Rear end wants to step out

Guys, sorry to chime in without being super educated on tires. But even I know S drives are shit. They’re cheap ass soft tires. Yoks make good wheels. Tires though, ehhh not so much in my own personal opinion.
 
Guys, sorry to chime in without being super educated on tires. But even I know S drives are shit. They’re cheap ass soft tires. Yoks make good wheels. Tires though, ehhh not so much in my own personal opinion.

Yokohama makes the ad08r and A048 which are excellent quality summer/ track tires. The S-drive is an economical option from yokohama, great for daily driving. That being said, I definitely did not like my car on s-drives but JC's issue wasn't tires as he states it drove perfectly before his flat tire incident.
 
My only gripe with the Yokohama’s I have had on other cars is durability. They wear extremely fast.
 
Thanks Mexi and Jinks. I would never have bought these tires on my own but that was what was on the wheels when I bought them and they were like new. I figured I'd run the hell out of them and then put some serious tire on these after that. The car handled perfectly neutral before the flat. With the new tire, not so much. But it does seem to be coming back. I'm planning a longish drive this weekend so we'll see how they perform after that. If it clears up, great. I'll stick to the original plan of using these tires up as fast as I can. If not, I'll put the Volk's with the Z2's back on and see if there is an improvement. I'll take it one step at a time.
 
I've always wonders if tires of the same model and brand either change formulations in a mid-model refresh or does it degrade enough over age to make a difference.

I could see where a change in tire compound or sidewall or other structural changes could happen whether caused by factory formulation changes or age.

If the problem occurs again.. I wonder if simply changing tire pressures between the two would alter things. OR if the tread depth on the new tire vs. the old tire would matter enough on a high performance car like yours.
 
All good hypothesis. I will discount the last one as the difference between the thread depth of the two rear tires is less than 1/32". Like I stated, the tires were like new. Damn it.
 
Update; the issue is mostly gone. It looks like the new tire took a while to seat itself in. I remember a new set of rears I put on the other NSX. It was like driving on ice for the first 3-400 miles. Then they settled in. But what a wild ride until they found their grip. I'm not saying these are great tires or i would buy them again. They are not. But I'll try and burn the hide off of them as quick as I can so I can purchase some REAL tires. Thanks all for the thoughts and suggestions..
 
Not clear to me: did you replace BOTH rear tires at the same time or just to one with the puncture? The diff doesn't like different tire depth nor different tires (even different models) and might act up. And maybe that's what you felt under hard acceleration.
 
Not clear to me: did you replace BOTH rear tires at the same time or just to one with the puncture? The diff doesn't like different tire depth nor different tires (even different models) and might act up. And maybe that's what you felt under hard acceleration.

I only replaced the punctured tire as they were relatively low miles to begin with. The tread depth difference is 1/32" difference if that. But age wise a lot different. Now that I have run the "new" out of it, it seems to be equal to the older tire.

Just had a thought and that is temperature difference and I'm talking about ambient. I had the tire pressure at around 33psi here in the desert at 167' of elevation and at 70F. The morning of the drive we were up at 5-6,000 ft of elevation and it was probably mid 40's. Could I have lost enough tire pressure that the tire flexed off the rim? Just wondering.....
 
I didn't read your 1st post carefully enough then. Different tires of different age is a BIG NO-NO on the NSX.
I had to replace one tire on the rear after 500 miles and 3 months with the same tire. After breaking it in it was fine, I'm CTSC but not at 445 rwhp. On another occasion a rear tire lost pressure (20-25 psi) while driving. The rear also wanted to step out during hard acceleration and felt very weird.

I don't believe in your possible theory stated above because normally you check both/all tires at the same time, not just one. Even if the tires had a different temperature at the same time the pressure difference won't be big enough.
 
I guess it's just a bedding in process that takes longer with some tires more so than others. I don't notice it now and the car seems stable again. But it certainly had my full attention while it was getting used to it's new place behind my left ear. Will plan a controlled canyon drive by next weekend to make sure we are back to "normal". Thanks to all for their advice and suggestions.
 
Rear end stepping out

A little background. '91 NSX with 445rwhp. Axles and boots repacked 1500 miles ago. BC Racing coilovers on 10/8 Swift Springs F/R. NA2 rear sway bar and Dali Trophy front sway on Carbon6 end links. Stoptech BBK on all four wheels. Tires are Yokohama S Drives 215/40 & 275/35 on Advan Model 5's 17/8 in front and 18/10 n the rear. Rear beam bushing has been replaced with TiDave's non-compliant bearing. Front Steering rack rebuild by Matt Lindsey and realigned to Type R specs in the front.

I sustained a flat rear tire which killed the tire and I replaced with a new S Drive. The old tires only had a couple of thousand miles on them so the stagger from new tire to old is minimal with the rears. I have heat cycled the new tire on over a dozen trips of at least 30 miles each. But ever since replacing this one tire, the rear end wants to step out on hard acceleration. The car doesn't seem as stable at speed either. It seems to want to move the rear of the car to the left (toward the new tire) and the car seems to float a little at high speed.

I've checked the damper settings and they match up. I pulled the wheels off to check the axle nuts. They are torqued correctly and the nuts are staked. The only thing I have noticed is on the passenger side, if I grab the rotor at 3 and 9 o'clock positions and tug in and out, I will get a fairly slight "clunk" in both directions. Nothing on vertical tugging, only on the horizontal. I can't see any movement in the toe link, ball joint or end links while doing this and I can't really identify where this "clunking" sound is coming from.

Westend alignment is 2 1/2 hours away and I don't want to travel that far for an alignment knowing that something will have to be replaced before they can align the car properly. If something is broken/worn/not right, I'd just as soon purchase that part and have them install before we align the car. Oh, previous to the car blowing a tire, there were no issues at all with the way the car handled. It was perfect. I mean it was the best handling, most perfect handling car I've ever owned. So any suggestions out there?


Hello,

Sorry to hear about your issues. I had a 1991 some years back that had similar issues. On right, high speed corners the read end would suddenly kick out, requiring countersteer to correct. No noises, just a little kick out. Wheels and tires were standard factory stuff.

I did some poking around with the car on stands. The toe control rod ends seemed tight but when I tugged on the ball joint end it moved - just a little bit (oh, maybe 1/16 inch). Note: I had to tug pretty good; little taps and pushes resulted in nothing detectable. Anyways, I backed off the nut, tapped on the ball joint to help seat it into position, then torqued everything to spec. No more drift. My point is to check everything very carefully, sometimes little things may be the large contributor. Good luck!

Kyle
 
Hello,

Sorry to hear about your issues. I had a 1991 some years back that had similar issues. On right, high speed corners the read end would suddenly kick out, requiring countersteer to correct. No noises, just a little kick out. Wheels and tires were standard factory stuff.

I did some poking around with the car on stands. The toe control rod ends seemed tight but when I tugged on the ball joint end it moved - just a little bit (oh, maybe 1/16 inch). Note: I had to tug pretty good; little taps and pushes resulted in nothing detectable. Anyways, I backed off the nut, tapped on the ball joint to help seat it into position, then torqued everything to spec. No more drift. My point is to check everything very carefully, sometimes little things may be the large contributor. Good luck!

Kyle
Well that's a nice post for someone with 28 posts. I'll give you a star - Kyle.
Seems like good info for others.
 
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Thank for the input Kyle. The car is rock steady now. Just required a lot of miles before that tire bedded in and played nice. New tires are sometimes like that.

Case in point is I bought some Dunlop Z3's for track duty. First time I drove on these, I was scared to death. It felt like I was riding on two bicycle tires going down the highway. The simplest steering input felt like the car was going to spin out of control. Finally settled down 50 miles later but that was one white knuckle ride. Tires are perfect now but what a way to start!
 
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