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275/50/15 on a '70 Javelin?

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steeters View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote steeters Quote  Post ReplyReply Direct Link To This Post Topic: 275/50/15 on a '70 Javelin?
    Posted: Jun/27/2008 at 10:42pm
Is anyone running 275/50/15 BF Goodrich drag radials on their 68-70 Javelin...and I assume the AMX would be the same?  on the other forum a driver said they had some fitment issues, but if it is a close fit I thought i'd see if anyone else had tried them and had better/worse luck.
I keep seeing good deals for used sets on criagslist and I would really like to go for these on my street car.  From what I have learned the diameter is fine...it's the 11" width that will be the problem (or not).
these would be mounted on 15x7 Machine wheels...I don't know what the offset is but I will figure it out if someone else has successfully used this size tire and knows what offset works.
 
Thanks!
 
From Summit:
Tire Size: 275/50-15
Rim Diameter (in): 15 in.
Sidewall Style: Blackwall
Tire Construction: Radial
Directional: No
Tire Diameter (in): 26.10 in.
Section Width (in): 11.30 in.
Minimum Recommended Rim Width (in): 7.50 in.
Maximum Recommended Rim Width (in): 9.50 in.


Edited by steeters - Jun/27/2008 at 10:45pm
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348AMX View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 348AMX Quote  Post ReplyReply Direct Link To This Post Posted: Jun/28/2008 at 9:47pm
  I have 275/50/15 BFG radial T/A's on my 68 AMX mounted on Amercian Racing torque thrust D's.  15x 8.5 rims. I am sorry I dont remmber the backspacing..maybe 3.5"?
 
 They fit very nice for a wide tire, about as wide as you can get without looking too much for the body of the car. They dont stick out beyond the top fender lip.    This is a hard to find size in all season radials anymore. The drag radial seems to be the most common route to get this size tire. Traction is very good, I can spin from rest for about 15' and then it will just hook depending on the pressure.   I am thinking about going to 245-50-15.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote poormansMACHINE Quote  Post ReplyReply Direct Link To This Post Posted: Jun/29/2008 at 2:50pm
Originally posted by 348AMX 348AMX wrote:


Traction is very good, I can spin from rest for about 15' and then it will just hook depending on the pressure.   I am thinking about going to 245-50-15.

Don't you only need one since it's only the r/r that spins?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 348AMX Quote  Post ReplyReply Direct Link To This Post Posted: Jun/29/2008 at 6:26pm

True that!   It depends on how I play with the air pressure.  If I let air out of the left rear say down to 20 PSI and leave the r/r at 30-35 it'll put down a huge slab of rubber.  Inflate both sides to the same PSI and it'll spin for a bit and the engine will rev through 1st but then 2nd will hook.   Turning a corner from a stop sign or from a slow roll...forget it, it'll smoke the r/r through 1st and 2nd.

  A few years ago before the rebuild I put 245/50/15 gatorbacks on, they have a very hard slippery compound and any inflation over 25 PSI and I could slide through 1st and 2nd from a slow roll. 

So I have to say I am impressed with the BFG Radial T/A's for straight line traction, although I have to be very careful NOT to bark the tire taking off from stop signs or red lights and it'll chirp 1st to 2nd if I lay into it. I bet the drag radial would really hook good, probably cause MY car to bog.

 

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Post Options Post Options   Thanks (0) Thanks(0)   Quote prostreetamx Quote  Post ReplyReply Direct Link To This Post Posted: Jul/01/2008 at 8:58pm
I ran 295x50x15's on my Donohue. They were mounted of Crager SST 15x10 Wheels. I didn't know much about offset back then, but the tread was fully covered by the wheel wells. I did run longer shackles to clear the tires untill I swapped in a few Concord leaf springs instead. The Concord springs have more arch and the tires never rubbed until I broke the model 20 and swapped to a wider 8 3/4" rear. I didn't like the new look and removed the tires.


Edited by prostreetamx - Jul/01/2008 at 9:01pm
Richard Payne

Las Vegas,NV

72 5.7 Hemi Javelin

77 Prostreet 401/727 AMX,

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Post Options Post Options   Thanks (0) Thanks(0)   Quote TheTortus Quote  Post ReplyReply Direct Link To This Post Posted: Jan/28/2009 at 2:12pm
My 69 AMX is sitting on a pair of 295 50 15s on stock springs no air shocks and 15x7 mopar police wheels... You won't want to go around corners very fast but it will diffinatly look cool!Thumbs%20Up
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Post Options Post Options   Thanks (0) Thanks(0)   Quote amc401t10 Quote  Post ReplyReply Direct Link To This Post Posted: Mar/12/2009 at 3:49pm
i have 2 hoosier 295/50/15 that have 2 runs on them, still have the nipples on them,(i hate them on the street where i do most of my driveing) for sale if any one is interesteed (they are mounted on weld 5-star alum wheels with tire screws). i run 275/50/15 street radials on the back of my gremlin with no clearence issues, looks great...
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Post Options Post Options   Thanks (0) Thanks(0)   Quote PHAT69AMX Quote  Post ReplyReply Direct Link To This Post Posted: Mar/12/2009 at 6:01pm
Would need at least 4-1/2 backspace, ideally 5 inch backspace, which no one makes afaik, so 5-1/2 backspace with 1/2 thicj spacers.  A 4-1/2 backspace is available but things will be close with the fender lip where the corner of the tire crosses over the curl of the vertical body line.  Maybe try to pick up a worn out 275-50-15 cheap and do a trial fit ?  I run 255-60-15 tires on 4-1/2 backspace 15x8 Mag 500's and have about 1-1/4 clearance with the leafspring.  Last year was loaned some 15x8 Welds with 5-1/2 backspace and they bolted on and fit with 255-60-15 BFG's but only had 1/8 inch leafspring clearance.  Ran them all last fall but used a 7/32 inch thick Mr. Gasket cast aluminum wheel spacer to get 3/8 inch leafspring clearance.  The 275-50-15's will be 20mm / 3/4 inch wider sidewall but will also be a smaller diameter, 275-50-15 = 25.83 dia. nominal and 255-60-15 = 27.05 dia. nominal, and the smaller diameter will help with fender lip clearance.  Imho 275-50-15 tires will work.  It all depends on getting the proper backspacing.  What is the backspacing on the Machine rims you have ?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote PHAT69AMX Quote  Post ReplyReply Direct Link To This Post Posted: Mar/12/2009 at 6:08pm
Guess ya know a 15x7 rim will measure 16x8 outside to outside.
Backspace measurements include the additional 1/2 inch that results from the rim bead lip.
So a 15x7 rim with 4 inch backspace is centered, or has 0 (zero) offset, is another way to put it.
Backspace and Offset are two different ways to measure and indicate the same thing.
If I can get this right, Positive Offset moves rim width inward towards the leafspring,
negative offset moves the rim width outward towards the fender, iirc.
It can be confusing since backspace is measured from the actual edge of the rim to the mounting face
and the measure rim width is 1 inch greater, 1/2 inch per side, greater than the stated rim size,
and Offset is a measurement of the how far the mounting face is moved off center of the rim width.
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