holset actuator on 20g

[gorf]

saw this topic and thought I would try it.

http://www.dsmtuners.com/forums/tur...oking-strong-internal-wastegate-actuator.html

I have a TD05 20g with internal waste gate. I was running a 14b actuator but would see boost spike and a little creep plus I thought my spoolup was slow from the gate blowing open.

I bought an ebay holset actuator and built a bracket for the 20g. The shaft that was on the actuator was the right length I just had to bend the end that attaches to the wg a little, you can see it in the first pic. I also had to use a piece of copper tube to make it fit tighter.

While installing I did some boost leak tests with the actuator on. It starts to crack at 15 psi and it is fully extended at 25 psi. If you are looking for an actuator with longer throw, this is it, the gate opens a full 90 degrees.
HOWEVER with my spring and ball home made MBC in the circuit the actuator would never open. Even when I used 30 psi and the mbc completely backed out. I think the bleed hole maybe too big, or it just loses too much pressure to let the actuator open.

I ran it with a straight piece of tube from presure source to the actuator. Results, I think my spool rpm dropped but it was also cold outside so not real sure about this.

NO boost spike

NO creep. It would boost straight to 20 psi and hold solid.

Now I just need to figure out what kind of MBC to use so I can adjust up to 25 psi - any suggestions?

 

[Weapon-X]

That bracket you made to hold the actuator looks a little flimsy.

 

[gorf]

That bracket you made to hold the actuator looks a little flimsy.

plate steel with a 90 degree bend the same as angle iron. It is much stronger and stiffer than the mhi bracket used on 14b/16g actuators.

 

[94awdcoupe]

I have one of these gates. It has double the travel of 14b gate. You can add more preload to what you have and still have plenty of opening. you should be able to run 25psi with no boost controller. maybe even higher.

 

[JusMX141]

You need to beef up that actuator bracket for sure. At some point you're not going to be able to adjust the actuator stiffer to add preload to the spring because it's just going to keep bending the bracket further toward the turbine housing.

Use some thicker metal for the bracket and adjust that arm a little tighter....I think you'll find your achievable boost level will go up drastically.

 

[gorf]

You need to beef up that actuator bracket for sure. At some point you're not going to be able to adjust the actuator stiffer to add preload to the spring because it's just going to keep bending the bracket further toward the turbine housing.

Use some thicker metal for the bracket and adjust that arm a little tighter....I think you'll find your achievable boost level will go up drastically.

That bracket was a prototype, I used what I had for steal. Agree it should be heavier gauge but with the 90 degree angle along the edge, it is very stiff.

A LOT more testing is required, but so far that bracket is doing what it is supposed to. It has not bent and it already has a good deal of preload on it.

When I get a chance I will pull the bracket and come up with a better design. I will post a drawing of what I come up with.

 

[JusMX141]

Here's one I built for a customer a month or so ago. I also rebuilt the turbo at the time- I could not have built the actuator properly without seeing the turbo. It's not like a 14B / 16G where the housings are always clocked the same.

The actuator itself barely needed any modification- only a slight bend to the arm to line up with the lever on the turbine housing.

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[gorf]

Here's one I built for a customer a month or so ago. I also rebuilt the turbo at the time- I could not have built the actuator properly without seeing the turbo. It's not like a 14B / 16G where the housings are always clocked the same.

The actuator itself barely needed any modification- only a slight bend to the arm. This particular MHI 20G turbo had a knockoff turbine housing on it, which actually worked better with the adjustable end to the Holset actuator.

Thanks for the pictures but they bring up another question. On that housing there are four tapped holes, you used two to mount the bracket and the other two have bolts in them. My housing is similar, but the two extra holes are a lot closer to the holes that I am using. Besides the compressor housings being clocked different do different compressor housings have different bolt hole spacing?

 

[JusMX141]

Besides the compressor housings being clocked different do different compressor housings have different bolt hole spacing?

All the bolt holes are for would be actuator placement. I've had 20G covers with (6) tapped bolt holes, and I've had 20G covers with none drilled at all. It doesn't matter which ones you use as long as the others are plugged and the actuator has the straightest path to the lever.

 

[TJCTalon]

Im confused. What PSI is the holset actuator? I just got a modified holset mhi actuator and I dont know what stock pressure is

 

[bryanwheat]

Im confused. What PSI is the holset actuator? I just got a modified holset mhi actuator and I dont know what stock pressure is

The holset actuator has a stronger spring so it won't allow the flapper to blow open at higher boost like the mhi actuator.

 

[JusMX141]

Im confused. What PSI is the holset actuator?

Anywhere from 15psi to 23psi that I've seen. There are tons of different spring tensions used on different Holset turbos.

The only way you'll know is to test the actuator itself with a pressure source and a gauge- but even this isn't entirely accurate because the actual holding pressure will vary by flapper size and turbine backpressure (turbine wheel size and housing a/r).