Are the GT-5 Type wheels pretty much the same off sets or do they differ from car to car ?
What are they for the front & rear ?
Thanks guys.
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Coz,
Funny you should ask, I just measured the backspacing on my stock GT5-S wheels just before I sold them. I sold them to a fellow who went to the Group 4 look and they fit just fine.
The backspacing measured as follows:
Front---> 4 3/8" to the flange (tirebead seat), 4 5/8" to the outermost lip
Rear ---> 5 1/4" to the flange, 5 1/2" to the outermost lip
I've included both measurements because different wheel manufacturers use either or.
These measurements do not include the 3/16" spacer that I had at all four corners.
I'm pretty sure that all of the 10" & 13" Campys are the same offset, respectively (I've never heard otherwise). I don't think deTomaso would go through the added expense of having an identical wheel cast with a different offset. However, there are a scant few pairs of 14" rear Campys, but I know nothing about them (except that they exist). I assume they would be stamped 14", like mine were stamped 13" & 10". I've heard that these were only offered on factory race cars. I'm not sure if they were available to buy over deTomaso's parts counter.
Hope this helps.
Michael
Funny you should ask, I just measured the backspacing on my stock GT5-S wheels just before I sold them. I sold them to a fellow who went to the Group 4 look and they fit just fine.
The backspacing measured as follows:
Front---> 4 3/8" to the flange (tirebead seat), 4 5/8" to the outermost lip
Rear ---> 5 1/4" to the flange, 5 1/2" to the outermost lip
I've included both measurements because different wheel manufacturers use either or.
These measurements do not include the 3/16" spacer that I had at all four corners.
I'm pretty sure that all of the 10" & 13" Campys are the same offset, respectively (I've never heard otherwise). I don't think deTomaso would go through the added expense of having an identical wheel cast with a different offset. However, there are a scant few pairs of 14" rear Campys, but I know nothing about them (except that they exist). I assume they would be stamped 14", like mine were stamped 13" & 10". I've heard that these were only offered on factory race cars. I'm not sure if they were available to buy over deTomaso's parts counter.
Hope this helps.
Michael
Yes, Thank Michael.
So without the spacers, which mine doesn't have, I just need to add back in the 3/16" to both, actually all measurements, correct ?
Thanks, appreciate the help.
Coz
So without the spacers, which mine doesn't have, I just need to add back in the 3/16" to both, actually all measurements, correct ?
Thanks, appreciate the help.
Coz
Coz,
Are you measuring for a set of aftermarket wheels?
If so, get the car level and hang a string with a weight (plumb bob) on the end from the center of the wheel opening on the inside (duct tape should hold it in place). With the wheel bolted in place, measure from the edge of the rim to the string. That measurement will tell you just about how far out you can bring the wheel without it hitting the sheetmetal.
Lets say that measurement is 2 1/4". If you wanted to move the wheel right out to the limit, you subtract say 2" from the backspacing. If it's the rear wheel, your new backspacing would be 3 1/4" (flange measurement). That's how you would order it. If you only want to come out 1", you'd be at 4 1/4".
The front requires an additional step. When you determine how far out you want to move the wheel (say 2"), find yourself something light and 2" thick and tape it to your sidewall as close to the tread as possible. Jack the car up and support it under the control arm so that the front is at ride height but off the ground. Turn the wheel to the extreme lock and rotate it slowly noting how far that taped object comes to hitting anything. Turn to the opposite lock and do it again. Knowing how Panteras are constructed, I would do both sides front and rear (no need to jack up the rear). Be sure to leave yourself enough room for suspension travel. If it hits anything, back it off 1/2" at a time and try again.
If you want to move the wheel in, you add to the backspacing. Again, make sure to check for clearance. You don't have to add the spacer in because you're taking a new direct measurement with the wheel in place. If you don't use the spacer, you'll get a slightly deeper dished rim.
Michael
Are you measuring for a set of aftermarket wheels?
If so, get the car level and hang a string with a weight (plumb bob) on the end from the center of the wheel opening on the inside (duct tape should hold it in place). With the wheel bolted in place, measure from the edge of the rim to the string. That measurement will tell you just about how far out you can bring the wheel without it hitting the sheetmetal.
Lets say that measurement is 2 1/4". If you wanted to move the wheel right out to the limit, you subtract say 2" from the backspacing. If it's the rear wheel, your new backspacing would be 3 1/4" (flange measurement). That's how you would order it. If you only want to come out 1", you'd be at 4 1/4".
The front requires an additional step. When you determine how far out you want to move the wheel (say 2"), find yourself something light and 2" thick and tape it to your sidewall as close to the tread as possible. Jack the car up and support it under the control arm so that the front is at ride height but off the ground. Turn the wheel to the extreme lock and rotate it slowly noting how far that taped object comes to hitting anything. Turn to the opposite lock and do it again. Knowing how Panteras are constructed, I would do both sides front and rear (no need to jack up the rear). Be sure to leave yourself enough room for suspension travel. If it hits anything, back it off 1/2" at a time and try again.
If you want to move the wheel in, you add to the backspacing. Again, make sure to check for clearance. You don't have to add the spacer in because you're taking a new direct measurement with the wheel in place. If you don't use the spacer, you'll get a slightly deeper dished rim.
Michael
Yes, looking at various after market wheels. Probably going to go with the Cobra style, polished in 17's. For the money, they are some of the nicest I've seen compared to the others out there and what the people selling them think their's are worth.
My current set up with the original GT-5 wheels are as close to the outer edge as I think they should be. I have about 1 finger room from the tire to the inside of the fenders, both front & rear. The current set up doesn't rub or hit anything. Going from 15's to 17's shouldn't change that, that is I understand you correctly.
But I am going to do the measurements as you instructed to see what I come up with.
As long as I stay within the proper total height wheel & tire wise, taller wheel, less sidewall on the tire, I should be ok rubbing wise during turning on the fronts.
Got to order these wheels, then they are made and there's no going back once their done. Want to make sure I do it right the first time.
Great advice, thank you very much Michael.
My current set up with the original GT-5 wheels are as close to the outer edge as I think they should be. I have about 1 finger room from the tire to the inside of the fenders, both front & rear. The current set up doesn't rub or hit anything. Going from 15's to 17's shouldn't change that, that is I understand you correctly.
But I am going to do the measurements as you instructed to see what I come up with.
As long as I stay within the proper total height wheel & tire wise, taller wheel, less sidewall on the tire, I should be ok rubbing wise during turning on the fronts.
Got to order these wheels, then they are made and there's no going back once their done. Want to make sure I do it right the first time.
Great advice, thank you very much Michael.
Coz,
There is a simple formula to determine tire width and diameters. Lets use the stock 285/40/15 found on the 10x15 stock Campy:
You take the first number, which is tire width in mm and divide it by 25.4. This converts the mm into inches:
285 \ 25.4 = 11.22" (inches)
Next you take this converted number and multiply it by the aspect ratio, or the middle number (the middle number is a percentage of the width, in this case 40%):
11.22 x .40 = 4.488" This is your sidewall height in inches, just about 4.5".
Next you take the sidewall height and multiply it by 2 (top and bottom sidewalls):
4.488 x 2 = 8.976"
Next you add in the rim diameter, which is 15":
8.976 + 15 = 23.976 or 24" tall
This formula helps you to determine 3 important things about a tire: width, sidewall height, and overall diameter.
You now know that your front tire is 24" tall. Let's do the back 345/35/15 tire:
345 \ 25.4 = 13.58"
13.58 x .35 = 4.75"
4.75 x 2 = 9.50"
9.50 + 15 = 24.5"
The back tire is 13.58" wide, the sidewall height is 4.75", and the overall diameter is 24.5" tall.
When doing this on a calculator, do not hit the = sign between each step, just keep stringing it along and hit = at the end like this:
345 \ 25.4 x .35 x 2 + 15 = 24.5. You will get your other values along the way.
Note that the sidewall height is 1/4" taller on the rear tire. Use the sidewall height figures to determine how a front and rear tire will relate to one another. I like to see a taller sidewall on the rear to excentuate the girth and the power that eminates from the rear of a Pantera.
To me, this is very valuable information in determining how far I can go clearance wise, and what will look right cosmetically.
Lets apply this formula to a likely 17" tire combo: 275/35/17 F & 335/35/17 R:
275 \ 25.4 = 10.83"
10.83 x .35 = 3.79"
3.79 x 2 = 7.58"
7.58 + 17 = 24.58"
Not bad height wise. It's just over a 1/4" taller on each sidewall, top and bottom.
335 \ 25.4 = 13.19"
13.19 x .35 = 4.62"
4.62 x 2 = 9.24"
9.24 + 17 = 26.24"
This tire is less than 1" taller on each sidewall. Nobody has a problem with this tire on their flared Pantera.
Another thing you can determine with this formula is how the tire shoulder will 'round' with a given rim width. Using your stock tires as an example:
285 x 25.4 = 11.22" across a 10" rim. The difference is 1.22"
345 x 25.4 = 13.58" across a 13" rim. The difference is .58"
The front tire has more width for its rim than the rear. This means that the shoulder of the tire will stick farther out in relation to the rim than the rear. This will give the front sidewall/shoulder a 'straighter' appearance, and the rear a 'rounder' appearance compared to one another. Go and look at your tires and you'll see what I'm talking about. If you subtract .58 from 1.22 you get .64". If the front rim were 10.5" (.5" is as close as you can get to .64" in rim width), you will get a shoulder 'roundness' that more closely resembles the rear.
Applying this to the 17" example, we come up with the same .64" difference:
275 \ 25.4 = 10.83" across a 10" rim is .83"
335 \ 25.4 = 13.19" across a 13" rim is .19"
.83 - .19 = .64"
If I were going with this tire combo, I'd order a 10.5" front rim. To keep the wheel located in the stock location, you would add the 1/2" to inside of the rim. This would increase backspacing by 1/2". Adding the 1/2" to the outside of the rim would keep the backspacing the same a stock.
If you're happy with where the rim sits in your fenderwell, ask whomever you're going to buy your wheels from where they take their backspacing measurement from: Is it the tire beadseat flange, or the outermost lip? Then use the measurements in my previous post to determine your proper backspacing.
I personally would pull a front and a rear wheel off to measure for myself to double check anyone's measurements regarding backspacing. I'm a perfectionist, so I measured mine 99 times (I believe in 'measure twice, cut once'). Like you said, once you order them, they're yours, so taking a little extra time will insure your happiness. There is nothing worse than not being happy with a major purchase, especially when it's a finishing touch!
To measure backspacing, place the wheel street side down. You will need a straight-edge strong enough not to sag in the middle as it spans the rim. The straight-edge should be long enough to intersect the middle, but not so long that it hits the tire anywhere as it rests on the rim's edge. With the straight-edge in place, drop a ruler down to the flat pad where the rim would meet the hub on the car (the flat pad has the lug nut holes, and the hub has the wheel studs sticking out of it). Where the straight-edge intersects the ruler (say 5 1/4") is your backspacing measurement for that wheel. Wheel manufacturers a lot of times only offer backspacing in 1/2" increments, so in this case, you'd have to decide if you'd want the wheel to sit 1/4" in more or out further.
This may seem like a lot to digest, but it's really not. It just takes a lot of typing to properly explain the hows and whys! I'd say good luck, but now luck has a lot less to do with your outcome! Share some pics with us when you finally get them on your car.
Michael
There is a simple formula to determine tire width and diameters. Lets use the stock 285/40/15 found on the 10x15 stock Campy:
You take the first number, which is tire width in mm and divide it by 25.4. This converts the mm into inches:
285 \ 25.4 = 11.22" (inches)
Next you take this converted number and multiply it by the aspect ratio, or the middle number (the middle number is a percentage of the width, in this case 40%):
11.22 x .40 = 4.488" This is your sidewall height in inches, just about 4.5".
Next you take the sidewall height and multiply it by 2 (top and bottom sidewalls):
4.488 x 2 = 8.976"
Next you add in the rim diameter, which is 15":
8.976 + 15 = 23.976 or 24" tall
This formula helps you to determine 3 important things about a tire: width, sidewall height, and overall diameter.
You now know that your front tire is 24" tall. Let's do the back 345/35/15 tire:
345 \ 25.4 = 13.58"
13.58 x .35 = 4.75"
4.75 x 2 = 9.50"
9.50 + 15 = 24.5"
The back tire is 13.58" wide, the sidewall height is 4.75", and the overall diameter is 24.5" tall.
When doing this on a calculator, do not hit the = sign between each step, just keep stringing it along and hit = at the end like this:
345 \ 25.4 x .35 x 2 + 15 = 24.5. You will get your other values along the way.
Note that the sidewall height is 1/4" taller on the rear tire. Use the sidewall height figures to determine how a front and rear tire will relate to one another. I like to see a taller sidewall on the rear to excentuate the girth and the power that eminates from the rear of a Pantera.
To me, this is very valuable information in determining how far I can go clearance wise, and what will look right cosmetically.
Lets apply this formula to a likely 17" tire combo: 275/35/17 F & 335/35/17 R:
275 \ 25.4 = 10.83"
10.83 x .35 = 3.79"
3.79 x 2 = 7.58"
7.58 + 17 = 24.58"
Not bad height wise. It's just over a 1/4" taller on each sidewall, top and bottom.
335 \ 25.4 = 13.19"
13.19 x .35 = 4.62"
4.62 x 2 = 9.24"
9.24 + 17 = 26.24"
This tire is less than 1" taller on each sidewall. Nobody has a problem with this tire on their flared Pantera.
Another thing you can determine with this formula is how the tire shoulder will 'round' with a given rim width. Using your stock tires as an example:
285 x 25.4 = 11.22" across a 10" rim. The difference is 1.22"
345 x 25.4 = 13.58" across a 13" rim. The difference is .58"
The front tire has more width for its rim than the rear. This means that the shoulder of the tire will stick farther out in relation to the rim than the rear. This will give the front sidewall/shoulder a 'straighter' appearance, and the rear a 'rounder' appearance compared to one another. Go and look at your tires and you'll see what I'm talking about. If you subtract .58 from 1.22 you get .64". If the front rim were 10.5" (.5" is as close as you can get to .64" in rim width), you will get a shoulder 'roundness' that more closely resembles the rear.
Applying this to the 17" example, we come up with the same .64" difference:
275 \ 25.4 = 10.83" across a 10" rim is .83"
335 \ 25.4 = 13.19" across a 13" rim is .19"
.83 - .19 = .64"
If I were going with this tire combo, I'd order a 10.5" front rim. To keep the wheel located in the stock location, you would add the 1/2" to inside of the rim. This would increase backspacing by 1/2". Adding the 1/2" to the outside of the rim would keep the backspacing the same a stock.
If you're happy with where the rim sits in your fenderwell, ask whomever you're going to buy your wheels from where they take their backspacing measurement from: Is it the tire beadseat flange, or the outermost lip? Then use the measurements in my previous post to determine your proper backspacing.
I personally would pull a front and a rear wheel off to measure for myself to double check anyone's measurements regarding backspacing. I'm a perfectionist, so I measured mine 99 times (I believe in 'measure twice, cut once'). Like you said, once you order them, they're yours, so taking a little extra time will insure your happiness. There is nothing worse than not being happy with a major purchase, especially when it's a finishing touch!
To measure backspacing, place the wheel street side down. You will need a straight-edge strong enough not to sag in the middle as it spans the rim. The straight-edge should be long enough to intersect the middle, but not so long that it hits the tire anywhere as it rests on the rim's edge. With the straight-edge in place, drop a ruler down to the flat pad where the rim would meet the hub on the car (the flat pad has the lug nut holes, and the hub has the wheel studs sticking out of it). Where the straight-edge intersects the ruler (say 5 1/4") is your backspacing measurement for that wheel. Wheel manufacturers a lot of times only offer backspacing in 1/2" increments, so in this case, you'd have to decide if you'd want the wheel to sit 1/4" in more or out further.
This may seem like a lot to digest, but it's really not. It just takes a lot of typing to properly explain the hows and whys! I'd say good luck, but now luck has a lot less to do with your outcome! Share some pics with us when you finally get them on your car.
Michael
Michael - what wheels did you eventually go with?
Kevin,
My car is currently in my garage on jackstands (needing only wheels). I have it narrowed down to 2 wheels: I'm either going to go with a set from Kinesis, or have a set made with custom centers. Believe it or not, the Kinesis wheels will probably cost more! At this point, I'm leaning towards Kinesis. I'll definitely post some pics when I get them on, but that probably won't be 'til after the new year.
Michael
My car is currently in my garage on jackstands (needing only wheels). I have it narrowed down to 2 wheels: I'm either going to go with a set from Kinesis, or have a set made with custom centers. Believe it or not, the Kinesis wheels will probably cost more! At this point, I'm leaning towards Kinesis. I'll definitely post some pics when I get them on, but that probably won't be 'til after the new year.
Michael
Thanks Michael for all the great information. I would say you have done some research on the subject. You're the man ! This is sure something I am going to oplay with calculation wise and measurement wise. Sounds a bit confusing, but looking at it more and more and the way you've explained it, it's starting to make since and fall together.
I will diffently print this post out and keep it for future reference as well.
Thank a bunch. I like the Kinesis too, but man, they cost an arm and a leg...
Thanks again Michael for all your time, though, typing & help on this.
Very much appreciated.
Coz
I will diffently print this post out and keep it for future reference as well.
Thank a bunch. I like the Kinesis too, but man, they cost an arm and a leg...
Thanks again Michael for all your time, though, typing & help on this.
Very much appreciated.
Coz
Awww Coz... you're making me blush!
It's not a problem. I enjoy passing on what I know. Afterall, I learned what I know from others passing it on to me.
When do you plan on buying your wheels? Will it be soon, or is it a winter project?
Michael
It's not a problem. I enjoy passing on what I know. Afterall, I learned what I know from others passing it on to me.
When do you plan on buying your wheels? Will it be soon, or is it a winter project?
Michael
Much of what I've learned about my Pantera's has come from the board and the people that post on it. Which is what this board is all about. I have met some great people thanks to this board that have helped me through many things by posting, phone calls and in person. We have Dave to thank for that!
At this point, I am saving my money getting ready for the the change. I still have some tread left on my front tires, about 50% worth and about 25% on my rear centers, 80% on the rear outters. So it's a game of, they wear down, save as they do, so when their almost gone I'll have the money to change over. The rears at this point are going to cause the change quicker than the fronts will. I went on a long drive, about 1500 miles and made a big mistake and didn't check tire pressures on the rears and wore the centers out because of the 100+ mph I did on a lot of it. They were new and I went by Discounts Tires recomendation of 32 lbs and found out it was to much air after I realized the centers centers were almost gone. Lesson learned the hard way.
So I figure before I'm going to give anyone 600.00 to 700.00 a tire for the fronts, and 400.00 to 600.00 a tire for the rears, it's easier to just bite the bullet and buy new wheels and tires in 17's for pretty much the same cost as a set of tires for the original 15" wheels and never have the problem again finding tires or paying outragious prices for them if you can find them at all.
I can get a set of the fully polished Corbra wheels in 17", for $1700.00 custom made with the offsets I want. Figure another 1000.00 for tires, and then I am done with the tire problem for 2700.00.
Just upgraded the power windows to brass gears and better motors. Also replaced the head light plastic gear to brass as well.
Have a Fludyne radirator sitting in my garage with Flexlite sucker fans for a laydown set up and a Dual Core Laminova Water to Oil Cooler. I'm just waiting for the opportunity to take Jack up on his offer to drive to his house and spend a few days with him installing them on my car and go through some other learning curves and testing of the car.
Then there is the brake upgrade that I still want to do.
One thing I've learned for sure is, the upgrades for our cars never seem to end, but the money sure does to do it with. So it's a slow process. But little by little I'm getting it done.
At this point, I am saving my money getting ready for the the change. I still have some tread left on my front tires, about 50% worth and about 25% on my rear centers, 80% on the rear outters. So it's a game of, they wear down, save as they do, so when their almost gone I'll have the money to change over. The rears at this point are going to cause the change quicker than the fronts will. I went on a long drive, about 1500 miles and made a big mistake and didn't check tire pressures on the rears and wore the centers out because of the 100+ mph I did on a lot of it. They were new and I went by Discounts Tires recomendation of 32 lbs and found out it was to much air after I realized the centers centers were almost gone. Lesson learned the hard way.
So I figure before I'm going to give anyone 600.00 to 700.00 a tire for the fronts, and 400.00 to 600.00 a tire for the rears, it's easier to just bite the bullet and buy new wheels and tires in 17's for pretty much the same cost as a set of tires for the original 15" wheels and never have the problem again finding tires or paying outragious prices for them if you can find them at all.
I can get a set of the fully polished Corbra wheels in 17", for $1700.00 custom made with the offsets I want. Figure another 1000.00 for tires, and then I am done with the tire problem for 2700.00.
Just upgraded the power windows to brass gears and better motors. Also replaced the head light plastic gear to brass as well.
Have a Fludyne radirator sitting in my garage with Flexlite sucker fans for a laydown set up and a Dual Core Laminova Water to Oil Cooler. I'm just waiting for the opportunity to take Jack up on his offer to drive to his house and spend a few days with him installing them on my car and go through some other learning curves and testing of the car.
Then there is the brake upgrade that I still want to do.
One thing I've learned for sure is, the upgrades for our cars never seem to end, but the money sure does to do it with. So it's a slow process. But little by little I'm getting it done.
Michael,
Would you please e-mail me. I want to run something by you before I order the wheels.
Thanks.
Coz
cozland@cox.net
Would you please e-mail me. I want to run something by you before I order the wheels.
Thanks.
Coz
cozland@cox.net
Coz,
You can e-mail me at: Cyboman@optonline.net, or you can call me at 203-380-1298.
Michael
You can e-mail me at: Cyboman@optonline.net, or you can call me at 203-380-1298.
Michael
Michael,
I know your dilemma well. The perfect fit just isn't the perfect look. The wheels end up to far inside the flared fenders for my liking. The spacer gave it a great look - you just rub a little up front on full lock. If your car is for the street only, you can avoid this almost completely. I'll try to find some "before and after spacer" pics and send them by email.
David
I know your dilemma well. The perfect fit just isn't the perfect look. The wheels end up to far inside the flared fenders for my liking. The spacer gave it a great look - you just rub a little up front on full lock. If your car is for the street only, you can avoid this almost completely. I'll try to find some "before and after spacer" pics and send them by email.
David
Hey Coz,
Here's something else to think about. I sold my old GT5 15s for about what it cost to buy new 17 wheels AND tires!
#9203
http://www.canspanad.com/pantera
Here's something else to think about. I sold my old GT5 15s for about what it cost to buy new 17 wheels AND tires!
#9203
http://www.canspanad.com/pantera
Cool, help me sell mine !
Here's something else to think about. I sold my old GT5 15s for about what it cost to buy new 17 wheels AND tires!
Here's something else to think about. I sold my old GT5 15s for about what it cost to buy new 17 wheels AND tires!
I believe I found the wheels I want. They are made by Kodiak. They are made to order. Once piece wheel. here is the website if anyone is interested.
http://www.kodiakmotorsports.com/
479.00 each, Fronts: 10.5 x 17"
509.00 each, rears: 13 x x17"
http://www.kodiakmotorsports.com/
479.00 each, Fronts: 10.5 x 17"
509.00 each, rears: 13 x x17"
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Talk to Koiak again, they said we can put 5 sets together, they would discount 20% for all.
If anyone is interested in a set, let me know.
cozland@cox.net
If anyone is interested in a set, let me know.
cozland@cox.net