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Wheel Widening and Tire Clearance Help


Madlock
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I've decided upon a rear wheel and tire alternative for my2011 GT500 Coupe with SVTPP – if I don't have to modify the vehicle. I want to leave the bump stop, insulation andshock cover intact. My goal issufficient clearance while maintaining the relative outer sidewall position.

 

I've decided upon Continental ExtremeContact DWS 315/35-20on widened OE SVTPP rear wheels. I'veread the terrific SuperSnake thread, but the different wheels and offsets maynot be relevant. The OE F-1 G: 2 has a27.6" diameter. The DWS's diameter is28.7" – not insignificantly larger. I plan to use 275/40-19 for the front – which will help retain the car's relative stance.

 

Though an FR-3 Pack may not provide sufficient suspensionclearance, the SVTPP factory stance seems to be able to accommodate the largerdiameter – without too much added risk of bottoming-out the wheel against the bodyor inner liner.

 

The factory (285/35-20) tire specification has a SectionWidth of 10.7" on a 9.5" (OE) wheel – with the sidewall protruding by .6". The DWS (315/35-20) requires a 10.5"wheel. The specifications on an 11"wheel are a 12.6" Section Width that protrudes by .8" – close enough to notmatter.

 

The key question is whether sufficient clearance exists for a20" wheel to extend inboard another 1.5" from the OE fitment – and whether sufficientclearance also exists for the tire's wider section width. Widened to 11", the tire should require anadditional 1.7" of inboard clearance – to at least another .55" higher to accommodatethe taller diameter.

 

Optimally, sufficient clearance would exist to widen thewheel to 11.4" – which would (at least theoretically) retain the OE outer sidewallposition. But this only furtherincreases the inboard clearance demand.

 

Firstly, are my thinking and presumptions correct?

 

Has anybody widened the OE SVTPP rear wheels? If so, how wide and with what width tire?

 

Is anybody using an11" (or wider) 20" wheel – if so, at what width and offset?

 

I realize I can use spacers to move the wheels outward – butnot without compromising aesthetics, or paint. I'd appreciate any additional available insight or guidance.

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Oh man... Madlock...you're gonna widen the OE rear wheels? I can't get myself to pull that trigger. If I could acquire a second set somehow, then yes... but to crack open the one and only stock pair? You're a braver man than I. As a side note..... the gentleman who widened his SVTPP wheels in the link from the previous post has good taste in colour and seeing those widened wheels on my doppleganger definitely gets my mind chugging about my next mod.

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Oh man... Madlock...you're gonna widen the OE rear wheels? I can't get myself to pull that trigger. If I could acquire a second set somehow, then yes... but to crack open the one and only stock pair? You're a braver man than I.

 

 

 

It's going to be a 2-step process - running 19's on the rear that will eventually move to the front and be paired with the widened 20's.

 

I'm only widening them to 10.5" - I want to LEAVE as much clearance as I can, and from what I measured on both sides of the car, it's as comfortable as I'm willing to be in terms of clearance - I DON'T want to start taking parts off the car. Furthermore, 10.5" will still work fine with the OE tire - if necessary.

 

You can always order a pair from parts - but it's about a $2,200 proposition for the pair. I've tried pursuing a couple of opportunities from other owners, but most were pikers wanting a huge amount of money for beat-up wheels - because they beat them up so badly they don't want them on their car anymore.

 

 

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It's going to be a 2-step process - running 19's on the rear that will eventually move to the front and be paired with the widened 20's.

 

I'm only widening them to 10.5" - I want to LEAVE as much clearance as I can, and from what I measured on both sides of the car, it's as comfortable as I'm willing to be in terms of clearance - I DON'T want to start taking parts off the car. Furthermore, 10.5" will still work fine with the OE tire - if necessary.

 

You can always order a pair from parts - but it's about a $2,200 proposition for the pair. I've tried pursuing a couple of opportunities from other owners, but most were pikers wanting a huge amount of money for beat-up wheels - because they beat them up so badly they don't want them on their car anymore.

 

 

Man this tire situation is frustrating. With the 10.5" OE tire could you fit a 305-315 on there? (edit: Looks like the 315 minimum width is 10.5 inches... hmmm) I think we're attempting to achieve the same goal of keeping mods to the car to a minimum (shock boot, bump stop) while getting the widest stock wheel rim we can. I'm open to the 19s however nobody seems to have attempted widening those yet. The 20s.... are going to take me a few nights of crying in undecided torment to make that decision. In the post about the guy who widened his 20s by 2 inches, he said he had to remove the bump stop and the shock boot touches. Obviously if the 20s cant go that wide without modification the 19s will fare even worse. I'm starting to wonder if this is a futile endeavour. Blasted Ford and their limited options....

Edited by Mulanzo
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Man this tire situation is frustrating. With the 10.5" OE tire could you fit a 305-315 on there? I think we're attempting to achieve the same goal of keeping mods to the car to a minimum (shock boot, bump stop) while getting the widest stock wheel rim we can. I'm open to the 19s however nobody seems to have attempted widening those yet. The 20s.... are going to take me a few nights of crying in undecided torment to make that decision. In the post about the guy who widened his 20s by 2 inches, he said he had to remove the bump stop and the shock boot touches. Obviously if the 20s cant go that wide without modification the 19s will fare even worse. I'm starting to wonder if this is a futile endeavour. Blasted Ford and their limited options....

 

 

Well, not so much Ford as limited tire sizes in decent, road-holding sizes. The only thing I begrudge Ford is choosing a one-option tire on an oddly-sized wheel (9.5").

 

The other thing about going even wider on the wheel is that you can always use spacers to gain clearance, but not without pushing-out the tire beyond the fender and subjecting your paint to all sorts of hell. I've actually done a spreadsheet that calculates the amount of added width, current sidewall placement, and what all the ramifications would be in terms of positioning and so forth.

 

It's not that options don't exist, it's just that they're f*cking dear. I went into this naively thinking any deviation from the OE would be at my own peril - and compromise performance by definition, until I did the math on the specs of the non-SVTPP GT500 and noticed the rear wheel is actually a smaller overall diameter than the front.

 

Since then, I've learned, like many things about the SVTPP, it's a great "canned" set-up - if you never plan to modify a thing. Otherwise, you're likely to spend over again the money you've already dumped into it. Fortunately for Canadians, the Track Pack is relatively cheap. For 2012, SVTPP is now $4K.

 

I actually considered forgoing it, but by the time I bought the wheels - or compromised by going with 19's all around and adding-in the combined 3.73/Torsen differential assembly that's now available, I'm right back where I'm started. The only upside would be a set of 19" pull-offs that I'd have to go through the process of trading or selling for the SVTPP style I want. I might as well have it on the window sticker for resale value purposes. I had meant for my 2011 to be the last car I'd ever buy - until I traded it for a 2012, through which I've already negotiated terms for first crack at this dealer's 2013 allocation (LZ1 competitor).

 

Once I abandoned the size as an absolute - and adopted it as a helpful reference, the options got much better - though my choice of tire remained the same because of the quality of the tire itself. And even though I don't drive my car in bad weather, it gets snap-cold here often enough - for long enough, and the F-1 G: 2's are so bloody awful that I want at LEAST one set of tires that's all-season.

 

I suppose I could open-up my horizons even further by going with different front and rear brands - and plenty of people do it. But the OCD side of my brain just won't let me go that far.

 

I never expected to find such a competent set of all-season performance tires (even P/S AS's are good, but not great), but Continental really seems to have come-up with some true alchemy on the DWS that make them terrific in every respect. I realize my Taurus SHO is no Shelby, but they keep 2+ tons in trim unbelievably well with road manners from finishing school and near-absolute silence.

 

So, for me, it's all about getting the DWS to work - and I have 2 good options, 275/40-19's all around or the staggered setup with 315/35-20's on the rear. I'm particularly eager to learn whether the extra sidewall and aggressive tread will help hookup to make the 275/40-19 hookup even-better than the OE 285's. Hell, even the SuperSnake uses 275's on the rear - albeit summer tires.

 

I'll be sure to post as I go - and I'd appreciate you doing the same. It'd be terrific if, among the community, a consensus could be reached as to a handful of specific wheel and tire paths to achieve certain goals that could leverage our collective learning curve - while providing clear answers as to clearance potential and so forth. For Christ's sake, enough people do enough kinky things to enough S197's that SOMEBODY must know what the maximums are.

 

After all, the only MEANINGFUL data is how much inboard clearance from the wheel mount point exists at given diameters. From there, you can plug-in any wheel and tire dimension and know exactly where you stand - even relative to the OE fitment. Unfortunately, the one thing I haven't been able to figure-out is a way to do this cheaply.

 

So far, I'm into the project for the following:

 

$3,500 - SVTPP

 

$1,500 - 4 x 19" x 10" FR Look-alikes

 

$1,000 - 4 x 275/40-19 Conti DWS

$500 - Widening

$500 - 2 x 315/35-20 Conti DWS

 

At least I'll have a pair of spare wheels and tires (if I ever want/need them).

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Well, not so much Ford as limited tire sizes in decent, road-holding sizes. The only thing I begrudge Ford is choosing a one-option tire on an oddly-sized wheel (9.5").

 

The other thing about going even wider on the wheel is that you can always use spacers to gain clearance, but not without pushing-out the tire beyond the fender and subjecting your paint to all sorts of hell. I've actually done a spreadsheet that calculates the amount of added width, current sidewall placement, and what all the ramifications would be in terms of positioning and so forth.

 

It's not that options don't exist, it's just that they're f*cking dear. I went into this naively thinking any deviation from the OE would be at my own peril - and compromise performance by definition, until I did the math on the specs of the non-SVTPP GT500 and noticed the rear wheel is actually a smaller overall diameter than the front.

 

Since then, I've learned, like many things about the SVTPP, it's a great "canned" set-up - if you never plan to modify a thing. Otherwise, you're likely to spend over again the money you've already dumped into it. Fortunately for Canadians, the Track Pack is relatively cheap. For 2012, SVTPP is now $4K.

 

I actually considered forgoing it, but by the time I bought the wheels - or compromised by going with 19's all around and adding-in the combined 3.73/Torsen differential assembly that's now available, I'm right back where I'm started. The only upside would be a set of 19" pull-offs that I'd have to go through the process of trading or selling for the SVTPP style I want. I might as well have it on the window sticker for resale value purposes. I had meant for my 2011 to be the last car I'd ever buy - until I traded it for a 2012, through which I've already negotiated terms for first crack at this dealer's 2013 allocation (LZ1 competitor).

 

Once I abandoned the size as an absolute - and adopted it as a helpful reference, the options got much better - though my choice of tire remained the same because of the quality of the tire itself. And even though I don't drive my car in bad weather, it gets snap-cold here often enough - for long enough, and the F-1 G: 2's are so bloody awful that I want at LEAST one set of tires that's all-season.

 

I suppose I could open-up my horizons even further by going with different front and rear brands - and plenty of people do it. But the OCD side of my brain just won't let me go that far.

 

I never expected to find such a competent set of all-season performance tires (even P/S AS's are good, but not great), but Continental really seems to have come-up with some true alchemy on the DWS that make them terrific in every respect. I realize my Taurus SHO is no Shelby, but they keep 2+ tons in trim unbelievably well with road manners from finishing school and near-absolute silence.

 

So, for me, it's all about getting the DWS to work - and I have 2 good options, 275/40-19's all around or the staggered setup with 315/35-20's on the rear. I'm particularly eager to learn whether the extra sidewall and aggressive tread will help hookup to make the 275/40-19 hookup even-better than the OE 285's. Hell, even the SuperSnake uses 275's on the rear - albeit summer tires.

 

I'll be sure to post as I go - and I'd appreciate you doing the same. It'd be terrific if, among the community, a consensus could be reached as to a handful of specific wheel and tire paths to achieve certain goals that could leverage our collective learning curve - while providing clear answers as to clearance potential and so forth. For Christ's sake, enough people do enough kinky things to enough S197's that SOMEBODY must know what the maximums are.

 

After all, the only MEANINGFUL data is how much inboard clearance from the wheel mount point exists at given diameters. From there, you can plug-in any wheel and tire dimension and know exactly where you stand - even relative to the OE fitment. Unfortunately, the one thing I haven't been able to figure-out is a way to do this cheaply.

 

So far, I'm into the project for the following:

 

$3,500 - SVTPP

 

$1,500 - 4 x 19" x 10" FR Look-alikes

 

$1,000 - 4 x 275/40-19 Conti DWS

$500 - Widening

$500 - 2 x 315/35-20 Conti DWS

 

At least I'll have a pair of spare wheels and tires (if I ever want/need them).

 

 

** VERY ** interesting thread.

 

I've been toying with a very similar idea except:

 

$800 - 2 x 19" x 10" FR Look-alikes (for the rear)

$500 - Widening to 11.25"

$665 - 2 x 335/30ZR19 Nitto NT05

$500 - 2x some NT05s for the front too

$0 - Moving the shock spacers like Justin (VMP) did.

$0 - Cutting the shock dust cover if necessary.

$? - Fabbing up some bump stop relocators.

 

If I thought I could get away with it without getting out the plasma cutter, there are some more nice choices of shoes in the 345 width.

 

Like you, I was thinking of a Fays2 variant Watts (although it's temping to start down the Griggs road of 'rip and replace' all that hardware I paid extra for on the SVT/PP :finger:). I have a Saleen Watts on my '07 GT and LOVE it.

 

I would like to see your spreadsheet if/when you are of a mind to share. Let's keep this conversation going!

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I thought I might try another tack after having a bit of (what I was certain was) a brainstorm.

 

Surely, among the myriad SuperSnake conversions which includes wheels and tires, at least one must exist from an owner whose donor vehicle included the SVTPP.

 

For the $2K cost of the kit, I could have a full set of second wheels, tires and all manner of backup accoutrement that I could either keep for spares or part-out on eBay to offset the net cost. All I needed Shelby to do was confirm the kit it would send me indeed came from a vehicle with the SVTPP (not TOO difficult given that SuperSnake conversions from SVTPP also receive a credit due to certain components (like the 3.73 differential) that don't need to be replaced.

 

So, I call Shelby - and was told, not only was there no internal distinction between the kits from different vehicles, they weren't even willing to try to look. Certainly there would be a VIN that could be tracked-back or the kits would be of differing fright volumes or masses, but nope.

 

Unless I'd be willing to pays my money and takes my chances, there'd be nothing further they could or would do - (which seemed to include not even asking around the shop if anybody might have any of the donor information that could somehow be cross-referenced).

 

I applaud Shelby being in such an "I dunno - take it or leave it" position.

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  • 4 weeks later...

This thread has gotten me to thinking. Has anyone tried to contact the manufacturer of the OEM wheel or a third party wheel manufacturer about the ideea of making a wider wheel in the OEM style? Perhaps something 11.5 inches wide that evening apportioned the additional width so that the bolt pattern was slightly more recessed (and thuse the rim comes out more)? It seems like there are a lot of people looking for wheel solutions and there is not much readily available. :banghead:

 

Just trying to think outside the box ....

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  • 5 months later...

Got my SVT pp rims back from weld craft went with widening to 10.75. Had Nitto NT05R 315/35/20 mounted ordered 25mm adaptors from Lethal performance. They wouldn't be delivered until Tuesday so I figured I'd see how close they fit. They fit perfectly no rubbing anywhere. I first drove around slowly them took them off checked both sides no rubbing. Then went out and tested launching first gear spins a bit but controlled straight no side by side action second gear no spin. If you dump the clutch they spin of coarse. This was on a 45 deg day on blacktop full tank of gas half 100 octane the rest 93. Since my car is all stock I figure this is the most hp I've got. So far so good. Hopefully Lethal Performance will allow me to return the adaptors. Now I'll need pulleys and tune.

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Got my SVT pp rims back from weld craft went with widening to 10.75. Had Nitto NT05R 315/35/20 mounted ordered 25mm adaptors from Lethal performance. They wouldn't be delivered until Tuesday so I figured I'd see how close they fit. They fit perfectly no rubbing anywhere. I first drove around slowly them took them off checked both sides no rubbing. Then went out and tested launching first gear spins a bit but controlled straight no side by side action second gear no spin. If you dump the clutch they spin of coarse. This was on a 45 deg day on blacktop full tank of gas half 100 octane the rest 93. Since my car is all stock I figure this is the most hp I've got. So far so good. Hopefully Lethal Performance will allow me to return the adaptors. Now I'll need pulleys and tune.

 

Pictures please!!!! How long did Weld Craft take to return the rims?

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