Author Topic: FWD hubs  (Read 7500 times)

0 Members and 1 Guest are viewing this topic.

Offline SpeedRacer93

  • Jr. Member
  • **
  • Posts: 47
FWD hubs
« on: July 26, 2018, 12:23:03 PM »
We are looking at better step for a front hubs in a front wheel drive independant setup.  Most everything now uses a unit bearing.  The only unit bearing that looks promising is the C6/C7 races bearing.  They are used on the factory C6/C7 race cars at Lemans and are now the default for ZR1 vettes.

Another options I was looking at is Howe hubs.  They use the same race hubs front and rear.  All we would need to do is put a stub shaft and bearings inside the front upright.

Offline Rex Schimmer

  • Hero Member
  • *****
  • Posts: 2625
  • Only time and money prevent completion!
Re: FWD hubs
« Reply #1 on: July 26, 2018, 01:04:44 PM »
When you say "unit bearing" are you talking about the double angular contact bearing with a common outer race. These are pretty popular for independent wheel driven setups.

Rex
Rex

Not much matters and the rest doesn't matter at all.

Offline SpeedRacer93

  • Jr. Member
  • **
  • Posts: 47
Re: FWD hubs
« Reply #2 on: July 26, 2018, 05:41:40 PM »
When you say "unit bearing" are you talking about the double angular contact bearing with a common outer race. These are pretty popular for independent wheel driven setups.

Rex

Yes the standard unit bearings used in most cars and trucks now.

The Corvette ones are used in the new ZR1s and have been used in racing for years.  You can get them with 5/8" or 12 MM ARP studs installed.  Corvettes use the same hubs and spindles front and rear.   We were thinking of using these in a FWD setup.   There are aftermarket spindles/up rights designed for 15 inch wheels.

I have heard some mixed statements about this type of setup in LSR.   IE non serviceable and you have replace everything when they go and they may come apart at speed.   They are about $400 each.




Again the other option I was looking at is using a Howe, Vogel and Coleman full floating style hubs.  They use the same hub/bearing/stub on the front and rear.  On rear they have a drive plate and on the front they use a dust cover.  Still about $400 total each but serviceable and you can buy individual parts.  Also the option of better bearings and lower drag seals. 

Gold colored parts are the dust cover verus the drive plate


You can buy front spindles for these hubs from Coleman.   I was think putting inner bearing/bushings inside the spindle to support the stub axle inside the snout for the FWD setup. I would also need to figure out a way to retain the axle into the snout/drive plate.   (Picture shows a longer snout for a W5 setup but they do have the short snout also.)

 
Coleman sells just the spindle snout if you want to build your own spindle setup or add to you rear housing.


A lot of the cars used a 4WD knuckle setup on the front.   The trouble with those is the king pin to hub wheel mount is offset so much you end up with crazy offset (dually) wheel to get zero scrub and then you have huge out hub hanging out in the wind (Golden Rod hub bumps)


Offline kiwi belly tank

  • Hero Member
  • *****
  • Posts: 3132
Re: FWD hubs
« Reply #3 on: July 27, 2018, 11:11:27 AM »
I don't know how fast you're looking to go but keep in mind for high rpm wheel speeds you need to get away from roller bearings as they tend to de-grease themselves. They're easy enough to replace with ball bearings & a spacer & you can use sealed bearings or pop out the inner seal & pack it or even run them in oil.
  Sid.

Offline Rex Schimmer

  • Hero Member
  • *****
  • Posts: 2625
  • Only time and money prevent completion!
Re: FWD hubs
« Reply #4 on: July 27, 2018, 01:54:58 PM »
Sid is so right about roller bearings, if you are going to run high speeds balls are better.

The very trickest setup I have ever seen was on an Indy car that was in our shop. They used CV joints for articulation and they machined the OD of the CV outer race to accept a set of angular contact ball bearings, this was then installed into the upright and a drive flange was bolted to the face of the CV. Very stiff, small and light. This was on the rear of the car but if you did this with FWD I would think you would want to make the steering axis run through the verticle center of the CV, this should keep things from binding. Just a thought.

Rex
Rex

Not much matters and the rest doesn't matter at all.

Offline Skip Pipes

  • Full Member
  • ***
  • Posts: 268
  • I hate being bipolar, its awesome!
Re: FWD hubs
« Reply #5 on: July 27, 2018, 06:23:33 PM »
So inquiring minds what to know; how fast is too fast?

Skip
Skip's Garage
Builder of the SUNBEAM ALPINE Police Interceptor

Offline kiwi belly tank

  • Hero Member
  • *****
  • Posts: 3132
Re: FWD hubs
« Reply #6 on: July 28, 2018, 11:12:46 AM »
Skip,
  If you are running tapered roller bearings you will see the problem in the bearings when you check them. Beyond the lubrication problem the ball bearing has less rolling resistance & once you set the spacer size it's right for ever. No more incorrect adjustments to line up the pin hole. Just torque the nut down a shove a pin in it & use C3 bearings or you can even go to ceramic bearings.
  Sid.

Offline SpeedRacer93

  • Jr. Member
  • **
  • Posts: 47
Re: FWD hubs
« Reply #7 on: July 28, 2018, 05:17:27 PM »
Sid is so right about roller bearings, if you are going to run high speeds balls are better.

The very trickest setup I have ever seen was on an Indy car that was in our shop. They used CV joints for articulation and they machined the OD of the CV outer race to accept a set of angular contact ball bearings, this was then installed into the upright and a drive flange was bolted to the face of the CV. Very stiff, small and light. This was on the rear of the car but if you did this with FWD I would think you would want to make the steering axis run through the verticle center of the CV, this should keep things from binding. Just a thought.

Rex

The CV in the hub idea is what Ohio State did for the BB3.   I like the idea because the force is not catalevers off an axle stub shaft.  I know some people had issues with 930 CV joints so we may look at the 934/5 joints or we also have the idea of crowned spline drive setup like used in sprint cars. I think someone else is using the crowned spline setup.   Not sure how much angle you can get from them.




Offline ntsqd

  • New folks
  • Posts: 5
Re: FWD hubs
« Reply #8 on: February 16, 2019, 03:58:49 PM »
Crowned Splines are/were used in cambered live axle housings on oval tracks. I suspect no more than 5° angularity.

The pass car unit bearings that I've encountered require a shaft (be it the CV's stub axle or a blank) thru the middle with a nut torqued in place to hold them together in use. As delivered they have a light press holding them together, but they shouldn't be run that way in service. Those Corvette parts, less the ABS sensor stuff, look like old Chevy S-10 4WD parts.  GM is good about recycling old designs like that. Rock crawlers have been using front application unit bearings to build light weight, full float rear axle assemblies. In looking for links I stumbled onto a thread talking about the late model Jeep JK unit bearings not needing a stub thru the middle to hold them together.

Most traditional full-float type axles, but not all, run the wheel bearings in the diff oil, not grease.

There was a period in time when the Off-Road Class 1 cars were (& maybe some still are) running a very large ID stub spindle that the half-shaft passes thru to the outboard mounted CVJ. No stub axle involved, wheel hub carries the CVJ body.

I too, would be interested to know where in the speed spectrum ball bearings become more advisable.
Cross-threaded is tighter than Lock-tite.

Offline SpeedRacer93

  • Jr. Member
  • **
  • Posts: 47
Re: FWD hubs
« Reply #9 on: February 16, 2019, 04:23:33 PM »
The newer ZR1s units use angular contact bearings and are the same unit front and back.  They do not need/use a stub shaft in the front.  In fact the uprights are also  the same front and back.   Corvette Racing has been using the same units on the race cars that run 24 hours or Le Mans and hit over 180 mphs on the straights.




Offline kiwi belly tank

  • Hero Member
  • *****
  • Posts: 3132
Re: FWD hubs
« Reply #10 on: February 17, 2019, 11:55:03 AM »
The newer ZR1s units use angular contact bearings and are the same unit front and back.  They do not need/use a stub shaft in the front.  In fact the uprights are also  the same front and back.   Corvette Racing has been using the same units on the race cars that run 24 hours or Le Mans and hit over 180 mphs on the straights.




Lots of bearing support for side loading is required when you go around a lot of corners in a hurry, there are no corners in LSR.
  Sid.

Offline Stainless1

  • Administrator
  • Hero Member
  • ***
  • Posts: 8948
  • Robert W. P. "Stainless" Steele
Re: FWD hubs
« Reply #11 on: February 17, 2019, 12:01:00 PM »
... there are no corners in LSR.
  Sid.
Sid.... at least we all hope that is always true  :-D  :cheers:
Stainless
Red Hat 228.039, 2001, 65ci, Bockscar Lakester #1000 with a little N2O

Offline ntsqd

  • New folks
  • Posts: 5
Re: FWD hubs
« Reply #12 on: February 17, 2019, 12:09:54 PM »
That they'll go ~180 with the weight & aero loads of a GTP car on them tells me that they're probably OK in LSR up to about that same speed & possibly higher if the car is lighter and/or the aero loads are lower. That old PV bearing rating. If their frictional loss is acceptable anyway.

I'm getting the impression that the speed threshold where ball bearings are more desirable is a "secret weapon." Nothing but crickets on that one.
Cross-threaded is tighter than Lock-tite.