ball bearing or no ball bearing??
 

I'm about to buy a To4s.... question is... do I want the ball bearing option for $475 more? Anyone out there have any experience and no if the ball bearing option is worth it? I dont mind spending the money, if the value is there.

BTW, whats the advantage of a big shaft?

BB Turbo's spool up about 500-1000 RPMS sooner than the non-BB equiv. I believe it is well worth it. Although it IS highly recommended that you use the water cooled center turbo housing provisions for the turbo to last. In other words you have to run water to the turbo.
The big shaft will allow greater pressure ratios, so if you intend to make over 400HP then you must get a big shaft for reliability's sake. I believe (im not sure) but I think all q-r trim shafts are "big" So if you plan to make serious HP you have to get a big shaft.

I think alot has to do with turbo design, Dual ballbearing from Innovative, or Garrett is a nice option. If you do a search I think you will find turbonetics single ballbearing turbos suffer from a mediocre track record(with regard to reliability). I agree water cooled is a good idea. To my point about design, Precision Turbo is using Garrett GT-Q wheels, and seeing response similar to that of Q trim dual Ball bearing units. This is a Dyno tested fact. The testing was done on a Supra, and should be more evident on a rotary due to stronger exhaust pulses. In addition, Turbo reliability aside , If you blow your motor it will cost you four to five times as much to rebuild a ballbearing unit. Of course this is IMHO. Carl Byck

bb is worth it...the big shaft is needed because of the force the large wheel puts on it when spinning. big wheel and big shaft equals lag..the bb will counterbalance that

i have garret gt30 internals and they are dual bb...im very happy with them.

j

I am curious, for all of you who feel a BB setup spools faster, have you done any back to back dynos? For all you engineers out there, which design has inherently less resistance, a floating bearing, or a ball bearing(that would be a floating bearing)? The only person I know of who has tested ball bearing, and non with the same setup is Andi Baritichi, what he saw is that a properly designed turbo with standard bearings outspooled a slightly smaller dual ballbearing turbo(itst64bb vs pt67h). I just think that it's not as simple as bb vs non bb. The rebuild cost is also far higher if you damage the turbo during a motor failure. The GT3540 is a great turbo unless you damage it, I think IHOR had to spend 800.00 to rebuild his after a motor failure vs 200-300 for a non bb. I'm interested in knowing if anybody has experience with comparably sized turbos with, and without the bb option? Just asking the question.... Thanks, Carl

I believe Ihor paid $600.00 for a brand new cartridge (the best way to fix a turbo) The price is really not that bad, when you figure you would spend that much on getting a Mitubishi or a K Warner Turbo repaired.
You also can't deny the numbers the turbo has been producing on RX-7's. Show me another turbo that spools that quick and will make 400+ rwhp on a stock motor.

I have fist hand experience with the non-bb and dual bb. With my motor unchanged, I went from a p-trim (.81) 60-1, and the turbo began to make boost at 4200 rpm, I changed the turbo to a q-trim (.81) 76mm bb(ITS), and the boost came on and ramped up faster right at the same 4200 rpm

Hey Carl,

You never called me back after we talked for 15 seconds that day when I had to go.... gimme a ring man, otherwise you never know you may end up with some other turbo and would be regretting it.. ;) ;) 972-489-4289.

Later man....
Andi
CTC67H 682rwhp on stock cams through a restrictive cast log-style exhaust manifold