Yet another tire and rim question...

Discussion in '1965 - 1973 Classic Mustangs -General/Talk-' started by Taranis, Nov 25, 2006.

  1. I was looking at getting the American Racing Torq-Thrust M for my 69 Mustang in the 17 x 9 size, 6" backspacing and outfitting them with either 275 or 285/40/17s Goodyear F1 GS-D3s on the rear axle. The axle will be outfitted with the Baer Track disc brakes (on order), the fender lip rolled, and a spacer to push the rim out a bit (I know that 6" backspacing is a little much).

    Onto the question: What is the ideal tire width to fit a 17x9" rim? I was trying to look at the ETRTO and TRA standards to see what they say the ideal size is, but they want people to buy the standard.

    Thanks much in advance.

    Oh, if you know the sizes I'm looking at is a crap setup or will take much more work than I've let on, let me know! :D
  2. gives specs on all tires they sell. Check em out.
  3. gives specs on all tires they sell. Check em out.
  4. Thanks. Actually, I looked up the tire specs on the Goodyear website. :doh:
    Now, I just have to puny up the bucks for the rims and tires.
  5. Another question: This time about engine power and tire size.
    With the classic stangs, If I have a 3.89 Rear, an AOD, and 275 or 285 series tires, how much power can I effectively get to the road with performance street tires?

    I mean, past 400 fwhp, is there a difference in traction between 255s and 275s or are they both toast?

    I'm trying to judge all the stuff I put on the car and not underestimate any single component and/or spending time and money working to make a single component handle buku power with the rest of the system not able to handle it.

    Any advice would be much appreciated.
  6. On the wheel/tire size (and backspace) question I've found this is a very handy site:

    It's lets you pic the tire size, wheel size and backspace and get all types of measurements to use.

    To me the main factor on the tire is going to be which one. Sticky drag radials will obviously be much more sticky than hard daily driver radials. It you can get the 275 or 285's to fit I'd go with them. If you're serious about using all that horsepower you will likely need a different tire anyhow. Another factor is the stall speed of the convertor.. low stall, big cam, hard to spin.

    My 2 cents
  7. That's a pretty sweet site.

    So, basically, if I want to get all that power to the road, I'm going to need drag radials. Street Radials will always break free, but wider is still better. I can leesen the tendancy to smoke the tires by installing a low stall torq converter.
  8. so are there any definite answers on this? I think you will also have to worry about the spokes clearing your brakes.
  9. I contacted Newstalgiaweheels and gave them my situation. They responded very quickly by saying that there was enough ID in the Boyd Smoothie 2s (what I asked for because the Torq-Thrust M's backspacing is too much) to clear the Baer Track system. I don't know about spoke clearance, though.
  10. I'm not sure how the Baer brakes change the equation, but you shouldn't need a spacer or have to roll the lips with six inch backspacing.

    A 255 series tire would be ideal on the 9 inch wheel. A popular size is to go with 9.5s and 275s.
  11. I made a little wooden mock-up to test back-spacing and tire size. It turns out that, with a 275 series tire, I will have to have a 4 to 4.25" BS. 4" puts the outside edge of the tire perfectly in-line with the sides fender of the car and about 1/2" away from the leafs. Hmmmm. Maybe the Torq-thrust Ms are not in the cards.