lol I thought this thread was a joke...and I think calling it a 'test' is a little generous.

 

Homer - yes, it is not a test. It is just a sample of how they spin differently...nothing more, nothing less.

 

This is not a proper test performed to any standards...

Many things appear better/worse in different situations... i.e. "Infomercials"

 

I understood the point you were trying to get across NosJohn. It's interesting to see how much more freely the BB spins. The people on this site are so f*cking critical and make such a big deal out of something so small. I see it on this site everyday.

 

I thought it was interesting. Thanks for posting.

Andy

 

Thank YOU - Big Mike and White Lightening !

I just thought it was a neat way to show people ...so they understand how a journal bearing turbo spins versus a dual ball bearing turbo. Do some racers benefit from this type of turbo? - YOU BET YOUR BUTT !

Is it cost-effective for everyone - probably not.

 

Wow pretty much everyone on the first page must have a engineering degree. Jezz, I thought that was pretty darn interesting and informative. Great way to demonstrate a point.

Thanks for taking your time and posting that John.

 

Keep in mind guys as well, their are journal bearing units out there that have best of both worlds. They are just hard to get.

 

I wasn't trying to be critical...it was a cool video nonetheless.

 

pretty cool


<- not a turbo smart person.

 

i agree! you say something thats not the norm and you are slated for it, even if it been proven in another market/situation. im not saying reinvent the wheel, just don't be sooooooo critcal/backwards all the time.

BB is a great idea! the Evo guys have really pushed these turbos. you can now get over 480bhp out of a stock 2.0ltr with bolts ons alone! and thats using a stock turbo converted to BB! most of the aftermarket run BB and it wont be long before oem stuff is BB.

and think about it for a second. what type of bearing are most of the bearings in a car?

and if you REALLY wanted to push the boat out then go for cermaic ball bearings! even lower coificent of drag than steel BB and they are more robust/work better at higher temps!

Chris.

 

It's a cool vid but I want to know the actual HP benefits of a BB versus a journal unit.

chuntington101 - Are you saying 480HP out of a 2.0L wouldn't be possible without a BB turbo?

BB turbos are expensive, at least 30% more than standard ones. If I don't gain at least a %10 increase in HP I'm not interested.
I don't have an engineering degree but I know that video doesn't prove anything, especially without oil in the other unit. Other people in this thread seemd to be stating just that, nice vid but don't expect the real world to work that way.

 

Didn't mean to sound like a know-it-all. Really cool vids. Just commented because I read a guide on scavanging used turbos, and it mentioned that its normal for a regular turbo to not spin freely without having oil to suspend the bearing.

 

No problem...it's tough to tell what someone is really saying in text over the 'net.

That is true - a journal bearing will obviously not spin as well as when it's oiled. Realistically, the bearing is similar to that of a cam bearing and a crank bearing. It is just a piece of metal the allows another piece of metal to roll upon. How much more freely do they spin with oil - not much. I pose these questions (food for thought):

How much better does your cam spin, by hand, with oil on it's journals and no valvetrain connected?

What has less frictional loss - a solid lifter or roller lifter? Much testing has been done in this area, as well and many people, when trying to free up more power, will go with a fully roller valvetrain.

Does it cost more? YES Is it worth it? Yes...to those who wish to spend the extra money.

Bens3rdGen - they don't make more power, per se, they can increase your rate of acceleration and free up lost power, thereby getting you to a higher power number more quickly.

 

Even with oil, regular turbo will not spin as easily.

I think the point is, that on smaller engines producing big power, they are of more benefit than on a big engine.
The slightly wider operating range, and faster spool mean they are worth it IMO.

But for a big V8, or if running twins on a V8, I'm sure any benefits would be much much smaller.

 

Up top for new viewers!

 

wouldnt the BB turbo actually not spin as free (by hand) if it had oil in it? That and the actual bearing clearance in the other one will be greater once it heats up.
Im sure the BB one has less friction and spins over all better, but not to a degree that the video shows.

 

Ding, ding.....thats why this is not a real test. A journal bearing unit properly built and broken in will spin almost as free as a BB. The advantage to BB is no thrust.

 

so how come heavy duty bearing (such as wheel bearings) run ball bearings???? there has to an advantage over journal!

is there anyone making a ceramic BB turbo???? now that would be ace!!!!

Chris.

 

I think it would be quite complicated to fit oiled journal bearings in place of rollers for wheel bearings.

Some bearings just work right for particular jobs. Others dont.

Only thing I know about ceramic turbo's is that they seem to be very fragile. At least with some Toyotas and Nissan Skylines they seem to be.