A customer of mine had me build his engine and install an APS TT kit. Hes been running around with much less HP then the potential of his engine due to the actuators being too light.

We are going to change the fuel system and engine management solution out for some more suitable stuff for the project once we can crank the boost.

I have come across plenty of actuators that I could "rig" up, but I dont want to put this car under the knife just to experiment with something at the customer's expense of time and parts. I am looking for something that has already been done, as this customers car is not my personal experiment.

If you have a solution to the light wastegates that you have tested and run on your own car, please let me know. What is the product (link?) that you are using, what is your min. boost setting, and how do you feel about the quality of the parts?

Thanks to anyone that has any information to provide.

-Charles

 

Charles,
Call Tuan if you get a chance. I sent him some Forge billet actuators a couple weeks ago to try on a couple of their cars. All I had to do is shorten the rods and rethread them at the time for prototypes but I believe Forge can do them now very quickly. If not just call me and I might be able to assemble some for you with springs ranging from 7psi to mid 20's. PM'd you my phone number. I think you would be hard pressed to find anything close to the modular nature, build quality, and warranty of the Forge actuator. I might be biased since I worked there for 3 years and I know a little birdy told me APS themselves are using a pair currently.

 

Had heard a rumor that some of the Forge actuators could tear diagrams under vaccum. Any truth to that , if so was it resolved?

 

PM RedLeader ....he has upgraded with new Garrett actuators.

https://my350z.com/forum/forced-induction/144846-who-s-ditched-unichip-or-aps-boost-controllers.html

 

I have the Forge actuators installed, however I haven't run the car at full throttle yet since I haven't had time to tune it. I may do it this weekend. The install is pretty straight forward, and the part is very simple, so I don't anticipate any problems.

 

What springs are you useing?
The 9-15psis?

 

Yep

 

Yes, on the srt4 there was an issue with vacuum pull on the diaphragm. This is not an issue on the APS kit as it is sourced solely from a positive pressure source. The srt4 was a hodge podge of reference lines that everyone and their mother had a different way of hooking up both the BOV and the actuator references. I know over the last three months Forge had redone the tool for manufacturing the diaphragms and is making them slightly thicker. I am not a fan of running vacuum to any actuator as most OEM turbo systems simply take the positive pressure reference from the front of the compressor cover to limit the length of the reference line. Problem is that way it doesn't account for any pressure loss in the system so the actuator might open at say 10psi, but the intake only sees 9 after going thru the piping and intercooler. A reference closer to the inlet of the TB allows for the pressure drop to be accounted for and in essence, higher boost at the intake manifold. This is similar to what APS does taking the reference just before the TB. Hope that helps!!

 

Thanx for the info.

 

Charles-
I bought the upgraded garrett actuators and had them installed when my APS TT kit was installed. When I took my car to Rob at Z-Car Garage for tuning, he found they were not set correctly. He pulled them and upped the preset level. I think you have to use the actuator arms from the ones that come with the kit. He's controlling them with an electronic boost controller very well. No final numbers, yet. Am I building up enough "brownie points" that I get to test the CJM intake?????

Bruce

 

+1 on the Forge Motorsport billet actuators.

 

Bruce cant wait to see your #'s. I was at the shop a couple days ago and they had the fuel pump out. Man you had a lot of junk in that filter! Seems like the guys are pretty much going through your car!

 

I do appreciate the info... as for testing the intake... well the prototype is 100% complete, done, poslished etc... what we are working on figuring out now is how to reproduce it cost effectively. I have to figure out how much it will cost to reproduce and what type of retail price the market will accept for it, and then we can decide if we are definatly going to reproduce it.

We are going to test it on a NA car within the next few weeks, but I expect the results on a NA car to be a little dissappointing, but who knows maybe it will surprise us. It really was designed for 600+hp.

-Charles

 

The Forge actuators work. I also ... uhh.. "tested" them under -25 psi (vac) and they still work just fine, so reliability of the diaphram doesn't seem to be an issue.

I put the 9-15 psi spring in there and they hold 9.2 psi just fine. I haven't tried to increase the boost yet as I am having some other tuning issues with the EU + 650's (gag).

Chris

 

Rob says he's boosted into the 15-17 pound range without any actuator problems on my new Garretts. Fuel delivery has been my problem. Like I posted earlier, the APS boost controller doesn't quite seem up to the job, so he installed an electronic controller that works great.

 

where can i get the garretts? i want to run around 15 to 17 psi. what boost controller are you using also? thanks red

 

Rob at Z-Car Garage convinced me to go with the new Greddy Profec Spec II. It's simple and it works perfectly.