wheels

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#2
Go to Tire Rack web site (one of this site's sponsors) and look for wheels and tires for your car. I just went through this and found that 215/40 17 tires would fit on my 91 325i convertible. This was confirmed by other members who have them on their cars. These will likely work on your car as well.

Got the wheels and the tires are on order. Can't wait to get them on and feel the difference.

Steve
 
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#3
the tirerack doesnt have my exact model does that matter? and thanks for the last post. they recommend a 205/45 is that a smaller size or soemthing? and they dont have the kinda wheels im looking for.
 
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#4
I was just suggesting them for comparison only. If you look up your original tire there and look at the specs you'll find the diameter and the width at the widest point. You can compare these to the tires you want and make a good guess as to what will fit. I'm going from a 195/65 14 Michelin MXV4+ to a 215/40 17 Goodyear Eagle F1 GS-D3. They end up being the same diameter and the F1 is only .2 inches wider. That difference is insignificant. The real question is how close the new wheels are to being centered in the same place as the original rims. If they're not I may need spacers. But I think I'll be ok.

I guess the main thing to be concerned about is how wide the rims are (mine are 7.5 inches), the bolt pattern, (your original rims are likely 4x100 - you can find out what that means with a search - if your new rims are 5 bolt pattern you'll need an adapter) and the offset (where the rim is centered). You can get tires to fit if the rims are right.

Good luck!

Steve
 

rjp325i

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#6
I'm using Borbet wheels with a 38mm offset. My preference is 205-50-16 and Yokahama AVS ES100s. Look into these. The reviews are great. I spoke with Mike Miller author of the Tech Talk columns in both the Bimmer magazine and the Roundel magazine and he recommends them highly. As soon as my Michelins wear down I'm going to install them. I think the 16s are more comfortable for the street especially if you've done suspension upgrades and have a high performance tire but its your choice. Stock E30 M3 wheels are 205-55-15 and 5 bolt but too expensive to adapt. Buy a 4x100 wheel. Don't play around with adapters.
 

rjp325i

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#8
I don't know the max & min but I believe stock is 30mm. The Tire Rack service reps should be able to help with the wheel sizes that would fit or try using one of the fitment guides on-line if you see a wheel you like. Like I said earlier I'm using a 38 mm offset. These work fine. Spacer plates are available from H&R and others if you use a very wide tire and rubbing is a problem. If you are not going to track the car 205s or 215s are more than adequate for the street and will minimize hydroplaning in the wet.
 
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#12
bichmgnt (love that name btw [;)] ...lol)

Anywho...hopefully I can answer your question without too much confusion [:D]

To start off...whee need to know the difference between positive and negative offset. To understand this...please switch to thinking mode [;)]. If you are facing the wheel from the front (looking at the tread not the rim face) draw an imaginary line down the center of the wheel.

Now...if the portion that mounts to the hub/the car is towards the outside/away from the car, this is called positive offset. If the mounting area is at the center of the wheel there is no offset. Anything that is closer to the car is considered negative offset.

Now...this means that if your wheels are the stock 6x14 wheels and have the 35mm positive offset...you're wheels will be in the normal place and will work just fine.

If the wheels are the same...6x14 and have a 25mm positive offset, since the mounting area is closer to the car...the wheel will mount further away from the car...to a point, the may even stick out of the side of the fender well.

If the same 6x14 wheel has a 45mm positive offset, then the mounting surface is further away from the car...and the wheel will move farther into the wheel well to compensate. At this point is where you run into rubbing problems. Normally, the best way to solve a problem like this is to purchase a set of HUBCENTRIC spacers. I say hubcentric because they hold the wheel in place more effectively than a flat spacer. H&R makes the best ones that I'm aware off. To make this wheel fit properly, you would need a 10mm spacer to compensate for the addition 10mm of positive offset.

So if you take nothing else away from this post...Positive offset brings the wheel closer to the car...Negative offset pushes it away from the car. For the e30 (not IX or M3) anything that is 35mm Positive Offset or less (i.e. +25mm, +10mm, etc) will fit fine...as long as there is room for the tire to clear. If you upgrade to a larger wheel...compensate by decreasing the series of your tire. Stock series is 195/60R14 or 195/65R14. If you go to a 6x17 (example only) rim...try 195/45R17 or 195/40R17.

Please let me know if I need to clarify more
[thumb]
 
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#13
i think what custom said was all good... i'm about to go to bed & i'm tired as hell so i didn't read the whole thing... i just wanted to emphasize one thing....




NEVER USE 5 LUG ADAPTERS!!! [?|] [xx(] [8] [:(!] [mad]

i'll most likely never even let a set of spacers touch my car, nevermind 4 to 5 lug ADAPTERS... [paranoid] (spacers are just too expensive for the proper kind... i'd rather get rims that fit properly & don't put more stress on the hub than what was intended)
 
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Ventura CA
#14
Custom3,

Good explanation. Followed it completely.

I just measured some new rims I got from Lowen (7.5 x 17 BBS RK replicas) and the offset is 40mm. This means my tires will be 5mm closer to the suspension. The tires I'm getting (Goodyear Eagle F-1 GS-D3 215/40 17) are 5mm wider than the 195/65 14 Michelin MXV4+ I'm currently running. Altogether my tires will be about 7.5mm closer to my suspension.

7.5mm ~ 0.3 inches or just over 1/4 inch

That shouldn't be enough to make the tires hit the car, should it? Or should I get 8mm spacers? Turner Motor Sports has 'em for $35/wheel.

Steve
 
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Wgtn-NZ
#15
Hope this clears it up a little.

The wheel will sit 5mm further towards the inside of the guards with the ET40 wheels, But they are also 1.5" wider, if you look at the drawing attached the inside of the wheel will be almost 25mm (1") further in, You'll have to check if you have that much room to move in, full lock steering and the rear trailing arms & shock will be the things to look at.

Glenn
 

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#16
Nice try Glenn, but you forgot to draw the tires on the rims.

Yes the rim is much wider and will be much closer to the suspension than the original rim but at a point much closer to the outer diameter of the original tires. The original tires were also over two inches wider than the original rims somewhere in the middle of the sidewall.

The cross section of the 195/65 14 tires on the 6 in rim is 8.3 inches wide at its widest point and the cross section of the 215/40 17 tires on the 7.5 in rim is 8.5 inches at its widest point. They have the same outer diameter. Going back to your drawing, since you have the centerlines overlapping, if you drew the tires on both rims, the top and bottom would line up (same diameter) and the sides on both tires would extend past the sides of the 7.5 inch rims. The 17 in tires would be 0.1 inches (~2.5mm) wider than the original tires on either side. Add this to the 5mm difference in offset and that's where the 7.5mm or 0.3 inches came from. This is the real distance that the tire is closer to the suspension. While the rim may be much wider than the original, it is wider at a point where the original tires are also much wider than the original rim. This is why you can go to a much wider rim with the larger diameter rims

So back to the original question - will 0.3 be enough to make the wheels rub somewhere? Probably no one knows for sure but I'll be sure to let you know what I find out.

Steve

All tire data taken from the Tire Rack website.
 
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#19
bichmgnt,

I did some background checking on your wheels and what you'll need to make the wheel clear. With a 40mm offset you'll need a 15mm spacer (hubcentric is best) minimum. In addition to this, you'll also need longer stud bolts to go with it (4 per wheel).

Also, FYI I can beat Turner Motorsports price on these and I have a distributor in Hunington Beach...so if you're able to pick them up there, you won't have to pay shipping either.

Just a thought...send me a PM or email if you need further help [thumb]
 
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#20
Can't I just take a couple washers and stick them in there? [;)]

Glenn - I am currently out to sea and won't be back until next week. My tires arrived but I was not able to get them installed before I left.

Jason - Huntington Beach, huh? What days are they open? I may be going by there this Friday but I often drive by there on Sundays. Email or PM me the prices and I'll get back to you if I can. I don't have very good web access out here.

Steve
 
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