[HoosierPE]

Greetings fellow F-body enthusiast!

I've created this new topic to introduce Hoosier Performance Engineering's first new product; a clean sheet approach to a billet front hub and bearing assembly for the 4th Gen F-bodies and C4 Corvettes. Many of the other hub/bearing threads are getting pretty long and don't really end with a sustainable solution, so I thought a new thread was in order.

I won't bore you with the details on HPE, other than to say a group of highly qualified and skilled automotive engineers have gotten together to create performance products for the 4th Gens and modern muscle cars. You can read more about HPE on the General Discussions forum where Kevin introduced HPE as a new sponsor.

I've been contemplating the 4th Gen front hub issues since I returned to Auto-X in the fall of '97 with the purchase of my first TA and began working in earnest on new designs in November of last year. What you see below is the result of two gear-heads' work for the past 7 or 8 months, plus over $6000 worth of invested in prototypes, tooling and CNC programming. Prototypes are installed and accumulating mileage and we will be ready to take orders as soon as the machine shop volume quotation is received and final pricing can is set. (Trying to wrap up pricing yet this week.)

I'll let the pictures do the talking first, and then will follow up with some detailed descriptions of the components. Enjoy.

Finished product:
(IMG:https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-ash3/1014542_375876139190953_1528206097_o.jpg) , (IMG:https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-frc3/976331_375876125857621_1907471607_o.jpg)

Here's a disassembled OEM hub and the new HPE replacement parts. Note the OEM uses ball bearings while the other is tapered roller. On Timken's website, the tapered bearings are rated much higher in every category vs. the ball bearings. Small bearing has a 1.25" ID and the large bearing has an 1.5" ID. For comparison, the old GM RWD cars used like 7/8" and 1" bearings with the front spindle design.
(IMG:https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-frc1/1009411_377277199050847_782089290_o.jpg)
(IMG:https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-ash4/999016_377277289050838_494724905_n.jpg)
(IMG:https://sphotos-b.xx.fbcdn.net/hphotos-ash4/1009351_377277345717499_1374075883_o.jpg)
(IMG:https://sphotos-a.xx.fbcdn.net/hphotos-prn1/1015137_377277329050834_2109600006_o.jpg)

We use an inverted spindle design, much like OEM part, except ours is a two piece design with a wheel mounting flange and pin (spindle) that we shrink fit together. The shrink fit provides three times the push out force of an equivalent press fit. Pin, flange and housing were all coated with a clear zinc treatment. The pin has been case hardened in the two areas where the bearing races will rest. The mounting flange is case hardened where the seal will run. Specs were per the Timken recommendations for the bearings used.
(IMG:https://sphotos-b.xx.fbcdn.net/hphotos-frc1/1008279_375876219190945_1586806985_o.jpg)

Pin with locking washer, nut and small cap screws. The washer engages the key way in the in threaded end of the pin, the nut is added and torqued to desired preload, and when the threaded holes in the nut lines up with the holes in the washer, the cap screws are added as the retention mechanism, basically replacing the cotter pin in similar parts.
(IMG:https://sphotos-a.xx.fbcdn.net/hphotos-prn1/1014577_375876269190940_1184777397_o.jpg)
(IMG:https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-ash3/1015262_375876245857609_442072466_o.jpg)

Sub-assembly shown with dry bearings for clarity.
(IMG:https://sphotos-a.xx.fbcdn.net/hphotos-ash3/1015600_377277409050826_1257648155_o.jpg)

These assemblies are completely rebuildable and repackable. Should be the last set you will ever need.

I will add some more pictures of the prototypes installed on one of our cars.

Please let me know what you think!

[StanIROCZ]

John sent me some of the design details of this hub unit so I could do a bearing life analysis.

I started by creating a duty cycle. This duty cycle is far from being perfect or actual. It is very simplified estimation of the loading and cycles that this hub unit will see on a car. After creating the duty cycle I made some assumptions for the vehicle and started calculating the dynamic corner weights at each wheel and the braking and cornering forces at the contact patch. Then calculated the loads and moments along the shaft axis at the wheel center. Plugged that data along with the duration (cycles) at each load case into my bearing calculation software. Add up the damage at each load case to get the cumulative damage and calculate the reliability. I can go into more detail if necessary.

(IMG:http://i116.photobucket.com/albums/o33/StanIROCZ/4th%20gen%20hubs/HPE_Bearing_life_calc_zpse78ff978.jpg)

(IMG:http://i116.photobucket.com/albums/o33/StanIROCZ/4th%20gen%20hubs/125_trail_brake_zps3696ff76.jpg)

(IMG:http://i116.photobucket.com/albums/o33/StanIROCZ/4th%20gen%20hubs/Inner_contact_stress_125_trail_brake_zps589346cb.jpg)
Inner bearing, roller contact stress, 1.25G trail braking

(IMG:http://i116.photobucket.com/albums/o33/StanIROCZ/4th%20gen%20hubs/Outer_contact_stress_125_trail_brake_zps23292a38.jpg)
Outer Bearing, roller contact stress, 1.25G trail braking

The short story is the damage is low and as a result the reliability is high. As you could probably guess even without doing these calculations that putting larger taper roller bearings in place of smaller ball bearings is going to result in longer life.


The small text:
Many assumptions were made and there might be mistakes in the analysis. No warranty expressed or implied. Use at your own risk. yada yada