anymore.
my air injectors are mapped fully open.
stu told me a -31 should produce 40-45psi with the air injectors fully open.
and what i was trying to get across was if i put a garratt -31 i still can't see it produce 40-45psi
what i want is to run 30psi but not with my air injectors wide open like it is now.
Last edited by B13 JUS; 07-12-2009 at 01:54 PM.
07-12-2009, 02:01 PM
#60
who said i wanted to run 40-45psi? i think you need to read the hole thread.
my turbo will only produce 30 psi with my brand new -31 actuator.it has a hole of preload. it does'nt matter what i do it won't produce anymore.
my air injectors are mapped fully open.
stu told me a -31 should produce 40-45psi with the air injectors fully open.
my turbo will only produce 30 psi with my brand new -31 actuator.it has a hole of preload. it does'nt matter what i do it won't produce anymore.
my air injectors are mapped fully open.
stu told me a -31 should produce 40-45psi with the air injectors fully open.
. I think you should find that even if you can't achieve 40-45psi, you won't be far off with a genuine actuator and 32psi will be a walk in the park 
. When Vince had the turbo, you should have got him to supply you one .
07-12-2009, 02:08 PM
#62
It just seemed from your last post, that this was the figure you were trying to achieve . I think you should find that even if you can't achieve 40-45psi, you won't be far off with a genuine actuator and 32psi will be a walk in the park . When Vince had the turbo, you should have got him to supply you one .
. I think you should find that even if you can't achieve 40-45psi, you won't be far off with a genuine actuator and 32psi will be a walk in the park . When Vince had the turbo, you should have got him to supply you one .i don't understand why other t4's will make more boost than mine
07-12-2009, 02:10 PM
#63
so you don't have a garret -31 you have a mickey mouse one then
-31 refers to a genuine garret one only as does -34 the fact that somecompany has chosen to put -31 on their actuator does not make it a garret -31
we only use genuine garret parts
heinz don't make beans for any one else either
without any pneumatic control pressure on the actuator on a genuine t4 turbine housing with the correct size by passport and penny you will see pressures at peak load over 5 bar
we have of late seen quite a few t4's with the wrong size by pass port and waste gate penny
-31 refers to a genuine garret one only as does -34 the fact that somecompany has chosen to put -31 on their actuator does not make it a garret -31
we only use genuine garret parts
heinz don't make beans for any one else either
without any pneumatic control pressure on the actuator on a genuine t4 turbine housing with the correct size by passport and penny you will see pressures at peak load over 5 bar
we have of late seen quite a few t4's with the wrong size by pass port and waste gate penny
07-12-2009, 02:15 PM
#64
. If the actuator can't hold the wastegate shut, then it is not unfeasible to assume that it is pushing it open to lose all the boost you are missing . I lost nearly 7psi on a pissy little 60 trim T3 with an actuator that wouldn't hold the boost..... I suspect that a T4 with a large wastegate penny will bleed off FAR more - don't you? 
Other T4s have a genuine -31
.
07-12-2009, 02:20 PM
#65
You are just guessing at the 2-4psi . If the actuator can't hold the wastegate shut, then it is not unfeasible to assume that it is pushing it open to lose all the boost you are missing . I lost nearly 7psi on a pissy little 60 trim T3 with an actuator that wouldn't hold the boost..... I suspect that a T4 with a large wastegate penny will bleed off FAR more - don't you?
Other T4s have a genuine -31 .
. If the actuator can't hold the wastegate shut, then it is not unfeasible to assume that it is pushing it open to lose all the boost you are missing . I lost nearly 7psi on a pissy little 60 trim T3 with an actuator that wouldn't hold the boost..... I suspect that a T4 with a large wastegate penny will bleed off FAR more - don't you? Other T4s have a genuine -31
.
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