Mustang GT 99-04 vs 05-09 painted aluminum wheels?

Discussion in 'Tires and Wheels' started by GT97222, Nov 21, 2020.

  1. Enfield

    Enfield Member

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    Pentalab, do you auto-x or do track days? Neg 1.5 seems like a lot of camber for good tire wear on a street car. With Bullitt springs [slightly lower] and the strut mounts reversed I'm right around neg 1 degree. I assume with just a 3mm spacer you are running oem studs.

    Another option that won't break the bank are the 19x8.5 "wide ten-spoke" rims, Ford #AR3Z-1007-E. Is there a graphic simulator somewhere online that will show those on the 2005-09?
    [​IMG]
    tia, Enfield [always a pleasure to belly up to the virtual bar with Norm]
     
    Last edited: Mar 1, 2021
  2. Pentalab

    Pentalab forum member

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    Nope, no auto-X or track days. Just a street car. ZERO inside wear from the -1.5 deg camber. I'm lowered .5" with Roush front springs. Roush struts are exactly .5" shorter than oem. ( from bottom of strut to spring perch). One strut sheared right off after hitting one too many bumps on our local shit roads. Roush front struts are rock hard, too hard, imo. I can't get the front end to deflect 1 mm, when pushing down on either wheel well, from above, as hard as I can, or sitting on it with my 150 lbs. So went back to oem front struts, so now I'm only lowered 1/2". (eng is also lowered 1/4" with steeda eng mounts).

    Ford spec sez anything from -.4 deg to as much as -1.4 degs is acceptable..and within spec. And the left front does not have to match the right front either. I had -.4 degs on left front..and -1.2 degs on right front with oem strut mounts. Got pissed off, and in went the steeda HD strut mounts, which allow for +/- 1deg of camber. That's +/- 1deg of whatever you have to start with. At least with the adjustable steeda HD struts, I can tweak the camber so both fronts are identical.

    Yes, I'm using oem wheel studs front and back. BTW, the oem front studs are longer than the oem rear studs. Same deal if longer studs are used, fronts are slightly longer.

    I would not go any more than - 1.5 degs on a street car, it's not required. At least I have the option to dial in any camber I want. My main concern was to at least make em exactly the same. The steeda struts have a far better bearing vs oem....and are adjustable camber. I don't require caster adjustment, the car has plenty of caster as is. If you even heavier duty bearings on an adjustable strut mount, the Vorshlag strut mount is as about as HD as it gets, with an even bigger bearing, and also adjustable camber and caster adjustments.
     
  3. ShelbySteve

    ShelbySteve Member

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    Is there a reason you’re wanting to stay with wheels that narrow? I see that you’re trying to stay within a price range, but there’s a wide range of wheel widths and offsets that will fit these cars fine. I’m running 20x 9.5 45mm front and 20x11 50mm rear and I’m lowered 1.5” front and rear with no issues. 255 front and 285 rear(I’ll be going wider on my next set as I was worried about poke).
     
  4. Norm Peterson

    Norm Peterson corner barstool sitter

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    As long as your toe is in a good place, -1.5° camber is do-able on a car that only sees street driving. That's easily enough camber to see, which is probably what makes it harder for many people to accept.

    That said, -1.5° camber probably is too much for a car that's never driven any harder than "moderately", or only a little bit harder than how your average Camry or Fusion driver drives those cars.

    At least for some years of S197, I think the factory preferred camber setting was -0.75°, with a ±0.75° tolerance. That would put -1.5° at "the very edge of the green" on an alignment rack.


    Norm
     
  5. Norm Peterson

    Norm Peterson corner barstool sitter

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    Regarding tire sizes appropriate for a 9" wide wheel . . . Ford has been putting 235/50 tires on 8.5" wide wheels (early S197 years), and later on 8" wide wheels.

    With that as a basis, a 9" wide wheel should be running tires no wider than 255/45. Otherwise, handling feel and steering precision are likely to end up being not as good as stock. IOW, you'd likely be spending money on a mod that at least in some respects could be a downgrade.


    Norm
     
  6. Enfield

    Enfield Member

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    SS, other than budget concerns, taller rims require shorter sidewalls. Below a 40 profile I suspect ride comfort will suffer too much; the car is already plenty firm with Bullitt springs, street Koni's and urethane bushings at front rear and rear top. Also has J&M rear lca's, but I don't know whether they actually firm up the ride. Ideally, I'd like to run something like 245/45 or 255/45 front and 275/40 rear. On 18" rims, that would run the engine just over 2500 rpm at 80 with its 3.73's. If I kept the 235/55 x 17 fronts, a 255/50 rear would keep stagger to an absolute minimum. I hesitate to go more than one profile size lower at the rear.
    Convertibles have more rear weight, so I would hope the handling would come out pretty close to neutral with the slightly wider rear tires. Fine tuning could be done with different sway bar thickness; at least that's the plan. Right now with taller and much wider rear tires it plows pretty badly, and the ABS kicks in at the front under any kind of heavy braking.
     
    ShelbySteve likes this.
  7. Juice

    Juice forum member

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    Im at -1.8* camber. (Max adjustment w/Steeda CC plates) Zero tire wear issues AND works on track.
    Toe set by string, camber measured by Android app.
     
    Pentalab likes this.
  8. Norm Peterson

    Norm Peterson corner barstool sitter

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    I think ride comfort is tied more to actual sidewall height and to a lesser extent where your wheel width falls in the range from minimum-recommended to maximum-recommended.

    There's "calculated sidewall height", which you can estimate from section width times profile ratio, and there's "visual sidewall height", which is about 0.6" less (the 0.6" is hiding behind the wheel flanges). 4" calculated or about 3.3" visual is about as short as you should go for unrestricted/minimally restricted street driving. Under 3" visual and you become a prime candidate for pinch-flats and dinged wheels.


    Work to keep tire outside diameters close and that'll happen except in cases where there is an extreme amount of tire size stagger.


    Norm
     
    Enfield likes this.
  9. Enfield

    Enfield Member

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    So, 225/45 and 255/40 are at the comfort minimum. For 35 profile, you'd have to go 295 section width to get that 4" sidewall height. That requires a 10.5" rim width: not happening here! My Volvo has 225/45's and it's dinged several rims - so many that I always keep a spare straight rim or two handy.
     
  10. Pentalab

    Pentalab forum member

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    There is NO camber adjustment on the S197, in oem format, which is a pita. The spec sez anything between -.4 deg and -1.4 deg is good enough. And the 2 x sides don't have to match, they just have to fall within their guidelines.

    Currently mine is -1.5 degs on both sides...and a very slight toe out. I think I would like it better with zero toe, but as is, it handles well.
     
  11. Pentalab

    Pentalab forum member

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    For fronts, I tried 255-45-18 on 9" wide rims on the front, worked superb...(stretched 1/2") Then tried 275-40-18 on the same 18x9 rims..and it sucked. Steering felt un-responsive..and 'rubbery', total fubar. Then changed to 275-40-18 on a wider 18 x 10 rim...and that worked really good....( stretched 1/2"). Currently I'm using a 285-40-18 on 18 x 10 rims..and that too works good, not quite as good as the 275-40-18 on the same 18 x 10 rim. IMO, the 285-40-18 really should be on a 18 x 10.5 rim...( and stretched 1/2"). In winter I use a 235-50-18 on a 18 x 8 rim...( stretched 1/2").

    Ideally, you want the fronts to be at least their measuring width as a minimum..and ideally 1/2" wider. With rims that are less than the measuring width, the steering/ handling is degraded, you won't like it.

    The rears are more forgiving.
     
    Enfield likes this.
  12. Norm Peterson

    Norm Peterson corner barstool sitter

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    You must be reading a different set of specs than I've seen. Not that 0.1° makes all that much difference.

    Yes, there is a spec for cross-camber (the difference between right and left side cambers). IIRC, that's 0.75°, which is sloppy enough to catch by eyeball if you know what to look for.


    I am assuming that you either have the ability to adjust camber or you've lowered your car far enough to push the cambers all the way to -1.5°. And there's the rare but possible chance that your car was built with that much negative camber (heh . . . my car was actually built and released with about -1.7°, so I know it happens).


    Norm
     
    Last edited: Mar 3, 2021
  13. Norm Peterson

    Norm Peterson corner barstool sitter

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    I'm not a bit surprised by your observations.

    What's interesting is that Ford was entirely comfortable running max-recommended wheel widths for both the 235/50 and 255/45 tires, at least on the earlier S197s. In 2008, the 235/50's went on 8.5" wide wheels and the GT500 ran the 255/45 front tires on 9.5" wide wheels.


    Norm
     
  14. Norm Peterson

    Norm Peterson corner barstool sitter

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    It's a rough guideline at best, so YMMV. You'd probably have a lot less trouble with the Volvo if you could run one size wider (235/45) and were OK with a softer ride - and softer cornering response/overall behavior.

    I've been OK with 285/35's on 11", which is just under 4" sidewall at 3.9-something (295/35 wasn't available in MPSS at the time).


    Norm
     
  15. Enfield

    Enfield Member

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    A good deal on Gt500 rims: https://www.lethalperformance.com/ford-performance-07-09-shelby-gt500-wheel.html . Would these work OK with 245/45 and 275/40? There's also a good deal on General tires right now, but they don't offer 255/45 and 285/40. On my last sporty car [e46 330i Sport], I ran Continental [oem], General, Kumho, and Michelin. Pilot Sport was the best, but they wore out very fast [less than 20k]; on that car the rears went first due to lots of negative camber on the drive wheels. Rear wear seems to be a trend with Mustangs, too. Based on Pentalab's comments, a slightly narrower front [relative to rim width] should be a good choice: 245/45 on a 9.5" rim. Proper [neutral] stagger then dictates 275/40 at the rear.

    On another note, I've been playing with slightly different toe settings as I zero in the spoke. The sweet spot seems to be 1/16" toed in. Nice turn-in, decent tracking, and predicted good wear.

    Comments welcomed.
     
  16. Norm Peterson

    Norm Peterson corner barstool sitter

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    9.5" wide wheels are just outside Tire & Rim Association guidelines for 245/45 tires (wheel diameter is basically irrelevant). You should be able to physically mount them up, and they'll probably be OK as the T&RA guidelines can't match 10mm tire size increments to 1/2" wheel width increments (12.7 mm) exactly for all sizes. But with 245-wide tires on 9.5" wide wheels you can count on the wheel flange poking out past the tire sidewall.


    Norm
     
  17. ShelbySteve

    ShelbySteve Member

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    There was 255/45 front and 285/45 rear on my gt500 wheels when I bought my car. To me it drove fine (normal street driving) but there was a good bit of sidewall bulge on the rear.
     
  18. Norm Peterson

    Norm Peterson corner barstool sitter

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    ^^^ should have been 285/40-18s on the rear. Minor point, really.

    More than likely, Ford wasn't ready to specify different wheels at that point in time, and it conveniently worked out for them that 9.5" is max-recommended for the 255/45 and min-recommended for the 285/40.


    I vaguely remember hearing somewhere that Ford may have originally tried to maintain a 'square' wheel and tire setup for the early-years S197 GT500, but couldn't get it to meet some corporate standard and ended up having to go with more rear tire.


    Norm
     
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  19. ShelbySteve

    ShelbySteve Member

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    Very well may have been. I know when I changed the wheels/tires last December the tires were stamped with the date of being 12 years old lol
     
  20. Enfield

    Enfield Member

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    Bearing in mind that my priorities include budget, proper stagger, and the right combination for ride/handling/safety, I've come up with three options:

    1. Buy 2 used and 2 new of the 2007 GT500 rims, total cost about $650 plus TPMS, etc. At 9.5 width, fronts would need to be at least 255, and if rears were wider they would need to be 285. Not many tires in that width; there's a pair of 40's [GY F1] on eBay now for $194 each. 255/45's would give good stagger and cost about two hundred each. Total outlay for wheels and tires: $1438.

    2. Keep my AM rear Bullitts 18 x 10 and get a pair of Vision 142's in 18 x 8.5 for the front. Cost $365. Add General RS summer UHP's in 245/45 and 275/40 for $570. Total cost: $935. Potential downside is the 32mm offset of the Visions at the front; is 32 on an 8.5" rim going to give too much poke or create other problems? Here's my rear with ancient 295/45 Nittos:
    122810101_1783878441771934_6671541698538436429_o.jpg ...and the Vision 142. Pretty good match, except for what appears to be an 83mm bore size. Are there spacers to make this hub-centric? upload_2021-3-9_10-50-4.png
    3. Get a set of FR500 rims with Nitto 555's in fairly good shape for $850 off FB. Downsides here include F/R offset of 24/27 for possibly even more poke, and with rear 285/40 x 17 my rpm would be almost 2000 at 60, over 2600 at 80. Here's the poke on seller's car: 120757752_717766052416735_4262540954956763210_n.jpg

    Comments? Suggestions?
     
    Last edited: Mar 9, 2021
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