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.
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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