I need to replace at least one front hub on the CMC car...
Has anyone noticed better success rate with particular brands? Oreilly lists Precision and Master Pro. I found some listed as Timken.
I don't mind the price spread if the value is there.
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I need to replace at least one front hub on the CMC car...
Has anyone noticed better success rate with particular brands? Oreilly lists Precision and Master Pro. I found some listed as Timken.
I don't mind the price spread if the value is there.
I've heard Timken is as good as it gets.
I bought a set of Timkens from Autozone and am getting play in them after 2-3 events. I pound my ARP studs out of them, pull the original studs back in, and go exchange them under warranty. Done this a couple of times already this year.
I have to replace one too. I barely finished R4 it was shaking so badly and darting under braking.
Wow, note to self.....buy multiple sets of hubs. Where's the RCR for this one? Anyone have a magic setup?
Although it's quite expensive, the Corvette SKF race bearings that I, Patterson, and White and are using are working quite well. I could never get a yes or no from the CMC directors as to whether they are legal in CMC.
The SKF vette hubs require an adapter, which I designed to fit the f-body spindle.
With the adapter, they are dimensionally equal to a factory hub, so there aren't any track width changes. They weigh 1.5# more than a Timken.
Any factory brake, or aftermarket kit that works with the factory spindle/hub will bolt on without issue. Once the adapter and race hub are assembled, it acts just like a factory hub. Owner can swap between the two on a race weekend just the same as any replacement hub. The blainefab spindle ducts do not fit, but I have 5 sets of plates cut to fit my hubs.
We have found the bearings to be very tight, and to have eliminated the pad knockback in the front. Mike and I have run them since NOLA, and they still feel as tight as they were when they were new.
I'm sorry that doesn't really help you at this point, but maybe you can throw Al some messages and get a ruling. I have 2 pairs of adapters in-stock, and I'm a Phadt dealer for acquiring the SKF hubs.
Jim's setup is the BOMB. We have 3 or 4 weekends on them now and they are as tight as when delivered. I also took a pretty hard wack on the right front wheel at hallett and there is ZERO play. I have also put a 10# residual pressure valve in the rear brake line and made sure the rear calipers float with ease. Nearly 98% of all our pad knockback is G-O-N-E! If actually feels as good as my mustang...maybe better.
Jim, can you email me a price for one of the sets? I am thinking about keeping a spare set in case one gets destroyed by an incident like what happened at hallett. Thankfully the rim ring is very thin and not built like some of the stock wheels CMC runs. The rim absorbed the force, not the suspension parts.
If you guys could get Jim's setup approved for CMC, you will have an "on the shelf" solution for the problem. some of the bearings we were getting crapped out on the drive from the TWS garages to hot pit!!! yeah, 300 yards. Some last a session, some last a weekend. They are terrible.
The hub adapter you guys are talking about, there's a similar solution out there as well that may or may be cheaper; bunch of guys came up with an adapter plate design you can have made, then you would cut/press the snout out of a 3rd gen spindle and press it into the adapter. From there you would either turn down a 3rd gen rotor into a hub or buy one of those special 3rd gen "hubs" that flynbye makes and bolt the "hub" on to the snout.
Glenn made up a prototype of his own a while back; I am unsure if we ever did get a ruling on it. I personally am still working through a bunch of other issues on the car but hope to make a move on this stuff in early 2014 once we get some clarity.
Took a look at the corvette bearings. Looks like a solid setup; how much for those adapters Dulaney?
Also how are the "regular" C5 hub offerings (Timken, Delco, etc) holding up compared to the SKFs?
The RCR needs to be submitted to allow the Dulaney Special.
I would go through a minimum of 6 and a maximum of 8 front hubs in 6 events. So conservatively, that's 6 hubs at $165 (Timkens) for $990 plus shipping plus swapping out ARP studs. This was by far the worst waste of money ever on my car. Burning through hubs faster than race brake pads. I've had new Timken hubs last less than 1 lap before exploding, others with massive play after one session, etc. as Matt indicated.
The Dulaney Special seems to have resolved the issue. Same hubs since NOLA. Three full events, zero play, less time working on the car, more money in my pocket, more time drinking beer. Most of my pad knock-back is resolved also (I may have an issue with my RF caliper that is currently causing some knock-back, but not like it was before the hub switch). We installed these at the track in less than 30 minutes. No machining/pressing/turning down, etc.
I'm a fan, two thumbs up. Nice engineering job Mr. Dulaney!
Unrelated to CMC - I am still using my factory ABS with this setup (simple re-pin of the plastic connector).
Who's gonna submit it? We need to do it pretty quick. I don't have a dog in this hunt yet but I would be more than happy to test
Sounds like a perfect RCR in my opinion. Anything that gives no performance advantage but reduces cost, labor, risk, etc is good in my eyes. As Mike points out, anything that increases beer drinking time is a major positive!!!
If I can help with something on this I will be glad to make them at cost. I have not seen it so I don't even know if I can help.
JJ
From what I can see, it basically puts the GM crowd on the same level as the Ford guys have enjoyed for years with the stock Ford SN95/99 bearing with racing grease repack... 2-3 seasons and replace. Get something official to Glenn and Al to get the ball rolling. Just don't advertise on the CMC site. Those guys bitch and complain more than we do.
The kit sells for $1200. The skf race hubs are $380 each, so that's most of the cost. I get a dealer discount on them, and can offer a reduced cost for Texas guys. Contact me for more.
Jerry, the adapter is made from 4130 chromoly. If you can machine this, please PM me your contact info.
As Pranav said, there is a less expensive solution, using 3rd gen spindles and bearings. From what I hear, it's a PITA to do. I designed this adapter because I wanted to keep ABS (AI).
I can't speak toward the durability of stock c5 hubs. I know Kevin Mixon went thru a lot, but he has Hoosiers and wider tires. If anyone wants the adapter only, to test these, I can oblige.
Ill post up some pics later, if anyone is interested, or PM me your email address, and I'll send direct.
I have seen these and they are super nice. Jim did an awesome job designing and building them.
Sent in.
---1) David Francis / Texas / CMC #39 / Orange@sbcglobal.XXX Mb. 713-294-6913
---2) 7.32.8 Braking systems shall conform to the following specifications:1. The one piece front or rear hub with rotor may be replaced with a separate hub and rotor or separate hub, rotor hat and rotor.2. Cars may use an adapter for the sole purpose of fitting identified front hub/spindle assemblies that allow for the installation of commercially available alternative hubs/spindles that retain OEM supsension geometries and provide no performance advantage.
a) Corvette SKF Race Hub Part #XXXXXXX
7.1 Allowed ModificationsOther than those items specifically allowed by the rules, no other part or component may be modified, removed, or disabled. If there are any "questionable" or "gray" area modifications, the competitor shall contact the CMC Board of Directors for clarification before competition. Replacement parts must be original equipment manufacturer (OEM) or others of equivalent OEM specifications. (i.e. – OEM replacement parts from any retailer are allowed provided they meet OEM specifications and do not offer a performance improvement over the OEM part they replace.) Limited production components and/or prototypes must be approved by a Director prior to competition to ensure their use and lack of availability to all competitors will not result in a competitive advantage.
---3) Room exists under 7.1, but highlighted language in 7.32.8 above.
---4) Reasoning for change MUST include at least 1 of the following:
---------->a) Current experience in AI already shows greatly increased hub life at higher loads
---------->b) Will increase driver safety because… current experience, though limited, shows longer time of integrity; avoiding front end parts failure is important to competitor and track worker safety.
---------->c) Will promote series growth because... potential cost reduction over time for long term competitors
---------->d) Will improve competition because… avoiding on track parts failures generally increases competition
---------->e) Will provide more clarity because... allows the part directly rather than as prototype/Director one-off approval
Some good info here: http://www.lgmotorsports.com/SKF-Racing-Hubs
I buy them here: http://store.pfadtracing.com/skf-wheel-bearing/
P/N 1121016
For all you wussy race-car drivers, this gives you "additional balls"! :) (watch video on LG's page) That should put you up front for sure.
Jim
While I agree with the cost savings over having to repeatedly buy new hubs, $1200 is a bit steep for the CMC crowd, but as it sits it is the only proven solution outside of someone stepping up and cranking out the 3rd gen style units. I'm wondering if the regular (Timken, Delco, etc) Corvette bearings are enough as they shave ~$400 off the price?
I myself am circumventing the issue by repeatedly abusing the Autozone/Timken warranty (hey if they can't make good hubs why should I suffer?), but something needs to be done while keeping it fair for the Ford guys that are able to get by with OEM equivalent hubs, because swapping hubs almost every other race weekend is insane.
Glenn, Al, let us know if this can be covered under rule 7.1 (OEM or OEM equivalent)? As it sits I think the last time Glenn brought this up, the other Ford-biased directors pushed back? Correct me if I'm wrong.
Here is what I was thinking of submitting if we can't get it passed under a 7.1 clarification, AND if we can just use regular OEM-equivalent corvette hubs (Timken, Delco, etc):
1) Pranav Patel / Texas / Car 51 / pranavyp@gmail.com 281 414 1482
2) 7.32.8
3) Insert bullet point #7:
Front one-piece wheel hub units may be substituted with rebuildable units provided they:
a. Utilize the factory spindle/knuckle mounting method with no modification to the spindle/knuckle assembly
b. Do not alter the vehicle track width
c. Do not alter brake assembly position relative to the spindle as compared to an OEM wheel hub units
d. Provide no weight savings benefit over existing OEM, and OEM-equivalent one-piece sealed hub assemblies available from retail sources
e. Cost no more than $400 each to reproduce, including machine labor and material costs
4) Reasoning for change MUST include at least 1 of the following:
---------->a) Current experience in other classes already shows greatly increased hub life at higher loads
---------->b) Will increase driver safety because current experience, though limited, shows longer time of integrity; avoiding front end parts failure is important to competitor and track worker safety.
---------->c) Will promote series growth because... potential cost and labor reduction over time for long term competitors
---------->d) Will improve competition because... avoiding on track parts failures generally increases competition
---------->e) Will provide more clarity because... allows the part directly rather than as prototype/Director one-off approval
I started out stating that my solution was expensive....
The cost and labor to swap the old hubs was an annoyance, but what truly bothered me was the safety aspects of the crappy f-body hubs. Crappy hubs were the root-cause of the Patterson/Kagan contact at MSR-H. It was at that point that I began looking for an alternative.
I don't know if its the down-force difference or what, but in AI, we go thru hubs much quicker than CMC. I still can't believe how long James gets his to last.
I'd personally pay a lot more than $1200, if it kept me from hitting a fellow competitor. I encourage you to explore any option other than the factory-style hubs.
Jim
Jim,
Not doubting that the cost of your setup is worth it, my concern is if we try to push a clarification or RCR, that cost level may not sit well with the others in CMC; as such I'm just wondering if taking that setup and ditching the expensive $380-440 SKF race bearing for a regular $130-150 OE-equivalent Corvette bearing would suffice for CMC's purposes. We may get a little more pad knockback and less life, but that puts us back into the range of what the Ford guys are getting.
How are the C5/C6 guys holding up with their regular front bearings?
Also as an alternative if more people try the DIY 3rd-gen based setup, that would be great also.
This was why I put that $400 limit under section E of my RCR, although I'm unsure how we can prove the 3rd gen setup's cost since it involves used parts.
Again, not trying to stir the pot, I am new to the class but would also like to get us away from using these crappy deathtrap bearings.
Jim, my bad I went back and re-read some of your posts; guess the regular C5 bearings may or may be a crapshoot...
I've got more than my own fair share of car/driving problems to deal with this so I'll sit this out for now; I'll happily send in a duplicate RCR or request for clarification if most of us agree on what to send in. In the meantime I've got the entire Autozone Timken hub-swapping scheme down pat...
To me it's just a choice when it is something that does not involve performance.
Big brakes are a choice and I believe are performance related. Same with 17" wheels for me.
The cost of hubs is just a cost - they don't roll any better, they don't leverage anything else on the car, they just *potentially* provide long term cost effective solution to a known issue.
Well, I haven't found anything on the web about massive C5 bearing failures, if I were to buy/make a pair of Dulaney's adapters I may roll the dice and try a pair of Corvette Timkens with the 3yr warranty.
The only issue I have right now is I have those nice blainefab ducts, looking to see if they can at least work with the 3rd gen setup...
Personally all this is filed away for "next year"; too many other issues to deal with but excited to see what we all end up doing...
I have some flat plates cut to fit my hub adapters. They're fitted for my wildwood rotors, so you might have to cut the OD down to fit whatever rotor you're using. And, you'd have to rivet a 3" hose coupler to them. I'm not saying it's easy, but I modified everything to work within about 1/2 hour. Stop by at ECR, and I'll take a wheel off, if anyone wants a peek. You really can't see much unless the rotor also comes off. If I think of it, I'll also bring an adapter for show-n-tell. I don't have any spare SKF bearings.
Post up some pics!
I'm a sucker for shiny new parts.
Photos here of the aluminum prototype. I was too busy getting ready for NOLA to take pictures of the install of the real parts. We did Mike's install in the dark, track-side.
Bolts for attaching adapter to spindle have been replaced with ARP in the kit. The socket head cap screws for attaching the SKF hub to the adapter are hardened, and have yield strength equivalent to ARP's hardware, but have a smaller head.
http://rrsusp.com/images/adapt1.JPG
http://rrsusp.com/images/adapt2.JPG
http://rrsusp.com/images/adapt3.JPG
http://rrsusp.com/images/adapt4.JPG
Installation instructions here:
http://www.rrsusp.com/docs/f-body_ve...stallation.pdf
Jim,
We don't turn any chips. We only work with flat metal. I can cut on the laser up to .500" thick in mild steel, .250" in stainless and .187 in aluminum. Send me what you need and I will see if I can help.
jjordan@picofab.com
JJ
Thanks, Jerry. This is a pretty complicated machined part. Much more complicated than I originally anticipated when I started the design. Attachment 1292
Found a couple pics, comparing Timken to the SKF adapter setup. Attachment 1293Attachment 1294
Just my opinion regarding the cost. I compare it partly to the big brake kits.
I paid $2k for the big brake kit and yes, I feel it gives "some" performance advantage but the main thing I am pleased about is the durability and wear of the pads / rotors. With the 2-piston setup I would go through a set of pads ever 2 or 3 events, depending on track. I would also go through 2 sets of rotors / year. That is $200 on rotors and about $650 in pads / year.
After switching to the big brake kit I ran the original rotors for 2 1/2 years and then bought a new set. The old rotors are still good and I keep them as a backup pair. I also go through a set of front pads about every 5 events now. I would say I spend about $500 / year on 1 1/4 sets of pads as well as some cost for the rotor wear. That is a savings of about $350/year plus WAY less maintenance on pad changes, fluid change, swapping out cracked rotors at the track, etc.
I have run the big brake kit for right at 3 years now so that is a saving of about $1,000. I am 1/2 way to paying off the kit. :^)
I see the hub kit of $1,200 being expensive but the savings will add up in a hurry if it keeps you from replacing hubs every event or two. I just hope this gets approved with the RCR's b/c the lack of maintenance and better safety would be well worth the cost!!
Print sent
I've had good hub life so far, but part of that is not driving the car hard enough.
With the brake ducts actually connected, I get pretty good pad and rotor life too for the number of events I make a year.
There's plenty of room in the rules to spend money because you can or just want to - seat, belts, fire system, custom wiring, wing/spoiler, paint, wheels, etc. This one at least adresses a known weakness in the cars.
IF (big if) the adapter cost $1 would this be rejected? If the answer screams "no," we should give racers the choice.
I am with Dave... not competitive advantage then I don't see an issue.
I have great pad life. I usually buy one new set each year and on occassion buy two sets. I don't quite get one full season out of a set.
The hubs are an issue though, especially with new ones. I have much better luck with the ones off of the old cars I have had than I do with new ones.
W/ a failing hub there is also a massive increase in pad knockback. This is one of the reasons I'm holding off on big brakes since a fixed mount caliper will make this issue much more apparent requiring hub replacement much more often thus increasing an already high cost.
update on SKF hubs.....They are still rocking solid. After the TWS event and a testing day of me driving the car over curbs and rumble strips with a passenger (total weight over 3500) and running sticky BFG rubber....solid. That is 7 track weekends on the hubs/adapters now and generally flogging the car mostly over the transitions at TWS. solid. Best money we have spent on the car in 4 years followed by the painless harness and the watts link I built. ;)
perhaps time to move forward with either these adapters or Richardson's custom spindles... 2014 cmc rules:
7.32.9 Late GM cars may substitute the OEM front hubs with aftermarket hub assemblies as long as there is
no change to the location and geometry of the brake rotor/hat to hub mating face plane and the hub
assembly weighs the same or more than the OEM units
Jim are you selling yours and expect to fill orders piecemeal or does there need to be a group purchase?
I have one set of adapters left. After that, I'd need a group order to keep the price reasonable.