Z3M on non z3 - tyre stretch

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Jonesy
Joined: Thu 05 Aug, 2010 18:30
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Z3M on non z3 - tyre stretch

Post by Jonesy »

hi all,

managed to pick up some z3m roadstars for a decent price and now im wondering what tyres to go for on my early narrow body 1.9
current tyres are 245/40/17 and are rubbing lightly over bumps, in sharp bends and at full throttle. if anyone knows better, what tyres should i go for to stop rubbing?
i was thinking 225/35/17 would that work?

i know its not to eveybodys tastes but any help would be appriciated
thanks
Luke Jones

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Jonesy
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Post by Jonesy »

oh and forgot to mention the rear is lowered 45mm
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c_w
Joined: Thu 19 Aug, 2004 16:50
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  M roadster S50

Post by c_w »

Does 225/35/17 even exist!?

Remember that as you go narrower the profile comes down relative to the width, so a 225/40 will be a lot lower profile than a 245/40 so I wouldn't bother reducing the profile.

Depends on the tyre but a 235/40 may do the trick, a 225/40 may go on though.
Jonesy
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Post by Jonesy »

haha i hope so, or i dont know what these guys are selling:

http://ssl.delti.com/cgi-bin/rshop.pl?d ... sowigan=So

complete noob to this subject, so do you think a 225/40 would be okay as this is what i have seen on a number of other z's allbiet facelift one and then arch rolling if there are still issues?
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Gazza
Joined: Tue 04 Oct, 2005 20:58
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  M roadster S54
Location: Romford Essex

Post by Gazza »

Worth checking with the tyre fitter also.
Gazza

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

Z3 S54 M roadster Image, BMW Z1, BMW M3 CSL, Z4M Coupe
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Jonesy
Joined: Thu 05 Aug, 2010 18:30
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Post by Jonesy »

garythefish wrote:Worth checking with the tyre fitter also.
tyre fitter is a friend of a friend who works at my local bmw indy, he said he will stretch to an extent
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c_w
Joined: Thu 19 Aug, 2004 16:50
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  M roadster S50

Post by c_w »

Yea I wouldn't get the 225/35/17 tyre it will be too low profile.

What is the front tyre you're running?
Jonesy
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Post by Jonesy »

the fronts are 225/45/17 i was just wondering if this would work on the back too?
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fwj01
Joined: Sun 27 Jun, 2010 13:02
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  Z3 roadster 2.0

Post by fwj01 »

Hi Luke, In reply to your PM:

I'm running 225/45 tyres to try not to run too much strech, but having major rubbing now the rear springs have bedded in a little... REALLY annoying when you wanna cane it. This is probably because my rear springs are too soft!

I would advise you having new rubber on the front too if you are going to add strech to the back to even it out. From what I remember of having 225's on the front they were quite balloon-like.

Have a looky at this site for some inspiration :wink:

http://www.tyrestretch.com/
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Jonesy
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Post by Jonesy »

Thanks. If your rubbing on thoses I probably will too as you have way more camber than me. Took a quick 5 min trip out and the arches were slicing the tire as opposed to rubbing solid 1mm groove all the way around. Lucky ones bald anyway.

I am now wondering as weather to go down the stretch and rolling avenue or wait for a front end damaged 2.8 to turn up and use the back end
By my reconing 4 new tires and arch rolling is around 500 but an accident damaged 2.8 will be at Least a grand but will come with loads of spares to sell.

This is getting complicated... Opinons please?
Luke Jones

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fwj01
Joined: Sun 27 Jun, 2010 13:02
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  Z3 roadster 2.0

Post by fwj01 »

I've rolled my arches, so when mine rubs, it's on a smooth surface so not doing any damage to the tyres.

Add some camber and get the arches rolled. Job done :thumb:
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Jonesy
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Post by Jonesy »

Camber plates or spring for coilies?
Luke Jones

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fwj01
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  Z3 roadster 2.0

Post by fwj01 »

When you lower it the rears obviously cambers naturally, this is all I've done. I'm seeing how long these tyres last to make up my mind wether to add more camber or not!

But...!! Being this low is a bit unpractical to be honest (I can barely get off my drive!!!) and not for everyone, so it's entierly up to you how to go about it. ''Low'n'slow'' or sporty.... Tough decision!

You can always mill the rears down a few mm??
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Jonesy
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Post by Jonesy »

Yeah its down 45 mill from standard already on lowering springs so have some camber but nowhere near enough to make the offset of m wheels. Would arch flaring be a good way to go or is it more trouble than its worth?
Luke Jones

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fwj01
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  Z3 roadster 2.0

Post by fwj01 »

It worked wonders on mine!! You could do it yourself if you are really careful, mine are a DIY job :oops: (purely because I was determined not to raise it up!!)
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Jonesy
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Post by Jonesy »

so you recon that you need to run abit more stretch? what would you go for next tyre size wise? think i'll run abit more strecth than what you have now and get the arches rolled and flared and all should be good :)
Luke Jones

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fwj01
Joined: Sun 27 Jun, 2010 13:02
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  Z3 roadster 2.0

Post by fwj01 »

Yep, next steps for me are more camber, more stretch and more lows at the rear ;) because you can't really see how low it actually is looking from the back :(

Post some pics as soon as you get everything sorted! ;)
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Jonesy
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Post by Jonesy »

Excellent mind is made up. What would you drop to next seen a few people on about 215's but I'm thinking this would be too low?
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Jonesy
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Post by Jonesy »

Excellent mind is made up. What would you drop to next seen a few people on about 215's but I'm thinking this would be too low?
Luke Jones

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spurs fan in a coupe
Joined: Fri 18 Apr, 2008 19:24
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  Z3 coupe 2.8
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Post by spurs fan in a coupe »

Well I have a 2.8 with Z3M wheels and standard spec tyres fitted.

Car can be seen here

http://www.zroadster.net/forum/viewtopi ... wheels+non

Lots of discussion on the tyres and protrusion.

I have had them on for over a year with no problems once the rear wheel arches were rolled.

Either way enjoy the car.

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If you are thinking of selling the ///M wheels then let me know

Cheers
we expres: " He did hear the bells ringing, but doesnt know where where the clapper hangs".
Jonesy
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Post by Jonesy »

Yours looks cool on them wheels but mine is quite abit lower than yours is which is causing the problems. Want to make them fit if I can as the look is amazing but if I do decide to give them up I'll Let you know.
Luke Jones

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spurs fan in a coupe
Joined: Fri 18 Apr, 2008 19:24
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  Z3 coupe 2.8
Location: woking

Post by spurs fan in a coupe »

Hey Luke,

I have had my Zed lower.... was slammed when I bought it

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Hit every bump and therefore the 15,000 miles I do a year were even more impractical than usual.

Rolling the arches stopped the rubbing on the rear wheel arch..... having said that the 19s I had on for a year ruined the front plastic liners.

They also fouled the lump between N/S/F wheel; and the engine bay.

A low zed really does suit standard size wheel I;'m afraid.

If you do sell thanks for the offer I'm v. interested.
we expres: " He did hear the bells ringing, but doesnt know where where the clapper hangs".
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