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Lateral Dynamics 3-Link

Hey all,

My `68 Camaro rear end is nearly complete, just have one problem.....what coilovers to use on the LD 3-link??

I know there are a few guys out there with this setup, Bad Penny :hail: , OneLap :hail: etc, but I need some guidance on shock length, spring rate etc. If I remember correctly, the coilovers need to be mounted upside down due to clearance issues?

Appreciate any help/advice.

Front has DS&E coilover setup (Koni).

Car will see street and track day use :thumbsup:

Thanks,
Mark

Quote:

Originally Posted by uk68327 (Post 297287)

Notes emailed to me by Mark at LD quite a while ago:

Quote:

Lateral Dynamics re Rear Setup - For the shocks, we engineered the kit to work with a typical 7" travel racing coil-over type shock. They are usually about 13" compressed, and about 20" extended, with some variation from manufacturers. Bilstein's are an excellent choice for a great, budget shock if adjustment is not a huge priority (or rather, these can be revalved easily by Bisltein and others, but no "knob" adjustment). The shocks do need to be gas charged, so they can be run "upside down" from the older, twin tube type configuration. In other words, the spring will be on the bottom of the shock, which in some cases puts the adjustment knobs installed on the top. QA1, and Varishocks are two examples of this, it's not a big deal, but you need to reach up in order to access the adjustments, and it could be really tight to exhaust clearance.

I would recommend a 200 lb-in spring for starters. My experience shows that this is a great spring to use on the street, it won't beat the crap out of you if the shocks are adjusted/valved correctly, and it's still firm enough for some weekend track use. Some of the folks have used a higher rate, approaching 275 in some cases, but this is for a dedicated track car with super tight front setups. I used a 175 for years on my own car, it felt great, but the 200's also feel fine and tighten things up just a smidge. I'd highly recommend either Hypercoils, or Eibach's. There are other less expensive springs out there, but these two brands seem to be at the top of the heap in terms of repeatability, etc. Eibachs are typically my first choice, they use really good steel so for a given rate/free height, they are usually lighter, and have a shorter coil-bind height. Not a terribly big deal, but they make good stuff.

For the links, I would recommend the following for the mounting points. Upper link, put in the middle hole on the rear end. Lower links should go in the bottom mounting hole, they will be angled up in side view a bit, from back towards the front. For the Watt's bellcrank, put it in the bottom most hole. This setup will give really good anti-squat, depending upon ride height it is typically about 70% or so. It will also have a good SVSA length, to help reduce the chances of rear brake hop in very heavy braking zones (I have never had a hop issue personally), and the car will have "nearly" zero roll steer. It's actually not the specific case, there is a bit, but it's small and should not feel even remotely noticeable, certainly not until you have a LOT of seat time in the car. The low roll center height with the bellcrank mounted low will result in the lowest amount of roll resistance in the rear, which would usually suggest the need for a rear roll bar. So far, I have not needed one, nor have any customers. Two options SHOULD you need to increase the rear roll resistance: one, you can move the bellcrank up a hole or two, it will tighten roll up in the rear of the car at the expense of a slightly higher rear weight jacking force. Or, of course, running a (very) small rear bar is the other option. At some point, we will be offering a rear adjustable bar, but it is a ways out, and again, we haven't shown that we "need" it so far. It'll just be another cool tuning tool for the future. Anyway, once you get it all mocked up, move the whole setup up and down and look for any clearnace issues, etc, make sure things move freely, etc. I usually run the pinion angle at 2 degrees up relative to a level rocker panel, and obviously, you'll want to set the thrust angle to be square (i.e. rear end housing perpendicular to the vehicle axis).

Mike, thank you very much for the info, just what I wanted :thumbsup:

Had numerous conversations with Mark myself, but forgot to get into the details of the rear coilovers! lol

Thanks again :)

Quote:

Originally Posted by uk68327 (Post 297439)

Mike, thank you very much for the info, just what I wanted :thumbsup:

Had numerous conversations with Mark myself, but forgot to get into the details of the rear coilovers! lol

Thanks again :)

You're welcome. I ended up getting custom valved AFCO double adjustable M2's with remote reservoirs. Called their sales line, told them what I was doing and they sent me the shocks. If you look in my build thread (search on "No Name" on Pro-touring.com - I didn't want to fill up the internet) you can see how they went in.

You want a shock with MINIMUM travel of 6". 7" would be about perfect. It has to be a gas shock so it will fit upside down. You want the shock to hit the bumpstops 1" to 1'5" before the driveshaft hits the upper link pivot or higher if your ride height is higher. Make sure your brake lines are not near the top of the housing or THEY will be the bumpstops! I like a spring rate of 250 to 275 depending on horsepower, more HP= more spring rate.
Don't forget that the bumpstop reduces shock travel, you should have 3" of travel before hitting the bumpstop, or at least 2.5" bare minimum, another inch of travel for compressing the bumpstop, so that's 4" of bump travel, on a 6" travel shock, you would have 2" of extension remaning. But if you decide to raise the ride height 1". now you have 1" of extension travel remaining and you will have snap oversteer when cornering hard (corner exit). That's why I like a 7" shock better than a 6" shock. Penny had a 5" shock which was terrible. Since they are behind the axle, the shocks move a bit more than the wheels do. A big advantage of a remote reservoir shock is, the gas chamber isn't inside the shock body so it can have more travel. Bilstein street rod shocks use a floating piston inside the main body to separate the gas charge from the fluid.

When the watts is in the lowest or next to lowest hole, driveshaft will move left to right much more than when in the 3rd hole up. On Penny, we had the shaft hitting the forward link crossmember on the left side. The watts looks nice in the 2nd hole but I'd start at the 3rd hole.
David

Thanks for the info David, much appreciated :thumbsup:

Mark

I was wondering if anyone has contact info for Lateral Dynamics, i cant find a email or anything. I love this set up after seeing it on Bad Penny and OneLap

Cheers

Dallas

They closed up shop...

Just wondering why Mark does not just sell this design to someone like Speed-Tech or DSE ? I love this setup, and can see there would be a good demand for the 3-link. Someone is always asking about Bad Penny/One Lap 's rear suspension. Just a thought!

Travis

Quote:

Originally Posted by itsals1 (Post 299152)

AME has a 3-link that is very likely comparable to the LD version. At least it is available now.

Don