For all considering 305-wide tires w/ stock suspension

Discussion in 'Brakes, Wheels and Tires' started by domesticpower, Jun 12, 2019 at 1:17 PM.

  1. domesticpower

    domesticpower Track Addict

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    I had a lot of doubts before pulling the trigger and it seems like I'm not alone judging by the number of wide wheel/tire threads on here and questions I got. Hopefully this thread helps everyone looking to fit something this wide, especially on stock suspension for class or budget. The tires do poke out a bit and I figured rubbing is all but guaranteed at full compression once I saw them on the car... but I couldn't be happier I trusted APEX and those on here who have run it. Here's what you need:

    1. Camber plates: I have MM C/C plates and they are maxed out at -2.3 deg with the stock struts. I have been running them for about 3 years with many track days without issue. APEX recommends at least -3 deg in their fitment guide but I had no choice because I was maxed out.

    2. 1"/25 mm spacer: I have Motorsport-tech 1" spacers and they look like high quality units. There is maybe a 1/4 inch clearance in the back so you can't go any narrower than 25 mm. http://www.motorsport-tech.com/adaptec/car/ford_s and you want Design 2.

    3. Elongated studs: your best bet is to get the FPP hubs with elongated studs instead of reusing the old one. Bearings are consumables anyway so if you're like me and you've been enjoying your car for several years, it might be a good time. They are a bargain considering that they come with ARP elongated studs already pressed in. https://lmr.com/item/M1104A/Ford-Racing-Mustang-Front-Hub-Pair-With-3-Arp-Studs You will need open ended lug nuts which are sold separately.

    4. A good quality 11" wheel: APEX of course! I got square APEX EC-7 19x11 ET52 for rotation, although APEX offers a different offset 19x11 so you don't need a spacer but the spacers will likely pay for themselves quickly in tire life (allowing rotation).

    Here's how the car sits on 305/30/19 RE-71R's all around. I'll post a review of the tires if there is interest, but after a couple of days at the track, I can comfortable say there is no rubbing. The car feels fantastic with this setup. It looks great too... which was a very popular opinion over the weekend.

    Boss 302 Paddock 1.jpg
    Boss 302 Paddock 2.jpg
     
  2. KRyn

    KRyn TMO Intermediate

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    Thanks for sharing this information and pictures, greatly appreciated. I am still trying to decide between 18" or 19" wheels. The Black Satin EC7s look great on the white Boss 302!
     
  3. JDee

    JDee Ancient Racer

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    Tire review would be cool. Where are you getting the RE71's?
     
  4. Norm Peterson

    Norm Peterson Corner Barstool Sitter

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    With respect to that last bit, you might try running the OE closed nuts down over the open-end nuts. You get a somewhat more finished appearance and the stud threads are better protected against the elements. Something like 30 ft*lbs seems to be enough to guarantee they'll stay put and not so much that there's much risk of thread damage.

    Shown on front 18x11 Forgestar wheels that work with no spacer. At offsets up in the +50's, part of the OE nuts sits inside the counterbores of the wheels (looks better). I do remove them and retorque the open-ended nuts before each track event, and replace them afterward. I *might* replace them after retorquing for a wet track day, but I haven't run across that situation since upgrading to the FRPP hubs . . . in the wet a few more in*lbs of rotating wheel mass isn't going to matter.

    Your wheels aren't wide enough - web.jpg


    Norm
     
  5. domesticpower

    domesticpower Track Addict

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    Happy to help! 18 vs 19 is a tough choice. Cons and pros to each but 19 is generally better IMO except for cost, and it was a no brainer for me because I was hitting the limiter in 4th on the old setup (18's) just before braking for one corner on our track.

    Thanks! I agree, it looks great! Those are anthracite, though, for what it's worth. I think it shows the detail/design much better than black (and will hide brake dust better lol).

    Sounds good, will post it. I bought them from a local OK Tire shop that sells a lot of race and time attack tires to competitors here and can typically get them at a good price.

    Thanks Norm, something to consider. I do like the idea of covering up the top of the thread but don't know how much I like double stacking lug nuts. Have you been doing this a while?
     
  6. Norm Peterson

    Norm Peterson Corner Barstool Sitter

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    Just on this car and just since replacing the front hubs and rear wheel studs. Maybe two years?

    But I'd do it again if a similar situation came up on a different car.


    Norm
     
  7. blacksheep-1

    blacksheep-1 TMO Addict

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    This is great info, when we run this stuff we throw spacers at it and do whatever we need to in order to make it work, someone taking the time to write it all down and pass it on is really helpful. With regards to the lug nuts, I've taken them in my lathe and cut the tops off so that I can see the how many threads are engaged. Since looks are kind of secondary from my perspective, it doesn't bother me if a few threads are past the end of the nut..in fact it kind of makes me smile.
    These cars need all the rubber they can get, in SCCA T2 they are required to run 275 (even though Camaros with an IRS get a bigger tire) and they are really marginal trying to get them to last for a 40 minute race. I've seen them burned off in a 15 minute practice session. They need at the very least a 295, or better yet a 305.
     

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