SC430icand

Well I finally got it figured out. The vibration and shimmy are gone and the car rides much better. Figuring this out I have to say has been most frustrating. I want to share everything that I have learned and done because when I was doing my research, I could not believe information was so limited.

Run Flat - now I understand why some call it Run Crap. They ride hard, makes the car feel a bit nervous on bumps, it only gives you 50 miles (false sense of security) if you run out of air - then you have to throw it away, expensive, EXTREMELY difficult to mount/dismount making damage to your rims a high risk, narrow contact patch (Dunlop), and so on. I think you get the meaning…

Mistake # 1 – I used the OEM Dunlop DSST Run Flat SP Sport 5000 on 8.5 inch HRE 843R wheels. With this combination I was getting a weird sound from the tires that sounded like rubber and nylon reinforcement stretching and ready to separate. When the Dunlop is mounted on the OEM wheel, which is 8 inch, it is quiet. It turns out that the Siping (find Tire Siping in Google) on the Dunlop are thin enough to rub but not wide enough flex. On the 8.5 wide wheel, this became worse, hence the weird sound.

Mistake # 2 – I used the HRE supplied metal band and so called lock to mount the tire pressure sensor (TPSM) on my HRE wheels. Between the Dunlop and metal band, I was never able to get the wheels balanced well enough to eliminate the shimmy and vibration. The HREs ARE NOT designed to be used with TPSM. The bands are an after thought and just do not work as well compared to a wheel designed to mount the pressure sensors. Do yourself a favor, if you want to use an HRE, forget using the TPSM.

I had to go back to the tire place so many times to get the wheels balanced and the bands figured out that the wheels were scratched a couple of times and had to be sent back to HRE. I finally got tired of this and decided to get rid of the Dunlop and TPSM metal bands. I followed the directions from Lex Lugar to turn off the TPSM alerts.

Using my experience with different brands of tires and online ratings, I focused on the Michelin Pilots. I chose the A/S (overall rating of 9.0) because it is close to the PS2 (overall rating of 9.6) in performance and has a tread life of 400. PS2 is rated at 220.

The car is now a dream to drive and I don’t have to deal with the stupid metal bands. For some of you that have asked about fix-a-flat kits, without the TPSM in your wheels, it should be safe to use this if you so desire.

FYI – I’ve also seen a lot of questions on how the TPSM work, i.e., can you rotate your tires? Will it only work with Run Flat tires? Is there a front/rear orientation and so on? I’ve also seen debates on whether the HREs are lighter than the OEM wheels and also questions comparing Run Flats versus a standard tire. Here are the answers:
1. The TPSM monitors air pressure. It does not matter what kind of tire you use. As long as it can sense the pressure it will work. When mine hits 27 psi, the light on the dash will come on. You can also move the TPSM around. As long as the antennas located under each wheel well can receive the signals, it will work. I’ve had my tires with the sensors stacked 20 feet away from the car in the garage and it still works.
2. I explained the facts about the Run Flats (Crap) above. Now here’s some facts comparing Dunlop Run Flat versus Michelin Pilot A/S
Weight – Dunlop – 30 lbs, Michelin - 26 lbs
Contact patch – Dunlop – 6.5inches, Michelin - 7.25 inches
Tread Life – Dunlop – 220, Michelin – 400
3. HRE – 22 lbs, OEM wheel – 26 lbs. Using the Michelin with the HRE, I shaved off 8 lbs each wheel…

Lastly, if you opt for the HRE and you feel you have to mount the TPSM, here’s some information that you may find useful. HRE sent me two sets of instructions and there is a subtle difference. One instruction says to “Place the band with the installed sensor around the wheel with the sensor located next to the wheel valve stem. Place the splice and lock 180 degrees opposite the tire pressure sensor.” The other instruction says “Place the band with the installed sensor around the wheel with the sensor located next to the wheel valve stem. Place the splice and lock next to the tire pressure sensor”. Notice one says “180 degrees opposite the tire pressure sensor…”. I believe this is correct one. I weighed the pieces and I think the positioning may make a difference. In addition, you want to make sure the band is centered on all points around the wheel. Here are the weights: TPSM – 1.8ozs, Splice/lock – 9oz. When they balance the wheel, they will have to make up the difference in weights so I think positioning is important.

There you go. I hope some of you will find value with this information and that no one has to go through the same ordeal as I did. Good luck!

SC430icand
2004 Indigo/Saddle
HRE 843R

Cruizing

Congradulations on your success to finally get a good ride. It is frustrating trying to solve all the little problems (and expensive too). From my research the Michelin Pilot A/S are pretty good. I wonder what the Michelin Pilot A/S ZP (zero pressure=runflats) are like. Unfortunately there are limited sizes. The 245/45-17 from the C5 Vette are the same 25.7" size as our tires. It would be interesting to try the ride.

rominl

iTrader: (4)

wow that's some very good infor man. sad to know that you were going through so much

there are couple of owners here with hre wheels on their cars, i wonder if they have the TPS and how it works with their wheels.

somehow i wonder, if you don't use the runflats with the hre and with the TPS, would you still have the shimmy problem

nonetheless, good stuff man!