Another 15G question :(

[Chilm]

Hi, I have two questions about the 15G on my 1998 945 B230FK:

I modified the oil return line from the turbo, and the line now has an ID of 16 mm.

I’ve read somewhere that this is too large because the oil needs some backpressure.
Is this true, and if so, what should the diameter of the opening be?

Question number 2: I also used the wastegate from a Volvo 850 15G, and it is considerably larger than the one on the 13C.
Does anyone know which spring is fitted in it, or at what pressure (bar) it starts to operate?

Thanks in advance for your comments and advice.

Cheers,
Chilm

 

[OVERDRIVE]

Restrictors for the oil drain are only used on ball bearing turbos. TD04s are journal bearing.

Use the 13C wastegate actuator as I understand, 850s use an electronic boost controller and the 13C one works best with the stock 940 setup. Someone could correct me, this is just what I've heard after asking others.

 

[Chilm]

Restrictors for the oil drain are only used on ball bearing turbos. TD04s are journal bearing.

Use the 13C wastegate actuator as I understand, 850s use an electronic boost controller and the 13C one works best with the stock 940 setup. Someone could correct me, this is just what I've heard after asking others.

Thanks, but it's a 15G and the actuator originally belongs to that turbo. It's a pure mechanical actuator
But the return line question is solved now, thanks.

 

[shoestring]

Somewhere in the Turbobricks forum world is a complete list of Mitsubishi TD04 wastegate actuator listings that includes the stampings on the actuator. It's claimed that these are the ratings on the opening/closing rate springs contained in the actuator. I did a bunch of testing earlier this Summer with the actuators from a 15G, a 16T, and a 19T, trying to find one that best matched our desired boost profile. I will tell you that while the number stampings on the actuators seem to indicate their relationship to each other (15G to 16T to 19T) where a higher number is a stiffer spring, I could not find any direct correlation to any pressure number. Example: stamping 218 isn't .218bar, or 2.18psi, or a length the arm travels, or anything like that.

Edit: I have to believe it's some kind of internal Mitsubishi rating system or something like that.

I can also tell you that the actuator off of a 15G is the softest of the bunch. I believe they all require different preloads, again, a Google (or European equivalent) search should find this info.

The reason the 850 was mentioned is that it uses an electronic boost control valve that bleeds off boost pressure before it reaches the actuator, despite the fact that it is mechanical. My testing shows that even at proper preload spec, the 15G actuator will start to move at about 2(ish) psi, softening the rate at which boost builds. Keep in mind, this is still a small turbo with good boost response and it will still feel quick to reach max number on a stock engine, even if it's not as quick as it could be.

For best result, any of the FWD turbos adapted for use on RWD applications should use an electronic boost controller. We use the GForce II and III from GoFastBits with good results.

I hope this helps. If you need me to I can probably dig up this actuator information, I'm known for documenting.

 

[Chilm]

Somewhere in the Turbobricks forum world is a complete list of Mitsubishi TD04 wastegate actuator listings that includes the stampings on the actuator. It's claimed that these are the ratings on the opening/closing rate springs contained in the actuator. I did a bunch of testing earlier this Summer with the actuators from a 15G, a 16T, and a 19T, trying to find one that best matched our desired boost profile. I will tell you that while the number stampings on the actuators seem to indicate their relationship to each other (15G to 16T to 19T) where a higher number is a stiffer spring, I could not find any direct correlation to any pressure number. Example: stamping 218 isn't .218bar, or 2.18psi, or a length the arm travels, or anything like that.

I can also tell you that the actuator off of a 15G is the softest of the bunch. I believe they all require different preloads, again, a Google (or European equivalent) search should find this info.

The reason the 850 was mentioned is that it uses an electronic boost control valve that bleeds off boost pressure before it reaches the actuator, despite the fact that it is mechanical. My testing shows that even at proper preload spec, the 15G actuator will start to move at about 2(ish) psi, softening the rate at which boost builds. Keep in mind, this is still a small turbo with good boost response and it will still feel quick to reach max number on a stock engine, even if it's not as quick as it could be.

For best result, any of the FWD turbos adapted for use on RWD applications should use an electronic boost controller. We use the GForce II and III from GoFastBits with good results.

I hope this helps. If you need me to I can probably dig up this actuator information, I'm known for documenting.

Great info Shoestring, at least I have good info from my turbo gauge and I know at which bar I've set my manual boost controller. So I can check things also in that way.

But... I (and others) wil be very grateful if you can "dig up this actuator information"

Cheers
Chilm

 

[dl242gt]

I used to use spring scales on my old job to rebuild Teletypes for the new service. Use a spring scale and it will read out what the spring pull is in the actuator.

 

[shoestring]

Great info Shoestring, at least I have good info from my turbo gauge and I know at which bar I've set my manual boost controller. So I can check things also in that way.

But... I (and others) wil be very grateful if you can "dig up this actuator information"

Cheers
Chilm

OK, here's what I recorded. It's not super-comprehensive but it was enough to say "well this one is a waste of time (15G)"

First of all, here's the link to the thread I mentioned that has all the actuators and stampings. See post #12:

https://turbobricks.com/index.php?threads/15g-boost.314285/

Next, some background. We were trying to find out how much preload to run on these actuators to have it work smoothly and correctly (as in an OEM application) for use in the white car at about 1 bar. The hope was to find a 15G/16T/18T/19T factory engine that used a similar amount of manifold pressure and duplicate what Volvo used for a preset and adjust from there. This ended up in failure as that didn't really exist from the factory. We had been using a stock 16T which worked well, but had swapped over to a 19T w/Ti exhaust wheel, plus an increase in boost pressure of about .35 bar (we're at about .9 bar now).

In my internet research, I was never able to find any definitive answer as to what correct wastegate actuator preload should be. There's a bunch of consensus: half your target boost, or 3mm, or half the wastegate arm pin diameter (which happens to be 3mm), but no formulas or fixed numbers.

I don't like that.

So here's what I recorded. I took no information on the 19T actuator aside from a quick check that it was stiffer than the 16T, and that it was stamped 300/70.

15G, stamped 150/30:

Would require 10.1mm of preload to set at 7.5psi (half target boost).
Maximum arm travel 11.8mm. Yes, if you set a 15G actuator to 7.5psi preload, it only moves an additional 1.7mm. Boost creep, anyone?

16T, stamped 216/60:

1mm preload is 2.5 psi
2mm preload is 3.5 psi
3mm preload is 4.5 psi
5.3mm preload is 7.5 psi
12.1mm preload is 15 psi
19.6mm is max travel, and that's achieved at about 30 psi.

So now you know what I know. I would only ever use a 15G actuator at stock (0.5bar) boost levels, mostly because I don't think it has the range of motion necessary for good control.

Hope you find this informative and that it helps make an educated decision.

 

[Chilm]

OK, here's what I recorded. It's not super-comprehensive but it was enough to say "well this one is a waste of time (15G)"

First of all, here's the link to the thread I mentioned that has all the actuators and stampings. See post #12:

https://turbobricks.com/index.php?threads/15g-boost.314285/

Next, some background. We were trying to find out how much preload to run on these actuators to have it work smoothly and correctly (as in an OEM application) for use in the white car at about 1 bar. The hope was to find a 15G/16T/18T/19T factory engine that used a similar amount of manifold pressure and duplicate what Volvo used for a preset and adjust from there. This ended up in failure as that didn't really exist from the factory. We had been using a stock 16T which worked well, but had swapped over to a 19T w/Ti exhaust wheel, plus an increase in boost pressure of about .35 bar (we're at about .9 bar now).

In my internet research, I was never able to find any definitive answer as to what correct wastegate actuator preload should be. There's a bunch of consensus: half your target boost, or 3mm, or half the wastegate arm pin diameter (which happens to be 3mm), but no formulas or fixed numbers.

I don't like that.

So here's what I recorded. I took no information on the 19T actuator aside from a quick check that it was stiffer than the 16T, and that it was stamped 300/70.

15G, stamped 150/30:

Would require 10.1mm of preload to set at 7.5psi (half target boost).
Maximum arm travel 11.8mm. Yes, if you set a 15G actuator to 7.5psi preload, it only moves an additional 1.7mm. Boost creep, anyone?

16T, stamped 216/60:

1mm preload is 2.5 psi
2mm preload is 3.5 psi
3mm preload is 4.5 psi
5.3mm preload is 7.5 psi
12.1mm preload is 15 psi
19.6mm is max travel, and that's achieved at about 30 psi.

So now you know what I know. I would only ever use a 15G actuator at stock (0.5bar) boost levels, mostly because I don't think it has the range of motion necessary for good control.

Hope you find this informative and that it helps make an educated decision.

Great info, thank you so much, that wil help

P.s. mine is stamped 150/40.