Factory Track Pack Recommended Set up

[Randy Chase]

I would love to see a pic of the new brace. I don't see anywhere else one could attach it.

[Stan]

Originally Posted by TimMullen

If the brace is not attached to the chassis, but only to the track rod ends, then it will not be putting the track rod ends in double shear. The loads from one side will allow the joint to flex, and transfer that flex to the other side. That would spread the load from the regular single shear joint, to two single shear joints. Which would be nowhere near as strong as a single double shear joint. And may even be weaker that the regular tie rod end in single shear. The new brace may just be a tube flattened at each end, but I bet it attaches to the chassis in the middle somewhere...

Nick Adams of Lotus described the new track braces to Myelise and myself at Lime Rock on Monday. Just a side to side, joint to joint, simple tubular brace. He does not care for the first design. Note that the loads are not the same side-to-side when the car is loaded in a car, which helps.

Mark - any chance you could take a picture of the brace, on a car or loose?

[Randy Chase]

Some updates on the install of my track brace.

You can remove the welded on nuts. It was not easy, but it could have been with proper tools. We used a dremel with a small bit on it to cut away the welds and the a hardened cutting wheel to clear away the front edge of the nut. Some wacks with a chisel and the nut came loose. Rinse, repeat. Took maybe 30 minutes of work to remove the 2 nuts.

By the way, remove the shield around the engine mount first.

We have cut away the heat shield and taken measurements of the existing trailing arms. Now we only have to install the new end joints and we are done, except the alignment.

One somewhat unclear point... in the document it states twice in bold print: "only at mid-laden ride height of 130mm." What do you think that means?

[Randy Chase]

Originally Posted by MyElise

Now I realize why you thought you couldn't get a dremmel in there. My shield went byebye with the turbo.

No, the shield that I removed is above the engine mount. There is a sheet metal bracket that goes around the two nuts, this bracket stays. We barely could fit a 1/8" diameter cutting tool in there.

[Rookie999]

Does this help? Ride Height section of attached.

[Patricko]

Originally Posted by Randy Chase

One somewhat unclear point... in the document it states twice in bold print: "only at mid-laden ride height of 130mm." What do you think that means?

I would think that was 75KG in each seat. I can ask Nick Adams tomorrow if you want me to

[TimMullen]

Originally Posted by MyElise

I don't think any rod attached in the middle would provide much support to the joint in an up or down motion.

The rod shouldn't see any significant up or down motion. It's purpose is to place the track (tie) rod end into double shear instead of single. The track rod should only see side to side loads while attempting to keep the wheels pointed in the "forward" direction - essentially it serves the same purpose as the steering tie rods at the front.

God, I'm beginning to sound like you.

Congratulations!!!

[Randy Chase]

Updated pics-

Shield you have to remove-


Stock Arm-

[Randy Chase]

End link installed, not tightened yet



Heat shield has been trimmed, but shown here temporarily pulled back for access.

[spider]

OK, this is the first non-Lotus kit I've seen. Anyone used it yet? Less than $400 (before shipping)...

http://www.elise-shop.com/index.php?...products_id=56

[ronin]

Spider... Not for Fed Elise....sorry......call Shinoo

[Mark Starr]

By the time that one is shipped and cleared through Customs, it's almost as much as the OEM kit which Lotus designed!!! I'd rather go with one that was designed for the Elise by the guys who built the car!!!!

[Stan]

I looked over the OE new-simple-light-design rear suspension brace on a track pack Exige yesterday at an autocross. (Yes the guy ran the car, and another Exige in the same color showed up to spectate).

Ayup, simple black-painted steel tubular brace fastened only at each end. What is MSRP on the new brace?

[trompazo]

Is it simlar to this one?

http://www.eliseparts.com/shop/index...roducts_id=307

[esprit89]

Originally Posted by Stan

...Just a side to side, joint to joint, simple tubular brace. He does not care for the first design. Note that the loads are not the same side-to-side when the car is loaded in a car, which helps...

As TimMullen mentioned earlier this may look like a double shear joint but is not. Double shear implies equal stiffness and equal load distribution between the restraining members.

If the brace is not tied into the chassis directly, all it is doing is pushing on the opposite suspension bolt which means the joints are still in single shear, you are just averaging out the load somewhat.

Also, for the same diameter tube, a brace which is attached to the chassis at it's midpoint can be 4x stronger in compression than a simple side-to-side brace. The critical buckling load (Euler) is inversely proportional to length squared.

With the bar Randy's installed, the percentage load carried by the chassis member verses the bar will be dependent on the relative stiffnesses between them. Attachment bolt stiffnesses, hole tolerances, relative cross sectional areas among other things influence the load distribution.

Is a simple side-to-side brace good enough? Maybe. Only with the suspension loads and fatigue loading spectrum could you answer that. All things being equal would a double shear brace be better - the answer is yes.

Michael

[Stan]

Originally Posted by esprit89

As TimMullen mentioned earlier this may look like a double shear joint but is not. Double shear implies equal stiffness and equal load distribution between the restraining members. If the brace is not tied into the chassis directly, all it is doing is pushing on the opposite suspension bolt which means the joints are still in single shear, you are just averaging out the load somewhat. Also, for the same diameter tube, a brace which is attached to the chassis at it's midpoint can be 4x stronger in compression than a simple side-to-side brace. The critical buckling load (Euler) is inversely proportional to length squared. With the bar Randy's installed, the percentage load carried by the chassis member verses the bar will be dependent on the relative stiffnesses between them. Attachment bolt stiffnesses, hole tolerances, relative cross sectional areas among other things influence the load distribution. Is a simple side-to-side brace good enough? Maybe. Only with the suspension loads and fatigue loading spectrum could you answer that. All things being equal would a double shear brace be better - the answer is yes. Michael

You are right...but note that Lotus did all the pondering and knows a few things. The simple, light, affordable brace is strong enough to do the deed.

I like their solution because it is simple, elegant and light. The old brace setup retailed for something like $1,100 plus install. With some shops charging about 200 bucks to install a Braille battery into an Elise I could imagine some charging 1800-2000+ to load in the old style brace soup to nuts.

I don't know the MSRP on the new brace but hope that it's about 1/2 the old price or less. And the install is very straightforward.

Nick Adams was personally involved in the new brace design. It's good to go.

[goelise]

Originally Posted by Stan

You are right...but note that Lotus did all the pondering and knows a few things. The simple, light, affordable brace is strong enough to do the deed.

I like their solution because it is simple, elegant and light. The old brace setup retailed for something like $1,100 plus install. With some shops charging about 200 bucks to install a Braille battery into an Elise I could imagine some charging 1800-2000+ to load in the old style brace soup to nuts.

I don't know the MSRP on the new brace but hope that it's about 1/2 the old price or less. And the install is very straightforward.

Nick Adams was personally involved in the new brace design. It's good to go.

Just because I'm the type of guy that needs to hear it...this new brace design is the one offered when one orders a '06 Elise with track pack?

[Stan]

Originally Posted by goelise

Just because I'm the type of guy that needs to hear it...this new brace design is the one offered when one orders a '06 Elise with track pack?

You've got it!

[esprit89]

Originally Posted by Stan

...note that Lotus did all the pondering and knows a few things. The simple, light, affordable brace is strong enough to do the deed.

True, but even the best can make mistakes I don't mean to digress too much (thread is Factory recommended what?) but there's an amusing and timely story involving Colin Chapman and the design of the Esprit (check out "Lotus Esprit The Complete Story" by Jeremy Walton).

The guys doing the original stress analysis added a cross brace for the rear suspension lower wishbone mountings. When Colin Chapman saw it he told them "No, no. That'll be OK without." They added it back in two subsequent times and each time he made them take it out. When he drove the prototype for the first time (they had picked him up at the airport with it) he only made it part way back to the factory before the rear suspension collapsed Needless to say they added the brace back in.

Here's what it looked like:

You'll notice the lightweight design is in single-shear and the fix is in double-shear. Actually the failure mode is different in the Elise so it is not directly comparable but it is amusing nonetheless.

Time will tell if the new design is good enough.

Cheers,
Michael

(8-year Lotus owner and loving every minute of it)

[fzust]

Randy, I am doing this install tonight before the event this weekend. Any advice other than in the install you can provide? Do you know if the bushings are any firmer than stock? It isn't obvious from the pic, but I think you did re-attach the weld-nuts through the track brace to lock it at the center, correct?