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View Full Version : Sumitomo HTR Z III belt failure



Grant B
02-03-2014, 03:34 PM
They lasted one damp session and one dry session with a passenger at Roebling Road. Damp times were 1:30-32s and dry times were 1:26s. Not exactly flying.

The car is a 2006 SRT8 Magnum. Its got Kooks headers, an ATI underdrive pulley (to help the power steering last longer), 275/40/18 tires, adjustable sway bars, poly bushings and adjustable FUCAs. Camber is only -2/-1; it does not produce much grip.

I'm not really out there to try and run killer times in a 4200lb boat, so I'd love to be able to run the cheaper HTR Z IIs or IIIs. Unfortunately I don't think they're safe enough. I will be switching back to the XL-rated Hankook V12 Evos.

Ron380
02-03-2014, 04:27 PM
Was this size HTR ZIII also XL-rated? I ran the ZIII's on my Charger, using 245/45/18 because they were XL-rated. I used them for about a dozen track days at Mid Ohio and NJMP (including a 1:58 lap at Mid Ohio), and never had any problems with them. They worked great in the rain with my AWD, too. :)

Sorry to see you had that issue, I hope the car wasn't damaged! Have you contacted the place you bought them from, or Sumitomo, about this?
(Not sure they'd do anything for you or not, since you were on a race track...)

Grant B
02-03-2014, 07:25 PM
I don't remember where I got the tires from; I think my local Discount Tire. I will inquire with them.

The Sumis are not XL rated, but should be good to 1709 lbs just like the OE Goodyear Eagle F1 Supercar fronts. The V12s in the same size are rated to 1929 lbs.

The worst part is the HTR ZIIs are now only $109 each.

joelvan
02-04-2014, 11:01 AM
Roebling is hell on left fronts . this one came off the Police car a few years back . A cornerworker saved my ass by blackflagging me. I never felt anything till after the black flag and slowed down . Then I knew something was wrong. http://farm5.staticflickr.com/4051/4657959496_dec8278bcc_b.jpg (http://www.flickr.com/photos/[email protected]/4657959496/) 100_1099 (http://www.flickr.com/photos/[email protected]/4657959496/) by joelvandiver (http://www.flickr.com/people/[email protected]/), on Flickr

Grant B
02-04-2014, 06:04 PM
Roebling is hell on left fronts . this one came off the Police car a few years back . A cornerworker saved my ass by blackflagging me. I never felt anything till after the black flag and slowed down . Then I knew something was wrong.Have you had any luck eliminating these failures? Do you think a higher load rated tire would help?

joelvan
02-04-2014, 06:29 PM
It's the only failure iv'e had in 6yrs

Grant B
02-06-2014, 03:40 PM
Is there anything you could point to which caused it? Tire pressure perhaps? I was running 47 psi hot. This may have been too much, but I've run that before when using V12 Evos.

Man I'd love to be able to run $109 Sumitomo HTR ZIIs... Sure they'd suck, but a Magnum is not going to be setting any lap record anyway. I just don't think I can trust them after this ZIII failure.

Ron380
02-06-2014, 04:42 PM
"Cheap" can be fine for regular street tires, but considering what you're using these for, do you really want to trust your car (and your continued good health) to cheap tires?

Save up for a while and get better tires, especially XL-rated ones. You'll trust them more on the track, you'll have a better-handling car, and you won't be risking your car and others to as high a chance of a tire failure. ;)

I trusted my ZIII's completely, but I can understand why you'd want to consider something else.

Grant B
02-06-2014, 07:44 PM
That is the thought, Ron. The V12 Evos are XL rated in most all sizes, including the 275/40/18 size which I run. I'll I've gone through 4+ sets of them on this car without issue, whereas this was my first set of ZIIIs. I'll also be reducing the car's weight.