88 front hubs for autocross racing (Page 1/1)
mcguiver3 AUG 21, 03:33 PM
Anyone have opinions on Rodney's rebuildable 88 front hubs for autocrossing?
I know his site says not for racing but thinking that is a legal disclaimer?
theogre AUG 21, 05:18 PM
No is Not just a "legal disclaimer."

The RD Front hubs claim is "better" then OE but won't last long for many racing types including autocross.
Nether does rear hubs made by anyone.

Use search or google w/ Site:www.fiero.nl after search terms.

Nearly all "car parts" and even most whole vehicle voids any warranty if you race or even use them for commercial use... including people use a car for Uber, grub hub, etc.
Car Insurance can Void a "normal" policy for cars for racing or commercial use too. Even w/o being voided... most using personal vehicles for side hustle have bare minimum car insurance that won't pay out for a lot of things after a wreck like need a lawyer when sued.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

mcguiver3 AUG 23, 03:35 PM
Thanks Ogre for the reply but I do realize the notation for "Not for racing" but wanted to know if anyone has any experience with these for Autocrossing.
My concern is not that they will wear but will they fail. My hope was that someone has/is trying them and could relay what they may know.
My car is a dedicated AX'er and my supply of OEM hubs is now depleted. The units at the box stores all appear to be Chinese crap.
Having a re-buildable unit looks enticing.
theogre AUG 23, 04:12 PM
Again. Use search. Some have tried this but many old PFF users are gone for whatever reason.
Patrick AUG 23, 05:44 PM

quote
Originally posted by theogre:

Again. Use search. Some have tried this but many old PFF users are gone for whatever reason.



Yes, the durability aspect of Rodney's '88 front hubs was discussed quite a bit several years ago.

[This message has been edited by Patrick (edited 08-23-2022).]

Will AUG 24, 10:24 AM

quote
Originally posted by mcguiver3:

My car is a dedicated AX'er and my supply of OEM hubs is now depleted. The units at the box stores all appear to be Chinese crap.
Having a re-buildable unit looks enticing.



If the options are to use Rodney's hubs or not race the car, I know which one I'd pick.

TheOgre thinks everyone needs a $multi-million insurance policy to cross the street.
sanderson231 AUG 24, 11:40 AM
There is an interesting post in the archives from "ebearing" who had the front hubs made that Rodney used to sell. They were bult in the USA to OEM specs. These hubs used ball bearings. Lots of good historical information including discussion of failure rates for these types of sealed units in cars that were never raced like the GM X body and the Chryler K car.

The hubs that Rodney is now selling use replaceable tapered roller bearings. Although the forgings is done in China, the heat treating and machinng is done in Taiwan. There's a case to be made that these hubs are superior to OEM for auto-crossing.

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formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged

Will AUG 29, 09:01 PM
GM's patented process for producing their hub cartridges involved induction hardening integral races on both the spindle and the housing.

A housing with removable races for the same size bearings will not be as compact as GM's.
A spindle with removable races for the same size bearing will not be as strong as GM's.

You can make the spindle as strong, but you have to push the outer bearing inboard to make room for the radius from the shaft to the flange.
Once you do that, you have to push the inner bearing FURTHER inboard in order to spread the bearings out and reduce load.
That leads to the inboard section of Rodney's rebuildable unit.
mcguiver3 AUG 30, 09:46 PM
Just received Rodney's front bearing hub and I'm impressed with what I got.
While I will continue to be autocrossing this car, I am confident that it will survive as my speeds as well as reaction times are now diminished due to age.
Will post updates.
sanderson231 SEP 01, 12:08 PM
This post by ebearing does make it sound like the 1988 OEM front hubs were on the bleeding edge

We manufactured a lot of wheel bearings and hub assemblies for drag racing, oval, stock cars, road racing, closed wheel, open wheel, street rods, you name it, along with the bread-and-butter automotive and industrial bearings. We invented the c-clip eliminator and for a long time had essentially 100% of the pro drag racing market. We put ball bearings into NASCAR stock cars for qualifying, and a lot of other stuff along the way. Automotive and industrial pays the bills, but racing was always was my favorite.
And I know what you mean about autocrossing and track days. I've been running local, SCCA and PCA autocross and Pro Solo and whatnot since the early 1980's, and track days with the PCA, BMWCCA, or whatever I had that was fast at the time.

The problem isn't so much the hub assembly itself, but its engineering era. The Fiero's rear hubs (513011) and entire rear suspension were engineered back in the late 1970's -- long, long before anyone at GM knew what they were doing. Even then, the X chassis stuff was engineered and produced to a strict budget. Design parameters revolved around the tires and suspension loading of the day, 165/15 to 175 tires, and so on and so on. Suspension geometry, knuckle designs, spring rates, squat, brake dive, brake proportioning, you name it ... 99% of it was a shot in the dark. Oh, and GM had never before designed or built a "cartridge" bearing or what we now call a hub assembly. Unless you count the Corvair, which would be a bad idea.

Anyway, those first few generations of GM FWD chassis and hub assemblies (particularly the 513011, which is a design and engineering abomination, I tell you) had failure rates so high that they single-handedly launched an entirely new segment of the U.S. bearing industry ... and our company was the first to engineer and produce aftermarket versions. Within a few years, we had a number of competitors, but GM was selling a lot of front-drive cars with crappy geometry and high bearing failure rates, so we were all happy for a very long time.

The 88 Fiero front hub is certainly an improvement over what had come before, but in reality it only benefeited from 3 or 4 years of GM building up some wheel bearing design and engineering know-how. For 1988, it was implemented for two main reasons: first, as an engineering exercise, and second because GM was determined to standardize all of their wheel bearings to unitized hub assemblies, and that eventually included all the 4x2 and 4x4 light-duty trucks and the Corvette, too.

Unfortunately, while the 88 Fiero front hub assembly and suspension geometry was an improvement, it was still not quite up to where it should have been, and specifically, the way the bearings are loaded. Also key is that their bearing designs had not kept pace with the requirements caused by wider wheels and stickier tires; they were always playing catch-up. Negative offset wheels were another monkey wrench into the works which messed with all of the "known" good suspension designs. There are a lot of other esoteric engineering and suspension design characteristics that get mixed in, and are not worth going into. The short story is that GM was still thrashing around trying to figure out how all these front-drive suspensions and new negative offset tires and wheels and ABS and so on should work together, and how to use hub assembly units and CV joints and front-drive without dangerous torque steer, and by the way, people are complaining that their X chassis cars all spin aournd backward under braking. Those were dark times at GM, and I would not have wanted to be in their chassis, suspension and brake group, that's for sure. Ulcer city.

Quick example: GM was trying to race X body cars but the 513011 bearings would fail too rapidly for them to get any track time. We designed a unit with tapered roller bearings in place of ball bearings, and that helped. But then the flange (where the brake rotor sits) cracked, starting at the balance/installation holes. Big crash potential there. So we made units with no holes (which meant we had to put the mounting bolts in at the factory, and they were a PITA to install on the car). That worked better, but then the bearings failed again, catastrophically. So we put even bigger bearings in. That worked, but then the knuckles failed. Even worse crash issue. They beefed up the knuckles, then the control arm mounts would fail. You get the picture. It's much, much safer to have the bearings be the point of failure, rather than the knuckle or control arm. I think they ended up building those cars with 4x4 truck hub assemblies.

Believe it or not, things were much, much worse over at Chrysler's suspension department. The K-car suspension geometry is even worse than the worst GM design, and stayed bad the whole time K the K car chassis was in production. We made a nice business out of those replacement bearings, too. When they started trying to race the Shelby Charger, they were getting only a handful of laps before the front bearings would fail. Practice session, change bearings. Qualifying session, change bearings. Anything longer than a sprint race and they were in real trouble. This is one I'm particularly proud of; we came in with an entirely new bearing, hub and spindle that fit within the stock suspension parts, and the Shelby Charger guys are suddenly able to run an entire season on one set of bearings. Yes, they were really expensive. But a fraction the cost of doing it any other way.

We've done the best we can within the constraints of the 88 Fiero hub assembly. Understand that the tires and mechanical grip and loads the Fiero's suspension and bearings were designed for are nowhere near what today's street tires generate, and that loads go up exponentially, not linearly. Autocrossing and track days destroy wheel bearings in older cars simply because the grip generated by today's tires is far beyond the engineering design envelope of the day.

But the Fiero isn't unique ... a fast way to destroy the wheel bearings on any old car is to slap a set of Hoosiers on wide wheels and go lap Mid-Ohio for a couple sessions. BTDT.

We have looked into the possibility of building the 88 Fiero hub with tapered roller bearings instead of ball bearings. Unfortunately, there is no standard tapered roller bearing size that will work, the hub assembly is too small; adapting a different design would mean the hub assemblies could be made, but then they would cost far, far more than you would ever be willing to pay. The engineering guys also wrestle with this question: if we make the bearings so they're not the point of failure, and instead the point of failure becomes the rotor flange or suspension mount, is that a design direction we want to go? The answer, of course, is no.

I hope that answers your question.

------------------
formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged