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Originally Posted by nitrorocket
I contacted Dennys on my driveshaft, they say it is good to go, especially after shortened for the overdrive. I run a 3.42 gear now and will probably just try that.
I run BFG Comp TA/ZR Tires right now so they are safe.
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Z-Rated tires are not even close - 146 MPH I believe. Z is "above" 146, but you dpon't know how much, so that means only 146 MPH.
Highest rating is Y - which is above 186, but they will never tell you how much above 186, so you can only assume 186 out of them.
Speed rating tests are a bit scary as well. If I remember correctly, they run the tires for 30 seconds at a time in 5 MPH increments (or actually KPH which is why we have 186 etc) and if it lives there it is rated for the speed.
Last time we were starting to rebuild I had gotten five different tires to have tested at 220 MPH and they were to be run for three hours or failure (whichever first), with temp reading data logged. Also some other tests were to be done. We hoped to see temp spikes before failure or identify characteristics to see precursors to failure. I purchased infra red temp sensors to mount on the car in each wheel well with on dash displays so for the specific tires we found to be best, we would have some warning before it failed - readouts are programmeable to indicate green, yellow and red conditions. There are very few tire monitoring systems that update quickly enough to be useful and they start at about $20K.
If you are serious about doing this - safely - this should give you an idea of the lengths we go to. I would also recommend running nitrogen.
Re: your driveshaft you need to calculate the RPM given your trans, tire size and rear gear ratio at the target speeds. Also, I would seriously consider at least an aluminum shaft as rotational mass can be an issue with the RPM's - unless you can go and get a NASCAR quality steel shaft.
One thing to keep in mind that many have learned the hard way - it's no small task to have a car that fast that is not single purpose built. Can be done, but many have failed trying.
John Buscema
XV Motorsports
www.xvmotorsports.com