A Wheel Hop Absorber Kit for ERA Jag/IRS
 

Bob P., Mike L / ERA626,

Per your request for pictures, here is the completed ERA/Jag Wheel Hop Absorber Kit. Final development and testing is complete.

With the correct shock adjustment, it measures to absorb up to 3/8" horizontal hub travel fore/aft; which proves there is steady oscillation and hop going on without this device.

We can tool up to make up orders in batches of five to start. Experienced drilling, tapping, and installation is recommended. NO welding is required. The absorber kit is 100% removable and transferrable to ERAs with the same frame and differential width, with rear tire widths up to 11.5" wide, on Trigo/Halibrand standard offset wheels.

If you are still interested, let me know so we can set up for this. It works, and there is a noticeable difference as the tires bite taking off and coming out of turns.


http://www.clubcobra.com/photopost/d...059DCEWHKT.jpg

Duane:
A couple of questions.
Have you received any feed back from Bob Putnam on this?
Is the assembly compatible with the ERA third member modified with the outboard brakes?
What will be the cost of the kit?
Can you post some more detailed photos of the installation? I know what I think I'm seeing but I like to be sure.
DonC

Hi Don,
Yes, Bob was waiting for these pics along with a group of others asking to see it. This was part of another very long thread started late last year. If you have the optional subframe setup from ERA with the outboard brakes, (and extra stabilizer arms) you may not need this. Please ask Bob and email me a pic of yours, if you can. We have not decided on a price yet. The dampners drive the cost up a bit. Quite a bit of labor and R&D as a result of a few prototypes.

Does your car wheel hop now? If so, how bad?. You can send me a PM if you'd like. Thanks.

Duane,

Looks pretty good. The only thing I would change is to extend the tabs on the hub carrier bracket closer to the bolt attachments. It might be small, but the "wrap" section of the bracket is probably flexing a bit.

BP, If I'm understanding what you refer to as the "wrap" section, Its hard to tell from this pic, but the wrap section is actually 3/4 square channeled steel tube thats been notched out. The 2nd prototype was a hair thicker, but there is fair movement in the shock ball joint, we went back to 1/8". If you think its worth it, its no problem to go a tad stronger there. And the part that wraps the hub is actually pretty stout - no flex there. Are you referring to the part where the shock mounts to the hub?

Right on Duane,

Nice work. Those things aren't going anywhere. In fact you could probably stream line them a bit. I'm sure they make a big difference when you roll on the power. Car should feel more stable under acceleration. Drag racers should just stick to a 9" solid axle and call it a day. Very nice.

Was up at the rod shop all afternoon.....thinking we need a cobra infusion there. Soon!

John

Hey there John.
Just had surgery on the hand/finger again last night. Had to re-break it + Titanium plate, screws and all. I'm out about 6 weeks to Cobra drive, but want to plan a trip there soon. We were waiting on your green light to plan it out.

Thanks for the feedback on the kit. Looks like it belongs there. It was a fun little development project.

Duane,

Bummer! I hope this is it, this time...and no more re-breaking bs. That's a nasty little injury there. If it makes you feel better, I have had a few pieces of alloy screwed to my skeleton as well. My orthopedic surgeon use to describe his procedures in great detail. I finally realized they are just a bunch of glorified tractor mechanics. The way they chop and hack their way around is amazing.

I'm on my third set of side pipes for the street now. My latest mufflers were still way too loud. This motor is so noisy, I have to tell my neighbor before I fire it off and can't really run it for very long with out feeling like a bad neighbor. The new configuration will rob over 100 HP but will be reasonably quiet. Who cares on the street. Probably a good thing.

I have a schedule set up with my German freind, Marcus, as far as getting the body and aluminum panel work done. We start next week. That makes me happy.

Take care of that finger,
John

DCE ERA/Jag rear wheel Hop Absorber Kit
 

Hi Duane,

Sorry to hear about your hand. My wife has had two rebuilds on her left thumb and it's still not right. I know how debilitating that can be.

When you have more information on the possible production and availability of your kit, please keep us advised.

My ERA W428 SCJ really wheel hops when shifted hard into second. It's a new car to me and I have not even tried a hard launch from 0 as I don't know how much abuse the IRS will take in that manner and I don't have any plans to "formally" drag race it.

Anyway it sounds like you have engineered your butt off on this project and you can put me down as an interested observer, potential customer.

Hi Hoppy,
Currently there are two ERA owners interested in obtaining this kit; but unconfirmed. I'm waiting for Mike/ERA626 to confirm or pass, and If we can get one more person, I can put together three kits for a little less. The dampners drive the cost up. My machinist has proposed his own custom made dampner to save a little more, but its only on paper so I'd say we'd just go with the existing dampner that works and looks good. PM me if you want details that I sent to Mike. Duane

DCE ERA/Jag rear Wheel Hop Absorber Kit
 

Hi Duane,
Have not heard any updates on your project lately. What is current status. Are you planning to proceed with limited production? If so, I am interested, so please keep me on the ready to send a deposit list.

This weekend finally had the courage to "drop the clutch" from a standing start. The wheel hop was so violent, I could not believe it. I am wondering if with or without your mods, my shocks are set up "right". Now I don't really know what right is, softer or firmier, but if everyone was experiencing what I did, all ERA's would have Ford 9 inch live axels.

Any suggestions for improvement/adjustment will be appreciated. I have never worked with Spax or any other coilovers, but am assuming (always dangerous) that if I had a spanner tool, I would back off the bottom "nut" and then tighten up the inner or closeset to the spring nut to firm up the suspension. But how much to take it up if tight is better. They look like they are pretty well up the range of adjustment now, 50% or more I would think.

Hope your hand is well on the mend by now.

Thanks,

Terry

Hi Terry,
I know, isn't it just scary.... Freaks me out it how it could behave in such a "violent" manner. Perfect description. If your car will spin the tires from a roll, it will do the same thing and thats what bothered me enough to get this going.

I took my car out yesterday for the first time; got my cast off last week. I tried it once, and feel about 70% of the hop has been eliminated with this kit. I also had another engineer look at it this weekend, and he gave me the thumbs up on it too - with no further changes to recommend. I'm going with it as-is and cannot see any other changes to try or make at this point.

Here is the status. 3 other people are considering it, but have not followed up with deposits yet. If you would like me to proceed with getting your kit together, please send me a PM. Did you get my last email/response on the breakdown?.

Do you guys have the standard rear end or the ERA modified rearend with outboard brakes?

....DISREGARD....I read the other thread and realize that this is the standard JAG rear end

Joe,
This thread refers to Standard Jag rear, inboard brakes, Spax coilover shocks.

------------------------------------------------------------------------
Update: 3/26/04

The current update is I talked with Doug at ERA again yesterday. ERA has no additional updates or recommendations but to try and continue to adjust your shock settings.

In absense of any other direction, Kits can be made available through me, for those who need it and still have wheel hop issues. Takes 3 weeks for me to get it all together including the rent-return tools. At this point, I don't want to put together any kits unless at least 3/4 people seriously want it and they can be turned out in batches of 4 more affordably for all. Too much work for just one or two sets and I can't get a break on pricing for the custom dampners unless I buy them in sets of four or more.

Driving season is here. Have Fun. Duane :)

Went out and did some more testing yesterday with and without the absorber kit as a result of some followup discussions with ERA and a few of the people asking about the kit again.

Without Kit - retest:
- Had to set the shocks sooooo stiff to try and elimiate it,with the kit removed, and the car rode and drove like crap. Even my better half noticed how much worse and uncomfortable the car was to drive with the shocks set so stiff as my last-ditch alternative test. It did help to eliminate the hop barely, but nearly as much as with the absorber kit on and doing its job. To me, adjusting the Spax shocks this stiff goes against the quality ride and normal handling of an ERA; just to eliminate wheel hop.

With Kit:
- Returned the shocks to a softer settings, for a softer more balanced ride, and at the same time did not get the any more violent wheel hop from a roll/stab of the throttle. Car rides nice again, handles well, and I don't have to worry about accidentally breaking parts as a result of violent Jag/IRS wheel hop any longer...

Kits/Availability:
We are proceeding with making up three sets, in a few weeks. If there are any more questions, feel free to send me a PM.

Thanks to all for your inquiries and feedback. Its been a cool little temporary project to keep me occupied from trying to buy other cars to tinker with; for now. :)

I installed Duane’s wheel hop kit (WHK) on my ERA several weeks ago but I’ve just recently found the time to test it out.

First let me say my wheel hop has never been as bad as that reported by some. When I first got my car on the road, I had the 4 coil overs adjusted completely soft. If I did a soft launch the rear end would squat nicely and break the tires loose with little noticeable wheel hop. But if I did a hard launch I would get a noticeable wheel hop but nothing violent like some others have described their wheel hop. Before I installed Duane’s WHK, I was able to eliminate all wheel hop by stiffening up the coil overs. I had to adjust them in about 2-1/2 revolutions to eliminate the wheel hop entirely. While that eliminated the wheel hop, it made the ride much too staff. The rearend would no longer squat nicely and the tires would spin much more readily.

After installing the WHK, I’ve been able to adjust the coil overs about ½ revolution in. The wheel hop is gone completely and I’ve got a relatively comfortable ride again (okay, comfortable for a Cobra anyway).

Chris

Feedback Results
 

Thanks for the tests and feedback, Chris. Glad it worked out for you.

Duane,

Nice going! Sounds like your WHK is working nicely. Great idea, to actally make it a kit, and nice job!

I'd like to come out to one of the breakfast meetings sometime and say hi. Also there's going to be a huge shindig at the rod shop in late August. Goodguys is doing a big feature on the shop and Dicks collection. I think Dick said something like 85 rods are coming up for it. I wonder if we could get a few nice cobras there? Just an Idea. I don't know any details yet but was just thinking out loud. Say hi to Marc for me.

John

Hi John,
Thanks... we'll see how it goes for some of the others. Works for me. Let me know on the August dates.