Steering, Suspension, & Brakes

Other than Corvette,(too bulky), I'm looking to save unspring weight. I also want bolt on steering arms. Anybody ? Thanks

Probably the best way to reduce unsprung weight on an MGB is to go to lighter brakes. I don't remember the weight of the various brake components but someone might. It's a substantial amount. By going to an aluminum caliper (Weldwood, Outlaw, Brembo, etc.) you can drop 5 lbs a side IIRC. Similar results with a ventilated rotor and hat setup, some of those Speedway rotors weigh as little as 6 or 7 lbs and an aluminum hat is 1lb. Serious weight reductions of nearly 25lbs a side are possible. (might require an aluminum hub as well)

Then you address wheel weight and also tire weight. After all that the weight of suspension components MAY come into play. Bear in mind it's a small fraction of the whole and most of the components are calculated at 50% due to the stationary pivot points. Upper arms serve double duty as well. Reductions here may not be nearly as much as you expect or nearly as effective.

Jim

If this question had been asked 10 or 12 years ago, I would've recommended sticking with MGB uprights but having them dropped by either Dick Luening (Killer Beez Racing) or Dave Headley (Fab-Tek.) Either way, the point wasn't to reduce weight but rather to correct a too-low front roll center side-effect of reduced spring height.

The advantage of Dick's version of "dropped spindles" was that he retained the stock weather shields and didn't modify the kingpin at all. (Surely the better solution for a street car you're hoping to drive a looong time.) The advantage of Dave's version was that he increased the overall height of each kingpin one inch to add camber gain. (Surely the better solution for competitive racing.) Either way, cost was about $500/set, and you retained bolt-on steering arms. However, upon installation you'd discover that the steering arm forgings needed to be heated-up and bent significantly to correct bump steer. (Dick did that for me for no extra charge. Worked perfectly.) Unfortunately, both of these gentlemen have passed away and I'm unaware of anyone stepping in to offer similar components.

In addition to the lighter brake options mentioned by Jim, aluminum hubs used to be available for MGB in lieu of the stock iron ones. Bill Guzman (Classic Conversions Engineering) offered them for a while. I didn't order a set quickly enough! I don't know if anyone else has offered them... but they should be straightforward for any competant machine shop. I also don't recall the weight savings of Bill's hubs, but it was significant!

Changing out the uprights to something more modern (i.e. without kingpins) seems like great idea, but it's sure to lead to scope creep, isn't it? I reckon anyone who starts that project is going to end up with an entirely custom front suspension. Or an aftermarket one. There are articles on this website describing in detail the features of the Fast Cars, CCE, Hoyle, and RV8 front suspensions. The Fast Cars option would probably have been most attractive to me if I'd been looking to widen track and fit fender flares and +2 wheels/tires.

Quote:

Unfortunately, both of these gentlemen have passed away and I'm unaware of anyone stepping in to offer similar components.

I read a few months ago that Dick Luening's two sons are continuing the business.

Cole, If you decide to go Full Monte, on the front suspension, how much time and $'s ? Many aluminum/light weight, OEM parts
are available now. Mazda RX 7 even had aluminum hubs. As mentioned usual 50% weight factor for A arms and springs/shocks.
FWIW, GM F body spindles are readily available with bolt-on steering arms.
Good Luck, Art.

Had a hub blow up on the way back from the BritishV8 meet so I'm right in the middle of this now. While talking to Max I weighed some components. Here's a pretty direct comparison. The stock hub and rotor assembly weighs IIRC 15 lbs and an aluminum hub fitted with a Willwood aluminum hat and a Speedway rotor that is ventilated, thin version, roughly the same diameter and not drilled or scalloped weighs a pound more at 16. A steel WW hub modded for a 5 lug pattern with a Ford Mustang rotor weighs 19lbs or 4 lbs more. There will be a few lbs savings with an aluminum caliper but the Mustang caliper and bracket are heavier than stock whereas my Outlaw calipers are lighter. Don't know how much, not going to remove them to weigh. Might consider weighing with hose attached. Also a scalloped rotor will get you under the stock weight, but they do tend to make some noise.

So although we've always thought there was a weight advantage, and there can be one if done strictly with that in mind, the real advantage is in improved fade resistance, plus the rotor and hat can be removed and replaced without disturbing the hub. This assumes your hubs will accept a hat of that type.

As for the uprights, they work pretty well if in good condition and when combined with EPS I doubt a ball joint system could be any better really. I am refreshing the kingpins, it turns out that I have enough spare parts to put together two quite serviceable assemblies. Along the way I have learned a few things.

The Moss reamer, which I became convinced was cutting oversized was most likely in fact cutting to the desired size and the cause of unwanted play in the kingpins on assembly was due to the replacement kingpins actually being a little undersized. These were aftermarket king pins and can be distinguished from originals by a short section at the end of the threads of reduced diameter, about the root thread size and maybe 2 threads wide. The originals were threaded all the way to the end. I measured the originals at .806+ and the replacements at .805- so there's the source of the play. Two of the spare parts I had on hand came off a low milage car and the one good spindle I had from my car fit it with no detectable play. The best of the spares for the driver's side had just slightly detectable play and I'm going with that. Not quite ideal but so long as I keep them well greased it will be fine. It may be slightly better than it was with the original spindle and aftermarket kingpin but it certainly is no worse so overall I will have improved things a bit.

Next, on to the thrust washers under the trunion. These bear the weight of the car and can be upgraded to Torrington type roller thrust bearings. You can buy the kit for about $65 + about $30 shipping but the cup that comes with that kit does nothing except add a spacer. The bearing that fits the kingpin is an AXK2035 which has a 20mm bore, 35mm OD and is 4mm thick or about .0160" which is very close to the thickness of the bronze spacer. Might cost around five bucks for the pair and will fit in the recess of the trunion. I have several sets on order from Amazon and plan on handing out the extras at the GCBCC meet in September (My birthday party) Any that are left will go to Townsend with me, provided I remember. End play should be set to under .005, about .001 should be even better. In addition to tightening up the suspension this will help control the loss of grease.

I expect that the reduction in friction will allow the car's weight to overcome the resistance in the EPS unit a bit more and bring back some of the car's natural inherent return-to-center steering characteristic. I formerly added caster wedges to increase caster to about 6 degrees and in combination I am hoping for a good result. We shall see.

Jim



Edited 1 time(s). Last edit at 06/13/2025 03:42PM by BlownMGB-V8.

More info: as near as I can tell given the limitations I'm working with here, the stock caliper is 8.6lbs, the Outlaw one with aluminum mounting bracket is 5.6lbs and the Mustang single piston caliper with steel bracket circa 1975 is 12.6lbs. (note the .6 in all three, using digital bathroom scales.) So basically the aftermarket setup is about 3 lbs lighter overall and the Mach I Mustang 4 lbs heavier.

Jim