Been a non member surfer for quite some time now. I have a 73 duster I picked up last winter and plan on a pro-touring road race car out of it. While I have read good things about the torsion bar suspensions on these cars, I am adding a 600 horse 440, 11.5:1 compression, tunnel rammed motor. I was considering their front K frame kits after reading another thread on here and went to their website, it seems they are selling a Watts link 4 bar rear suspension too, does anyone have one? Thoughts on a watts link system?

here's the link to their kit,

http://www.gerstsuspensions.com/gerst-contender-series-rear-suspensions.html

thanks

Doug

Or a triangulated 4-link !!

Why compromise if you are going with a custom setup?

A 3 link with a good watts link would be a much better way to go. (the one in the link above doesn't look all that amazing to me)

could you elaborate please?

Elaborate in regards to what ?

Why not keep it stock(-ish) for now, take it to a circuit and then decide if upgrades are needed?

the 3 link vs the watt's link kit i posted




This isnt my first mopar, I previously had a 73 duster with a moderate 360, around 450 hp in it, i put 1.03 bars in it and mopar super stock springs and it handled alright but not perfect, lot of understeer and the back end stepped out from time to time rather unpredictably, it ended up catching fire and burning it and my shop down 2 years ago, probably from me skimping and using 40 yr old wiring, so im starting over.

I'm not exactly a novice/beginner with road racing, I'm 31, been doing it now since i got my drivers license and dad made me do SCCA auto cross, said that was the best way for me to find out exactly what the car would do and do it safely. His goal was to keep me from racing, well that didnt work.

My biggest reasons for upgrading my suspension from the good factory mopar are:


Adjustability, I want to play with spring rates and roll centers this go around. I've already upgraded to a tubed K frame and coil overs upfront. May as well do the rear too.
Leaf springs just dont provide that. My only tuning tool would be shocks and maybe an adjustable sway bar if i stayed leafs.

He is saying if going to a Watts, go to a 3 link instead of 4 link. The Watts is just an axle locating method.

Yep, and regards to the mentioned triangulated 4 link, they just induce bind, so to go with something non-stock, I couldn't see why use something that wasn't more of an ideal setup.

(I have a triangulated 4 link-from the factory car that the same models have been road raced since the 70's until right this moment and everyone who can change when the class allows, seems to ditch it for a 3 link/watts link setup.)

http://www.msfracingcomponents.com.au/wattslinkandpanhardkits/

A few styles of watts link there..

And general idea in car (non Mopar, this is a Torana track car setup with a 3 link and a similar to above link watts setup)

What front coil system do you have? None of the kits currently offered are very good for performance driving.

Not entirely true, although I will admit changing coil springs is a much cheaper and easier exercise.

Up front, changing ride heights, whether torsion bar or coil over, will net similar results in geometric changes. Altering pick up points between an aftermarket tubular coil over system or the OEM torsion bar system is not done easily, although...by retaining the original mopar parts, you can swap to taller spindles (FJM or C body) and taller ball joints (offered by several oval track parts suppliers) to alter intersection points, and ultimately, roll center locations. None of the aftermarket systems I have seen allow these changes, use compatible parts to adjust spindle heights, nor offer control arm mounting point adjustments. But, a big drawback to the OEM system is that t-bars are expensive and you are limited to 4 maybe 5 decent rates, provided you match them up with big enough sway bars.

Out back with a stock leaf spring set up, no, you can't alter roll center easily. However, changing the front eyes to pivot style eyes and adding an adjustable panhard bar will now allow easy changes in roll center height for a live axle set up. However, quick rate changes with leaf springs is not easily accomplished.

FWIW, the original AAR and TA race programs used both watts and panhards with leaf systems when racing the TA series in 1970. Plymouth had panhard bars and Dodge used Watts links. As Plymouth was qualifying better, the Dodge team elected to dump the watts for panhards and improved their qualifying positions.

Now, that isn't intended to say a watts in ineffective, as they have been used successfully in many applications. However, what it does tell me is that in a competition environment, sometimes the simplest solution is more effective in application than the ultimate solution.

I wonder if the added unsprung weight of a watts over a panhard was the difference the Dodge team was seeing?

In theory the watts setup is superior from a lateral movement aspect, but reality has a way of dealing with theory.

BTW, Afco 20229P are on clearance at speedway.

Could have been. Plus, when you are using a 40"+ panhard bar spanning the entire rear housing and only moving the suspension a few inches up or down, the lateral movement of the rear due to the panhard's arc of motion could be a non-issue in the bigger scheme of things.

Thats a decent price on the Afcos at Speedway. Might have to pick some up since I've been considering Afco leafs.

A pan hard actually has a tuning advantage over a watt's link. I still chose a watt's link, again. Previous setup and current setup under construction.

You got bored waiting for that engine huh?

If I'm viewing your pic correctly, the 3rd link is slightly offset or the watts?
I like your lower over the tunnel upward bent tie the bottom main bar bottoms together. I don't see that around here often. Very Nice, again

first, I'm steering away from the 3 link, I just think with the power im running and knowing that i'll probably take it to a drag strip once or twice, i feel it's better to go with a 4 link, distribute out the power better.

Also, Craig, that set up looks very nice.

well with a panhard bar,to a certain you can actually tune it to unload a certain tire, depending on which corner you want to make time up in, watts link can't do that. Normally, you want max grip on both tires equally, but there are occassions where one tire having less grip could be an advantage. Plus Panhards are easier to grasp the tuning in my opinion having played with both before. I just lack welding skills or i'd build my own. I really just like the watts link over the panhard, call it a preferance. And since I lack the skills i mentioned above, Gerst Watts link looks like the only off the shelve mopar kit with a watts that is adjustable. At least that I can find

Doug

Thanks for the input.

I have ordered a Gerst kit. I'm curious as to why you claim no kits offered are very good, have you in fact driven cars with all those kits?

My experience is that in most cases, the driver is a huge part of the problem. What I mean is, these aftermarket kits have to be put on and properly tuned. Do they come with the correct spring rates for your car? the same 2 Duster per say can weigh vastly different depending on how they are set up. This would change the spring rates need to be in the right spectrum. Also, how many of those cars with aftermarket kits are still running factory rear suspensions, or slightly modified rear suspensions? How's the weight balance of the car? There's so many different factors that I don't think its fair to just lump all aftermarket kits into one and say they all suck for performance driving. Especially since 9 times out of 10, the people making those comments haven't messed with one. Not saying this is your case but im just making a general assumption.

Good news is that I have some baseline numbers to compare with out of my car so I'll post them when i get the ones with the Gerst. I will say this, I watched a 68 dart tear it up at a bowling green event earlier this summer, I got to talking with him and he's the one who turned me onto the gerst idea. I got to drive that dart and was pretty happy with how it handled, it drove flat, tires hooked and didnt push, very predictable landings. Something my duster never has had. Gentleman said he picked up over 2 seconds on the same course with the swap. But take that with a grain of salt of course as I have no way to verify that for you. Plus, like I mentioned above, there's so many factors in setting up a car, that's why I wanted adjustibility.

I'm not married to the Gerst watts link, so if there's other off the shelf options out there that have that much tuning capability, please link me.

Thanks for the opinions all. Keep them coming

Doug

Spent forever waiting on heads and now 7 months for rockers! Yep, can rebuild this before the engine is done.

Good eye. Yep, offset 3 link to compensate for torque steer.

Looks like this:

What heads did you go with?

I've built and set up some of the fastest Mopars in the country. I've played with all the coil over kits except for the Gerst. None of them have the tunability and adjustability of the Hotchkis System. And the durability has usually left something to be desired. NONE of them are sold as a tuned kit and most don't use quality components.
None of the aftermarket systems have been able to beat the Hotchkis Torsion Bar and Leaf Spring setup on the track or at the Autocross. Good luck with the Gerst setup, if you would like to share the Camber, Carter and Bump curves when you get it, I'd love to see it. Maybe they figured it out.

sure, I'll get things measured and recorded for you when i get everything set. Some of those numbers are ride height dependent if i'm not mistaken. Would be interesting to put a full GTS equipped car up against a Hotchkis equipped one day on the same track, same conditions.

Hotchkis does have some very nice products and results out there for sure. But it's mostly plug and play, not sure where you're getting that the hotchis kits have more adjustibility , if anything its about equal or even behind the aftermarket coil over kits, at least in the case of the Gerst stuff. I wanna tune and play with stuff. For example, I ordered my Gerst kit with both stock height spindles and 2 inch drop spindles and this winter, I'm ordering springs from vikings to play with spring changes, planning on springs from 250 to 450 in 50 lb steps. it's not gonna be exactly cheap to get all those spring sets but i added it up, it's still gonna be cheaper than multiple torsion bars, by about 50% per pair. So if I do go coil over on the rear(99% sure I am), i'll be able to get all 4 springs for the cost of 1 set of torsion bars. that are a tad harder to change out at the track. Plus Hotchkis doesnt sell Torsion bars for A bodies.

I got the new Edelbrock Victors and Crower is just now finishing my stainless rockers.

Thanks!

Don't worry about power on a properly design 3-link. The setup I'm using is in some 1000+ HP race cars with slicks.

The question you have to ask yourself is how serious do you plan on being with the road race/autocross? To just to play and have fun, the Hotchkis is all you need. To be competitive and win USCA, CAM, or Goodguys, going to take a much more serious front and rear suspension and 315 minimum front tire.

ok cool, im doing it in SCCA mainly. probably just a midwest tour on the weekends. I'd like to be competitive, but i'm trying to stay within a certain class as well. So I'm limited by the class rules some too. a 315 wouldnt fit even a stock A body front without some serious mods to the fenders and i'm trying to steer clear of a wide body kit. Plus, part of this is to play weekend crew chief/driver, tests some stuff out and play around. Am i gonna do it professionally or be sponsored, nah, more of a hobby but i do want to at least run in the upper 1/3 of the class, i think that's a realistic goal.

Thanks for the tips.

That is a false interpretation of use. Four links does not allow you to put more power through them than three links simply because of the extra rod. A prefab parallel four link will allow much more tuning for instant centers related to accelerating, but any prefab unit have the potential for binding and lack adjustments that would be beneficial to cornering whereas a three link allows greater articulation during body roll.



Not to be argumentative, but it sounds like you're throwing stuff at the tarmac to see what sticks. You should be able to calculate your needed spring rates to be within a 100-150# of optimal without ever buying a spring, then pick up the 50# variation to dial in to your specific preferences. See a topic further below in this forum on formulas for handling and recommendations for reading.

Additionally, changing ride height via either spring position or drop spindles can also be done on the stock mopar stuff. T-bars can be turned up and down and drop spindles are out there. You are spending a lot of coin to gain no more adjustability than the stock mopar stuff and actually may have less adjustability because of the base components used. Mopar based ball joints have been used in the oval track world for decades because of their robustness and easily changed design. This means that are a broader range of units out there with varying geometric differences to achieve different results, differing materials to reduce friction, even rebuildable units. I don't think such parts exists in the M2 based components used in most coil over kits.

Perhaps you glossed over my previous post to tell me about panhard tuning and missed that I pointed out no aftermarket system allows you to alter suspension pick up points in a manner like the stock system does. You can achieve adjustability with the stock set up using stock components. Taller, shorter, and drop spindles can all be utilized in OEM form. Changing pivot centers with ball joints is possible. Altering arcs of motion with spacers and adjusting rods can be done. All adjustments that will change intersecting points of the geometry.

The biggest advantages I see of an aftermarket coil over system are possibly lighter weigh, although since Gesrt uses .25 wall everywhere, that weight loss may not materialize with their unit, and cheap(er) springs. They all tend to have turning radius issues as well because of rack width limitations, and in my opinion, offer less adjustability than stock.


There also is all the rules issues fitting an aftermarket unit into a particular class will entail. This alone would make a good argument for the Hotchkis system.
-
I suppose since you already ordered it, its your burden to make it work within the framework of your expectations. Please keep us advised on how it goes.

Oh dont worry, you're no being argumentative at all. I asked for opinions, I was expecting multiple view points.

I do understand the 3 link vs 4 link differences, pros/cons etc. I do have to disagree about the extra rod/strength of a 4 link, but we'll leave it there. I'm pretty set on the 4 link but I did look into 3 links, seems to do it right, I'd have to ditch the rear seat and modify the floor pan in the duster, both of which I'm willing to do. I crawled under and measured last night, even off set, I'd only behind to fit an 8 inch top link, if i located the pivot point/mounting point on the axle to being behind the axle centerline, I'd only gain about 1.5 inches before running into clearance issues. So for packaging, without extensive chassis mods, the 3 link just wont fit. So 4 link it is, that leaves parallel, which yes will bind more than a 3 link, but less than a triangulated. And it wont require me to modify the rear passenger compartment. I may change my mind down the road but for now, that's where i'm at.

as for the point you brought up about the pick up points. I didnt gloss over it, just didn't want to comment until I fully researched it. Everything you mentioned that can be raised or lowered on the OEM can be done with the Gerst and Im fairly sure with RMS,Hemidenny or the others that use Mustang II spindles. Just like the OEM, you can get taller or shorter height spindles both in stock ride heigth and 2 inch drop form. I know Wilwood makes them, Ron sutton sells them. You can even get Mustang II spindles with shorter or longer snouts and bigger bearings, different degrees etc. You can even get Mustang II spindles with custom length steering arm attachment points. So how would the Gerst not facilitate this change? It'd be no different than swapping in similar spindles in an OEM platform, it'd change the angles the same way.

As for the upper control arm mounting, I'm assuming you mean the points where the arm connects to the frame? the Gerst and from what I've seen, all the other aftermarket kit use the same upper control arm mounting points as the OEM. Gerst upper control arms like many aftermarket uppers are adjustable. So I'm not following on how you can adjust the non-adjustable OEM arms mounting points and not be able to adjust the mounting points of the aftermarket ones the same way?

also, if the Gerst uppers are designed in a way to gain camber much like say Hotchkis, that's a mute point between the 2 there as well. I know the factory Arms have an issue with negative camber.

As for taller ball joints and offset center ball joints, I've emailed Gerst to confirm, but from what Ive found, assuming he uses a common ball joint size, you can get pretty much any aftermarket/racing ball joint you can imagine. Taller, off center, rebuildable, adjustable ball joints all seem to be sold.

***Edit*** just got a response from Carl Gerst, says it comes with a QA1 rebuildable Mopar Ball joint that has an extended stud. So based on that, any mopar ball joint you can get, you can use. Although he did mention that he runs the tallest available mopar ball joint so all you could do is go shorter.

Also, since the gerst kit claims to be adjustable on the track width, and both control arms are adjustable, wouldnt that also change the intersect points, as well or am I wrong on that?

as far as turning radius, I'll have to let you know on that one when i get it in the car. I'll try to take measurements off the stock setup before I take it out if i remember too.


As to the throwing what sticks and seeing what works, yes I am. It's not from lack of knowledge, its just I have several theories I want to try out and play with. I'm divorced, no kids, no other bills than utilities so I have the money to experiment around and try things out. I'll run a base line with the suspension set to the recommendations from Gerst, then experiment from there. The local road course charges 500 a day rental fee, 7 am to Dusk so I'll rent it for a couple days and play around. That, or they run open test days for 50 bucks, as many laps as you can. They do that i think twice a month

As for the weight savings, from what ive read on other reviews and the Gerst website, it's about 30-75 lbs depending on the car and whether or not you orginally had power steering.


So with all this in mind, I'm still not grasping how you're saying you can only change those things in an OEM component suspension but not an aftermarket????

I was unaware that such a wide variety of spindles and joints were available for the M2 based components. I have never seen any mention of the availability of alternate components offered through the variety of coil over kit suppliers, so never knew they existed. Since I don't play in the coil over world, I've never had any reason to look up if they existed either. This availability obviously changes what can be adjusted in the aftermarket system and opens up new possibilities. IMO, the original system is similarly adjustable, but it is not as easily accomplished, and yes, this would include control arms of varying length to alter track width. Since all the racing I've done has been severely rule restricted, I've always found ways to make "stock" parts work for the application to avoid the penalty of using obviously aftermarket parts.

If they offer it, I would suggest having Gerst build your system with a splined sway bar mounting system instead of an off the shelf bar. This would allow almost infinite bar tuning options. I suspect you may be looking at some soft spring, big bar combinations with the variety of springs you are chasing down. The ability to change the sway bar to balance the roll couple percentages would go hand in hand with spring changes.

I'll ask Gerst about the splined bar. I know he uses a 1 inch front bar that's hollow, dont know if one could use a splined bar on it or not.

as to availability, yeah, probably 10 fold what's out there for our Mopars. Dont get me wrong, I love ma Mopar but lets face it, we're the red headed step child of the hobby. We have far less products available then say Chevy and Fords. And when it is available its usually 3 times the cost. Forged drop spindles for a mustang II are 175 for the pair from Wilwood, Wilwood doesnt make any for a Mopar, but PST is the cheapest forged drop ones I could find, 499.....

Just an FYI, doesn't seem to be a standard for KPI on the M2 spindles. Everyone is a little different. Also, the bearings are way undersized for 3K plus cars being tracked.

Been watching this thread with interest. Thought I'd chime in. There's been some very good points discussed so far. But one thing I want to discuss is the bearings not being suitable for 3000+ pound cars on mustang II spindles versus mopar spindles.

lets look at these bearings. I see this brought up a lot, that mustang II bearings are smaller, so they are weaker, yet find it difficult to believe based on these numbers.

A body Mopar (73+) factory disc spindle wheel bearing sizes(note, the 73-74 B and E bodies use the same bearings):

Front inner bearing: 1.3772 in inner diameter, overall diameter is 2.362 in and width is .66 inches, static load bearing 10,700 lbs, dynamic load rating of 8800 lbs. thrust rating is 922 lbs

Front Outer bearing: .75o in inner diameter, overall diameter is 1.168, width is .655 in, static load bearing is 2120, dynamic load rating is 2680.

Mustang II:
Front inner bearing: 1.3775 in inner diameter, overall diameter is 2.328 and width is .625 in, static load bearing is 10700 lbs with the dynamic load rating of 8800 lbs per bearing..... the same as the mopar rating..... thrust rating, 917 pounds

Front Outer bearing: .861 in inner diameter, overall diameter is 1.7810, width is .458 in, static load bearing is 2160 pounds, dynamic load rating is 2670 pounds.


So lets recap, the load ratings are the same as the Mopar A body bearings for the inner bearing, the outer bearing, the Mustang II load bearing is HIGHER by 40 lbs but the Dynamic is lower by just 10 lbs. now that's per bearing. and a 5 pound thrust rating difference. That's not a huge difference at at all ether way. The only advantage I can see the Mopar having is that since it is a tad wider than the Mustang II bearing, is load surface, which translates into slightly better heat dissipation. But just how much heat dissipation difference can there be with a bearing width difference of .04 inches, that's less than a 1/16 of an inch

Mustang II spindles are used throughout the aftermarket and some aftermarket kits use even bigger bearings that fit on the Mustang II spindles. See Ron Sutton and Wilwood for example. Sutton sells brake kits for pro touring that use bearings with almost double the load ratings for mustang II spindles. Wilwood just uses wider and bigger bearings in their kits, especially their larger brake kits.

Bottomline, there's not a lot of strength differences, or differences in general, between the 2. Besides, most of these aftermarket kits are running forged mustang spindles that are improved over the 73-78 mustang IIs OEM ones. I know the spindles I have are wilwood pro and they are certified by SCCA and others for racing. The only thing I can say really is that if you are experiencing a heat issue and heat caused wear, keep extra bearings with you or get one of those kits with the longer/stronger bearings in the hubs. Really, as cheap as bearings are, I'd do that regardless of spindle or bearing type or size. And if you're going to be racing, probably should check those routinely anyway. If you wanna be sure about it.


***Disclaimer***. These numbers came directly from the bearing manufacturers. In this case, Federal Mogul and Timken, both display the same numbers


As for the watts link, I should have mine installed shortly. I'll get pics for you dusterpt440

Good numbers and good research, but, the conclusion with the above info is IMo, if you are satisfied with 73+ Mopar spindles, forged M2 spindles/bearings are not much of an improvement.

Thank you.

Never said they were. I'm merely disagreeing with the theory that mustang ii spindles and bearings are more failure prone than mopar spindles. I just see that everytime someone talks about one of these tubular K frame kits. Kind of gets old after awhile so I decided to look into it. I was actually expecting to find some credence to this theory or myth about the mustang bearings, was actually surprises just how close the ratings are. Ive even searched the pro touring and road race forums for 2 hrs this morning trying to find reports of mustang ii bearing failures. Couldn't. I also didn't find any for mopars either. So if it is happening, it must not be common. Or its just a busted Internet myth. Thats all I can conclude anyway.

The biggest reason these companies are using the mustang ii spindles is the front steering and Ackerman reasons. There's no way to make a rear steering rack and pinion work because of the Ackerman issues of the factory spindles. On top of that, in order to clear the rack, the engine would have to be raised a full 1 to 2 inches. Before ordering my GTS last year, I was actually trying to make a rack from an 3000gt work. And it would have, but the rack would have hit the oil pan. So I can see why the mustang ii is used. I don't think it's because it's a better spindle overall, it just works better in the packaging they're trying to do. So it's more of necessity then a performance thing, at least to start with.

I assume, I know, that the bearings you looked up were for stock spindles and not aftermarket larger bearing spindles?

If so I'd say you laid that one to rest.

Yes, stock bearings compared to stock bearings. Stock spindles to stock spindles

Wow, thanks for the in depth research there CS. Got to love the internet, right?

CJD, I think you're right on the KPI, I've seen everything from "stock KPI" to -2 degrees, to +8 degrees KPI. So that's something I'll need to email Gerst on and find out the KPI of the spindles that come with the kit

No problem. I seen in the other thread youre down by China, I'm only an hour or so north of you, you're welcome stop on by and check out the Gerst stuff on my dart first hand, or just to even have a beer. We've got a big cruise/car show up here in Columbus in 2 weeks too

May have to take you up on that. You off on weekends?

On this M2 spindle topic, there is one thing not yet mentioned, that IMO becomes a shortcoming, and that is the typical wilwood M2 alum hubs. As first noted, a 3000lb+ car on the track, running hot laps, with the related likely brake temps heating the alum hub, is far from ideal, being at 375F? (if I'm reading graph correctly?)6061 has lost nearly half its strength, combined with a non robust bearing already mentioned, ie small outer race diameter, and alum expansion, things cannot be improving. There are of course aftermarket steel hub solutions, but some weight reduction is lost and cost now becomes a factor.

http://www.burnsstainless.com/images/technology/YieldStrength-1.gif

Go back and reread the information CS posted about the bearings.

Then read it again.

Then go to sleep, wake up, read it again.

Then don't post.

Now you're really grasping at straws. First, the bearings are almost identical between the mopar factory bearings and the mustang 2. Second, all of wilwoods kits for mopars use aluminum hubs just like their kits for mustang 2, if there was a heat problem with aluminum hubs, it would affect every wilwood kit regardless of bearings or brand spindles. 3rd, ypu can get steel hubs for the mustang 2 just like you can for mopars. Heck, speedway sells a kit for 200 bucks with hubs, rotors, calibers the works. Granted it's just stock style brakes but those aren't any different than a stock mopar brake kit.
4th:aluminum doesn't hold heat like steel. Aluminum will dissipate heat much quick, so while it does have a lower melting point (1280 degrees for 6061) than steel, it's going to take a lot longer to heat via braking to get to that point. 5th: everyone from nascar to IRL to GT use aluminum hubs. If there was a heat problem with aluminum hubs, we'd know it. 6th: if youre getting your hubs heated to the point of failure, youre gonna melt a bead on the tire long before the hub fails and you probably should adjust your line and driving style. 7th: I just looked up the temp ratings for both the bearings used in stock hubs on stock spindles for both the mustang ii and the mopars, both have a operating temperature of -140 degree C to 1030 degree C, if you can get that bearing to 1030 degrees C, you've got some serious issues, far more than just the type of spindles you're running. That'd be well over 2000 degrees F and close to the melting point of even steel.

This mustang ii heat bs theory is easily debunked with simple research from the makers of the bearings and hubs themselves and some simple common sense and math.

Fyi, I deal strength and load testing every single day for my job. I have to find out the bending and breaking points of all sorts of metals and alloys. It's what keeps the engines of the company I work for together.


Also, one last note. The mustang 2 bearings are actually larger in diameter than the mopar bearings, they are however, slightly thinner in the bearing width, less than a 1/16 of an inch. So if you're gonna say the mustang 2 spindle bearing isn't big enough diameter wise to handle a 3000 lb car, then the mopar bearing isn't either........using your line of thinking

To continue my post from above, let's look at physics and chemistry of the metals commonly used. Below is the heat transfer rate of those metals. The higher the metal, the faster they lose aka dissipate heat. This assumes the metal at the same mass as one another.

Copper – 401
Aluminum – 273
Brass – 109
Stainless Steel – 16

So what this means is that stainless steel is the SLOWEST to lose its heat. In other words, it retains heat in itself.


Now, the flip side of this is that aluminum will heat up a tad quicker from a cold start than stainless steel, assuming the same mass and same heating intensity. However, as soon as the heat source stops or reduced, the temperature of aluminum will drop almost instantly. Steel or stainless steel however will stay closer to the temperature it was heated too MUCH longer than aluminium. So in a braking action, as you as you let off that brake pedal, the aluminum is already cooling down by the time you get to the next braking section, steel however, isnt, at least not as quickly. This is why on race cars at night, say nascar at bristol, you'll see the rotors glowing red almost entirely around the track. Because they take forever to cool.

You can test this youself, all you need is some aluminum and steel rods that are the same mass, a blow torch, a digital laser thermometer and some safety equipment. Heat both pieces up to the exact same temp, then use a stop watch to see which drops faster. But I'll save you the time, it'll be the aluminum one.

Hope that makes sense, I'm not always very good at explaining things via type.

Your last point, that IS what I'm saying. As to the rest, We could have done without the straw comment. You missed some dots in the above. First , nobody I think is worried about melting temps. I stated my concern was "on track" that means at speed, repeated use. I clearly stated alum and included a supporting graph that indicates pretty well alum loses strength at fairly low operating temps forget melting. Most front hub heat is received by radiant and conduction, from the brakes, thru often, an alum rotor hat/plate. I have not mentioned nor really am I concerned about any bearing generated heat. However, with these smaller bearings/races, in an alum hub, with alum having a much higher expansion relative to steel, I am concerned about the combined effects of heat induced expansion of hub in the race area and loss of strength rating. Comparing what we do to IRL/Nsacar is pointless. And Nascar I believe, does not allow in higher classes alum almost anywhere in the wheel area. Additionally, they have extensive cooling ductwork, fans etc to try and keep heat out/remove from this area. There are very few here with any brake ducting, unfortunately. The Wilwood typical alum Hub, was originally intended for weight reduction and drag use. Its designed has changed little for over 2+ decades, I do not know if one can infer that is due to great adequate design, luck, or lack of interest, etc. I agree, a failed hub will alter one's driving line. As for as steel available in aftermarket M2 hubs, I can't comment on price, and the weight gain is obvious and likely counterproductive for the goals.

No, you said, and I quote "a non robus bearing, ie a smaller outer race DIAMETER"

The mopar bearing outer diameter is SMALLER than the Mustang 2 even, though not by much. If the bearings are rated dang near identical, there's no difference. So youre missing the point. If the mustang 2 aluminum hub kit is going to have issues with heat, THE MOPAR ALUMINUM KIT WILL AS WELL.

Also, you grab whatever graph off google that you want. But posting it with out knowing how to actually read it and posting it without all the testing parameters is like trying to drive your car with half your windshield painted over. There's a LOT of factors that go into testing. Also, do note that on the graph, the starting tensile was 40,000 lbs per square inch. At roughly 400 degrees, that'd drop to right at 30,000 psi, and yes it kept dropping. Do you know the how much pounds per square inch you're putting on your hub during a hot lap? I'm not gonna do the math tonight, but let's just say you're not gonna get anywhere near 40,000 psi. Or 10,000 psi. Your control arms would bend first.

Also, this aluminum hub weakening and failing is a pure myth. I've looked through out the day for an example of an aluminum wilwood hub busting. I can't find one anywhere, on any forum or any google search. I have found their rotors busting or grenading, but nothing on their hubs. If you can find an example of one, by all means, please share it with me as I am curious.

the thing about a M2 front suspension i have observed over the years [and all of it's adaptions to anything on the planet] has been this. the M2 was available with the 302v8. it's position was almost centered over the spindle center line in the original car. although it's weight is not as much as a 318 [i think, but please correct me if needed], i believe all engines in our brand have a setback to where the engine[s] are mounted rearward of the spindle center line, thereby if using a M2 suspension design, even a stock cradle deal, the engine setback on our brand allows the M2 design to be almost, or just as stout as the original suspension due to the weight being positioned to the rear of the spindle center line. i hope you can understand what i'm trying to explain here. when putting this type of suspension in a 30's/40's/50's car, it is even more pronounced. at one time, a M2 kit manufacturer had several pics showing what i'm trying to convey here. it was stated that was the reason most guys complained the ride was way too stiff using V8 coils in their conversions, and had much improvements in all aspects using 4 or 6 cylinder springs instead. the bearing information was a much better presentation on why these things can work because of the loads involved, but i found the above diatribe a simplistic explanation without getting involved in the scientific explanation. and it seems using a quality M2 type kit made today pretty much eliminates any worries concerning failures of any kind. "quality" being the key word. i'm pretty sure i would not change over a suspension from an A,B, or E body to a M2 type, but over the years, i have been involved in many conversions on older and odd ball stuff, and the M2 derived kit swaps have all worked flawlessly. just an old guy's experience and observations over 50+ years of playing with cars. your results may vary. nascar cup cars not included.

Hmmm very good points. Didn't think of it that way before but it makes sense.

Not sure if this is still a discussion anymore....

I stand by what I say in that the thrust load of the M2 bearing is not designed (rated) to handle a sticky WIDE tire with lots of brake on a 3000+ lbs. car. The fact that they are almost identical to the Mopar bearing, only moves my point to include them as well. They were designed for hard compound, narrow 14" or 15" tires, not 18" tires with 300mm + rubber at any where close to 1G load. Same goes for all other period makes.

I know someone will say they been doing it for 30 years, but the tire compounds, coefficient of friction, and widths I'm talking about simply weren't available until just a few years ago.

Wade on here had heat warped Wheel seals on the stock bearing aluminum hubs we use with SRT rotors and Viper calipers. Anything has a limit, you may never see it.

100 percent agree.

, I must have a reading comprehension problem, or that is a 180 degree u turn? But then this whole thread has been a SF Lombard Street anyway.

Man you keep on moving the goalposts in your argument, are you a politician in RL?

Yep you do. I'm agreeing with him on the point that mopar spindles are no better and no worse than mustang ii spindles. I'm also agreeing with him about the wider, softer tires being used today not existing till recent years.

"Also, one last note. The mustang 2 bearings are actually larger in diameter than the mopar bearings, they are however, slightly thinner in the bearing width, less than a 1/16 of an inch. So if you're gonna say the mustang 2 spindle bearing isn't big enough diameter wise to handle a 3000 lb car, then the mopar bearing isn't either........using your line of thinking"

And simultaneously disagreeing with his earlier comment here:

"Just an FYI, doesn't seem to be a standard for KPI on the M2 spindles. Everyone is a little different. Also, the bearings are way undersized for 3K plus cars being tracked.


Edited by CJD AUTOMOTIVE (09/09/16 06:24 PM)"

My beef is with the dainty alum wilwood hubs, the bearings are what they are, and that track induced braking heat weakens them, find any graph online that suits your fancy, it is still a fact, especially at the temps we might see on the track, and the drop off in strength is sharp and profound. Choose whatever decrease in strength you can accept is your choice, I'm not changing my driving line because of poorly chosen, lightweight alum drag hubs. Stating alum cools faster and therefore not an issue, completely ignores the fact it also heats faster, the bearing issue dovetails with the this, because smaller bearings/races are more likely mire prone to the heat expansion issues of the hub, in addition to the observation the wilwood hubs are not a Robust design, ie very thick in stressed areas, even when compared to steel OEM hubs, and alum needs to be thicker then steel in almost every case in similar applications, but you know all that.

Okay, been watching this back and forth. I think what csmopar is trying to say, or at least how I understand it from his posts, is that wilwoods uses aluminum hubs on ALL their kits for all brands. So if the hubs were an issue, they'd be having that issue on all brands. Also, seeing csmopar's challenge above about finding an example online of a wilwood hub failing, I tried as well, I didn't find anything when search "wilwood hub failure" other than this very thread. So maybe it has happened but perhaps it was years ago? I just dont know.

while I was doing that though, I decided to check other "name brand" brake kits and see what they use for hubs for both mopar and mustang II.

Baer Brakes: Uses aluminum hubs for all their big brake "road race kits" regardless of make or model, ford,chevy,mopar, etc

Brembo: doesn't make kits for either, but scrolling thru the kits they do make, they also use aluminum hubs

Aerospace: Aluminum hubs on ALL kits

Wilwood: aluminum hubs on ALL kits

Strange: Aluminum hubs on ALL kits

SSBC: Aluminum hubs on ALL kits(kind of a misnomer considering their name)

Heidts: Aluminum hubs on all kits for all brands



These are just the companies i knew off of top of my head, others dont make kits for mopars, like brembo, but their hubs are aluminum as well. Yes, you can get cast iron hubs from any of the above, if you want stock brake rotors that aren't drill or slotted and that feature 1 or maybe 2 pistons. From what I' seen this morning, you CANNOT get an aftermarket brake system without getting aluminum hubs.

So based on this, jcc, I think csmopar is right and I dont think his comment about you grasping at straw was off base or uncalled for. Im beginning to think you have something else to prove and are simply putting down mustang II spindles like you've tried to this entire thread. Mustang II spindles are used throughout the hobby, arguably as popular or more popular than C5 spindles. Surely if there was a problem, someone somewhere would report it.

Why not just get steel hubs made and then make your own brake setup ? It isn't all thaaaaat hard. (I've done it)

I suppose you could, if you're concerned about the aluminum hubs in the off shelve kits. And who knows, might be able to do it cheaper.

If you were worried about using aluminum hubs in the first place I did mean.

ah gotcha.

I'm running aluminum hubs, front and back. They are 7075. As long as the part was designed for the application, I don't see any issue. Their are 4 grades of 7075, and 3 on 6061, it greatly affects their mechanical properties, so getting hubs from a reputable manufacture with an engineering staff is critical.

hey dusterpt440, I will have my car back on the ground, suspension fully installed next weekend, so hit me up if you wanna come check it out. I sent you a pm with my phone number

You seem to keep avoiding my main contention, heat effects alum much more significantly then steel. Why?

Wilwood is the typically lightest alum hub from what I have seen. I thought my point was understanding that wilwood using any small bearing makes for a small hub, a large bearing, even though having higher bearing capacity, makes for a larger (stronger hub). The others I have less experience with. Alum can be and is best solution in almost all applications, IF the design is correct, concerning material, material thickness, additional cooling to reduce brake generated heat, and finally the intended application, drag vs open track, vehicle weight, track speeds, braking duty, driving style, tire/wheel combos, etc. Your list only means no one has reported failures or are not reaching the limits (show cars?), not that the design is ideal. I guess this discussion should really be for those that have track time that have actually had on track heat related brake issues/concerns vs those that have not. I'm speaking from the former.

There are racing organizations (and/or manufacturers) that do not allow RF alum hubs, I suspect that reasoning is more based on fatigue failure from repeated high loads.

The Ron Sutton alum hubs for instance and the Wilwood alum hubs are light years apart, and not intended to be part of this discussion.

ok, so lets see the kits you recommend running then. I know im not the only one to ask you for proof to back your theory. Yet you've provided none. And you are not the only one with track time. Also, I'm still waiting for you to provide proof aluminum hubs are failing due to heat. I'm not saying there's zero chance its happening, because like anything mechanical, it can happen. But lets see the examples.

and why does heat affect aluminum different than steel? is that what you're asking?

also, what Ron sutton hubs? I just got done looking over his website, he sellings wilwood brake kits exclusively. Only thing I see from Sutton is his own Track star brand spindles. so could you please point me to those Ron sutton hubs?

Oh goody, hes back. Seriously, prove me wrong.

You claim that you have had the personal experience of having heat related hub failures, let's see the pictures of these hubs failing YOU due to heat. I can't fin a single report, from the scca forums to several pro touring forums, to google, to any website. In today's online age, if someone had aluminum hubs failing due to heat, someone would have posted it. But let's put that aside. You now claim that you've suffered such problems, alright, let's see the pictures. Let's see the proof.


I'll dive more into material strength again later. But please, let's see these failures caused "inadequate aluminum hubs"

Doug, the ron Sutton hubs would be under his custom track star packages.

I'm out of quotes here. This most recent claim you are making that states I made claims, is incorrect in making that claim. I made no such claims as you state. You might want to reread what I wrote and return.

You want a real deal alum hub, its right here.

https://board.moparts.org/ubbthreads/ubbt...tml#Post2179960

here, I highlighted the very statement typed by YOU. You are implying that you are the former, aka the person experiencing such failures. So lets see them. You've yet to provide a single shred of evidence to back your theory in this entire thread. Seriously, other than this thread on google, find us where you have all this information as to aluminum hubs failing. Or even just Wilwood hubs for that matter.

Guys, there is like 8 people on here that care about making a Mopar actually handle and stop like a modern car/race car. If we get into a pissing contest with one another, someone's going to end up leaving, and there is simply not enough of us for that to start happening!

But for some people it's more fun to have a pissing contest instead of actually driving their cars.

JCC is the "conspiracy theory" guy or maybe "Don Quxote" He's got some things that he believes and no amount of contradictory evidence will change his mind. He just moves the goalposts of his argument, then wanders off. I.E. stirs up [censored]. Not quite a Troll, but close enough for me to use the "ignore this user" on him. I will occasionally click thru, because much like a broken clock, some useful info pops out of the dung.

For me it's fun to DRIVE the car. Then modify it, and then DRIVE it some more. It's also very fun and INFORMATIVE to read what others do to their cars that I wish I could do.

Some people spend their life splitting hair's instead of actually applying the hair's. I have aluminum hubs, and I know they're beefier than Wilwoods.

I guess we have found the core issue here, lack of reading comprehension, combined with conclusion jumping. "Failure" is your word, not mine, I said "issues/concerns".

My "theory" has been for nth time, is alum gets weaker at low enough temps on this subject, that strength is effected negatively. You have yet to address that other then obliquely, by negating it overall because you can't find an online example.

And Craig's point has a lot of validity, there are likely a very select few here that will ever drive into a corner at enough speed, and brake hard enough, repeatedly, to understand brake related temp issues.

So you keep tapping your brakes lightly and checking online line for my imagery alum hub failures, and I'll keep my wilwood hubs on my show cars, while on my other cars I keep diving under others, while braking into the hairpins, lap after lap ,in the summer.

Haha. I agree.

I guess i missed this warning


So can we get back to my original question? Anyone else running this watts link kit (which doesn't even use aluminum hubs)

How do I do this?

Click on their name

view profile

click on ignore this user

I think would be great, but it would be easy to make it a 3 link and then it would be as good as you can get short of an IRS. If you are serious, talk to Him/Them about it.

I cut out the rear section that has my old (but new) watt's link and not using the old (new) Moser 9" housing that has the brackets. Pics in the build thread of the old setup. Email me if interested. Let you have it stupid cheap.

I have no experience with the Gerst setup, but I do like the fact that it is substantial and looks to be able to handle any side loading you could throw at it. Might even be overkill, but as my son says "there is no kill like overkill".

Contrast this setup with the Ebay 4 link kit someone posted and you'll see the difference.

yeah, you're right. wow.