Picked Up A REAL KR Hood!!

[Robert M]

The 18" KR rims are UGLY as SIN compared the the 20" Alcoa rims. Ford should of stuck with the KR Protypes 20"'s.

The problem with the 18's, they look too "production". The 20's have that "prototype/SEMA look". 18's are common place on many cars, tall side walls, very production.

People who excercise a KR on a road course are not going to be using the Alcoas, so the handling issue with 18's vs. 20's is a non-issue. These production wheels would not be used on the car in competition anyway. I think there are other factors that came into play when the "18's" choice was made for the production KR. Handling might have been one consideration, by I think there were more things that came into play as it relates to the final product.

I don't think the KR looks "bad" with the 18's, I look at two KR's side by side in a local Ford dealers showroom two weeks ago. They just look more "production".

I have been attempting to compare sidewall height on some other performance cars like the Corvette. I noticed that their sidewall is short, kind-of like the 20's look, but on a 19. Because the Corvette has a shorter sidewall, similar to what is found on the 20" Alcoa wheel with 20" tire, does the Corvette also suffer from poor handling as has been claimed by some who say the short side wall 20's don't handle well? It seems from what I have witnessed in automotive history, the better handling cars have less and less side wall, is this not true? :shrug:


R

 

[Ry_Trapp0]

i dont think anyone has said that the shorter sidewall makes the car handle worse(infact, that goes against all rational and conventional thought), rather the car may handle better with the shorter tire of the 18" wheel. also keep in mind that the sidewall on the KR is a little thicker for ride quality too. the KR, while being the track version of the GT500, is still a full interior street car.

another thing to keep in mind about rim size is that they are usually only as big as neccesary to fit the brakes behind them. the ZR1 for instance has 20" wheels to fit the 15" front discs, while the 2000 cobra R had 18" wheels to fit the 13" brakes(although i believe the inside of the wheel may be tighter than other 18" wheels, dont quote me though).

 

[Robert M]

i dont think anyone has said that the shorter sidewall makes the car handle worse(infact, that goes against all rational and conventional thought), rather the car may handle better with the shorter tire of the 18" wheel. also keep in mind that the sidewall on the KR is a little thicker for ride quality too. the KR, while being the track version of the GT500, is still a full interior street car.

another thing to keep in mind about rim size is that they are usually only as big as neccesary to fit the brakes behind them. the ZR1 for instance has 20" wheels to fit the 15" front discs, while the 2000 cobra R had 18" wheels to fit the 13" brakes(although i believe the inside of the wheel may be tighter than other 18" wheels, dont quote me though).

Then I am confused even more when comparing the correct KR original 18" Goodyear F1's front and rear, to the Super Snake 20" Pirelli P Zero's front and rear...............The Super Snake has been condemed, well not condemed, but you and I have read the posts about the 20's and handling.

The Goodyear F1's listed specifically for the GT500KR are 255/45/ZR18 for the front and 285/40/ZR18, both are shown in the specifications to be 27" overall diameter. >>>>27" front and rear.

I then went to the Pirelli specs......

The 255/30/20 P Zero used on the front of the Super Snake is 27.2" overall diameter. I can hardly believe that .2 on the front tires, the ones that have to do most of the gripping into, and through a turn is going to make a huge difference in handling?? .2" on the front?

So now onto the rear. Yes, the rear 275/35/20 P Zero's are larger diameter at 27.7. In this case the rear tires on the Super Snake are .7 (or slightly over 1/2" taller) than the GT500KR 27" tire diameter.<<Is this 1/2+ diameter larger going to throw the Super Snake under the bus when it comes to handling? On the rear especially?

To me it appears that other than the .7 on the rear, in reality these two cars are very close in tire overall diameter, and the Super Snake has a much shorter sidewall with its 20's, which would lead me to believe that "reason" would say that the shorter sidewall, as you have mentioned would be the better handling tire/wheel combo when the overall diameters are virtually identical......

True? :shrug:

Of course if the Goodyears are superior to the Pirelli''s or vise-versa that is a consideration, but if these two cars had "like brand tires", 20's vs. 18's in the same sizes mentioned above, which would handle better?<<From a rational/conventional mindset? The shorter sidewall combo?

BTW - I did not realize that these two tire combo's were so close until I looked them up and compared their specs. I "assumed" that the 20's were considerably larger in overall diameter. I was incorrect in my assumption.

R

 

[Ry_Trapp0]

dont forget that the tire weighs less than the wheel too. i believe that an 18" with a taller sidewall but equal sized tire could potentially handle better than a 20" simply because of the weight difference too. unsprung weight is far more important than the overall weight of the car afterall.

 

[Robert M]

dont forget that the tire weighs less than the wheel too. i believe that an 18" with a taller sidewall but equal sized tire could potentially handle better than a 20" simply because of the weight difference too. unsprung weight is far more important than the overall weight of the car afterall.

Since I have my take-off GT500 wheels front and rear, and the removal of the Super Snake 20's front and rear will not be a problem, I will bring each tire/wheel combo to a FedEx near me to verify the weight of each on their scale. I would assume that the 20's weigh more, but I also know that Alcoa prides themselves in a lightweight alloy wheel, at least in the truck world. I do not have a KR set for comparison, but at least that will let the guys who are interested in Alcoa 20's for their GT500, the reality of the weights. Hummm, I wonder if the 255/30/20 tire weighs more, or the 255/45/18?? :shrug:

R

 

[Imatk]

I would be very interested in the weight difference thanks

 

[ViperBlueCobra]

dont forget that the tire weighs less than the wheel too. i believe that an 18" with a taller sidewall but equal sized tire could potentially handle better than a 20" simply because of the weight difference too. unsprung weight is far more important than the overall weight of the car afterall.

I remember this argument. When I started a thread about GT500 KR vs GT500 SS. Everyone was stating how much better the KR would handle and such because of the suspension and 18" tires.

Funny as I think both the GT500 SS and KR have almost identical suspension components/brakes, and the only issue is the tires(or that was the argument). Which to me, isn't an issue. I don't think anyone can argue that the production KR wheels and tires are that much more superior to the Alcoa rims and tire combo. So again states why purchase a KR for 80k plus, when you can build a SS for same price have a beast of a car?

 

[Blaine]

I remember this argument. When I started a thread about GT500 KR vs GT500 SS. Everyone was stating how much better the KR would handle and such because of the suspension and 18" tires.

Funny as I think both the GT500 SS and KR have almost identical suspension components/brakes, and the only issue is the tires(or that was the argument). Which to me, isn't an issue. I don't think anyone can argue that the production KR wheels and tires are that much more superior to the Alcoa rims and tire combo. So again states why purchase a KR for 80k plus, when you can build a SS for same price have a beast of a car?

20" SS wheels are for LOOKS. If you want performance you stick with the 18"'s.

 

[ViperBlueCobra]

20" SS wheels are for LOOKS. If you want performance you stick with the 18"'s.

but like a few have said, if you are really going to go "race" this car, high doubted that you would stick with the factory 18" rims or 20" rims for that matter.

 

[Robert M]

I remember this argument. When I started a thread about GT500 KR vs GT500 SS. Everyone was stating how much better the KR would handle and such because of the suspension and 18" tires.

Funny as I think both the GT500 SS and KR have almost identical suspension components/brakes, and the only issue is the tires(or that was the argument). Which to me, isn't an issue. I don't think anyone can argue that the production KR wheels and tires are that much more superior to the Alcoa rims and tire combo. So again states why purchase a KR for 80k plus, when you can build a SS for same price have a beast of a car?

I have seen a few quote the "unsprung weight" multiple times......and then I see that the shorter sidewall quoted as superior to a taller sidewall when it come to handling. So, I would think that these two cars should have offsetting factors built into them to equalize their handling, this is assuming that the 20's, which are very close in overall diameter to the 18's weight more.<<This has not been proven, only guessed. Then we have the full coil over Shelby/Eibach suspension that is optional on the Super Snake.<<Is this a benefit to the handling of a car?? I would guess that a fully adjustable coil over suspension would be better from a handling standpoint? If it is, then we now have an advantage factor in the handling area, or if nothing else, they (the SS and KR) "should" at least be even in the turns, and then the Super Snake leaps away on the straight away waiting for the KR to catch up.<<<This is only common sense also given the wide power level spread? :shrug:


But no, neither of these cars are going to be raced/competed with their Alcoas, 18's or 20's so what does that matter?

R

 

[Ry_Trapp0]

I remember this argument. When I started a thread about GT500 KR vs GT500 SS. Everyone was stating how much better the KR would handle and such because of the suspension and 18" tires.

Funny as I think both the GT500 SS and KR have almost identical suspension components/brakes, and the only issue is the tires(or that was the argument). Which to me, isn't an issue. I don't think anyone can argue that the production KR wheels and tires are that much more superior to the Alcoa rims and tire combo. So again states why purchase a KR for 80k plus, when you can build a SS for same price have a beast of a car?

the KR suspension was actually tuned for the car, as far as i know, the SS stuff is off the shelf. performance increase, yes, optimized, no. and i have little doubt that the 18" rims would easily out perform the 20", all else being as equal as possible.

and i dont see why anyone wouldn't use the 18" rims for an open track session. 2000 cobra R rims get used afterall. i certainly wouldn't have a problem with it, but maybe thats because im different from most here(i would treat it like a car, not a million dollar art piece).

 

[Robert M]

the KR suspension was actually tuned for the car, as far as i know, the SS stuff is off the shelf. performance increase, yes, optimized, no. and i have little doubt that the 18" rims would easily out perform the 20", all else being as equal as possible.

and i dont see why anyone wouldn't use the 18" rims for an open track session. 2000 cobra R rims get used afterall. i certainly wouldn't have a problem with it, but maybe thats because im different from most here(i would treat it like a car, not a million dollar art piece).

I have thought about the 18" vs. 20" further, and I believe you are right. 18's are much better for on-track performance. For one, there is a broad selection of tire options which probably is not the case with 20's, BUT the second very important variable is the actual tire that is selected for the 18" rim. "If" a shorter sidewall is the optimal handling as we have agreed it is, then a 255/45/18 (as provided from the assy. line on the KR front) is not going to be the best choice for handling. A 40 series, maybe something like the 2000 Cobra R's 265/40/18 is going to be the shorter sidewall answer.<<This tire is almost 1" shorter than the KR tire and gets much closer to the sidewall height of the 20" Super Snake, thus optimizing the 18" wheel tire combo for handling. If the KR had an 18" wheel with a shorter sidewall tire that closer matched the SS, then yes, the 18's would outperform the SS 20's, but this is not the way the KR is sold to the public.

The 255/45/18 is the same size and profile as is standard on the regular production GT500, taller sidewall. The one thing that the KR has is the "R" compound which will help in the grip, BUT, then there is that taller sidewall.....:shrug:

If the KR's "R" compound were anything like the 2000 Cobra R 100 tread wear BFG KD's that were original equip. in 2000, they are very sticky. If they are anything higher than 100 treadwear (150, 180, 220, etc.) they only get less sticky. The replacement BFG KD's for the 2KR are 200's, the 100's were original "1 time only tires" unless you were fortunate enough to find a spare set of NOS 100's as I did.

Looking at Tire Rack, the Goodyear F1 Super Cars listed specifically for the GT500KR say 180 treadwear.<<This is better than many performance tires in the "grip" area, but definitly not 100. For comparision purposes the 1995 Cobra R came with 180 treadwear rating. If these Tire Rack replacement F1's are the same tread wear rating as the original assy. line KR tires, they are about the "R" stickyness of the 1995 Cobra R BFG Comp. T/A's. Since the replacement listing does list these F1's specifically as "GT500KR", I would guess that the originals and the replacements are the same, 180. By comparision the Super Snake P Zero's are 220 = not as soft, but then we have a better sidewall height?

I do agree that the KR has a tuned suspension specifically for the KR application. I have also read in a few different places that the KR testing was performed at the Shelby test facility in Las Vegas. The articles also mentioned that Ford Racing, SVT and Shelby personel were on hand for the testing. I can hardly believe that the Shelby guys were not taking notes and gathering data too, especially since the Super Snake was to begin production in the next few months.

BTW - I wonder who makes/provides the KR specific parts? By this I mean, who is the vendor/provider of something like a sway bar for the KR, once the testing was done and the specs. were compiled? Possibly Eibach? WOW, the Super Snake has Eibach too. Could Shelby have suspension parts built for their Super Snake kits by the same vendor who is providing KR parts for the KR build? Sure!! The difference, a Ford part number, and that is not going to add to, or take away from, the handling of the specific car. This is done all the time, especially if there is collaboration on a project, as there was with Shelby and Ford on the KR project. The Super Snake goes through a complete suspension make-over (springs, struts, shocks, sway bars, brakes, etc.) with the Eibach coil overs being an option. Could this be because of data gather during the KR tests? Again, Sure!!

R