Too little boost, solenoid, MAP or something else?

[jimmydanny]

Hmm, this is weird. I tried with a boost controller between the nipple after the turbo and on the pipe going around the turbo to the actuator. No matter what setting, I only got 0,4-0,5 bar. Now, that yells actuator arm? No, when I put on the new silicone hose, it got bent too much and let no air past. What happened? Fast up to 0,9, then dropping down to 0,6-0,7... Not the actuator arm after all?

[Prof]

Hmm, this is weird. I tried with a boost controller between the nipple after the turbo and on the pipe going around the turbo to the actuator. No matter what setting, I only got 0,4-0,5 bar. Now, that yells actuator arm? No, when I put on the new silicone hose, it got bent too much and let no air past. What happened? Fast up to 0,9, then dropping down to 0,6-0,7... Not the actuator arm after all?

 
That fast boosting and then dropping off is typical of the stock turbo / actuator combo - the actuator can\'t hold that boost so it lets it go, and the peaking is the turbo basically limiting.
 
If you are using an aftermarket boost solenoid, you should not use that pipe around the front of the turbo at all, but rather run a line from the compressor outlet nipple to the NO port on the solenoid and a line from the COM port to the actuator.  The NC port on the solenoid should be left free and must not be blocked or capped.

[jimmydanny]

And plug the pipe around the turbo then? Makes no sense compared to what I\'m used to on other cars.

But anyways, my car is capable of 0,9 bar, why do I only get 0,5 when I remove the kink in the hose? The solenoid (Without testing it properly) works, it clicks when ign is on.

[Prof]

And plug the pipe around the turbo then? Makes no sense compared to what I\'m used to on other cars.
 
But anyways, my car is capable of 0,9 bar, why do I only get 0,5 when I remove the kink in the hose? The solenoid (Without testing it properly) works, it clicks when ign is on.

Because the spring in the wastegate actuator is set for that - actually it\'s about .4 BAR, but will usually go a bit higher if your exhaust flows well.  To get more boost you must either restrict the pressure to the actuator or bleed some off - either will delay the operation of the actuator and provide more boost.  That\'s what you\'re boost controller is supposed to do.
 
Wiki explains it:
 
http://en.wikipedia.org/wiki/Boost_controller
 
The stock system is effectively a \'bleed type\'.
 
The three way valve in most electronic boost controllers only bleeds air pressure off the actuator, so does not represent a continous boost leak on the engine.

[jimmydanny]

Well, the stock system gives me 0,4-0,5 (I think the freer flowing intake helps a bit, it did increase the boost it seems), the aftermarket manual boost controller gives me the same. When clamping the hose I get 0,9. So it can\'t be the actuator arm being too loose, and it can\'t be the duty solenoid or MAP not working, as the same happens with the aftermarket boost controller.

This doesn\'t make sense anymore...

[jimmydanny]

Are there any turbos or ways to get a bigger compressor side easily? That means, minimal to no modification on the in our out flanges, so I can keep my RB downpipe and stock exhaust manifold?

Or, for a shorter term fix, while waiting for a proper sized turbo and standalone, swapping the actuator, is this doable? To something more.. Springy?

[Prof]

ok, so looking at the facts:
 
using a straight piece of pipe you get the spring boost setting for the turbo - which is about 5 psi or .4 BAR - you may get a little more because of you\'re intake.
 
Then with the pipe pinches, the wastegate will not operate, so the 0.9 BAR is the maximum your intake and exhaust are allowing the turbo to spool to.
 
I would summise that your after market boost controller and the stock boost solenoid are doing nothing at all and basically not working.
 
As for turbo upgrades, this is what you can do:
 
1) Upgrade actuator - you can get after market actuators from HKS, Forge and a few others that will work with the stock turbo, but you will probably want to port the wastegate...
 
2) Porting the wastegate - this is necessary to avoid boost creep - where you\'re boost isn\'t controlled and just increases with higher gears, and increases when in gear as the rev\'s rise.  You can use the stock exhaust housing - just needs a lot of work with a burr
 
3) Spacing the exhaust plate or using a bellmouth - this allows the flapper to open much further and is similar to porting the wastegate - it will give less turbulent flow as well.
 
4) Replace the compressor section -  the Turbo is a Hitachi HT18S2, and the bolt pattern for the compressor is identical to Garrett T04B compressor housing - you can get various blade profiles to fit on the front, you will be able to make much more boost, but the turbo won\'t spool till later in the rev range.  I have a Garrett compressor on mine, and it spools around 4400 rpm, but holds boost to past 7500 rpm.  It will easily give more than a BAR of boost - but you do need to do something with the fuelling or you will kill your engine.  This isn\'t just a straight swap, you will have to have the turbo re balanced when you change the compressor.  It\'s also worth having the journal bearings replaced with 360 degree bearings which offer better balance and support.
 
You can find some units second hand, it\'s worth talking to the tuners to see what they have.

[jimmydanny]

Spacing the exhaust plate, that will remove the need for porting the wastegate then? Also, can this be, say, making a new, thicker plate with CNC? Got friends in higher places than I should

[Prof]

Spacing the exhaust plate, that will remove the need for porting the wastegate then? Also, can this be, say, making a new, thicker plate with CNC? Got friends in higher places than I should

it doesn\'t really replace porting, but it will help a little.

[jimmydanny]

Will it help me when I get the REV TII exhaust and my boost goes close to 0.9? Compared to porting, which is a much bigger job as I understood it?

[BinoX]

When clamping the hose I get 0,9.

I\'ve been thinking about doing this recently... I\'m not getting much boost (sometimes as little as just atmospheric pressure, sometimes more) and I think my wastegate spring may be a bit weak... (The arm is still attached)
 
I take it that the hose that you clamp is the turbo to actuator vac hose? And is there anything else I would need to do?
 

1) Upgrade actuator - you can get after market actuators from HKS, Forge and a few others that will work with the stock turbo, but you will probably want to port the wastegate...

Where would I get an HKS actuator from? I haven\'t seen any for the FC on any of my regularly visited sites, maybe I just missed them?

[jimmydanny]

I am clamping the one from the pressure side, aka on top of the turbo, where the pipe to the BOV sits. But you can clamp it between the actuator and the turbo piping yes.

But I have a fuel cut defender in my Rtek, if you don\'t have, you probably will blow your engine at that boost level. I did it last year, did not see why it happened untill some time after.

EDIT: Also, the engine will go lean, maybe too lean, which is second worst to total fuel cut, either of this will occur if you clamp it. So I do not recommend it. Ebay an HKS actuator instead, much easier.

[BinoX]

Yeah, I realise the dangers... I just want to do it as a test to see if it IS the actuator or something else... Literally gunna drive it until up to temperature, jack it up, clamp the hose (yes.. I have temperature resisting gloves) and literally just go down the road and see if the boost gauge goes any higher... if it does, then I will be stopping quickly before blowing anything...
 
I don\'t want to start needlessly throwing parts at it and I can\'t think of an easier way to test...
 
Edit:
I DO have an afermarket ECU, but I haven\'t fitted it yet.. I want to make sure everything is working first, although I may have to switch out before that, lol.. Since, if I remember correctly, it has a maps for the higher pressures anyway

[jimmydanny]

Hmm, okay, I fiddled with the wires to the MAP sensor, and still running without my wastegate connected I got 1.1-1.2 bar, which is around 14-16 psi somewhere? 1.0 is 14.4 I think.

When I think about it, that got nothing to say vs. the wastegate, since the hose was kinked. But, 1.1-1.2 bar makes this turbo workable for me with new REV exhaust as well.

 Anyways. Connected the wastegate again, 0.4 bar again.

 Any good method to test the MAP sensor? Anything I can do while not driving to see what readings I get from it in volts at idle, reving, and ohms when off.

[m1tch]

Whoa! Careful with that boost level, im amazed it didn\'t detonate if it isn\'t mapped there lol