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Discussion Starter #1
Hi all -

A little background:

This weekend, I got a chance to get out on an awesome twisty road for the first time since having my suspension upgraded to Dinan stage III, which has camber plates, thicker swaybars, koni adjustables and stiff springs. All in all it's supposed to be a kick-ass system, and not cheap (what do you expect from Dinan?). I've got the '96 M3 17" multispokes with BRAND NEW pilot sports 245/40 rear and 225/45 front, which is the stock size for the '96 M3 wheels. I just bought the car, and the tires were brand new when I picked it up.

a friend of mine showed me the road. he's a great driver with a '92 325is w/ a full M3 suspension, x-brace and 17" wheels with P7000 tires.

My problem is this: we were both terrified by how my back end slips out. His car feels like it's on rails, and my car should feel far better. My body roll is certainly less, but the pilot sports don't even make a sound before slipping right out. We had to back way off on our driving for fear of spinning. not good.

One possibility:
I had a Kawasaki ZX6R; when I bought a new tire for the rear they told me to take it really easy for the first 200 miles or so until I'd worn down some of the rubber. They said it would be really slippery. Is this possibly the case with my new pilot sports?

I'm going to go back to the guys who installed the suspension and ask their advice, but I don't feel the back end should just slip out without warning and WAY too early. I've also thought it could be the tire pressure (I need to check it, but I assumed they would have done it with the 4-wheel alignment and suspension testing...). I just hope it's not something serious. There aren't any noises or anything, and it feels great up until it slips out, which is at about 30% of when you'd expect it to. Yeah, about 70% early, if that makes sense. I haven't tried to get on the throttle to correct, but it feels like they would just keep spinning out even further.

any advice is appreciated.
 

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did you get adjustable sway bars with the dinan setup? if so you need to loosen up the rear. you could also try stiffening up the front to cancel out the oversteer since the koni's are adjustable. a lsd might help aswell since they are non-tq induced, from bmw. however it sounds more like a tire problem to me if you say its slipping that early, maybe you should try going to an empty parking lot and putting on 200miles of wear the easy way :D :driving
 

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Discussion Starter #3
Originally posted by MrM3@Sep 22 2003, 03:43 PM
did you get adjustable sway bars with the dinan setup? if so you need to loosen up the rear. you could also try stiffening up the front to cancel out the oversteer since the koni's are adjustable. a lsd might help aswell since they are non-tq induced, from bmw. however it sounds more like a tire problem to me if you say its slipping that early, maybe you should try going to an empty parking lot and putting on 200miles of wear the easy way :D :driving
yup, the swaybars are adjustable - I got this installed at Fall-Line (highly respected in the Chicago area), and it's definitely going back for some adjustment. At least I know that no one's been driving my car hard (another place replaced the belts and changed the oil), since they would have experienced this right away.

I do like the parking lot idea, though. I've actually been driving around looking for someplace to spin the tires :D

I need this fixed before I get my AA s/c (ahhh 315hp)!!
 

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yeah your tires need to be broken in before they reach optimal grip
 

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Discussion Starter #5
Originally posted by lwebb12@Sep 22 2003, 04:27 PM
yeah your tires need to be broken in before they reach optimal grip
thanks. that's what I figured - the strangest part about it is that the tires didn't make a sound. they just lost grip and started to slide...

so what's the best way to break them in, other than sitting in a parking lot doing donuts??
 

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from Tire-rack.com

Tires are comprised of many layers of rubber, steel and fabric. Due to these different components, your new tires require a "break-in" period to ensure that they deliver their normal ride quality and maximum performance. As tires are cured, a "release lubricant" is applied to prevent them from sticking in their mold. Some of the lubricant stays on the surface of your tires, reducing traction until it is worn away. Five hundred miles of easy acceleration, cornering and braking will allow the mold release lubricant to wear off, allowing the other tire components to begin working together.It is also important to note that your old tires probably had very little tread depth remaining when you felt it was time to replace them. As any autocrosser or racer who has tread rubber shaved off of his tires will tell you "low tread depth tires respond quicker." Don’t be surprised if your new tires are a little slower to respond (even if you use the exact same tire as before). Their new, full depth brings with it a little more tread squirm until they wear down.
 

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Discussion Starter #7
Originally posted by lwebb12@Sep 22 2003, 05:26 PM
from Tire-rack.com

Tires are comprised of many layers of rubber, steel and fabric. Due to these different components, your new tires require a "break-in" period to ensure that they deliver their normal ride quality and maximum performance. As tires are cured, a "release lubricant" is applied to prevent them from sticking in their mold. Some of the lubricant stays on the surface of your tires, reducing traction until it is worn away. Five hundred miles of easy acceleration, cornering and braking will allow the mold release lubricant to wear off, allowing the other tire components to begin working together.It is also important to note that your old tires probably had very little tread depth remaining when you felt it was time to replace them. As any autocrosser or racer who has tread rubber shaved off of his tires will tell you "low tread depth tires respond quicker." Don’t be surprised if your new tires are a little slower to respond (even if you use the exact same tire as before). Their new, full depth brings with it a little more tread squirm until they wear down.
thanks a lot. That makes sense. I think it's a combination of new, slick tires and my rear swaybar being dialed in too stiff, I guess. I've love to learn more about suspension geometry and forces, as I only know what intuitively makes sense to me. five hundred miles. wow.
 

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aye but after that your tires should work much better. and hey 500 miles is fun to drive around. have a blast
 

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if it really is that big of a deal take the car to dinan and demand a refund....
 

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Discussion Starter #10
Originally posted by BlackTape@Sep 24 2003, 12:04 AM
if it really is that big of a deal take the car to dinan and demand a refund....
whoa. no, it's not that big. It feels like a tire issue; I was just surprised at how easily they slid out without ANY sound or warning. I guess I'm just not used to the Pilot Sports, and the cold weather didn't help, since I hear they don't grip much if it's below 45-50. Time to get a good all-season tire for this Chicago climate... I'm not sure I want tires I can only use about 4-5 months of the year (maybe beginning of May to middle of Sept.)

I'll also get the guys who installed to check it out.
 
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