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The "Howard Mitchell" Suspension Setup is done!

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Old 09-22-04, 07:51 PM
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The "Howard Coleman" Suspension Setup is done!

I followed Howard's recommendation on what suspension setup to go with. Over the past week I did the following:

Stock Touring Shocks, used with 40K, went from an R1 shock
Eibach Pro Springs
New upper control arm pillow *****
RX7 Store Adjustable Toe Links
Mazdatrix solid stay bar links

I also have the Mazdatrix Stay Bar brace, but I have to rig it up with the LS1 since the rack moved and I think there is way too much to shim, need to get some bosses welded onto the steering rack possibly.

Car does sit lower than before in the front, by quite a bit, rear is tough to tell, this was from a stock R1.

I'll start with the front. My stock stay bar endlink bushings were shot, completely, I bet I wasn't getting any action from it until the car was seriously articulating, you could jiggle it all around.

That made the biggest difference. Before I had heard RX7's were twitchy, mine was twitchy but not terribly so...well now it is Without the PS it likes to lead alot, I set the adjustable links to the same length as the stock ones, I'll have to play with the tuning on them.

The car turns in hard now, I mean REALLY hard. I was doing some sawing back and forth to listen for noises and the difference between doing a circle and doing a spin is now a very small motion of the wheel.

In the rear I had 4 bad pillow *****. I originally thought I only had 2 realyl bad ones and 1 so-so one. The upper to knuckle units were shot completely. Those were replaced. I took the arm off and took it to work with a press and changed them in 5 minutes. The trailing arm units were ok, not great, just a minute amount of fore-aft movement....I bought 2 more units but was running short on time so I decided to leave them alone until winter.

I re-assembled the rear end and the driver side wheel still had a little bit of play, turns out not only is the trailing arm one having some play, but also the knuckle to lower control arm. The passenger side is rock solid all the way around. I'll order 2 more and replace them all now.

My toe links also were gone in the rear, you could move the tires almost a 1/8 of an inch in either direction. Set them to stock length until I get it aligned.

Good news...90 percent of my noises are gone. The biggest one is on/off gas clunking which I was hoping was not pinion related or carrier bushings, must not have been since its super tight now. I still get a clunk at low speed braking, which must be the knuckle to lower pillow ball.

Ride improvement is dramatic, if I were to rate ride quality improvement its a 7 out of 10, impact harshness on mild to moderate road conditions I'd say is 8 out of 10, harsh conditions only a 5 out of 10.

Still, this is easily a car I can now see myself in for a 5-6 hour trip just based on my limited test drive, its a huge improvement over the old setup.

I'd put its general ride quality at 75-80 percent of our Liberty, compared to 20 percent with the R1 setup.

The wandering steering input is gone...the car wanders and follows road crown worse than before, but now it responds to wheel input immediatlely unlike before. Thats a trade off I can live with, I don't mind it following the crown too much if it responds.

The bad....I have a wheel shake above 80mph up front. This could be, and I hope it is, related to mis matched lug nuts. Somehow I lost my lug key so I bought some 80 cent lugs at Autozone after getting my locks removed, they are lighter than the other lugs but I think that may be too close to the center of the wheel to make a difference. I'm not sure what else it could be, I'll go out and retorque the wheels again and see whats up. Its also possible that the old lugs were stretched at 140K miles, the new one is not so its applying more torque to that area than the others.

I plan on replacing all of the lugs now.

All in all a easy project, time consuming since I did it in the middle of repainting the house and I had to deal with some errors on my end...like mistakenly putting the front springs on the rear, then having to take it all back apart again.....letting the upper control arm fall under the front brake hose bracket, then putting in the shock, 4 TIMES! Installing one of the shocks backwards, I put the label up pointed out, just the wrong label.

Fronts are a job for 1 person IF you can get the ABS sensor out, I could not and figuired better to leave it in rather than screw it up. A bottle jack is required, some patience, and luck. I did the one side by myself with some minor swearing and alot of up and down to tighten down the nuts up top a bit to get everything into position but the other side was a complete loss and I finally called for help.

I did have a buddy help me with the rear, especially re-assembly after the new pillows, they are a VERY tight fit.

But thats it...for sure the improvement was worth the money even thought 60 percent of the cost was maintainence and not improvement.

I'll swap out those 4 pillows next Monday and get it aligned on Tuesday to the specs Howard recommended and see how she turns out.

Last edited by NoOne; 09-22-04 at 08:09 PM.
Old 09-22-04, 08:40 PM
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congrats on your the conclusion to your project.

your 80 mph vibration is not lug nut imbalance. since your ride hight was changed your camber is too negative... which is probably not your vibration either.

my guess is your rear toe is off. (you did add new links...) make sure they set your rear toe at a zero thrust angle and that you set your suspension as per my suggestions and you should cure your high speed vibration.

as to your remaining clunk on/off power-brakes.... did you replace the bushing at the front of your lower longitudinal link in the rear of the car? 'most likely candidate....

enjoy,

howard coleman
Old 09-24-04, 10:09 PM
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Getting closer....

First off, sorry about the name screw up...I work with a Howard Mitchell, I did change it to Coleman after I realized my mistake however it doesn't show the change for some reason on the mail page.

Had the alignment today, went with Pettit Long Track 17" wheel setup. They call for 6.0 degree's of caster, we could only get 6.5 but everything else is dead on.

Car is far far better, no shake upto 120mph and with the lowering it really helped out with underbody airflow. The biggest detractor from the LS1 conversion(no wise *** remarks) is loss of the under engine deflector, the forward one does stay.

I'm still learning the car, but there are some differences...it feels 'longer'....it feels like a longer wheel base car than what it is....the neutral drift feeling is there alot earlier in a turn and with a little less gas, but the point where it goes from neutral to oversteer is now a much smaller area than before. While your in the neutral area the car feels super stable. Before even though the breakaway point was harder into the turn, it was vague until you reached that point, now its controlled until you hit it.

Overall without more time behind the wheel I like it, alot. We drove to dinner and back tonight and felt comfortable ride wise in the car for the first time.

I'm going to lengthen the stay bar front end links tommorow to see if I can move the oversteer break away point a bit farther along than currently. Oversteer is very easy in the car with the LS1, with 300+ft lbs from 2200rpm up its just a goose of the throttle and your on your way.

I'll get some more time in it tommorow afternoon, going to take a nice ride out into the twisties and see how it does.

Thanks again Howard, a very cheap and worthwhile improvement.
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