Earlier post mentions the GT understeers with the stock setup?? I must have been driving a different GT on the track because mine oversteered ....I went with the REO 50's 275 front and 345 rears..NOW the car understeers...pushes the front..HRE 18 x 9 front , 19 x 13 rears..
Definitive Wheel and Tire Thread with Pics
- Thread starter getbit
- Start date
Fubar
Totally ****** Up
If you are saying that your GT "pushes" through turns, then that is understering. Oversteer is when the back end comes around on you.
HeritageBruce
GT Owner
My GT defiinitely understeered in at the limit steady state cornering with constant throttle w/ the Goodyears. Our car does have a tendancy to power-on oversteer which's when coming out of a corner with a over zealous right foot, no matter what size front tires you have, you WILL experience oversteer in that situation.
Are your 275's rubbing at all in the front?
No rub at all...I actually tried 255's then 265's then 275's....the big meaty 345's push any combination. I even tried the Nitto NT01 - 275's on the front.My experience on the track with the stock tires was oversteer....when pushed the car goes from mild understeer to contollable oversteer. With the big tires on the back, it is harder to judge the right amount of throttle to rotate the car.....I would guess that the stock setup would be 1 - 2 seconds quicker on our 2 .50 mile track. THe hoosiers mounted on stock rims was 4 seconds faster. I would leave the Hoosiers on the car, but for normal street driving ( and our horrible HOuston roads) they make way too much noise on concrete...they are quieter on asphalt. I would be curious if Goodyear had made the rears 325's instead of 315's if the car would be more neutral.
B O N Y
MODERATOR & FGT OWNER
Contact Alex for alignment settings to dial in/out oversteer/understeer. Alex knows, my gal is neutral to slight oversteer, zero push.
HeritageBruce
GT Owner
Kosupply,
So you are saying the Goodyears are 1 to 2 seconds faster than the Bridgestones?
View attachment 5817Yes...turn in on a corner is better with the stock tires. The 345's on the same corner pushes the front when you turn in and finding the right amount of throttle to induce a little oversteer with the torque we have on tap is difficult....real easy to go from not enough throttle to too much. I just find the stock set up more predictable. For street driving and straighline performance the 345's are great. As mentioned in Bonys reply, they have a camber kit that will probably dial out some of the understeer with the big rears. I have the kit and have not installed it. I race SCCA and have three different class cars that I usually want to drive when I get out to the track...see my other Ford
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JOETWINT
FORD GT OWNER
Has anyone done 20" front and rear?If so any problems?I am worried it will throw off the look of the car.
John B
GT Owner
- Jan 28, 2006
- 158
At last!!!
I think these might work!!!
Ever since I first drove my GT on the track I have been longing for a good set of soft compound tires like Michelin Pilot Sport Cups that wont screw up the rake and balance of the car. I took up the quest again in earnest about four months ago and discovered that Pirelli had something in the works. In their PZero Corsa System asymmetric tires they already had rears that would work but fronts were not yet in production. I placed an order none the less. Well I just got the call that they are in yesterday. I will put them right on and report back.
Pirelli PZero Corsa System
F 235/40-18 asymmetrico 25.40 diameter
R 345/35-19 asymmetrico 28.50 diameter
Stock: Goodyear Eagle F1 Supercar
F 235/45-18 26.32 diameter
R 315/40-19 28.92 diameter
Rear width increases by 30mm while front is unchanged which will shift the mechanical balance slightly towards understeer.
This will lower the front -0.46" and the rear -0.25", increasing rake by 0.25" which is probably not a bad thing as it will move the center of pressure slightly forward shifting the aero balance slightly towards oversteer, somewhat offsetting the change in mechanical balance at higher speeds. Really I would rather have it the other way around (mechanical oversteer, aero understeer) but what can you do? I think the balance changes will be miniscule in comparison to the increase in overall grip. Circumference change is -1.5% front -3.5% rear so it probably wont be a big enough difference to interfere with ABS. Speedo will read 3.5% faster.
http://www.tirerack.com/tires/tires.jsp?tireMake=Pirelli&tireModel=PZero+Corsa+System
I think these might work!!!
Ever since I first drove my GT on the track I have been longing for a good set of soft compound tires like Michelin Pilot Sport Cups that wont screw up the rake and balance of the car. I took up the quest again in earnest about four months ago and discovered that Pirelli had something in the works. In their PZero Corsa System asymmetric tires they already had rears that would work but fronts were not yet in production. I placed an order none the less. Well I just got the call that they are in yesterday. I will put them right on and report back.
Pirelli PZero Corsa System
F 235/40-18 asymmetrico 25.40 diameter
R 345/35-19 asymmetrico 28.50 diameter
Stock: Goodyear Eagle F1 Supercar
F 235/45-18 26.32 diameter
R 315/40-19 28.92 diameter
Rear width increases by 30mm while front is unchanged which will shift the mechanical balance slightly towards understeer.
This will lower the front -0.46" and the rear -0.25", increasing rake by 0.25" which is probably not a bad thing as it will move the center of pressure slightly forward shifting the aero balance slightly towards oversteer, somewhat offsetting the change in mechanical balance at higher speeds. Really I would rather have it the other way around (mechanical oversteer, aero understeer) but what can you do? I think the balance changes will be miniscule in comparison to the increase in overall grip. Circumference change is -1.5% front -3.5% rear so it probably wont be a big enough difference to interfere with ABS. Speedo will read 3.5% faster.
http://www.tirerack.com/tires/tires.jsp?tireMake=Pirelli&tireModel=PZero+Corsa+System
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AZGT
GT Owner
New wheels and tires - kind of.....
I haven't read all of the posts here, so forgive any duplication.
I replaced the standard tires with the Bridgestones RE 050A and RE 050A Scuderia.
Just for comparison
Stock: 235/45/ZR18 88 Y - wheel and tire 45.2 pounds - 26.33 diameter / 9.3 wide
Stock: 315/40/ZR19 103Y - wheel and tire 56.0 pounds - 28.92 diameter / 12.4 wide
Naturally the stock tires are missing some rubber, but I think I made up for the weight with nails.
New: 265/40/ZR18 101 Y - wheel and tire 52.4 pounds - 26.35 diameter / 10.4 wide
New: 345/35/ZR19 110 Y - wheel and tire 61.4 pounds - 28.51 diameter / 13.6 wide
Now for the wheels. Something I have been trying to do for a while. They are the stock wheels minus the crappy plastic center cap. Lug nuts are those from the optional BBS wheels. Center caps at the moment are cheap ones from an SUV wheel. I am having a screw in cap made with a custom FGT logo - machine guy has been been slow getting at it. I will have several sets of those made if anyone else wants one.
I like the look. To me the optional BBS wheels I had were not the right ones. They are a good, contemporary look, but I wanted something more in flavor of the original car, something not so prissy. I was also not crazy about the standards with that ugly cap (don't throw stones - I also have a car with those still on). I also think these are a good approximation to the wheels that were on the concept cars - with the wheel look that should have been on ours in the first place.
Curious of opinions - my feelings won't be hurt.
I haven't read all of the posts here, so forgive any duplication.
I replaced the standard tires with the Bridgestones RE 050A and RE 050A Scuderia.
Just for comparison
Stock: 235/45/ZR18 88 Y - wheel and tire 45.2 pounds - 26.33 diameter / 9.3 wide
Stock: 315/40/ZR19 103Y - wheel and tire 56.0 pounds - 28.92 diameter / 12.4 wide
Naturally the stock tires are missing some rubber, but I think I made up for the weight with nails.
New: 265/40/ZR18 101 Y - wheel and tire 52.4 pounds - 26.35 diameter / 10.4 wide
New: 345/35/ZR19 110 Y - wheel and tire 61.4 pounds - 28.51 diameter / 13.6 wide
Now for the wheels. Something I have been trying to do for a while. They are the stock wheels minus the crappy plastic center cap. Lug nuts are those from the optional BBS wheels. Center caps at the moment are cheap ones from an SUV wheel. I am having a screw in cap made with a custom FGT logo - machine guy has been been slow getting at it. I will have several sets of those made if anyone else wants one.
I like the look. To me the optional BBS wheels I had were not the right ones. They are a good, contemporary look, but I wanted something more in flavor of the original car, something not so prissy. I was also not crazy about the standards with that ugly cap (don't throw stones - I also have a car with those still on). I also think these are a good approximation to the wheels that were on the concept cars - with the wheel look that should have been on ours in the first place.
Curious of opinions - my feelings won't be hurt.
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your wheels do look great, a different look from the optional BBS but in my view not better. just a matter of taste and a different look. .. how do your bridgestones work? have you had the car on a track? earlier post complains about understeer relative to the goodyears which i dont see happening if suspension is adjusted a bit.
AZGT
GT Owner
Have only been on for a day. Did notice they also broke loose in first gear ( :biggrin ) - but I do have a pulley and tune.
It will be a while for a track day again, so won't know anything for a while. Fit appears good as has been said. Not close for either front or rear, but may be different under track conditions with some roll.
AZGT
GT Owner
Front and rear added about 1 inch in width, so shouldn't really be any different than stock.
SYCO GT
GT Owner
AZGT - I think it's a good look that you have without the large center caps. I also like the factory standard look too with the cap.
fjpikul
GT Owner
AZGT
GT Owner
Thanks.
Yes, rubber stems. Just left off the BBS covering cap. At the moment I am also leaving it like that - rubber stem also seems more "appropriate".
The setup looks better in person. The standard wheels have the same contours as the optional - just the spokes are different. When the plastic cap is off, you see those curves, and the wheel overall doesn't look so flat.
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