New 4th Gen Front Wheel Hubs/Bearings, New front hub & bearing design from Hoosier Performance Engineerin Options

[Chevy053]

What was the reason for the design decision to go with a 2 piece flange. Was a single piece considered?

[HoosierPE]

What was the reason for the design decision to go with a 2 piece flange. Was a single piece considered?

Primarily it was a cost & affordability thing, for material, machine time and tooling. Ideally, you'd like to have a one piece forging that is near the final shape and then machine that piece down to the final product. That is how the OEM pieces are done. No way to justify the forging tooling right now, which would probably be $10k or more, with what I believe will be low volumes (hundreds not thousands). We use pre-hard 4140 for both the pin and the flange which is a lot more costly than mild steel, and starting with a 6" diameter billet and whittling it down to 1" diameter in some spots generates quit a bit of waste.

At first we thought we would use a heavy press-fit and then I remembered shrink-fitting from my college days and started researching that process. The Machinery's Handbook goes through the process in great detail. The added bonus was the much higher retention force over a press-fit with the same amount of interference, 3.66 times for an axial pull and 3.2 times in torque or rotation. (This application doesn't see any rotational torque since it is not a driven axle.) An interesting side note; all of the train axles and wheels are a shrink-fit.

Turns out the two piece design might be the better performing design when you consider the stress concentrations and reverse bending cyclic loading of the application. On a one piece design, the transition from the flange to pin diameter becomes critical to avoid stress concentrations and a fatigue failure. If that radius or filet is too small, or there are surface imperfections, it becomes a stress riser and the focal point of crack initiation.

Update: We ran our first Auto-X on Sunday in my son's '95 LT1 (383) Camaro running 315 Khumo's. We had 6 runs on 65 second course with no change in preload on the prototype hubs.

[SuperMacGuy]

I am all for anything that is stronger than the current design- in that I mean if the 2 piece design can be made to handle stress better then that is what I would want. I had 2 of the MJM hubs break on me (please see my long threads on it elsewhere here) and the pieces that were used for the spindle weren't forged properly despite efforts to source the best possible blanks. It seems like the stresses can be high and heat treating is a sort of black-art/science. I'd much rather have a part that bends out of round and I have to replace it, than to have a full on failure (like I had at speed). The taper bearings are great, but, from my first hand experience, I want that spindle to be stronger than the Wrath of Zeus.

[HoosierPE]

I am all for anything that is stronger than the current design- in that I mean if the 2 piece design can be made to handle stress better then that is what I would want. I had 2 of the MJM hubs break on me (please see my long threads on it elsewhere here) and the pieces that were used for the spindle weren't forged properly despite efforts to source the best possible blanks. It seems like the stresses can be high and heat treating is a sort of black-art/science. I'd much rather have a part that bends out of round and I have to replace it, than to have a full on failure (like I had at speed). The taper bearings are great, but, from my first hand experience, I want that spindle to be stronger than the Wrath of Zeus.

Wow Chris, I just read about your escapades with the previous hubs. I'm glad it wasn't worse.

I had not read about these failures before we finished our design, but I sure was thinking about all of the possible failures during the design process. I'm glad we did a clean sheet approach for this new design as it removed many constraints or compromises in the design process. With a completely new housing, we were able to grow the size on everything; the bearings, the pin diameter (1.5" at the big bearing, 1.25" on the small end), and the pin and hub length for a wider bearing span. Unlike the one piece hubs (OEM or aftermarket) we don't have that high stress corner area in the flange to pin transition. All three major components are pre-hard 4140 that has been case induction hardened only in the pin area where the two inner bearing races rest and the step on the flange where the seal rides. We did pay for extra samples required for sectioning in setting up the hardening process. (I'm keeping these samples and reports indefinitely...) The 4140 material is billet, which removes the bad casting or forging issues.

I talked with my machine shop this afternoon and we are ready to kick off a 100 piece batch of these things. I believe we have covered all of the questions posted on the design. If anyone sees any glaring issues, please let us know as there is time for a few changes. Parts should be available before the end of July. I've started a list, so if you are sincerely interested in a set, please let me know. Price is $650 each, $1300 for a set of two. (Right now, we have not located a source for the ABS sensor cap, so you will need to reuse the ones from your old bearings.)

BTW, we did a trial fit on a '91 C4 Corvette. They bolt right up, just need to run the OEM fasteners in from the back side and discard the nuts.

[MarkT]

It's not that critical of a question (or issue for that matter) but can they be set up for screw in wheel studs? I went with 1/2" screw in ones on my Strange axle shafts and would at least like to get back to the same lug nut all around (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif)

[HoosierPE]

It's not that critical of a question (or issue for that matter) but can they be set up for screw in wheel studs? I went with 1/2" screw in ones on my Strange axle shafts and would at least like to get back to the same lug nut all around (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif)

We might be able to do something special for you. Send me the info on what thread you need in the flange and I'll talk to our shop and let you know.

[00 SS]

FYI, if you can get the flange holes threaded, Turner motorsports sells a threaded stud that's reasonably equivalent to the ARP studs in length and size.

[SSTAT]

Jut this spring I officially depleted every junk yard I know of these hubs. I definitely want some (NEED some) but not with only some daily driving and one autocross worth of testing on them. There were high hopes for costly past designs that failed. I will shell out $1300 but only after someone has a season or so of actual racing on them and makes sure the wheels don't fall off. From a marketing standpoint wouldnt it make sense to get some real world (ie. not just one autocross) racing data before presenting these to the 4th gen/C4 crowd? Street cars don't need these.

This post has been edited by SSTAT: Jun 26 2013, 01:17 AM

[93FirehawkTA]

Very interested. Thanks.

[FASTFATBOY]

In for pricing and durability testing.

I want to know if they will handle a set of 315 NT-01's on a 3800 lb car on track.

[Chevy053]

What was the reason for the design decision to go with a 2 piece flange. Was a single piece considered?

Turns out the two piece design might be the better performing design when you consider the stress concentrations and reverse bending cyclic loading of the application. On a one piece design, the transition from the flange to pin diameter becomes critical to avoid stress concentrations and a fatigue failure. If that radius or filet is too small, or there are surface imperfections, it becomes a stress riser and the focal point of crack initiation.

Thats what I was getting at. Was just curious if that was by accident or not.

[HoosierPE]

Jut this spring I officially depleted every junk yard I know of these hubs. I definitely want some (NEED some) but not with only some daily driving and one autocross worth of testing on them. There were high hopes for costly past designs that failed. I will shell out $1300 but only after someone has a season or so of actual racing on them and makes sure the wheels don't fall off. From a marketing standpoint wouldnt it make sense to get some real world (ie. not just one autocross) racing data before presenting these to the 4th gen/C4 crowd? Street cars don't need these.

SSTAT,

That's one view point, but as you pointed out, the supply of seasoned salvage yard parts are drying up and we all know the parts store replaces don't last like they should. I understand the community has been burned by past attempts, and that is exactly why I created the parts shown here. I studied all of the previous attempts and their short comings and also the original part design and improved on every aspect of these other designs. In a perfect world, with nothing but time, yes, it would be great to wait until we had a season or two exposure on these before we offer them up, but I believe the need far out ways the risk at this point. If, in my professional engineering assessment I thought there was any possibility of catastrophic failure, I would not have offered them up to this forum in the first place. If the improvements are not apparent to you in the pictures and descriptions above, then you should probably wait until next year.

[camarokid91]

Any thoughts on these being ESP legal ?

[Chevy053]

Any thoughts on these being ESP legal ?

We never got a straight 100% answer on the design in THIS THREAD.

This design is similar so I wouldn't expect much of a different result. If anything these might be less legal (or more illegal). The other design re-used the original hub base which made them visually more similar to a stock replacement hub.

[SuperMacGuy]

I'm not on the SEB, but my opinion is that, locally/regionally, no one would have a problem if I used them. In fact no one would ever notice, nor care, I bet. Nationally, maybe there is a question, but this could be viewed as a direct replacement part for worn out parts. There's not an allowance in the rulebook for "more well designed replacement hub". Then again, there's no mention of replacement of mundane items like fuel filters, valve stems, oil filters, or rear axle bearings. It's just assumed no one cares nor it makes any difference.
There is no performance advantage gained. In fact, the additional weight could be viewed as a weight penalty. Or, you could argue it is a safety improvement, as there is less chance of pad knockback from worn hubs and thus less chance of losing braking ability. Could you claim you bought them as direct replacements and didn't know the differences internally? If it were sold at AutoZone in a black box with a rusty patina on them, would anyone know the difference?
Anyone who would argue this is any type of actual on-track performance advantage would need their decision making authority revoked.
I think the previous SEB "no comment" (other thread) was sort of saying, "it's not a big deal and it would be too restrictive to put an actual ruling/wording on them. run them as is, and don't worry about protests". Wasn't Sam on the committee back then? I hope he would have said these would be OK to use.

[SSTAT]

Jut this spring I officially depleted every junk yard I know of these hubs. I definitely want some (NEED some) but not with only some daily driving and one autocross worth of testing on them. There were high hopes for costly past designs that failed. I will shell out $1300 but only after someone has a season or so of actual racing on them and makes sure the wheels don't fall off. From a marketing standpoint wouldnt it make sense to get some real world (ie. not just one autocross) racing data before presenting these to the 4th gen/C4 crowd? Street cars don't need these.

SSTAT,

That's one view point, but as you pointed out, the supply of seasoned salvage yard parts are drying up and we all know the parts store replaces don't last like they should. I understand the community has been burned by past attempts, and that is exactly why I created the parts shown here. I studied all of the previous attempts and their short comings and also the original part design and improved on every aspect of these other designs. In a perfect world, with nothing but time, yes, it would be great to wait until we had a season or two exposure on these before we offer them up, but I believe the need far out ways the risk at this point. If, in my professional engineering assessment I thought there was any possibility of catastrophic failure, I would not have offered them up to this forum in the first place. If the improvements are not apparent to you in the pictures and descriptions above, then you should probably wait until next year.

Fair enough, but I think the other designs were by engineers also, and had more than one event on them before they failed. Nothing in those pics is apparent to me as I'm not an engineer, but I thought professional engineering assessments generally included testing (in the target environment). I truly do have the highest hopes for you and your design.

[mr.beachcomber]

...I think the other designs were by engineers also..

I think that the original design was more than adequate for the task at hand. (After all, GM had to take into consideration that their product would be raced, auto-xed, and subjected to more stress and strain than simple straight-line driving.)

Just wanted to point out that even though the OEM and aftermarket designs were developed by professional engineers, there is a world of difference between a product whose price is controlled by bean counters looking to maximize profit and a product designed/manufactured by someone concerned more about quality, e.g., tolerances, use of higher quality steel, racing quality studs, etc.

A case in point: Years ago, Chicago Rawhide used to supply the best C4 wheel hub assemblies until a bean counter sent their operation off shore to maximize profits. Now you get the luck of the draw. I have seen new hub assemblies that had as much or more play than the worn assemblies they were meant to replace.

Personally, I would rather have a product like that offered by Hoosier Engineering than a bucket full of Chicago Rawhide hub assemblies that I have to test to find the best units. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/beerchug.gif)

[93FirehawkTA]

After all, GM had to take into consideration that their product would be raced, auto-xed, and subjected to more stress and strain than simple straight-line driving.

I would say exactly the opposite. I think all GM designed 4th gen f-bodies for was "Friday night drags". All the money was in the drivetrain.

This post has been edited by 93FirehawkTA: Jul 3 2013, 07:54 AM

[HoosierPE]

Hey guys. Sorry I've been out of touch recently. Traveled to Oregon and Texas last week and getting caught up on somethings this week, now the 4th is here. I wanted to let you know that I ordered 100 assembles from our machine shop last Friday (will make 50 pairs of hubs). They have promised to have them machined and plated by the end of the first week of August. So we should be shipping assemblies by the second week of August. We will be setting up a PayPal account for the business in the next couple of weeks and will accept orders at the end of July.

SSTAT, I just wanted to let you know that you are correct; in a perfect world, you would perform extensive laboratory and vehicle durability testing to prove out any new design. When you can spread this cost over a 100,000 or 1 million of something, it really becomes a non issue. If you have to spread this extensive cost out over several 100 assemblies, it really is cost prohibited. It could easily add $1000 to every assembly at such low volumes. So our approach was to over-design this assembly to the greatest extent possible. We have the largest tapered bearings that can physically be packaged in this design space and still fit the stock upright/knuckle. The tapered roller bearings out perform ball bearings in every category.

Relative to the legality of these hub assemblies, it was covered in the other thread referenced above, and they didn't receive a final ruling from the SEB. I for one, will be running these in all four of our 4th Gens and hope to take one or two of them to the Solo Nationals. I would think you could argue a performance disadvantage with the nearly four lbs added to the front of the car.

[shortbus]

I am in. I will PM with my best contact info.

Thank you.