Hks Adjustable Actuator On Gcg Highflow. Trying To Get 20psi

[Luke_GTS-T]

Hey everyone, I'm running a gcg highflow on my r33 gtst and my boost control methods include a greddy profec and hks adjustable actuator. Even though i have adjusted the hks actuator by changing the length of the rod, I have boost tappering off in higher rpm? I beleive this is due to the fact that changing the rod length is only changing the preload etc... So my question is, what actuator should I get in order to hold 20psi, and where can I get it from?

Has anyone used the Power Enterprise ones? refer to link http://www.rhdjapan.com/power-enterprise-s...-actuator-57475 any thoughts on these?

Luke.

[hypergear]

Its not going to work with just actuator. Tubine housing is too small. Which results very high exhaust manifold pressure.

When manifold pressure > Actuator spring load = pressure forced open wastegate = boost drop.

Force = Pressure x Area

We spent lot of time investigating this problem and there are 2x solutions this problem.

Type 1: fixed Force which is same as using a ultra high pressure actuator. This resulted massive boost spike at certain conditions.

Type 2 which we currently using is made to reduce Area. That worked out very well by giving a very nice creep up top.

Also depending on the combination of turbo that you've got. Not all turbos produces more power with more boost.

[Luke_GTS-T]

Hey, so basically your saying even if i go for the higher psi actuator im not necessarily going to fix boost drop off?

Tell me more about this "Type 2" how exactly do you reduce area?

[KiwiRS4T]

How much power are you looking for ? I got 245awkw out of a GCG highflow (R33 not R34) at 16psi - could probably have got a bit more with a better front mount.

[discopotato03]

To get the most from OE housings you need the OP6 turbine side one from some R34s and the single BB Z32 VG30 four cam engine .

It will help reduce the turbine inlet pressure so you make more power per pound of boost and reduce the force/area on the face of the wastegates flat valve .

I know people who cranked about 266 RWKW out of an RB25 with head work/cams/GTR IC/larger injectors and a PFC .

I think the boost was around 16-17 pounds .

A .

[andymoocow]

my 2 cents, i am far from a turbo guru, but my old R33 had a R33 GCG high flow on it, not sure what actuator, with all supporting mods and profec B spec II boost controller and i was running 20psi and made 255rwkw on a nice conservative tune from UNIGROUP.

I used 15psi around town most of the time.

[Harey]

Hey, so basically your saying even if i go for the higher psi actuator im not necessarily going to fix boost drop off?

Tell me more about this "Type 2" how exactly do you reduce area?

Have a read of the Hypergear thread in this section, its a big thread but lots of useful info.

[Luke_GTS-T]

Hey thanks everyone for your input. Took car to unigroup today, don't think the actuator or boost controller are the problem, maybe a restrictive cat is causing the issue im having.

[Tangles]

found I had a lot of boost drop in higher rpm with HKS adjustable (1bar) actuator

changed it out for a garrett 18psi adjustable actuator and fixed the boost drop

now have an area around 5500rpm where the compressor wheel of the turbo slows down then speeds back up again

might try bending the actuator rod a little

[T04GTR]

i have seen this problem alt with high flows.. has to be a turbine back pressure issue. so a big stiff wastegate is the only option.

[Luke_GTS-T]

found I had a lot of boost drop in higher rpm with HKS adjustable (1bar) actuator

changed it out for a garrett 18psi adjustable actuator and fixed the boost drop

now have an area around 5500rpm where the compressor wheel of the turbo slows down then speeds back up again

might try bending the actuator rod a little

Hey Brendan, where did you buy your garrett actuator from?

[manuel]

I run a r33 gcg hi flow and also had it tuned at Unigroup. I made 254kw atw with stock air box. I notice that my car boost to 20psi then drops off to 16.5psi from 5500rpm through to 7000rpm. I run a 10psi actuator from a r32 stock turbo.

If you find a soloution to this boost drop then let me know as well. As far as i know i think im on the limit of power for this type of turbo. Ideally though, i would like to hold 18 to 20 psi through to red line...

[600hp]

get one with a 17psi spring in it

[Tangles]

Hey Brendan, where did you buy your garrett actuator from?

ebay, around $100~

[Karadeniz]

Found this thread via search, and i currently have a similiar issue and cannot find a solution thus far.

Have a hiflow turbo setup on an rb25 neo motor.

currently making 240-250rwkw , boost peaks at 19-20psi and drops off around 5000rpm down to 14-15psi

What ive tried:

-i have tried replacing the stock actuator with a 14psi actuator from gcg... this didnt seem to fix much

- I have changed the split dump pipe setup to a single belmouth dump and also replaced the cat with a higher flowing cat (to exlclude possible restriction)

it could be that this is it for this type of turbo and even at 20psi if it were to hold it wouldnt make much more power, but my concern is why does it drop off so much? and is there a possible fix

any help on what i could check please?

[KiwiRS4T]

What kind of boost controller? I had a Jaycar with my GCG highflow and could tune it finely holding 16psi but boost started dropping off from 5000 and I think that was all the turbo could make.

[Karadeniz]

What kind of boost controller? I had a Jaycar with my GCG highflow and could tune it finely holding 16psi but boost started dropping off from 5000 and I think that was all the turbo could make.

Electronic Boost Controller

but have tried it on tap also just to see if its the EBC.

oh and tried it with a different ebc also. still drops off after 5000.....drops about 5 pounds... this might be normal/turbo running out of 'gas'

but just not sure

[Harey]

Yup thats all the turbo can flow. I am yet to see a hiflow on an RB25 hold over 18psi flat to redline.

[SkudR33]

Hey guys,

I know I'm reviving an old thread but I wanna ask these GCG highflow turbos that these guys are talking about - are they a stage 1 or stage 2 highflow?

Gettin my turbo highflowed to stage 2 so I'm slightly concerned after reading this... The guy behind the counter told me it'll hold 20psi before gassing out!

[KiwiRS4T]

I bought my GCG about four years ago - if I were doing it today I would go Hypergear - better and cheaper. If you are determined to go with GCG ask the "guy behind the counter" to put in writing that the turbo will hold 20psi up to x revs in x gear!