steve96gst

I was wondering why the garret GT series is more popular than the turbonetics gt-k series. does the garret gt bb spin quicker than the GTK series turbo/out perform it? in particular the GT42 and GT - K1000. thanks for the space

John

the Garrett's have been out longer, so people have had more experience with them, more data is available, and last I checked, they were significantly cheaper as well.

steve96gst

the turbonetic is cheaper than the garret turbos and looks like they have more time put in them than the garret.

steve96gst

the only diffrence i can see between the two turbos are one is water cooled bb and the othere one is oil cooled bb. would one cool better than the othere?

A80Girl

Turbonetics GT-K turbos are nothing special. They are comprised of Borg Warner cartridges. Borg Warner turbos do not last long, however, they are becoming increasingly popular. They are intended for Truck use (mostly Semi). Very good bang for the buck....but not the GT-K series. Overpriced.
Turbonetics USED to use Garrett cartridges, but Garrett dropped them a couple years ago. Thats why they are using Borg Warner cartridges now.

Garrett BB technology is the best.

The main reason why they spool faster is because they reduced bearing friction. Basically, they have MUCH less moving parts, therefore, making the cartridge lighter. This allows for much faster spool time.
Also, they can handle higher boost pressure (partly in fact because they are oil and water cooled).

punx

More info on the GTK series turbos here:
Turbonetics Owners Club

GTK-1000 Specs:
Compressor: 76mm Wheel, .70 A/R
Turbine: F1 S Trim 68mm Wheel, T4, .96 A/R

GT42R(s) Specs:
Compressor: 94mm Wheel, .80 A/R,
Turbine: 56 trim 94mm Wheel, T4, 1.01 A/R

As you can see, the GT42R is a larger turbo altogether. The GT series turbos are dual ball bearing, and the turbonetics GTK series turbos are single ball bearing. The GTK series turbos comes with an ultra lightweight F1 turbine wheel, and ported compressor housing. I would think that the GT42R would be capable of flowing for a little bit more power, but the GTK turbo would spool faster based on the above specs. I have not seen a side-by-side comparison though.

I'm currently running a GTK-854/650 hybrid turbo with water cooled jacket (a bit smaller turbo). You can get a turbo custom built if you contact a Turbonetics dealer and specify whatever specific features you need.

Orion ZyGarian

I'm pretty sure the ball bearing cartridges are heavier and have more moving parts than the journal bearings..the spool time is due to much less friction and nothing more, but it makes a considerable difference.

punx

The type of bearing section used in a turbocharger has very little effect on spool time. This is a common internet misconception that seems to be perpetuated on forums such as these.

The largest factor in determining spool time is the rotating MASS of the center rotating section of the turbo. This includes the turbine and compressor wheels. The enhanced spool time on the Garrett dbb turbos is more derivative of the design of the wheels than of the bearing housing. This is the reason why Turbonetics went with Inconel turbine wheels was the vast weight savings over standard turbine wheels. This is how they claim to have lower spool time than the gtdbb turbos.

I have no idea where you heard Turbonetics is using BW cartridges. I've always been under the impression they used their own ceramic ball bearing cartridges. I'll verify this today.

Both companies offer water-cooled bearing housings. Garrett turbos will burn up without a water source due to the high temp operation inherent with a dual ball bearing cartridge. However, the single ball bearing turbonetics turbos will run just fine even with no water cooling.

punx

Friction has very little to do with it. Whether you have a ball bearing or journal bearing turbo, the object is to have no friction.

It's all about mass (see above).

Orion ZyGarian

Thanks for setting me straight..I didnt see that specifically mentioned on Garrett's website (which appears to be down right now).

I thought BB and journal bearing turbos both used the same wheels..do BBs use a smaller central shaft connecting the two wheels?

Also, perhaps you can explain why journal/BB hybrids are better than dual ball bearings...I never did understand or get a straight answer from anywhere.