SLC Hubs/ race worthy

[Ken Roberts]

The C7 hub was designed to replace the C6 33 spline X Tracker hub that was so successful in the C6 ZR1 Corvette. GM decided to put in in production across the full C7 Corvette line up. For this reason mass producing it brought the price down dramatically. In this case.....the cheapest hub is also the best hub to use. Also if you are tracking the car "hard" then your wallet will thank you in the future.

 

[Mario]

Just a question. Would it be be a safe bet just to upgrade these as you build the car. I’m ordering mine in dec. I’m using an LT 5. With the Graziano. V 10 trans axel and sequential gear box. My concern has alway been. Will the race stock hubs and axel s truly handle the power. Every this was designed or spec. For LS 3. With the lt 5. Version I’m going to order. Some mods. I’ll be at 850. Hp. 830. T q. Even tho. Rcr. Says it’s rated at 1000 hp. For axel and hubs. My gut tells me no. Any feed back will help.

 

[Howard Jones]

Listen to your gut Mario. With a 800 ft/lbs of torque you will need the same stubs I used IMHO. They are rated at 900HP EACH!
But the current "race" pieces may be the right ones. I don't know what the actual parts are that Fran supplies with the race setup. The axles may be OK. I think that they are made by the same guys as my stub shafts the Driveshaft shop.

As a thought, ask Fran if you should upgrade the standard driveshaft with the super duper high HP ones the Driveshaft Shop can supply.

Ken is correct. The current C7 GM piece is the equal of the best of pervious aftermarket suppliers. They simply bought the rights to make the same piece from SKF I believe. So all you need to do is make it fit your upright at the rear.

The fronts should not be neglected on a track car running slicks IF you have the C4 bearing installed. Everything known on this subject I believe is contained in this thread as far as the SLC is concerned.

Ron, I am not familiar with RCR's GTR however. In the end I would think that it is going to be somewhat the same path you will need to follow if the standard bearings are C4's.

Don't forget that there IS a race suitable suspension available from RCR for the SLC. Maybe a inquiry to RCR about the suitability of those parts for use on a GTR might be a useful discussion.

 

[Ron McCall]

Anyone spoken with Pacific Customs about these bearings?? I see their shafts mentioned but not their bearings.
https://www.pacificcustoms.com/mm5/...=ac501430-33&Category_Code=adapter-stub-axles

Ron

 

[Howard Jones]

They are one of four possible sourced pieces.

SKF parts made custom for PAFDT. I don't think so because they are not black. I used the C6 part for the front of my SLC.

SKF X TRACKER. They look like them.

GM C7 parts. These were SKF's until GM bought the rights. I used these on the rear of my SLC.

Or god knows what quality Chinese copy's. I have no idea how many of these there are under what branding. But I would not use them...…….ever.

Call them and ask. Please post what you find out here. Ask them for the age of the stock.

 

[Ken Roberts]

They are 1.90" thick. Not the same as any SKF X tracker (C6 or C7)

 

[Ron McCall]

They are 1.90" thick. Not the same as any SKF X tracker (C6 or C7)

Any idea what the bolt pattern is on these? If it is the same as the C4 pattern,they are 1.9" thick and the C4 bearing is 2.160"-2.165" then a .260-.265" shim would put them in the same location . And they come in 27 spline so you could reuse the stub axle and the CV axle would stay the same length.
Just looking at all available options.

Ron

 

[Ken Roberts]

The C4 hub is 1.86" thick (flange to flange). Even if it did work with a shim I still wouldn't use it on a track only car because of the 27 spline stub shafts.

I bought the Dulaney adapters and C6 X tracker hubs (for the front) and C7 hubs with my shims (for the rear) again for my up coming GT-R build.

I have no information on the hubs in your link. They have no proven track record. Your stock WBI hubs that lasted one day were also made in the USA. That doesn't mean much. I would recommend sticking with whats known to be a high quality option. Unfortunately it's not cheap but your life and $100000 car is worth it.

Talk to Paul Robertson with his extensive track use. He went with the C7 hub. I think he twisted one stub shaft and broke the other 27 spline stub shaft.

 

[Ron McCall]

The C4 hub is 1.86" thick (flange to flange). Even if it did work with a shim I still wouldn't use it on a track only car because of the 27 spline stub shafts.

I bought the Dulaney adapters and C6 X tracker hubs (for the front) and C7 hubs with my shims (for the rear) again for my up coming GT-R build.

I have no information on the hubs in your link. They have no proven track record. Your stock WBI hubs that lasted one day were also made in the USA. That doesn't mean much. I would recommend sticking with whats known to be a high quality option. Unfortunately it's not cheap but your life and $100000 car is worth it.

Talk to Paul Robertson with his extensive track use. He went with the C7 hub. I think he twisted one stub shaft and broke the other 27 spline stub shaft.

Ken,
I was not asking because I was considering these for my car. My intent ( as was Howard's in starting this thread) was to explore all options so that all of the information is in one single thread. This may very well be an option for a street car that will never see slicks. I have a feeling that the parts that are supplied with the cars are inadequate for even that application.

Ron

 

[Ken Roberts]

To answer your question in case anyone wants to contact them about the 3 bolt mounting flange. The stock C4 mounting flange bolt circle diameter is 4.75".

The bolt circle diameter for the C6 and C7 X Tracker hubs is 4.567"

I have a PDF template for the shims I made I can send you Ron if you decide to upgrade to the C7 hub.

 

[Ron McCall]

Ken,
Please do. I am curious, if you were to bolt up the C7 bearing without your shim ( I'm well aware that the wheel flange would be .190" closer to the hub carrier) would the Driveshaft Shop 33 spline stub axle clear without machining the inside of the carrier?


And BTW, the GT-R uses the same hub carrier as the SL-C. It has a different top portion bolted on though.


Ron

 

[Ken Roberts]

If you bolt the C7 hub up without the shim then the rotor would be .190" out of position with the brake caliper unfortunately. Paul took this into account with his new upright by machining the caliper mounting bracket inboard by the same amount. Howard took this into account by machining the rotor hat.

To answer your question.....yes it would just clear. The bolt heads would still need to be countersunk level with the surface though. (shown in the picture). Howard countersunk his bolt heads as well. Same with Paul I believe. The next set of rear uprights I have machined will have less clearance although the extra clearance might be better in case of a failure.

Please send me a PM with your email Ron for the shim.

 

[Ron McCall]

Thanks for the clarification Ken.
Howard /Paul , what did you end up doing about your CV axle length?

Ron

 

[Mario]

Listen to your gut Mario. With a 800 ft/lbs of torque you will need the same stubs I used IMHO. They are rated at 900HP EACH!
But the current "race" pieces may be the right ones. I don't know what the actual parts are that Fran supplies with the race setup. The axles may be OK. I think that they are made by the same guys as my stub shafts the Driveshaft shop.

As a thought, ask Fran if you should upgrade the standard driveshaft with the super duper high HP ones the Driveshaft Shop can supply.

Ken is correct. The current C7 GM piece is the equal of the best of pervious aftermarket suppliers. They simply bought the rights to make the same piece from SKF I believe. So all you need to do is make it fit your upright at the rear.

The fronts should not be neglected on a track car running slicks IF you have the C4 bearing installed. Everything known on this subject I believe is contained in this thread as far as the SLC is concerned.

Ron, I am not familiar with RCR's GTR however. In the end I would think that it is going to be somewhat the same path you will need to follow if the standard bearings are C4's.

Don't forget that there IS a race suitable suspension available from RCR for the SLC. Maybe a inquiry to RCR about the suitability of those parts for use on a GTR might be a useful discussion.

Howard. Thanks for the info. My gut is usually always right.

 

[Ken Roberts]

Just got finished talking with Jim Dulaney and he said his latest version of front adapter will work with the C7 front hub bearings now. I bought my last set from him before he revised the design to fit the C7 hubs (rear only). He said he will only be making one more run of them and then stopping. Too much competition with the Strano and Detroit Speed adapters. The Strano adapters can be bought for $250 now. Pretty sure they don't work with C7 hubs though. The Dulaney adapters cost $475, are chromoly and have mounts for a cooling plate.

The C7 hubs are only $90 each. Probably less than a C4 hub.

http://www.stranoparts.com/partdetails.php?PartID=1494&CategoryID=364&ModelID=2

 

[Howard Jones]

Ron, as far as the driveshaft length goes, my advice is to finish whatever modifications you are doing and then measure what it needs. I would also advise make some measurements of the existing setup at ride height before you begin as follows. Record them and attempt to keep 1 and 2 the same after making modification. I was able to preserve 1 but not 2 and needed to correct rotor alinement with machining the hat thickness. If you can keep 3 the same or within a 1/4"range, (+1/8 -1/8") I think the CV plunge will make up the difference and remain within tolerance due to the limited rear suspension travel we have.

1. back of upright face to stubshaft CV flange.
2. front of upright face to wheel mount flange.
3. gearbox output drive CV flange to stubshaft CV flange. (center to center)

Ken, wooden you know it, I paid a bit under 500 bucks for my front adapters.

If you guys are thinking front bearing change I would get the adapter that fits the C7 bearing now before they go away. This is a 1 time expense and you would save the money on the C7 bearing anyway.

 

[Frank Clark]

I am looking to incorporate wheel speed sensors on all 4 corners (for traction control). It sounds like I might as well do the bearing upgrade at the same time and use the ABS rings in these newer hubs.

Looking at the C6 ZR1 hubs, the front and back are the same hubs.

Is there any reason not to just use the C7 rear hubs front and back? I am happy to machine as needed to get all to fit correctly.

The C7 hubs are about the same price as a 930 sized tone ring from DSS!

Are the wheel studs in the C7 hubs longer than those in the RCR provided hubs? The RCR hub studs are "just" long enough, I keep expecting the tech guys to point out I need longer wheel studs...

 

[Ken Roberts]

The rear C7 hubs do not incorporate any sensors unfortunately. You could use the C6 ZR1 hubs with the built in sensors but keep in mind they are "active" sensors and almost three times the cost. Ron McCall is using C7 rear hubs front and back. Try and buy the Dulaney adapters now because they fit the C7 hub and he won't be making them anymore. He is doing one last run of them. If you are using a Graziano then you could use the inboard sensor setup I show on my build log.
https://www.gt40s.com/threads/kens-slc-build-thread.38446/page-37#post-535344

https://www.gt40s.com/threads/kens-slc-build-thread.38446/page-38#post-535522



Here is a picture of the C7 stud length.

 

[Frank Clark]

Those studs look about the same length.

On RockAuto, the ACDelco's are listed as:

Anti Lock Braking System = Yes, Anti Lock Braking System Type=Encoder

I took that to mean the "tone wheel" is in the hub (but not the sensor). From the limited diagrams I can find, it kind of looks like the sensor is placed in the upright on the backside of the hub. In the Timken unit, it looks like you can "see" the outline of the tone wheel.

Of course the tone wheel could be steel or magnetic, but I can deal with either. For the price of these, it is hard to imagine the tone wheel being anything other than some type of steel. The C7 abs sensors look like 2-wire (non powered) units.

If the C7 are the 'best' bearing solution, I think I will order 1 and play with it to make sure I'll have no insurmountable issues.

 

[Ken Roberts]

Pretty sure that isn't a tone wheel. Even if it was there would be no way of getting a outboard sensor close enough to read it. The stubshaft flange faces that area not too far away. Zero chance of getting any type of sensor in between the face and the 33 spline stub shaft. My abs BMW sensors are two wire and also "active"