will the aps turbos even flow to 20 psi? where do they max out?

 

They will spool past 20psi, but wont make much more power past 20psi. 18-19psi is the sweet spot, in terms of efficient airflow.

 

ok, sorry - that helps clear things up - I thought you all were talking internal wastegates...

Just want to clarify that with a good electronic boost controller, an internal wastegate can go as high as the boost controller can withstand, yes? The internal wastegate only sees atmospheric pressure until the boost controller decides to allow any flow at all, correct?

 

So what's the minimum blue will make?

 

19...well when you say make, 19 is the lowest you can technically run, if you run just spring pressure, the minimum is 19 at WOT. now, you can make lower, if you only go half throttle, but who wants to do that? LOL.

 

it all depends on the preload created when tightening the plunger into the actuator...meaning, the plunger has a threaded shaft, the further the shaft is threaded into the actuator arm, the tighter the wastegate is pulled shut,= the higher base boost pressure it will create, one can differ 1-2 psi just on the tension created as explained here...

so the variance comes from the fact that this is not an exact science with setting an internal wastegate/actuator setup...this is the reason some don't like the aps kit, I have mastered swapping springs with my turbos and actuators in the car, take sme less than 2 hrs to swap em out..I have done it a few times, and have it set up exactly how I like it

TODD

 

another note: we did tons of bench testing with the aps turbo/forged actuators to attempt to "set" the boost pressure before putting the turbos back in the vehicle, conclusion--> not accurate..it will give you a gross ballpark, but in no way will simulate the exhaust flow, backpressure, etc that is created in a real world situation..so, as everyone has unanimously stated, go with the red spring and save yourself from having to swap springs several times...

tighten the plunder rod at least 4-5 threads in, just tight enough so you can put the actuator cap on without it touching the plunger, that will be the least ammount of tension you can set with the red spring--> will/should yield between 10/11-13 psi with the bc off

 

Tig,

I'm looking at the spring ratings written on the box, and it says:
Green: 5-10
Yellow: 9-15
Blue: 14-18
Red: 19-24


Red is rated at 19psi to 24psi!!! When I press on the blue and the red spring, I can definitely tell that the red spring is stronger than the blue. Perhaps forge motorsports changed the spring color and I have the old one?? Hmm...

 

That is exactly what I understood to be the facts as well. I'm glad my tuner suggested and went with blue springs.

 

thats right , i had them backwards.

 

hi guys.. contacted forge UK.

and they confirmed that the yellow spring is 5-15.. :S i am confused here