Please Help Me With My Very Lazy Gt2860-9's!

[tommis85]

tommis85: with your foot pump hooked up what pressure did the wastegate start to crack open? how much preload have u dialed in (1 full turn is equivalent to 0.8 mm) and as a result what is your peak boost.

Cheers

Linkems,

When I originally hooked it up it cracked at about 5psi and opened from there onwards to be fully open by around 10-12psi.

I wound on about 10mm and it then proceeded to crack/budge at about 10-12psi then gradually open up from about 15psi onwards to be wide open at around 18psi.

I think the 10mm is about enough to counter the actuator spring and also the exhaust gases pushing on the flapper...to make it open at around 15psi when driving as to not boost over 18psi. Obviously my footpump only simulated intake plenum pressure and not exhaust pressure etc etc.

I haven't been able to check peak boost because I don't want to push it that high without tune.

Today, in 3rd I got about 16psi by 4000rpm.....prior tests were only in 1st and 2nd around town where it got around 12psi max at 4000rpm. Today I was also going up slight hill in 80/100 zone.

Hope all that helps a bit I'll probably be able to wind a bit of preload off again with the EBC provided the flapper stays shut long enough till EBC starts feeding a signal to the actuators.

[tommis85]

You should try it with a footpump yourself.....I recommend the foot version because you can place it on your strut tower and then gradually pump it or stop halfway thru a pump to see what the actuators are doing. It's also an AWESOME way to get the tightened up rods on and off

[linkems]

thats interesting, it's almost like we are looking at two completely different things. Note i am in the process of fitting brand new 15.6psi actuators to my -7s (already on the car) i'm assuming that -9 and -7 have same physical housing.

with my actuators off the car it takes around 14-15psi to see any movement on the rod. With it connected to to the wastegate i could only dial in 8mm before the rod was minimum length. The start reference point being when the actuator rod just manages to connect onto the wastegate tightly (if you spin it half a turn counter clock wise it will connect to the gate loosely). With 8mm preload it takes the air compressor 22-23psi before the gates even begin to open.

Can you confirm that you are using the same start reference point when you adjusted your preload and also if your actuators have the part number 430819-367 on the sticker. If you find it hard to see the sticker try checking if the last digit ends with a 7 and not a 9.

Edited July 9, 2012 by linkems

[tommis85]

Yep those would be the same ones I have.

I'll go double check the actuators now. I'll also test the gauge to make sure it's not fibbing.

I suppose it is just a sticker. Some monkey out there is in charge of sticking them on and who knows how many he stuffs up Or, maybe I was sold a softer pair by someone who just stuck the 430819-367 sticker on.

[tommis85]

Linkems, I just checked the actuators again and they crack at piss weak boost. I'm going to send off an email to the fella I bought them from and see if he as any reference material. Looks like yours are performing like they're meant to....they're 15lb units.

[linkems]

dont forget mine are brand new yours probably a bit softer now, but cracking open at 5psi with no or little preload sounds more like my std 8psi actuators. If you find out they are 100% not 15lbs units and want to get a pair pm and i'll link you.

[tommis85]

The full sticker reads like this, just FYI

A 430819-367

100511 PF

1808392

It has that letter "A" infront of the first number, over to one side in italics.

[linkems]

yeah that's the exact same part number

[tommis85]

dont forget mine are brand new yours probably a bit softer now, but cracking open at 5psi with no or little preload sounds more like my std 8psi actuators. If you find out they are 100% not 15lbs units and want to get a pair pm and i'll link you.

Nah these buggers were brand new as of 2 weeks ago or so. I bought them with brand new turbos. The interesting thing is that with very little preload these guys will ramp up exponentially in where they crack etc. I'll only be needing 7-8mm of preload and I'll have my 18psi (or more, hence probably having to wind some of it off again)

I guess it just comes down to exactly how the spring is loaded into the canister and what kind it is. It's obviously not loaded in their pre-compressed etc...for all that I know, it's just sitting in there which is why all of them require at least the standard 1.5-2mm worth of preload (ie, half the flapper shaft diameter)

I reckon these will be alright...if I only end up needing like 8mm of preload for now and I have plenty of travel remaining I'll leave them as they are. I want to couple them with an EBC anyway where you want them to open a bit under target boost.

[tommis85]

Hey fellas, would anyone be able to compare exactly how the -7's and -9's are? What I know is that the -9's are meant to give a bit more up top which yes, I've already noticed thanks to an f load of lag Is it just that the -9's are shifted back in the rpm range with their slightly smaller compressor blades?

Where abouts in the rpm range do the -7's actually pick up and when in the rpm range do they achieve say, 1 bar on an idealy tuned engine?

I'm thinking that 16psi by 4000 is still too laggy for me.

90% of my driving is in the city, so in 60 zones and all of it is under 3000rpm. I'm not liking the fact that the -9's only work properly a whole 1000rpm above where I do 90% of my driving.

[Piggaz]

Two tenths of nothing really.

It's a GTR, they weren't designed to be stump pullers at 2000 RPM. Stroke it and add VCT. That will fix it!

[tommis85]

So there really isn't much difference at all between the -7's and -9's down low?

Just weighing up all options before I spend another cent on something that I may not be happy with etc. Funny how people will always build something they actually don't want

Yeh that's true Piggaz, they're not a stump puller but they DO come on very hard down low with the ceramics, especially with upgraded actuators....I was hoping to not throw toooooo much of this awesome response away with my turbo upgrade.

I'm starting to think I'd rather my 350hp of awesome response and torque than the 400hp of pure lag where I have to stay in a lower gear just to keep with traffic.

[Hadouken]

He just needs a good tuner.

[R31Nismoid]

Hey fellas, would anyone be able to compare exactly how the -7's and -9's are? What I know is that the -9's are meant to give a bit more up top which yes, I've already noticed thanks to an f load of lag Is it just that the -9's are shifted back in the rpm range with their slightly smaller compressor blades?

Where abouts in the rpm range do the -7's actually pick up and when in the rpm range do they achieve say, 1 bar on an idealy tuned engine?

I'm thinking that 16psi by 4000 is still too laggy for me.

90% of my driving is in the city, so in 60 zones and all of it is under 3000rpm. I'm not liking the fact that the -9's only work properly a whole 1000rpm above where I do 90% of my driving.

The -7s aren't 1000rpm better... So what are you asking?

Mine were coming on hard @ 3300rpm, if you ones are not, then you have issues. Anything below 3300rpm is really not going to happen on a 2.6 even with stock turbos really.

[Hadouken]

For you to reference. Besides I highly HIGHLY suggest you go and get a tuner who knows what your meant to get and be able to tell you there is a problem with your setup

[sydking]

-9s are very linear huh.

[R31Nismoid]

Should start a -9 run from 2800rpm really and using 500rpm increments as they should be making 10psi before 3800rpm... Starting @ 3800rpm makes it hard to discern.... Even the above graph isn't great as 4800rpm before 22psi is seen is a bit lazy.

[Hadouken]

Should start a -9 run from 2800rpm really and using 500rpm increments as they should be making 10psi before 3800rpm... Starting @ 3800rpm makes it hard to discern.... Even the above graph isn't great as 4800rpm before 22psi is seen is a bit lazy.

Agreed. Cam gears next week

[XKLABA]

Should start a -9 run from 2800rpm really and using 500rpm increments as they should be making 10psi before 3800rpm... Starting @ 3800rpm makes it hard to discern.... Even the above graph isn't great as 4800rpm before 20psi is seen is a bit lazy.

fixed, and yeah that graph can't be scaled right, 20psi at 4800rpm with -9s definitely doesn't sound right

[XKLABA]

starting at 3800 rpm does give a good power curve though