ball-bearing hybrid turbo results

[88turboii]

so i did it, i made a BB hybrid using a garrett BB chra, but did not get the results i expected. I was running a 60-1 hifi compressor with p-trim turbine wheel on stock journal bearings before. all i did is order a garrett BB 60-1 chra with p-trim wheel and swapped compressor backplate with my hifi and bolted the hifi compressor cover on. With some minor clearancing it fit pretty well. and the coolant ports were 14mm instead of 16mm, but no big deal

but.. spool seems to have gotten worse by about 500 rpm, i used to get 15 psi by 3500 rpm with the journal bearing, now it doesnt hit 15psi till after 4k! what gives? the only reason i can think of why it spools slower is the added rotating mass from the inner race on the turbine shaft.. where as journal bearing has no inner race

[RETed]

Interesting...

Assumed the turbine housing is identical?

Long shot...turbine wheels clearances are different?

Maybe the BB CHRA wasn't broken in?
How many miles did you run it before you ran it on the dyno?


-Ted

[88turboii]

yah same turbine housing. ive put about 250 miles on it. turbine clearance could be it.. i will pull it again and check that

edit: turbine clearance is the same with the stock center section..

[88turboii]

just an update i found out my turbo-manifold gasket is blown out. Last weekend i swapped the journal bearing setup back on and it was having trouble making 5psi! the bb would make 15psi, just late. so with the new gasket the bb should spool hella fast. gasket will be here next week

[sen2two]

is this dual or single ball bearing?

[lt1_fd3s]

just an update i found out my turbo-manifold gasket is blown out. Last weekend i swapped the journal bearing setup back on and it was having trouble making 5psi! the bb would make 15psi, just late. so with the new gasket the bb should spool hella fast. gasket will be here next week
so when u coming back up to the hill with it?

[junito1]

Interesting. Waiting for results.

[N.RotaryTech]

.

[88turboii]

well i replaced the gasket, still have the leak.. the engine-to-manifold gasket looked good to me, but i guess ill try replacing that next. it is a dual bearing center

the one problem i did notice is the garrett "top hat" looking thing on the exhaust side has a thicker lip than stock, and i think it may be causing the leak. If i did it again, i would use the stock piece

[88turboii]

to date ive replaced both gaskets, did some minor resurfacing of the manifold and checked for cracks, and i can still hear a slight exhaust leak. sounds like rattling on decel. started hearing it ever since i first installed the bb chra. im thinking their is a leak at the top hat piece between the turbine housing and the center.

weird thing is im not sure why the stock center had problems when i swapped it on, i cant remember if i heard the rattle with it, maybe i didnt have the compressor and turbine wheels lined up right and were out of balance. would wheels out of balance cause such a difference?

[captanmike]

Hello

Did you ever get this working?
I would be very interested to know what sort of difference it made.

-Mike Brunt-

[88turboii]

ok i finally got another housing milled out for the thicker bb heat shield piece, and spool problem is fixed. 10 psi by 3000 15psi by 3500. i think it was spacing the turbine wheel too far away from the turbine housing. spool seems to be about the same as the journal bearing, although i still hear the exhaust leak rattle sound. but im happy with it. i will try to get it on the dyno soon and see where shes at