ptrhahn

iTrader: (9)

Jim,
Here are measurements given to me by a friend, who bought Brad Barbers old 17x10.5, and 17x11" wheels. They fit his rear w/ trailing arms, and light fender roll... here are his interior measurements including those to the rim and those to the 275/40/17 hoosier that's on it:

Ok here ya go (measurements on the backside): Rear rim

7 7/8" mounting surface to the outer tire
7 11/16" mounting surface to rim

dclin

iTrader: (4)

They say they'll do custom widths - no idea on how much it would add though. GB?

dclin

iTrader: (4)

Thought this might interest you:

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2427223082

Nice closeup shots of how the 245/35/19 and 285/30/19 SO3's look mounted on 19X9 and 19X10. Sidewall looks ok. I had saved these pics to my computer a few weeks back while scouring for info, and found the auction relisted.

I ended up ordering 245/30/19 and 265/30/19 in Dunlop SP 9000s today. I figure I might as well be the guinea pig hehe, as far as how those 245/30s ride. The Pirelli Nero's were not in stock in 275/30/19s either (for the 255/30/19 and 275/30/19 combo I was considering), so that was a factor as well.

If the 245/30's are unbearable, I'll just move the 265/30 to the front, and put 275/30 or 285/30 in the rear. When it comes time to replace, I'll try the Neros, which will hopefully be instock at that time.

Other possible combinations I was considering included 235/35/19 and 265/30/19, 255/30/19 and 275/30/19, 255/30/19 and 265/30/19, 265/30/19 and 275/30/19, and, 265/30/19 and 285/30/19.

As far as my thoughts on tire size selection, my biggest concern is the overall diameter of the front tires. My experience is that too tall diameter of a front tire (coupled with other factors, such as how much lowered, etc) causes fender lip contact under specific situations - specifically where the suspension is under compression with the tires turned, like when entering an inclined driveway too fast. I've set a maximum of around 25.4"ish diameter up front for my selection.

A large deviation from the stock diameter may also effect the ABS function. The only advice I've found so far is to keep the difference less then 6%. They did not have anything to back this up though, so I set my limits to around 3% difference. Since I believe you've removed your ABS, this not really a concern to you.

Looking at theoritical diameters of tires:

225/35/19 = 25.2"
235/35/19 = 25.5"
245/35/19 = 25.8"
245/30/19 = 24.8" <- available only in Dunlop SP9000 and Pirelli PZero Rosso at the moment
255/30/19 = 25" <- available only in Pirelli PZero Rosso and Nero at the moment
265/30/19 = 25.3"
275/30/19 = 25.5"
285/30/19 = 25.7"

These are pretty much the range of sizes that one can use for 19" wheels for *most* FDs - V8 converted FDs not included (at least for the rear) . These are theoritical diameters of course, and actual diameters may vary. Ex. 285/30/19s range from 25.7" to 26" according to the specs listed at Tirerack.

Other considerations include:

- selecting a staggered set that is close in overall diameter, front to rear. A severe difference front to rear may also affect the ABS function as well.
- keeping the widths as close as possible to help maintain handling balance
- staying with a size that maximizes air volume. Greater air volume may result in a better ride - more air is more compressible then less.
- wide enough tire that doesnot result in an overly-stretched look. A little is ok with me. Besides aesthitics, there is also the issue of how it will effect the dynamics of the tire, as Sleep and others have brought up before.

Going with 19X9 up front allows a greater range of tires, specifically allowing the possiblity of mounting 265/30/19s. Other sizes that should work well with a 9" width include 255/30, 245/30, and possibly 235/35 (a 235/35 has an approved rim width of 8"- 9.5", though likely noticeably stretched in the 9"). My concern with 245/35/19 is that is a bit taller then stock, but maybe not lowering the car may help avoid fender lip contact.

265/30/19 has an actual diameter of 25.2" in Continental Contact2's, 25.3" in Yokohama AVS Sports, and 25.4" Toyo T1S. The Dunlop SP9000 and Pirelli PZero Neros do not have specs listed (yet), though should be somewhere in this range. In either case, it's still somewhat close to stock diameter of 24.8".

265/30/19 will have a greater air volume (for a theoritically bettery ride), at least compared to other side of the range, such as 225/35/19. 245/35/19 is taller then a 265/30/10 of course, so might mave a similar volume.

265/30/19 is naturally wider as well (again, compared to the other side of the spectrum), and will not hurt handling balance as much as a severely staggard selection), when paired with a 275/30 or 285/30. While it's possible to tune understeer out of course, I figure it's better to avoid the situation as much as possible.

The same thoughts can be applied to 255/30/19 (with a correspondingly narrower rear) as well, though only available in Pirelli PZero Rossos and Neros at the moment. The Pirelli Rossos and Neros appear to run a bit on the taller side. As I said earlier, 255/30/19 has a theoritical overall diameter of 25", but the Pirellis actually measure 25.3" according to Tirerack.

In the end though, I choose to try out the 245/30/19s front and 265/30/19 rear in Dunlop SP9000s - more out of curiosity of the extreme profile the 245/30's have then anything else. General concensus is that the SP9000s ride on the softer side, but we'll see. If I don't like them, I can always swap out like I mentioned earlier. I decided against 275/30/19 in the rear due to the larger difference in diameters of the front compared to the rear.

In retrospect, I should have had some custom 19X9.5" wheels made for all four corners, and run 265/30/19 all around. Maybe my next set.

Anyways, that's just a bit of what I was thinking of. Or maybe I'm just thinking too much.

dclin

iTrader: (4)

Added pics of rough measurments of the clearance of the rim edge and the sway bar link and the stock trailing arm. Keep in mind that these measurements were taken with the rear end in the air. Don't have the tires yet, so did not take any measurements with the suspension settled.

http://www.imagestation.com/album/?id=4289403857

Pretty sure the sway bar link stays in the same place (in relation to the rim edge) thu-out suspension movement though. I remember that there is a slight lateral movement of the trailing arm, though not much IIRC.

The sway bar linkage sits just below the edge of the rim, with approximately 15mm of lateral clearance (19X10 +45, 10-15/16 overall width). Sorry, could not get my digital caliper in there, but it was about one of my figure widths.

The stock trailing arm has approximately 14mm of clearance to the same wheel. (Again, with the car up in the air)
Sorry for the blurry images. Hope that helps.

jimlab

Thanks for taking the time to take and photograph the measurements, Daniel. Those are nicely polished suspension pieces you've got...

I still have my ABS and plan to keep it. I believe that the discrepancy of 6% that you mentioned above is from front to rear, not in variation from stock. The ABS system doesn't care how big your wheels and tires are, it just cares about what the rear wheels are doing in relation to the front.

At any rate, I've never heard of any limitation on wheel size, since people use widely varying heights without problems. I measured my front and rear tires at 25.5", or about 0.5-0.6" over stock. By comparison, the P275/40-17s that most people run are around that tall, and Nitto P275 drag radials are 25.9" tall, by my measurement of my own, yet I've never heard any complaints. I'm not looking for a slammed/tucked look, just a nice even gap at the top comparable to the front and back as far as the wheel well is concerned.

Also thanks for the link to the M3 with the same S03 sizes I have. I think they look a little stretched, but not nearly as bad as the tires shown in the Z3 pictures.

Manny, would you pull the 19" wheels off a Saleen S7 if you were given one? Just curious.

My cousin is good friends with both Boyd Sr. and Boyd Jr., so he'll find out if half-sizes are an option. I can also look into group purchase pricing if enough people are interested. I'm not sure that they'll discount the price any, but it's worth a shot. Also, the weights given are the same for each wheel type, I've noticed, and obviously the ones with less material should weigh less. I think the weights given on the site are just ballpark. I'll see if I can find out more about that, also.

SleepR1

nope...hope half sizes are available. I'm told they are not...

dclin

iTrader: (4)

Honestly, if you have contacted me before I installed them, I probably could have been talked into sending them back to you. FWIW though, I've experienced the pain (in the wallet) of changing my mind too many times as well. Thanks again for the really nice suspension pieces.

Yes, i've never really seen anything conclusive about the limits for the ABS - but playing it safe and keeping the diameters the same as much as possible. I wish there was a 265/30/19 and 285/25/19 combo available (to keep diameters the same, front to rear), put the latter size is not made by anyone.

Only real concern is how it effects the speedometer/odometer reading, and the final gearing as well. If the diameter is close enough to stock, should be no problem if off a few percentage I'm guessing. Then again, with all the custom work you are doing, it was a non-issue anyways.

That's interesting that your measurements are slightly smaller then Tirerack's numbers - this might show that the figures that Tirerack publishes should be taken with a grain of salt, and may open up more possiblities of size selection (at least for me, based on my criteria).

Tirerack did not ship my Dunlops until today, but I'll measure them when they come in.

jimlab

Daniel, did you get the tires and wheels mounted yet? I'm interested to see how they look on the car and see what clearance looks like with tires (inside and outside).