DBB question

[Big Turbo Scott]

I just recieved my 6776RHPS and noticed a considerable amount of up and down play (.020-.030) in the shaft. I was told that once oil is introduced that the slack should be gone. Has anyone faced this same issue? Thanks for the insight.

 

[RUQWKNF]

I have the exact same turbo on my car.
PT6776RHP

I was able to check it out the day that my friend bought it from PTE. It too had the same slack as you mention. And still does to this day. Every dual ball bearing turbo that I've ever laid hands on while working at PTE had this play.
The cartridge does allow the wheel to move around slightly. Here is a picture of the Garrett DBB cartridge that we have.

As long as the wheels do not touch when you pull them over to one side or the other, you will be ok. Due to the very limited oil that makes it way to the cartridge, I am sure that the internal oil pressure is higher on the DBB chra than it is on a standard journal bearing chra. Because of this limited amount of oil used for lubrication purposes only, it is manditory to run the water lines to turbo. The regular journal bearing turbos use oil not only as a lubricant, but also as a heat transfer medium to help remove the heat from the chra. The dual ball bearing turbos only use oil for lubrication, and water to remove the heat away from the cartridge.
HTH

Patrick

 

[Big Turbo Scott]

Thanks Patrick! Good info. Is that a 4" maf? Ive only been able to find a 3.5.

 

[87NAT]

Patrick, Have you gone to the track yet? I still have not made it to see what this turbo is gonna do. How does it feel on the street...does your butt-dyno tell you good thing?

 

[RUQWKNF]

Original 4" Big Mouth Cold Air kit from Mark at TR Custom Parts 84-87 Turbo Regals, 94-6 Impala SS, 93-up F Body Cars, Olds G-Body Cars

Haven't made it to the track yet. I need to get my converter installed and roll the fender trim before a track visit. I wanted to go tomorrow, but it looks like it's going to be way too hot and I don't want to waste my passes on a hot day.
I know that might sound pitiful to some, but I know that my next track visit will fry this tranny, so I want to make it count no matter what. 11.30s or bust. She runs good tho. Pure C-16, 27* timing in all gears and 26psi, feels really good.
I'll keep everyone posted. Maybe next weekend.


Patrick