Jump to content
SAU Community

Recommended Posts

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.

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.

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?

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.

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 .

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.

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.

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.

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

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?

  • 2 weeks later...

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...

post-68689-1281575968_thumb.jpg

  • 1 year later...

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?

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.

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

  • 1 year later...

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!

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!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • And if you want more power, more reliably, and cheaper, go get the Aussie RB... The 4L Barra and put that in instead.
    • No cats will keep discolouring the rear bar. Sends white paint a weird yellow stain. Cut and polish normally gets it out, but you'll be doing that every fortnight I found.
    • Both heads will be equally reliable or unreliable depending on what you do to them.  Stock the RB26 head will flow more. You have access to the stock intake ITB manifold on the RB26 cheaply which flows really well(1000hp+).   Arguably more aftermarket support for RB26, though in Aus we love our RB30 SOHC heads too.    The only downsides to the RB26 head is if you have a VL commodore and want to keep the SOHC look.  Where you may have an issue is drilling out the rb30 block for the bigger head studs but if you are building a big power motor you'd probably put bigger studs on the SOHC head too.  This is just about finding a good machine shop, sometimes easier said than done.  RB30 head worked can make big power just like a Rb26 head, so really it actually more comes down to what your preference is for your car.  People now even making billet versions of both.
    • 2630s work perfectly well. There is something to be said for just using the 30 head, as it saves all the pain of the conversion, still makes tons of power, still sounds cool, etc etc. 2630 will obviously make more power again, but the differences are not stupidly big. It really depends on whether you're racing for sheep stations or not. If it's dead serious, then it's a 26 head. If it's just for fun, it could go either way. But the 26 head and the effort to get it set up, etc etc, is part of the fun.
    • I've been building a 26/30 for a few years now. I've had the head built with all the good stuff. I had a 32 gtr but blew it up and yes its all going into a vl but im looking for some advice from some RB nuts on pros and cons on putting a 26 head on a 30 bottom end is it worth it Works are as follows Head -Extensive porting 1mm oversized supertech valves Supertech double springs Supertech valve guides Supertech titanium retainers Tomei solid lifters Tomei 270 x 10.25 cams Head drain Bottom end series 2 rb30 block Cp ceramic coated pistons Eagle rods Romac balancer Oil restrictions  O ringed blah blah spent a fortune And will get a girdle because the 30s arent used to handling that much rpm Nitto billet oil pump Hypertune plenum 6boost mani Refurbed astra pump thats the cover for it in the boot I did have a precision 6262 but sold it because drag car life. Currently building the ass end full 4 link floater rear end with a 2 speed  But the dilemma i have is my mate rekens I should just stick with the 30 head for reliability. Has any one had any issues with mounting the 26 head ie compression blowing gaskets etc. Just looking for some advice from people who have gone down this route. Here's some photos. Blew the oil pump in the gtr and decided to rip the motor out at the time and do a full build only to find it had been a repairable write off so went down this path.     
×
×
  • Create New...