Anyone got a high flow turbo from GCG?

[muffas 180]

I bolted on my new high flow turbo which i got from GCG and it spikes to .95 bar from 5000 rpm on. I replaced the hose from pipe to actuator and even put my original actuator on but as soon as you get to 5000 rpm it jumps to .95 bar. This is on an R33 GTST. GCG stopped making their 500 hp high flow because of surging problems and the one i got is 470 hp then there is one lower rated at 450hp. Has any one else had this problem

Cheers Michael...

[2fardown]

Just a question... Do you still have the factory boost solenoid in place?

[BHDave]

Sounds like the factory step up, just at higher boost levels. The turbo by itself won't do that.

I have a stage 2 on an RB20 atm, once it peaks it stays flat. Just using an HKS actuator plumbed straight off the compressor cover nipple.

[muffas 180]

Power FC and boost solenoid kit, Front mount, blah blah blah. Its yet to go on the dyno. I was thinking today that its probably leaning out at 5000 rpm on as im reaching 100% duty cycle around there which will cause the boost to rise. My knock level is still low. I will see what happens thursday on the dyno.

Michael...

[Jay95R33]

Just a quick question, how much on an improvement is the CGC highflow over the stock turbo??

Did you notice any more lag, came on boost stronger etc...

Thanks

J

[Talej]

apparently the boost solenoid kit for the power fc has been known to cause a few problems. I got mine put in a while ago and the boost is all over the place.... I went to croydon and they suggested trying a different boost controller...

I haven't got around to it yet but it could be something worth looking into for you...

[Sydneykid]

Hi guys, I have never heard of or seen a problem that can be proven to be caused by an Apexi Power FC boost controller kit. It uses the same solenoid to control boost as the AVCR, so if it has a problem then the AVCR's would have it as well.

I keep hearing about boost control problems on cars with Apexi controllers, but it always turns out to be something else.

[Talej]

got any examples/ideas of what else it might be then? I am only going by what CRD have told me and would be happy to hear other ideas as it could save me a lot of money...

the problem I am having is major loss of power at high revs.... boost "flutters" really bad (e.g. up then down then back up etc...)... On a dyno I got 3 totally different figures after the car was all warmed up and ready to go... figures differed by about 20rwkw each time...

sorry about the thread hijack muffas....

[muffas 180]

Just a quick question, how much on an improvement is the CGC highflow over the stock turbo??

Did you notice any more lag, came on boost stronger etc...

Thanks

J

Yes huge difference. Pulls so much harder and longer on the same boost setting. It is a little bit laggier. Makes 1 bar by 3700rpm. Thats with a standard map. After tuning should be better.

Car is at the dyno now so ill see how the boost spikes ends up. I completely by passed the solenoid and ran a new hose from pipe to actuator and it still spikes to 1 bar from 5000rpm on.

Michael...

PS ive never heard of problems with apexi solenoids either.

[Sydneykid]

Hi Talej, this is thread hi jacking, but sorta relevant...

A boost controller solenoid works by opening (bypassing) and closing rapidly to limit the boost the wategate actuator sees. So you can have say 15 psi but the wastegate actuator only gets say 10 psi.

The boost controller also works when you are trying to steepen up the boost curve by keeping the wastegate shut longer. Some are rated at 10 psi but start opening at 5 psi, some people call this "boost creep" which is not strictly technically correct.

The problem with all boost controllers happens when you have a big difference between the initial opening psi of the wastegate actuator (say 5 psi) and the boost controller (say 15 psi). The solenoid has to work very hard to bypass this much pressure.

What we have found works well is to increase the pressure of the wastegate actuator. A stronger spring, lengthening the actuator rod, spacing the actuator away from the turbo body or using a higher psi wastegate actuator (eg; a RB20DET actuator on an RB25DET) all achieve this.

If the wastegtate actuator is now say 10 psi, this means the solenoid (still 15 psi) only has to bypass half as much. This results in much better accuracy of boost control.

Another issue can be the size of the wastegate itself, if it is too small it won't allow enough exhaust to bypass the turbine and you end up with boost creeping upwards. This can also be a problem with dump pipes that don't allow enough exhaust flow from the wastegate.

There are a number of other possibilities but I have hijacked the thread enough with this post.

Hope it helped in some way

Merry Xmas to all

[Talej]

thanks... what you say makes a lot of sense... I guess time will tell.

[muffas 180]

I got the car back yesterday morning. It made 229.2 kws @ wheels on standasrd injectors. ive got PFC, PFC boost solenoid, 1 bar of boost, GCG FMIC kit, Malpassi reg, GCG 470hp high flow turbo, pod, exhaust and dump.

The guys said they haddent had a skyline on the dyno with standard injectors make that much power before. Mind you the reg was set at 90psi at full throttle and boost. The car makes 1 bar of boost at 2700rpm. AFR's were 11.5 the whole way through. They attempted to tune @ 1.2 bar but one of the coil packs broke down after 1 bar.

The only way to run less than 1 bar boost with this turbo is to take it off and send it back to GCG. Spewin.

Michael...

[Sydneykid]

Hi muffas 180, the minimum boost is controlled by the wastegate actuator spring. If it is set at 14.7 psi (1 bar) then the wastegate won't open until 1 bar. I have never seen a GCG hi flow with a 1 bar actuator, in fact I think the highest I have ever seen is 12 psi. Ours is 10 psi.

So you don't have to "spew", either something else is holding the boost up at 1 bar, in which case fix it. Or shorten the wastegate actuator rod. The worst case is send the wastegate actuator (not the whole turbo) back to GCG and have them fit whatever rate spring you want.

Hope that helps

[rb20-calais]

Sydneykid,

What power do you think that the GCG Stage 1 & 2 would make (approx) on an RB20 with Wolf 3d v4, GTR Injectors, Bosch910, Exaust & Dump, Hyperflow Cooler & POD at around 18-20psi.

I am considering getting a GCG High Flow opposed to my GT28 because there is less fabrication and I will be able to do the work myself.

GCG quoted me $1550 for a Stage 1 @ trade price which is damn good I thought.

Evan

[muffas 180]

$1550 is what i paid. I replaced the actuator with my original one but it made no dif. I think its n the exhaust housing. They were talking about having to machine it. They said they can only fix the prob if i send them the whole turbo. The boost spikes to 1.1 bar when its cold.

Thanx Michael...

[rb20-calais]

Did you get it new from them? Trade? It says on there site that the stage 1 is 450hp and the stage 2 is 500hp ... is the stage 2 now a 470hp?

Evan

[Cubes]

I think its B-Man from memory has a stage 2 500hp GCG turbo that also came with a 1bar actuator. I am pretty sure the bloke who fitted and supplied the turbo for him ordered the 1 bar actuator specificially.

[rb25]

more bad stories......

[Sydneykid]

Hi guys, I am not a fan of the 500 bhp (or Stage 2) RB25DET ball bearing hi flow. It runs too close to the compressor surge line on RB25DET's, let alone RB20DET's. That's probably why they may have respecified the turbine down a little to 470 bhp, that would give some headroom. We use quite a few stage 1's on RB20DET's, RB25DET's and Neo's and never had a problem.

As for muffas 180 problem, I guess anyone can make a mistake, even an experienced turbo shop like GCG. I am always sceptical though, as I have heard a number of times about hi flow problems, but it usually works out to be something else.

I am sure there is more data to come on this issue.

[Cubes]

So the Stage 2 GCG turbo would work well on the RB30DET then?!?