Author Topic: 14x7 to 15x7 Rally Wheel Swap...  (Read 18771 times)

oneZ11

  • Member
  • ***
  • Posts: 67
    • View Profile
14x7 to 15x7 Rally Wheel Swap...
« on: February 21, 2012, 02:15:00 PM »
I've got a '69 with original 14x7 Rally's and am looking to put a set 15x7's on. Do I have to find '68-69 wheels, or will the early 70s "FW" code wheels work the same?

My research shows that the original 14x7's have a 4" backspace. 15x7's?

tom

  • Hero Member
  • *****
  • Posts: 1146
    • View Profile
    • Discount Internet Services
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #1 on: February 21, 2012, 02:39:39 PM »
Mine had FW wheels when I bought it. Still needs work, so can't comment on fit or clearance issues. I know the owner for several years before me did not add them.
69 X11 Z21 L14 glide
looking for a 69 export model (KPH) speed
o

oneZ11

  • Member
  • ***
  • Posts: 67
    • View Profile
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #2 on: February 21, 2012, 05:04:52 PM »
Yours were probably added later. "FW" code doesn't show up on 1969 code chart for Camaro Rally's, so that's encouraging. Are yours 15x7s?

(You can research this site for wheels codes.)

69Z28-RS

  • Hero Member
  • *****
  • Posts: 5778
  • owner since 4-Apr-1976
    • View Profile
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #3 on: February 21, 2012, 05:49:11 PM »
I believe FW was a Monte Carlo code, and many of them have been used on Camaro's over the years... might be a fractional inch difference in offset from the YH?   I can measure the offset on one of my YH's tonight if you need (tired is dismounted so should be easy).. :)

Gary
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

oneZ11

  • Member
  • ***
  • Posts: 67
    • View Profile
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #4 on: February 21, 2012, 06:54:27 PM »
If not too much trouble, that would be great. I think it's 4.25" on the 15x7 wheel, but I could be wrong.

mcharter

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #5 on: February 21, 2012, 07:19:33 PM »
Hope this is not off topic but I had done some research a while back on wheels.  I think I found that 15x7 YH wheels were identical to FW wheels.  I thought they even had the same GM part number 3997899-D.  Does anyone know if this is correct?  Thanks

oneZ11

  • Member
  • ***
  • Posts: 67
    • View Profile
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #6 on: February 21, 2012, 10:47:51 PM »
YH code would be Z28 wheels – would love to have an original set of those! Sorry, can't answer the part number question. I'm mostly interested in proper fit, so there's no tire rubbing. Also, want the 15" rim, so I can run the deeper style trim ring.

oneZ11

  • Member
  • ***
  • Posts: 67
    • View Profile
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #7 on: February 21, 2012, 10:50:46 PM »
Found this on another blog, RE: backspacing...

FW  15X7  Backspacing 4 1/4  71-up most any GM

YJ  14X7  Backspacing 4 3/8   69 Camero/ Chevy II L72- ZL1, 70 Nova

Stingr69

  • Hero Member
  • *****
  • Posts: 900
    • View Profile
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #8 on: February 22, 2012, 06:25:16 AM »
The Monte Carlo FW rims are fine.  Those are what I have been running for many years.  Same dimensions as the Z/28 YH code wheels.  Only slight visual differences under very close inspection. 

The biggest tire that you can run on all 4 corners with those is a P245-60-15 but that size will require a very slight bend in the inside flange of the front fender extension. You can just about do the mod with your hand and it is easy to reverse so it is no big deal.  A P235-60-15 might be a better look to some eyes as it is slightly less aggressive.

-Mark.

69Z28-RS

  • Hero Member
  • *****
  • Posts: 5778
  • owner since 4-Apr-1976
    • View Profile
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #9 on: February 22, 2012, 06:33:45 AM »
I have an FW wheel unmounted, and a YH wheel unmounted in my garage.  I measured the back spacing tonight from those wheels tonight:

YH       4-1/4" backspace
FW       4-3/8" backspace

I only measured one wheel each, but I have others of both codes if there's still question...

Gary
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

Kelley W King

  • Hero Member
  • *****
  • Posts: 1407
    • View Profile
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #10 on: February 22, 2012, 01:20:15 PM »
FW,s are everywhere. They work on camaros fine. I have 2 with them now.
69 Z28 RS Scuncio Hi Performance
69 SS L78
67 SS Chevelle
64 Corvette
66 GTO Tiger Gold
77 Trans Am Special Edition

oneZ11

  • Member
  • ***
  • Posts: 67
    • View Profile
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #11 on: February 22, 2012, 09:29:31 PM »
Thanks for the info guys - and thanks for measuring "69Z28-RS."

"Stingr69", thanks, I will probably run a 225 or 235 but no larger. It's weird how tire diameters run. A 225/70 R14 is a larger diameter than a 235/60 R15 !

69Z28-RS

  • Hero Member
  • *****
  • Posts: 5778
  • owner since 4-Apr-1976
    • View Profile
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #12 on: February 22, 2012, 10:29:55 PM »
You should be able to calculate the tire Dia (height) using the formula; to keep your effective gear ratio and speedo cal the same, you should try to keep your tire height the same or very similar.

Height of 225/70R14 = Rim (14*25.4) +  2* tire section (0.7*225)= 355.6 + 315= 670.6 mm =  26.4" Dia
Height of 235/60R15 = (Rim (15*25.4) + 2* tire section (0.6*235) = 381 + 282 = 663 mm = 26.1 In Dia

Is this close to what your tire book said?

Gary
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

oneZ11

  • Member
  • ***
  • Posts: 67
    • View Profile
Re: 14x7 to 15x7 Rally Wheel Swap...
« Reply #13 on: February 23, 2012, 04:17:36 PM »
Actually, no book, I'm using Tire Rack.com. Look up any tire, and click "specs" in the table below. They provide all dimensions of the tire including diameter. Very nice feature...

 

anything