We agree, in fact, one of the biggest things we looked at was the expected ride height variation with the system. This is the primary drive for the relatively long shock travel, actually it is pretty typical, but "well" thought out. If you go to one extreme or another, it "may" necessitate a different free height spring. For certain, and this is not exclusive to our setup, but the lower you make things, the stiffer the spring you'll need to keep the booty end of the car off of the bump stops. Less travel means higher wheel rate for a given chassis. Nice thing about springs, they are COMPLETELY linear in rate, no matte how much you preload them, f = kx, nature helps here. This applies to linearly wound springs, only. Of course, when they get into coil bind, the rate changes pretty dramatically.

Completely agree, the "good" thing is that the rear roll resistance required is not that large, a really small tubular bar is basically all that will be needed, so it'll be light one way or the other, it is really more a fine tuning tool than anything. Frame mount (like the Watt's...) is preferred, but if it sits on the axle, it won't be terribly heavy and a subsequent addition to unsprung weight.

Excellent. One thing that is not so obvious from a force distribution standpoint is that the upper arm, in our setup, only sees about the same (in relative terms) as ONE of the lower links under throttle, everything is a lot less strained under brakes due to bias. Not trying to be nasty, but the upper links on a four link aren't only redundant from a roll-bind aspect, but also from a load consideration (provided there is a crossmember to handle loads). Anyway, for anyone using a high horsepower serious drivetrain, well, we strongly feel that safety is critical, and a full cage is a necessary thing. In this case, a good chassis shop will know to triangulate the load path from the upper link back into the cage. Beyond that, the stock setup is darned capable for a street tire'd car, even if they're sticky ones.

On the top, in all honesty. There is nothing that a really high performance, well thought out setup suffers from, and again, in our approach, we have traded the convenience of bolting on a set of brackets for a system that is extremely high performing, but still completely reasonable installation. You simply cannot match the performance potential of this design with a bolt on setup, period. Now, let's be a bit more specific, street/auto-cross/road course all need the same basic elements to be friendly. The drag strip differs the most, you want a ton of forward bite, but other aspects of overall performance aren't nearly as important. Driven a really fast drag car on the street? Enough said. Here's something to consider, a contemporary Trans Am car can bust out a high ten second ET, with a 310 ci motor, can reach 170-180 on the fast straights, but most importantly, can brake REALLY well, and can mange sustained 1.8!!!! G's in the turns. Can we do that? No, but, it does make you ask what's "really" important, overall balance, or one particular aspect? We like balance. Extreme balance.

Back to work, consultants can pm me for a t-shirt!!!
Mark

Looks like I'm gonna have to talk to you at the show. I just have to find you now. :willy:

Starting at the ATS booth, walk out, hang a right , go to the end of the isle, hang another right down the next isle, and look about 3 booths up on the left side, and you'll find Lateral Dynamics.
We will be torrmenting them with ATS paper air planes the entire show.

Mark-
Killer setup. I wish I hadn't already done the T56 transaxle in 50/50, or it would have gotten your 3 link.

Tyler

Might I suggest

http://www.northerntool.com/images/p...s/45088_lg.jpg

'80s babes not required, but would be a nice touch

Or perhaps one of these: The AirZooka

Am I the only one that thinks this thing is a bit over designed? What is the wall thickness of that mess of tubes on the axle?

I am going to go out on a limb and ASSume you some sort of clue as to what you are looking at. You do do realize that this arrangement includes a frame mounted Watts link and the bracing nesessary for that and the bellcrank correct? Yes, running a Watts link and frame mounted vs. rear housing mounted is overkill but might as well go big. The frame mounted Watts link requires a great deal of trial and error to get it right, I can tell you Mark has been working on this for over a year (everyday) and is fanatical about things being done right.

Pretty bold post for one of your first, how about sharing some of your background for making such a statement since we haven't gotten to know you yet. (This is a pretty tight community and Mark is well known as a expert in his feild).

First, what do all the tubes on the axle have to do with a frame mounted watts link? The only thing that connects to the axle are the links?

Second, are you telling me this design was accomplished through trial and error? Shouldn't it have been designed by engineering principles.

It just seems like there is a bunch of unsprung weight on that axle.

Hmmm...my background...Internet poster. What is the background of Mark. I would assume he is a suspension engineer or has a great deal of race experience. Maybe we should be concerned about his background.

The question was intentionally open ended. I want justification for all the tubing on the rear axle. I am not making it, I am buying it, so I want to have some level of confidence that I am buying something from a qualified company.

OK, so you don’t like my vague questions. So, I will ask engineering questions. Then I can do the math to see if this is something I need.

1. Was this designed for a range of ride heights? If so, what is the range and the Jounce and Rebound levels for each ride height.
2. It looks like the tubes for the watts link hang below the diff. How far below, and what is the ground clearance at curb and full jounce?
3. What is the rear roll steer % at each curb height?
4. What is the range of anti squat and anti lift %?
5. What CG height are you assuming?
6. I know you need to remove a portion of the tunnel, do you need to remove any of the floor or trunk to accommodate the rear mount for the three link. It seems like it would limit jounce travel.
7. How long are the links for the watts link? What about the length of the bell crank?
8. What are the tube diameters and wall thicknesses for this setup?
9. What is the weight of the whole system and how much of that is unsprung?

There a few questions to ponder. I assume at the very least Mark is an ME.

Mark and his partner Katz are both experts in this field. Trust me I know first had had from working directly with Katz he cuts weight wherever it is possible he is concerned with performance first and looks secondary when it comes to this type of stuff. I suggest you read this from the begging before making random assumptions form the viewing of only a few pictures.

What Are your engineering credentials?

And buy the way this was designed "by engineering principals." but this is not a exact science and still takes a long period of trial and error to find the just the right amount of compromise to build a well balanced and functional system.

I have read this entire thread.

I edited my original post to include engineering questions. My engineering credentials MSME. Again, the beauty of this is I can ask questions. I am not selling my wares. If he can answer my last few questions I may have some confidence in the system.

So I ask again, what are marks engineering credentials, or for that matter "katz"?

3 link
 

ipityapun, its obvious you need to do some more research on 3 links and suspension, but i am sure mark can CLUE you in, look here for pics of marks 69 camaro with 3 link in it. https://lateral-g.net/members/magers
there are a few pics there to wet your pallet
jake