EVO8LTW

iTrader: (41)

I have an 18 psi actuator on my Black and I'm wondering whether that might be causing some erratic boost issues I have on spool-up. Does anyone else with a Black have the 18 psi actuator?

For those with a 25 psi actuator, what does your boost curve look like when you run at wastegate pressure. Is there creep above 25 psi up top? How high does your boost spike at wastegate pressure?

Thanks.

bbyevo8u

iTrader: (14)

i thought the black only comes with the 25wga, did you opt. for it?

EVO8LTW

iTrader: (41)

When I bought it I was given a choice.

bbyevo8u

iTrader: (14)

are you sure your wga is preloaded correctly?

Jerm__

http://store.forcedperformance.net/m...e=Lancer-Turbo

Thats correct. You have the choice between the 25psi and 18 psi wastegate actuator.

How much PSI are you boosting?

Evoryder

iTrader: (55)

Your preload is probably not where it should be. I have the 25psi gate on my red. Boost is consistent always(Forge MBC)

wizzo 8

iTrader: (35)

I have a 18 psi forge wastegate actuator and when I run on wastegate pressure I get boost creep up to 25-27psi after about 6500rpm. When I run my normal psi its fine.

EVO8LTW

iTrader: (41)

I have about 1/2 circle of preload and at wastegate pressure I have an even 19 psi. I'll probably try adding some more preload. I'm boosting to a peak of 30-31 in the midrange and tapering (intentionally) down into the mid-20s above 7000 rpm.

sparky

iTrader: (1)

With the 18# actuator and running 31# I would run a fully filled circle. Probably you should try getting it up to a minimum of 23-24 spring pressure. If you are at 1/2 circle/18# spring pressure then add 3&1/2 complete rotations more clockwise on the turnbuckle to start with. You may end up wanting to do another full turn to end up at 4&1/2 more than what you currently have... if 3&1/2 additional turns isn´t enough.

You may have to cut the end of the actuator rod to get enough tension on that puppy. But me I wouldn´t even try to run the 18# actuator on a Black at over 26-27# peak. I would just go straight to the 25# actuator if I was running the Black at 31# peak...don´t pass go! Don´t collect $200.

tscompusa2

iTrader: (22)

when running off the gate mine looks like this;

which is odd.. turn the boost up and it will spike then tapper off.. complete opposite of what it does when running off the gate pressure.

this is a FP 25psi actuator pretentioned to hold 25-30psi.

EVO8LTW

iTrader: (41)

With the 25 psi gate I worry about creep up top from the higher spring rate reducing the travel of the actuator rod. Running a heavily preloaded softer spring should give similar seat pressure with a more widely opened wastegate once it starts opening. I'll try adjusting the preload tomorrow or Saturday. As long as I can bring boost down to 23-24 psi up top (my conservative altmap when things go wrong), I'll be okay with the additional preload (reduced range of travel of the WG puck).

tscompusa2

iTrader: (22)

Basically you'll get what i get shown in the boost plot. It is not a good combination for someone that is running 91octane and needs to keep boost low

I would say the 18psi gate fp sells would be a better bet with lots of preload as you just suggested.. i suspect the creep would only go about 22 instead of 30. its still going to creep i think tho.

heres log for reference: (ignore the crappy spool - didnt tune a/f yet there)

Boosted Tuning

iTrader: (12)

IMO you should try preloading the 18WGA you have now, all the way.

Also, me and a couple others could only get 22-23 off of our FP25WGAs when preloaded ALL THE WAY.

EVO8LTW

iTrader: (41)

tscomp-- That's wastegate pressure with the 25 psi WA? Holy cow. That definitely would not work for me when I get on the road course. 28 psi at 7000 rpm on pump would push the EGTs into the danger zone for road course sessions.

Boosted Tuning -- Are you sure that those cars didn't have the 18 psi gates on them?

FWIW, on my old FP White Rabbit turbo, I ditched the FP 18 psi actuator because it crept to 24-25 in the mid-range on wastegate pressure. I went back to the stock 11 psi actuator. Of course, that was back around 2004 when we all thought 24-25 psi was a race gas boost level.

The-Evo

iTrader: (20)

I am running the 18psi waste gate on my fp black and I dont see any boost creep. It holds a constant 27psi all the way to redline. Iam not sure what you guys are talking about when you say to adjust preload. How is that done and why?