Pros and Cons on BB or Journal Turbos
- Thread starter suprahooked
- Start date
BB = less friction, quicker spool, longer life.
I believe they are more finiky about oil feed, though - ask Jon @ MDC or Jtamulis - they are both on here
I believe they are more finiky about oil feed, though - ask Jon @ MDC or Jtamulis - they are both on here
I wish IJ could put in some words on this one.
From what i understand BB = better spool at lower RPM, longer life
IIRC I think the journal turbos can be rebuit, and some BB's can not.
I am not definite on this. It would be good if someone with more knowledge could chime in
From what i understand BB = better spool at lower RPM, longer life
IIRC I think the journal turbos can be rebuit, and some BB's can not.
I am not definite on this. It would be good if someone with more knowledge could chime in
Although Doward would be correct on most cases, I think BB tubos are overrated. (just my opinion.) I have run with a non BB turbo for years with zero problems. If the non BB turbos were to wear out quicker than the BB then it would take a LONNNNNNNNG time since mine has been on the car 2 years with racing, track time, dyno, cruisin time and I even got it used to begin with. :biglaugh: (my turbo choices have been GReddy FYI.)
HTH
Duane
HTH
Duane
yeah, i've used journal and bb turbos on my subarus, the decrease in lag or faster spool is negligable.
upgradedsupra said:
Thats why i am asking this ?? I am looking at getting a Gt 4088 from garrett or percision and i know it rebuildable . I dont want to spend tons of $$ on something that cant be rebuilt. But do want to hear opnions . Thanks Duane for your input. And Thanks to all of the Sm members input. John
Last edited:
The newer Garrett BB turbos are completely new designs, fewer parts, better aero and the benefit of quicker spool. They are rebuildable. The ONLY downside is cost.
I was going to get the gt35r but after looking into to it more iam leaning towards a gt4088 mainly cost and rebuildably.:evil2:suprahero said:
Adjuster
Supramania Contributor
Too much oil will cause problems for any turbo, but the BB CHRA's generally need less oil volume than the bushing type.
Spool up is going to be a combination of wheel size, design and housing air ratio. (AR.)
Too large a hole, and it's going to flow a ton, but it's going to take longer to spin up the turbine to a speed that really produces results.
Design can improve, and has proven to improve the performance of smaller faster spooling turbo's, but anything you can do to decrease frictional drag is a good idea no matter what size turbo and AR your going to use.
Cost v/s benefit is up to the individual. (Same story on lubricants use in your motor, some say the more expensive types are not worth it, and others swear it's the only way to go, but it's up to the individual owner to decide how much to spend.)
Spool up is going to be a combination of wheel size, design and housing air ratio. (AR.)
Too large a hole, and it's going to flow a ton, but it's going to take longer to spin up the turbine to a speed that really produces results.
Design can improve, and has proven to improve the performance of smaller faster spooling turbo's, but anything you can do to decrease frictional drag is a good idea no matter what size turbo and AR your going to use.
Cost v/s benefit is up to the individual. (Same story on lubricants use in your motor, some say the more expensive types are not worth it, and others swear it's the only way to go, but it's up to the individual owner to decide how much to spend.)
QWIKSTRIKE
475rwhp459torq an climbin
ToyoHabu said:
That is incorrect sir.
The ball bearing garrett turbos are "non serviceable."
Im currently working on a rebuilding kit for the gt35r - it will be the first of its kind.
As for BB vs journal bearing.
A journal bearing turbo will tollerate a "dirty" climate.
There are several journal bearing turbos on the market installed in over the road trucks that have 1,000,000 or more miles on them.
The ball bearing design was created out of performance - decrease friction both radialy and axially and you decrease the spool time of the turbo.
This makes it possible to run a larger wheel (turbine or compressor) and have the same or better performance of a smaller diameter wheel.
As stated before, the ball bearings are HORRIBLY picky about oil temp, type, amount, and contamination.
Any other questions, be sure to fire them out.
~Jon
Boost Lee said:^If ANYBODY knows turbos....I *think*...just, *think*, Jonny boy is the man for the job.
I hope, but never admit to it.
ITS BB CHRA's are rebulidable...
I bought a DDB ITS 67MM
Check the SF under BL section there was a good review of the two... The BB version was 400-500 RPM faster everywhere... which is huge as it gave more then 50-60 RWTQ at 4500 over the non ball bearing version.
IMO thats wroth the money right there..
I bought a DDB ITS 67MM
Check the SF under BL section there was a good review of the two... The BB version was 400-500 RPM faster everywhere... which is huge as it gave more then 50-60 RWTQ at 4500 over the non ball bearing version.
IMO thats wroth the money right there..
haven't read any of the pages....but here is some fact:
-BB turbos help most w/transient spool (i.e. the transition from vac to boost, cruising @ 4k RPM and then going WOT), affect on total spool time is almost nil.
-BB turbos are VERY picky about their oil supply (i should know, i fried a brand new GT3582R thanks to a bad oil filter)
-garrett GT BB turbos cannot be rebuilt (see above...), some other mfg's BB turbos are rebuildable (i know innovative's are...)
EDIT: should have read....MDC's post sums it up....
-BB turbos help most w/transient spool (i.e. the transition from vac to boost, cruising @ 4k RPM and then going WOT), affect on total spool time is almost nil.
-BB turbos are VERY picky about their oil supply (i should know, i fried a brand new GT3582R thanks to a bad oil filter)
-garrett GT BB turbos cannot be rebuilt (see above...), some other mfg's BB turbos are rebuildable (i know innovative's are...)
EDIT: should have read....MDC's post sums it up....