Debating run-flats

[Viperfreak2]

It was a terrible night at the dragstrip. First run 8.2 @ 89mph (1/8 mile) second run 8.4, third run 8.6. That's when I threw in the towel. I had 100 lbs of dogfood in the trunk and still couldn't keep the tires hooked up (first second OR third). This morning (first really cold AM) I pull out of the driveway and spun the tires. ***? I knew these run-flats probably weren't as sticky as normal tires and that the sidewalls wouldn't give as much, but there's so little traction when cold, it's almost dangerous. I wouldn't dare let anyone else drive the car when it's cold outside (In SC, 35 is cold) Maybe I should park it for the 'winter', or possibly buy a set of non-run flats? It was 75 degrees two days ago and in this area we get some warm weather even in January. Heck, I even had the top down at 9pm Wednesday night! Anyone put non run-flats on their SRT yet? Any difference? Should I be worried about no spare???? Carry a can of fix a flat and a compressor?

 

[Gary C (GaryCSilver04)]

I took off the run flats on my Prowler for a better ride(Dunlop sp9000's) and never gave it another thought about having a flat. The ride difference is night and day. The treadware on the Dunlops are 320 and 180 on the run flats, lower the number the softer the tyre. The car didn't quite handle as well.

Now on our Vipers the OEM run flats treadware are 400, man that is HARD. Michelin was another tyre with the treadware at 220, almost twice as soft.( I was discount tyre yesterday checking). I went in there yesterday after scaring the sh*t out of myself 3 times, one time I almost spun out all of 2 mph in a parking lot(that looked cool).

This summer I will try the others(220 treadware) for better traction I hope but for more of a creampuff ride.

 

[Skip White]

How much air pressure are you runing in the rear?

If you have the 29 rec. pressure, thats way to much, and I can tell you that the track had to been a bit slick. Was the track freshly prepped? There are certain surfaces that are very slippery, with the wide tires that Vipers have, but just as bad as they are on some surfaces they are as good on others. I have seen tracks that are like this, and the outside temp does make this worse.

Interesting post from Gary about the 220 treadwear tire. Are they runflats? I can't even find the treadwear rating on my tires.

As for run-flats having stiffer sidewalls, yes they do, and this is a factor in traction, but thank God for the Hdro-Lok diff. in the car. This is so much better than the former setups.

As I said about the air pressure, I would lower it to 22 or so, and this should make a big difference.

Watch out for lube shops airing up youre tires to the max pressure, I have had so many of them do this while your not watching and you know what that is on the Viper tire, 51lbs, wow what a nightmare.

Skip

ps, I love the run-flats, so much peace of mind.
as I had a low tire on my last Viper and did not know it till it was to late, and that was the worst night I've had in a long time, not to mention loosing a tire and damage to the rim.

 

[GR8_ASP]

I agree Paul. When mine were new they would stay in the up position while driving. That was highly desireable to reduce the cabin heat. Now they only stay up for a few seconds so I find myself holding it up to cool the cabin. Need to find a non-destructive way to make them stay in place.

 

[Gary C (GaryCSilver04)]

Tirerack

Skip, I looked too, there is sooooooooo much print on the tire is mind blowing, these tires I speak of are not Zero Pressure(run flats), this is what the guy at Discount Tire told me, I had him call Michelin to check, there is somewhere on this site where someone said these tires I speak of are not recommended. Who know's who is correct.

Maybe I am having a flash back from the 70's...

I will look further into this Monday

 

[Chuck B 98 GTS]

I've never seen a car run soooooo hard like the SRT. My first impression was this car is unbelievable But dang, it drives hard over bumps. I feel bad for you guys that have dentures. Not knocking the car, it's one of the best DC has to offer so far. Just that it rides HARD

Cheers,
Chuck

 

[Gary C (GaryCSilver04)]

It rides better than my 01 GTS. taking off the runflats will make ride like a RR.......lol

 

[viperz]

The car rides a little rough but I love it. I had an 02 Porsche turbo and I really missed the ride of the 99 gts I had.

I love the car, it has to be driven unlike the Turbo that drives itself. As for the tires, I'm in Canada and even in the cold I really don't notice a lack of traction unless you push it real hard cold.

I'll check the pressure but in the winter we keep the tires pretty much fully inflated to prevent the flat spots.

 

[Viperfreak2]

I run 26 psi in the rears for the drag strip, 30 in normal driving. I think I'll buy some rear non run-flats as a test to see if they are 'night and day'. I'm not worried about a flat, I've never had one. The drag strip I go to is about as redneck and UN prepped as you can possibly imagine. After a radiator hose blows, a bunch of guys carrying propane tanks walk around burning off the anti-freeze. Yes, the kind from your backyard grill. Everyone was having trouble hooking up, unless they were on slicks. New Cobras were running mid 9's, Vettes running low 9's, etc. On the street (closed course, professional driver-do not try this at home!) I can run 7.5 @99 without drama. I have a quarter mile time on my G-tech of 11.6 @ 123! I don't think I could duplicate that when the temp drops below 40, only because of the tires.

 

[viperz]

My brother has a Cooper S. He switched from run flats to regular and it made a big difference in terms of ride and grip.

 

[Gary C (GaryCSilver04)]

I got some bad info, forget it.......

OK, here's the scoop, I just talked to Michelin, the OEM tires on the 03-04 treadware is 220 and they are runflats(we know that)

Ok, you can get from Michelin the same treadware 220, same size, same make, same tread design WITH NO ZERO PRESSURE/NO RUNFLAT side wall/construction.

So we have a choice of standard tire or a runflat tire.

Phew

Sorry for some confusion.

So for a better ride and I would guess better handling, the non runflat would be the way to go.

 

[luv2race2]

I have ran both sets already. The run flats for the first 4500 miles, then the regulars for the next 2500 miles. At first I wanted to save the original rears so that if I sold the car I could put the OEM ones back on and say its never been raced!! So , I found a set of these non-run flats here on the website...mounted them up and away we went. I really didn't notice to much difference in the ride, but did notice a difference in the handling. Tires hooked up well until yesterday. Driving onto the freeway and accelerating up to speed, I had spun the tires in first and second. No dropping the clutch, just pure torque!! It was awesome but that had never happened on the runflats. I will drive 'em good today and reply just in case the ground was wet or oily just in that area.

Otherwise, I liked the cheaper tire just to have some fun with the car! Hoping to take it to Laguna Seca this coming weekend!

 

[Viperfreak2]

I would have asked if the weather had anything to do with it, but then I noticed San Jose. Probably doesn't get too cold there. I think temp has a LOT to do with the slippery run-flats. The temp here was about 75 yesterday so the drag strip asphalt was warm. My first run was an 8.0 @ 91mph. Not bad for spinning in second halfway down the track. The second run was later in the evening and the temp had dropped a bunch. 8.2 seconds. I didn't want to repeat the earlier weeks results so I quit. By the end of the night, even cars on slicks were spinning more than normal and getting wobbly going down the track. One guy even spun into the woods after a 5.2 @ 134mph run. He's OK, but the Camaro was toast.