Jump to content
SAU Community

Recommended Posts

I had a brand spankers gcg highflow on my rebuilt rb25det. Now it had a series1 rb25det rear housing that was milled out and a rb20det front cover. The car occasionally blew some smoke on cold start if you accidentally boosted it but I never found the cause.

Was running about 10psi and making roughly 200kw as it was waiting for a full power tune. I was driving it one night and it suddenly made a VERY loud whirring noise so I immediately throttled off, I then drove home slowly, at one point the noise went away so I reved it to about 3k and I believe the bearing seized as it made no boost, the car refused to rev and it had no power. Once again I throttled off and babied it home around 1500 rpm. About 30 seconds later it un-seized and started making the horrid whiring noise.

Once home I removed the turbo, upon inspection the shaft was twisted/bent and the compressor blades had made very slight contact with the housing, there was no oil to be seen in the front or rear of the turbo, however plenty came out of the oil feed along with coolant from the coolant feed.

I started the motor with no exhaust and did an oil flow test, got about 400ml out the oil feed in approx 15 seconds at idle so thats about 1.6L per minute of oil the turbo was getting, ample according to Adelaide Turbo Services.

Now there was zero sign of foreign material ingestion and the bearing still seemed ok and it would spin alright, I'm not sure if it was the blades touching the housing that stopped it free spinning for more than a second or the bearings were shot. Now I am sending the turbo off to GCG for inspection and to see if it will be covered under warranty. I would open it up and look at the bearings to see if they are blue and cooked from oil starvation but I don't want to void my warranty.

What could cause a problem like this? Providing it was getting adequate water and oil and it had a good tune, how could the shaft warp itself and cause the impeller to hit the housing? The only things I can think of are an impossibly small manufacturer defect (if it lasted 2500kms theres no way their balancing machines would pick it up) which caused the shaft to slowly get worse and worse over 2500kms or contaminated oil making the bearing f**k out.

Oh also the car had had an oil change about 800kms prior to the failure with fully synthetic mobil 1 oil and there was zero (visual) evidence of bearing material in the oil.

It is being sent off to brett at gcg tomorrow for a full inspection and report, I really hope it is covered under warranty as a new shaft, impeller and bearing will be at least $1500.

Also the use of a the rb20det front cover, will that restrict the top end power much? Is it just a smaller inlet or a smaller overall cross sectional area?

Cheers guys and wish me luck

:D

  • Replies 42
  • Created
  • Last Reply

Top Posters In This Topic

was it a bush turbo or ball bearing?

did it have the standard oil lines going to it? if so then that why its gone. if its ball bearing then one of the oil passages is blocked in the turbo.. thread tape, silastic etc etc.

if you grab the comp wheel, does it pull in and out?

Ball bearing turbo and oil seems to pass through it with no problems. No shaft play, its just warped and off centre. It was set up exactly as the manufacturer specified. If thread tape had blocked the oil feed surely it wouldn't have lasted more than a few hours let alone 2500kms ?

Edited by Rolls

thread tape has a tendency to work loose or deteriorate over time, it should never be used for oil feed anyway as the banjo washers is what seals it, or if your using dash fittings use a liquid pipe sealant instead.

as for what caused the prob, i dont think we're going to know until its stripped down so maybe wait and see what GCG have to say.

hopefully they are more helpful then ATS who i might add, are a bunch of dickheads, a mate of mine had a turbo rebuilt by them, and it didnt last one track day. they then refused to repair ir under warrenty as they suspected there was an oil supply issue, where there was not.

Yeah there was copper washers on my oil feed and oil drain, no thread tape anyway. The blokes down at gcg have always been very friends/helpful and nice on the phone so I'm confident they will find the problem and help me out.

Will do, I took it to Adelaide Turbo Services so I could get a quick opinion before sending it off as the bloke there knows his stuff and he was fairly stumped, he seemed to think that either the shaft was bent the tiniest bit from day one or something else strange had happened.

It left today so should get to them sometime this week. Hopefully hear back from them early next week.

Details of intake setup?

Apexi super induction pod, standard AFM (not hooked up) with stock bendy piping, rb20 elbow going to rb20 compressor cover.

Rb20 bov attached to r33 intake pipe venting back to intake via a rubber hose. Bov nipple attached to the standard location.

Hybrid FMIC.

Vented catch can

Here is the only picture I can find, doesn't really show much.

skyline2h.jpg

Edited by Rolls
brett at GCG is a good guy anyway... hopefully something gets sorted for you.

Yep he was very helpful on the phone and seemed like a nice guy. I'm confident it will get sorted out, I've only ever heard good things about their turbos before, who knows it could be an exterior fault that caused it anyway.

The RB20 compressor housing is smaller than the RB25 one so it may limit airflow a little on an RB25 . I'm a bit surprised they didn't ask about that if they knew it was going on an RB25 . It may be worth trying to find the right housing if you want all 43 beans out of it .

If you can't PM me as I think I still have a VG30 BB one which from memory is the same casting as an RB25 one . I'll possibly be back at GCG on Monday so could drop it off .

Cheers Adrian .

Apparently the balance something drooped which caused everything to spin out of balance and eventually eat the bearings and the compressor wheel. He said the cause was excessive exhaust gas temperatures as everything was blue.

My dyno sheet says the afrs are around 12:1 and the cat, middle exhaust and rear cannon aren't blocked so what could cause this? I am going to get a complete re tune when the turbo goes back on the car but I don't want a repeat performance.

Was quoted $1200 for new bearings, front wheel, shaft and balance weights, quite cheap as he said he would do it minus the labour charges which I really appreciated. Basically an entire new turbo with new warranty minus the housings obviously.

Spoke to the guy who originally looked at it (adelaide turbo services) and he said they it looked like nut on the front of the wheel had been ground all the way around and had huge chunks taken out of it which he said suggests they struggled to balance it in the first place, also at 8psi even with a blocked cat nothing should melt and droop from heat.

Oh well live and learn, I can't really argue with them and it is a cheap price considering it is 1 year out of warranty and I am essentially getting a new turbo.

Edited by Rolls

For $1200 id be talking to hypergear about a brand new turbo

Try the ART28G4 including internal gate kit oil line and dump pipe its costing me $1330 delivered will flow over 300rwkw

For $1200 id be talking to hypergear about a brand new turbo

Try the ART28G4 including internal gate kit oil line and dump pipe its costing me $1330 delivered will flow over 300rwkw

It won't be ball bearing though and if its good for 300 it will have bigger wheels so it will be laggier for two reasons. I liked the gcg one because it reached my target of 250kw and is ball bearing so has response almost as good as that of the stock turbo. I'd imagine that turbo wouldn't come on hard until 4k+ where as the gcg one comes on pretty strong by 3-3.5k.

It is a street car so I want the smallest laggiest turbo possible for my target power. For $1200 nothing else is going to go to that, If I was starting from scratch I'd go pay bill at Adelaide turbo services $2k and get him to set me up one with garret wheels and bearing core in the standard housings.

edit: I had a look at their website and a comparable turbo is this one:

http://www.digi-hardware.com/tr28gt.html

The G2 450hp model which is $1500 not including delivery or GST so it would be more like $1700+ and $1200 is already stretching my budget as I didn't plan on a turbo failure.

I still need to get this thing tuned and through a regency inspection which is another good $700 I don't have.

Edited by Rolls

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



  • Latest Posts

    • Place the new daughterboard in the case and mount it using the 3 small black rivets provided, and reconnect the 3 factory ribbon cables to the new board Then, use the 3 piggyback cables from the daughterboard into the factory board on top (there are stand offs in the case to keep them apart. and remember to reconnect the antenna and rear cover fan wires. 1 screw to hold the motherboard in place. Before closing the case, make a hole in the sticker covering a hole in the case and run the cable for the android unit into the plug there. The video forgot this step, so did I, so will you probably. Then redo the 4 screws on back, 2 each top and bottom, 3 each side and put the 2 brackets back on.....all ready to go and not that tricky really.      
    • Onto the android unit. You need to remove the top screen because there is a daughterboard to put inside the case. Each side vent pops out from clips; start at the bottom and carefully remove upwards (use a trim remover tool to avoid breaking anything). Then the lower screen and controls come out, 4 screws, a couple of clips (including 3 flimsy ones at the top) and 3 plugs on the rear. Then the upper screen, 4 screws and a bunch of plugs and she is out. From there, remove the mounting brackets (2 screws each), 4 screws on the rear, 2 screws top and bottom and 3 screws holding in the small plates on each side. When you remove the back cover (tight fit), watch out for the power cable for the fan, I removed it so I could put the back aside. The mainboard is held in by 1 screw in the middle, 1 aerial at the top and 3 ribbon cables. If you've ever done any laptop stuff the ribbon cables are OK to work with, just pop up the retainer and they slide out. If you are not familiar just grab a 12 year old from an iphone factory, they will know how it works The case should now look like this:
    • Switching the console was tricky. First there were 6 screws to remove, and also the little adapter loom and its screws had to come out. Also don't forget to remove the 2 screws holding the central locking receiver. Then there are 4 clips on either side....these were very tight in this case and needed careful persuading with a long flat screw driver....some force required but not enough to break them...this was probably the fiddliest part of the whole job. In my case I needed both the wiring loom and the central locking receiver module to swap across to the new one. That was it for the console, so "assembly is the reverse of disassembly"
    • But first....while I was there, I also swapped across the centre console box for the other style where the AV inputs don't intrude into the (very limited !) space.  Part# was 96926-4GA0A, 284H3-4GA0B, 284H3-4GA0A. (I've already swapped the top 12v socket for a USB bulkhead in this pic, it fit the hole without modification:) Comparison of the 2: Basically to do the console you need to remove the DS and PS side console trim (they slide up and back, held in by clips only) Then remove the back half of the console top trim with the cupholders, pops up, all clips again but be careful at the front as it is pretty flimsy. Then slide the shifter boot down, remove the spring clip, loose it forever somewhere in the car the pull the shift knob off. Remove the tiny plastic piece on DS near "P" and use something thin and long (most screwdrivers won't fit) to push down the interlock and put the shifter down in D for space. There is one screw at the front, then the shifter surround and ashtray lift up. There are 3 or 4 plugs underneath and it is off. Next is the rear cover of the centre console; you need to open the console lid, pop off the trim covering the lid hinge and undo the 2rd screw from the driver's side (the rest all need to come out later so you can do them all now and remove the lid) Then the rear cover unclips (6 clips), start at the top with a trim tool pulling backwards. Once it is off there are 2 screws facing rearwards to remove (need a short phillips for these) and you are done with the rear of the console. There are 4 plugs at the A/V box to unclip Then there are 2 screws at the front of the console, and 2 clips (pull up and back) and the console will come out.
    • So, a bit of a side trip, but one that might be interesting for people with JDM cars and japanese head units. I know @Pac previously posted about a carplay/android auto adapter he installed which used the AUX input, and @V35_Paul put in one of the Tesla style units that replace both screens. The option I went with was a Lsait LLT-YF-VER5.87_2 (https://www.alibaba.com/product-detail/Lsailt-8GB-Android-Multimedia-Interface-for_1601187633672.html). Price was $1,150 for a single unit although they are much cheaper if you are willing to buy 2....$857ea. Make you you get the version 2 not version 1, it is faster and has a better UI - this is the manufacturer listing: http://www.lsailt.com/product/348.html. BTW if you've never bought from Alibaba before, don't be concerned....these guys can't stay in business unless they are responsive, ship fast etc, they were excellent (probably faster shipping than most local places) So, this was my task for a lazy Sat afternoon....looks complex but was all done in a few hours (it probably helps that I had some of it apart before so it was a bit familiar). I also decided to add a HD USB drive recorded at the same time and the unit also supports an aftermarket reverse cam (if you don't want to retain factory) and also AV in and HDMI out It looks much worse than it is, in fact in was genuinely all plug and play (no custom wiring at all). This video was pretty good (skipped a few steps), unfortunately they are an Aussie seller but no longer sell this unit (I guess Carplay/AA adapters are easier to install and much cheaper) https://www.youtube.com/watch?v=T5hJfYOB8Dg
×
×
  • Create New...