Turbo Rebuild...

[jermzfree]

Hi everyone. My stage 1 rcc kit turbo might need a rebuild down the road. It has some moderate shaft play, no propeller scraping on the housing yet, and a decent amount of oil in the charge pipes and plenum. Every time I ride it the water injection nozzle gets clogged, i hope from just the oil. I bought the kit used so I don't know the exact millage, but I have put around 5k miles on it.
So I guess I have 2 questions:
1-Are the Garrett journal bearing turbos easy to rebuild for a novice? I have no experience with rebuilding a turbo, but have rebuild a Hayabusa motor and most other parts off a bike.
2- The one thing that has bothered me about my turbobusa since day one is the turbo lag! This is a street bike only. I think this turbo makes 425hp and I plan to stop at 300hp (no really) currently at 257hp. Would a ceramic ball bearing turbo with a smaller a/r make a SIGNIFICANT improvement on response time from what I have?

Thanks for all input!

 

[OZBooster]

Journal brg turbos are not hard to rebuild , mark the compressor and shaft so you can reassemble to same position
exhaust housing removal is usually the hard bit, needs lots of heat if the turbo casting is weathered or carbon caked after a few yrs use , tapping the housing and feeling for contact on the exhaust wheel by rocking the compressor side as you do it
use a t bar socket to remove the compressor nut so you dont sideload the shaft and potentially bend the shaft
i get a helper to hold the turbo while the exhaust side is mounted on a socket with short bar mounted in vise
the area you want to look at is the piston ring type seal at each end, compressor side usually not as bad as the exhaust , i have seen the exhaust side worn to a inverted L shape and a very rounded shaft groove
otherwise similar to big end bearings (allowing that these are a floating bronze bush )you want both the inner and outer of the bearing to have correct clearance , if there is any doubt send it to a turbo shop for machining housing, shaft or both to take oversize bearings

 

[Screwy]

Sounds like your turbo is to big for what you need,I run a TD04 turbo it comes in at 3000/3500rpm with no lag at all and will top out at around the 300hp mark,my mate has a gsx1400 with a big ass turbo on it and that comes on at 5000/5500rpm and has terrible lag,his is a road bike too! No good for road riding at all

 

[POWERHOUSE]

Hi everyone. My stage 1 rcc kit turbo might need a rebuild down the road. It has some moderate shaft play, no propeller scraping on the housing yet, and a decent amount of oil in the charge pipes and plenum. Every time I ride it the water injection nozzle gets clogged, i hope from just the oil. I bought the kit used so I don't know the exact millage, but I have put around 5k miles on it.
So I guess I have 2 questions:
1-Are the Garrett journal bearing turbos easy to rebuild for a novice? I have no experience with rebuilding a turbo, but have rebuild a Hayabusa motor and most other parts off a bike.
2- The one thing that has bothered me about my turbobusa since day one is the turbo lag! This is a street bike only. I think this turbo makes 425hp and I plan to stop at 300hp (no really) currently at 257hp. Would a ceramic ball bearing turbo with a smaller a/r make a SIGNIFICANT improvement on response time from what I have?

Thanks for all input!

First off, there should be some play in the turbo, you are correct in checking for any scraping on the cold side housing. If that is not there, odds are the turbo is fine and your oiling issue is something else. Don't chase your tail, find the problem first. Secondly, lag is not a big complaint when it comes to RCC turbo systems, your turbo is properly sized. It is more likely that your bike is not tuned correctly, or there is another issue. The GT35 on my street bike doesn't lag at all, it is just not something that we see commonly on fuel injected turbo bikes, it is more common on the carbureted turbo bikes from 30 years ago . . .

 

[jermzfree]

Journal brg turbos are not hard to rebuild , mark the compressor and shaft so you can reassemble to same position
exhaust housing removal is usually the hard bit, needs lots of heat if the turbo casting is weathered or carbon caked after a few yrs use , tapping the housing and feeling for contact on the exhaust wheel by rocking the compressor side as you do it
use a t bar socket to remove the compressor nut so you dont sideload the shaft and potentially bend the shaft
i get a helper to hold the turbo while the exhaust side is mounted on a socket with short bar mounted in vise
the area you want to look at is the piston ring type seal at each end, compressor side usually not as bad as the exhaust , i have seen the exhaust side worn to a inverted L shape and a very rounded shaft groove
otherwise similar to big end bearings (allowing that these are a floating bronze bush )you want both the inner and outer of the bearing to have correct clearance , if there is any doubt send it to a turbo shop for machining housing, shaft or both to take oversize bearings

Thanks for the great info as always!

 

[jermzfree]

First off, there should be some play in the turbo, you are correct in checking for any scraping on the cold side housing. If that is not there, odds are the turbo is fine and your oiling issue is something else. Don't chase your tail, find the problem first. Secondly, lag is not a big complaint when it comes to RCC turbo systems, your turbo is properly sized. It is more likely that your bike is not tuned correctly, or there is another issue. The GT35 on my street bike doesn't lag at all, it is just not something that we see commonly on fuel injected turbo bikes, it is more common on the carbureted turbo bikes from 30 years ago . . .

I ran a turbo blanket for a short time, but removed it when I saw fumes coming out of the breather hose after boosting. This was in January. Could there be oil residue caked up in the feed lines? Should I ck the oil return line off the turbo for blockage? Thanks as always.

The lag I have is normal I think, 1,000-1500 rpm. Quicker when its warmed up. Comes on around 4500 rpm. If a smaller turbo would come on faster, and at a lower rpm I might spend the money. 4 years ago I spoke with Richard over the phone about his kit. I think I remember he said the ceramic turbos come on really freaking quick. If anyone has one on their bike I would love to hear your opinion.

 

[POWERHOUSE]

Ceramic bearing turbos do come on quicker, the GT35 is one. Really freaking quick is not how I would describe them, it still depends somewhat on sizing. One exception to that is a Gt4202, which is a freak and what Warner was running on his land speed bike. We have done many, many plain bearing Stage Ones that we also tuned, and again, lag was a complaint I might have heard once in about six or seven years. Hopefully, someone will chime in with their impressions of the smaller turbos with ceramic bearings. On the oiling thing, if you are putting the bike on a rear stand and lifting the rear, that angle can promote oil into the turbo, past the ring seal; a kinked or partially blocked return line, or a breather that is not wide open can cause the same issues. On Gen 2s, its important to remove the reed valve plate in the stock breather for the same reason.

 

[jermzfree]

On the oiling thing, if you are putting the bike on a rear stand and lifting the rear, that angle can promote oil into the turbo, past the ring seal

That is good to know. The engine was out of the bike with the turbo still on and the oil still in, so maybe some oil got to the turbo.

 

[turbojonny]

I've heard the duty life of RCC's stage1/2 plain bearing turbos over 1 million miles if not oil starved.