GT wheels?? Ball Bearings??

[CTX-SLPR]

Howdy,

What's the big deal about GT wheels and ball bearings?? They seems to be all the rage for new stuff. Can someone explain what each does as far as power production and effeciency? Then since like everyone else I am on a budget, are they worth the money, which is more bang for buck, and finally do they even make them for TR's?

Thanks,

 

[Reggie West]

The GTQ wheels are a new compressor wheel that Garrett has come out with. They are a definite step up from the 60, 70 and other wheels that we have known for a while.

I have been told that the GTQ wheels spool much better than our " normal " turbos. The GTQs do make more power because of their fin design.

Ball bearing center sections, especially the twin ball bearing set ups, allow the same 70 mm compressor wheel you may have now spool up right against the stall speed of your torque converter. the ball bearing sections allow you to run a big turbo with a converter that is not as loose as it would be without one. For instance a ball bearing turbo can spool up with a 3800 rpm stall on a foot brake and not take an eternity to spool.

On a street set up you can use a 3000 to 3200 stall and have very good response with no lag at all.

 

[turbo2nr]

I have been told buy many people that the GT wheels do great for what they were designed to do...spool up fast in the normal operating range. But, Red Armstrong, and others have found that they do not like to go into the big boost zone. At least, for the GT compressors. Now a 45 GTQ, only has a GT wheel on the hot side, so it can have a wider range of performance, but may not spool up as fast as the same turbo with two GT wheels, but it could make more power. Ask Red Armstrong. He has tested alot of turbos on five different cars, dyno and track. He likes the older style compressor wheels.

Scott

 

[CTX-SLPR]

Well the car is a street car first and a stip machine later. I'm looking to make the power down pretty low to increase the durability of my production 4.1 block. I was thinking GT35R but I know it doesn't bolt up to the standard headers though this is going in a 65 Riviera so the plumbing is a slight be of mystery even now. Which would be a better investment a GT wheeled or a ball bearinged turbo or should I wait to find one with both? I'm looking about 450 hp at the flywheel on pump gas and maybe 600 on alky or race gas. I know that I can get there on an old style turbo but I like the added effeciency of running the high tech stuff, especially since this car will be nearly daily driven when the weather is nice and I want to get the best mileage I can.

Thanks,

 

[turbo2nr]

Go with a GT if you never plan on going over 25psi. A ball bearing turbo is of course going to spool up quicker, and going to a water cooled center is even better. But you need a resivor on top of the turbo to allow water to percolate, as steam will form in the center after shut down. A subaru turbo coolant tank (wrx) is designed for such a turbo. Many options, but in the end, only a racer on the edge will notice the tiny improvements of each new change to turbos. $$$...How much are you willing to spend?

Scott H.

 

[Reggie West]

I would recommend a 66 twin ball bearing unit.

Rick Head recommends you plumb it for water cooling on the center section. It is not that difficult to do and I have not seen a need for a reservoir tank above the turbo.

My dad is using a 74 from Innovative on a Stage 2 car and the water cooling lines that are ran to it have been more than enough to cool the turbo. Believe me he is pretty hard on that motor and turbo. There have been no problems with these center sections at all.

Jeff Rand is using one too and he has had no problems.

Another guy is using a 66 ball bearing on a stock block motor and it is very responsive and he has not maxed it out yet. Still tuning on the translator.

 

[turbo2nr]

Sounds like you need a lesson from John Craig. Every factory turbo that is water cooled has a resivor higher than the turbo (a mini tank). The water cooled feature is only for cooling after shut down. To prevent heat soak and coking of oil. I suggest you research the system. E-mail John on the subject. He should know, he worked at Garrett! Inlet air is cooling the turbo during operation. It is a large volume of relativly cool air to keep compressor side and center cool. Oil is also helping to keep center cool. After shut down, the turbine side will heat soak the center, etc. etc. oil and air stop flowing. On buicks, as with most turbo cars, the turbo is mounted very high in relation to the rest of the coolant. Listen to a water cooled turbo after shut down, you will hear water (coolant) boiling and the center section will be filled with only steam. Not cooling anymore!!

Scott H.

 

[Reggie West]

What you are saying makes sense but I am not seeing the kinds of temps you are talking about to require a reservoir.

The only time I have ever cooked a bearing on a turbo was on a water brake dyno at Duttweilers shop. That was not even a water cooled center sectionor a ball bearing cartridge.

On a street or strip car the water temps are not any higher than normal operating temps. The only thing I am hearing when the motor is shut down is the turbine still spinning for about 60 seconds.

Maybe if you get the headers and turbine side glowing cherry red on a regular basis you might need it but who is doing that?

 

[turbo2nr]

I hear you bro. I am not going to argue with you. To each his own. I have three water coooled turbos for my 10sec wrx. I like to hear them spinning for almost 1min. after shut down. I also hear them boiling the coolant. E-mail John about the subject. It will be hard for me (a total stranger) to tell you anything. Have fun!

Scott

 

[tyrod]

CTX, check out Stangbanger's sig. 61 series old school hard to beat for street/strip.