Who's running wide tires on the front?

Chassis, Suspension and wheels

  1. Opticon77

    Opticon77 Well-Known Member

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    I want to squeeze a 255 on an 8" wheel in the front. I'm trying to figure out max backspacing before the I run into suspension bits. The problem is I'm starting from the stock 14" pizza cutters and a sketchy alignment there's too much room for error.

    If you have specs throw me your front tire width, rim size, backspacing, etc. I can do the math from there.

    I promise I'll post pictures when I get these weapons under the wagon on some deep steelies. Thanks.

    (And yeah I'm looking at you, Duke5A.)

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    Last edited: Jul 24, 2018
  2. AJ/FormS

    AJ/FormS Well-Known Member

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    Have you thought about how you are gonna be able to align it afterwards, so you can actually drive and steer it?
     
    Last edited: Jul 24, 2018
  3. mike2

    mike2 Well-Known Member

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    i saw a super coupe with 255/60/15 on front , they looked like factory rims . I think they have a negative offset .
     
  4. 89.Fifth

    89.Fifth Well-Known Member

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    I will tell you that Jeep wheels and Dakota wheels have too much backspacing and will hit your control arms. I don't know the numbers offhand but that's definitely too much.
     
  5. Opticon77

    Opticon77 Well-Known Member

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    I'm a little confused by the question. Yes I intend to have it aligned (by an old local street rod suspension wizard). As far as specs... aggressive. Something like -2.5 deg camber, 5 deg caster, toe-in near zero. And I'm open to pretty much every suspension mod short of those $6k drag cradles. FirmFeel is just going to love me.

    Is there any specific intrinsic problem with wide wheels on F bodies I should look to solve? Wild scrub radius? Bump steer? Upper control arm or fender contact?
     
  6. Opticon77

    Opticon77 Well-Known Member

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    Modern cars tend to have a positive offset so this doesn't surprise me. I'll do a little searching for Jeep and Dakota offsets just to confirm they are positive.

    EDIT: Dakota looks like a 16x8 with 5" backspacing (+25mm offset).

    I have a set of 16x8 with 4" backspacing (zero offset) inbound for the rear of the car. I'm going to mount up tires and test them up front for basic clearance.
     
    Last edited: Jul 25, 2018
  7. AJ/FormS

    AJ/FormS Well-Known Member

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    Comments in the quote,click to expand
    Before you do one single thing, go talk to your wizard.
     
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  8. Opticon77

    Opticon77 Well-Known Member

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    Greetings earthling. It would be easier to show you... *touches forehead


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    Old Poly 318 stroked to 392 and cammed. Cobra disc brakes with all custom stainless lines, Sway bar mounting points added to the K frame. Vulcanized goldline sidewalls onto a set of Yokohama Sdrives around Wheel Vintiques 17x8 smoothies on a 1966 C body.

    I know there's at least one guy rolling around here that runs 255s over even larger 17x8 wheels on a very tuned up Mbody. Share your secrets.
     
    Last edited: Jul 25, 2018
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  9. XfbodyX

    XfbodyX Well-Known Member

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    It looks by the sidewall of that stack of tires they are 15s, right?

    What type of driving do you plan to do? Do you plan to do anything to the front suspension?
     
  10. Duke5A

    Duke5A Well-Known Member

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    Got your page. :cool: I ran 255-45-18 on an 8" on the front of my Fifth Avenue until last week. At full lock it would rub ever so slightly on the t-bars and k-frame. Now I'm running 245-40-18 and they clear just fine. 255-40-18 might also have cleared, but the tires I have were special order and I had to be certain.

    Rears are 285-40-18 on a 9" rim. They rub when the ass squats in the forward part of the wheel well on the backside. I don't think it's bad enough to warrant going smaller though.

    Ask Firm Feel about their custom torsion bars. I have the 300# bars on my car and wouldn't have minded going stiffer. 300# are about the equivalent of a 1.14 bar in a B body.
     
  11. Opticon77

    Opticon77 Well-Known Member

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    Do you know your offset or backspacing?

    Is this the clearance on your 255 up front? ...

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    I see that Firmfeel upper control arm. But it doesn't look like a requirement for fit. Even at a tighter 16"diameter... but I might go that route just for the additional caster.
     
  12. Aspen500

    Aspen500 Well-Known Member

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    I've got 15x7 Rallye's on the front of my Aspen with 225/60R15's. The lip of the wheel is about 1/4-3/16" from the end of the control arm. IIRC, the 15x7's have a 4.5" backspacing. Any more than that and they'd be into the control arm.
     
  13. Raff

    Raff Well-Known Member

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    I'm pretty new to the whole F body thing but didn't Super Coupes come stock with 15x8 all around. I've been trying to find the back spacing on those wheels without success. I'd like to do 8" rims all around on my wagon. I'll definitely follow this.
     
  14. Duke5A

    Duke5A Well-Known Member

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    Yeah, these are the two areas. I know you don't want to with a $6k front suspension conversion, but if running wider tires is that important a conversion would get ride of these obstructions.

    Front rim is a VN515 18x8 with 4.5" of backspace and the rear is a VN515 18x9 with 5" of backspace.

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  15. AJ/FormS

    AJ/FormS Well-Known Member

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    Ok so
    back in post #1 when you first posed the question, and also posted the pic of the Volare wagon,and then said "I promise I'll post pictures when I get these weapons under the wagon on some deep steelies"; I guess I was wrong to assume the question pertained to the Volare?
    So what has the "1966 C body", got to do with the wagon?
    So once again, good luck aligning your FJM to the posted specs,and then driving and steering it, on the street.
     
  16. Opticon77

    Opticon77 Well-Known Member

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    Price relative to the value of the car is certainly one sticking point but it's mostly the horrible ground clearance on those frames that makes them not an option here on PA streets.

    Aha. So with 4" backspacing it sounds like my biggest concern up front will be not with suspension contact (maybe even giving me the room I need for that more aggressive camber) but out at the fender lip to the tune of 1/2 inch or more. Maybe this calls for a different strategy...

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    That is correct. My current victi.. er.. project is the Volare wagon.

    You asked "what world I was from" and suggested I prioritize seeking guidance from someone who you probably expect would crush my dreams after I set some unconventional targets for a largely unsupported Mopar platform. The tastefully upgraded Fury was a cheeky response to your implied notion that I don't know what I'm getting into. And a small attempt at warming your cold cynical heart.

    Do you like it?

    Why thank you.
     
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  17. Duke5A

    Duke5A Well-Known Member

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    I don't know about rolling the fender lip....might work. I wonder if you could get fender flares that would both fit and look cool. That would give you plenty of room and even Mad Max kind of look. I think it would be bad ass.

    Something like this, but maybe not nearly as wide:

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    Your biggest immediate concern is going to be the weak torsion bars upfront. Call Firm Feel and talk over your end goals with Dick or Dennis.

    Here are the specs I just had my front end aligned to.

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    Last edited: Jul 27, 2018
  18. Opticon77

    Opticon77 Well-Known Member

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    Good stuff. Did you run out of slot for further camber adjustment or chose not to run any more?
     
  19. Duke5A

    Duke5A Well-Known Member

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    Could put more caster into it if I wanted. The FF upper arms are longer than factory to give even more adjustment if wanted. My primary concern right now was for it not to eat tires. I'm not doing any autox with or the like at this time. Still need to do something with the factory brakes before I start thrashing up parking lots.

    BTW, I edited my previous post as you were replying.
     
  20. Opticon77

    Opticon77 Well-Known Member

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    Trying to avoid flares. So rare that they're clean. I don't even like the kit car stuff (wide flat with exposed hardware). The only time I ever saw them done well on an F was one very specific Kellygirl car #61. And even these could have had a softer angle returning to the bottom of the body.

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    But I'm not really trying to get that wild... yet.