Going Square, what is needed?

Discussion in 'Suspension and Chassis' started by VoodooBoss, Jun 11, 2014.

  1. VoodooBoss

    VoodooBoss Rick Moderator

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    After seeing the light with wider sticky R comp tires I'm now seriously thinking about moving to a square tire setup for the track. What's the simplest way to modify stock suspension to move to a square setup?

    Also what is needed to run square 305/35/18 tires on stock suspension? NT01's for example? Will you most likely need spacers up front depending on offset? What about with Ford Racing 18x10.5" wheels, do you need a spacer for the front?
     
  2. Grant 302

    Grant 302 OPM Spent: $665,833 Moderator

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    Re: Going Square, what it needed?

    I think the 10.5" rims would take a big spacer up front. Backspace of 7.7" would need 1/2"+?

    And I think you'd be fine going square with your MGTAA suspension. You're running the FRPP sway bars? Otherwise I think the minimum mod would be going to a smaller rear bar or an adjustable rear.

    Might also want to check out this thread:
    https://trackmustangsonline.com/threads/how-to-go-from-staggered-to-square.7523/
    How To Go From Staggered To Square
     
  3. neema

    neema TMO Race

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    Re: Going Square, what it needed?

    Most may disagree, but I would drive the car first without changing any suspension components. That's probably the simplest modification ;). I make the huge mistake (over and over again) of changing too many things at once and never can put a finger what made the difference. anyways, with that out of the way, I'll walk you through the BBS 18x10.5s.

    They're 47mm offset, which is great for the rear, but cannot fit the front strut unless it's an offset Cortex strut. I can't speak for a stock strut, but on my old stock-ish KW strut, an 18x10.5 PF01 with the 305/35/18 was tickling the strut body with tire nubs. I used 1/8" or ~3mm spacers and never had an issue. The strut had slotted holes for camber adjustment but I did not position the strut in a way that would allow for more tire/wheel clearance (aka less camber). This makes me fairly confident that you would be in the same predicament. With 3mm of spacing, my 10.5" wide wheel with a 305/35 fit as close to the strut as I felt comfortable. It's an effective 35 offset. Like Grant said, you would need a 1/2" or 12-13mm spacer to make the BBS 47 offset 7.7" BS wheel work up front. Of course your sway bar end link stud would need to be either trimmed or spaced back to keep from rubbing.

    Everyone has a different comfort range regarding wheel spacers. I've seen the Boss WC cars use the 10.5" wheels in a square setup with a big spacer for the front, so there's some comfort in knowing that.


    If you want to swap tires and are comfortable running a spacer, 18x10.5 et47 is the happy medium. You can fiddle with the offset a little, but keep in mind that going lower means your rear wheel protrudes more and going higher means you need a thicker front spacer.

    If you don't mind forgoing wheel rotation all around, then you can go with an 11" setup just as easy as a 10.5. Go with a 50-55 offset in the rear and (based on my front wheel as a reference) a 28 offset in the front. I would go with an et 30 front just because the same tire on a wider wheel won't bulge as much. If the tire still got close to the strut, I have no problem running a tiny spacer although I'd rather not. If I could test a few fitments, I'd even try a 32 offset.

    I forgot to mention camber is a must, but I assume you have camber under control.

    Sorry for rambling. These are my observations over the past few years of fun wheel fitments.
     
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  4. 06mach1

    06mach1 TMO Addict

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    Re: Going Square, what it needed?

    I ended up with 18X11 Forgestar wheels purchased from Vorshlag. I run 305/35 NT01's and have P springs and factory struts. I run 2.7 degrees camber up front which is required but no spacer. I did have to trim some of the inner fender liner on in the right rear as for some reason it stuck out compared to the left side. These wheels do not allow you to rotate the tires front to back as the offsets are different.
     
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  5. 13Boss#3328

    13Boss#3328 TMO Race

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    Re: Going Square, what it needed?

    Rick, I went square setup ( 295/35-18) and I was looking for the simplest and least expensive way to accommodate for this change, so I decided to get 20mm rear sway bar (2005-2009 GT take-off).
    Absolutely stunning results with dampers set to 5 all corners! Which means neutral balance and you can get on throttle earlier, in a twisted kind of way it reminded with my previous Subaru STI with less understeer.
    Next time I see Nick on the track I will ask him to drive my car and give his opinion, him being more experienced driver after all.

    But it is really cheap and effective. I am not saying it is the best way though, since a lot of people advised me to get adjustable front/rear setup, but I refused because I wanted to keep it as stock as possible and also reduce the cost, $$ obviously $$ ;D
     
  6. steveespo

    steveespo Lord knows I'm a Voodoo Child Moderator

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    Re: Going Square, what it needed?

    Rick
    I am not running square 285/305 but do have the Ford Racing 18mm rear bar and have maxed out the Koni dampers in the back and 75% up front. The car just plants and goes, I try to get back on throttle before the apex and it has helped my corner exit speeds without making the rear twitchy. With the stock bar I felt like the car was on top of the track in the rear and I had more understeer than I have now. Doesn't seem right to add rear grip but reduce understeer but that is what I feel. The race cars are running tiny or no bar at all out back and if you look at some of the photos you see how much weight they are getting on the rear tires to the point of lifting the inside front wheel.

    Our cars have high horsepower and are pretty porky so we won't win many pure cornering duels with 911s and M3s but if you can get to the power earlier on exit and lengthen the straights we can increase speed and also utilize the good y-axis bite in the brake zones.
    I also think the cars should have more spring rate both front and rear to prevent going on the bump stops.

    Just my humble opinion.
    Steve
     
  7. VoodooBoss

    VoodooBoss Rick Moderator

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    Re: Going Square, what it needed?

    Thanks guys. I'm on stock sway bars and use Enkei wheels and my 10.5's are the 38mm offset. I was hoping Neema would stop in as I've seen his car with a square Enkei setup and he was flying at LS. Your comments have killed the BBS idea.

    Is a 10" wide wheel too narrow for 305's? I know some of you run them and that makes the Blowfish TD wheels an option. According to the Nitto specs a 10" will work but seems wider would be better.

    So a smaller rear bar or adjustable would work. I have my eye on Cortex JRI dampers but don't want to need that if possible.
     
  8. ArizonaBOSS

    ArizonaBOSS Because racecar. Moderator

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    Re: Going Square, what it needed?

    I run 305 Pirellis on the SVE Drifts and the Roush wheels, both 10" wide. They will work.
     
  9. F.D. Sako

    F.D. Sako TMO Addict

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    Re: Going Square, what it needed?

    So far, 13Boss#3328's 05-09 stock GT rear sway is sounding the best option, as far as cost vs. performance. Since I want to leave stock components in as long as possible, as well.

    13Boss#3328, did you have to purchase anything else to make the swap work? (e.g. bushings, endlinks)
     
  10. Tucson 302

    Tucson 302 2013 Black LS #439

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    Re: Going Square, what it needed?

    I have 305 Conti take offs all around on the 18x10 Team Dynamics wheels they fit great
     
  11. cp85gt

    cp85gt TMO Advanced

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    Re: Going Square, what it needed?

    I have a staggered set-up and will be looking to go square as well. I want to eventually run the take-off/used 305 660 18 slicks. It seems the 18 x 10.5 +38 Enkei wheels fit great in the front with a small spacer, but poke out a bit in the back, but allow tire rotation. Since you already have this wheel in the rear, is there some other reason you don't think it is a good wheel for the front? It seems the easiest thing to do is just stick with a 18 x 10 and be able to rotate the wheels, and with an SVE drift being priced at $150 each that is hard to pass up especially since I think it will fit the 15" gt500 brake set-up as well. The Enkei wheels are more expensive, lighter, I think also fit the GT500 brakes, but run the compromise of a little bit of rear tire poke, but can still be rotated using only a small spacer. The higher offset wheels will probably require a good sized spacer, probably 5/8", but allow rotation without the rear tire poke. The BBS wheels are lighter and expensive, with the small 5% SVTP discount from Tasca about $550 a wheel but have the same large spacer requirement for the 18 x 10.5 size. You early adopters need to hurry up and get this figured out for what works and is reliable so the rest of us can copy it. One other thing is rear tire clearance to the sway bar. With the stock sway bar and an 11" wheel with a +55 offset there is about 1" of clearance and so far there has been no rub, but I have a watts link. With the Strano adj. rear bar there has been some reports of rubbing with the +38 offset 18 x 10.5 Enkei.
     
  12. modernbeat

    modernbeat TMO Advanced

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    Re: Going Square, what it needed?

    Yes, it physically fits. But in my testing once you pass 285 on a 10" wheel, the contact patch does not get any larger and the performance does not improve. I like a 295 on a 10" wheel for a daily driver because of it's height and aesthetics. But for performance, I'd go with an 11" wheel if I was contemplating a 305. And though a 315 will fit an 11" wheel, it works much better on a 12" wheel, though that will require a flared front fender.
     
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  13. cosm3os

    cosm3os TMO Addict

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    Re: Going Square, what it needed?

    Anyone else find it ironic that there isn't a tire sticky enough to slow a slide down the slippery slope? Actually, the stickier the tire, the faster the slide . . .
     
  14. 13Boss#3328

    13Boss#3328 TMO Race

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    Re: Going Square, what it needed?

    The stock sway bar comes with its end links and bushings!
    I got it for $70 from Rehagen racing, they had piles of sway bars, literally :)

    Rabee
     
  15. 13Boss#3328

    13Boss#3328 TMO Race

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    Re: Going Square, what it needed?

    not to turn this thread into a picture showcase, but I thought I can post a couple pictures with my car rolling as it may be helpful to give you an idea about the new tire setup/ smaller rear sway bar and the body roll/tire contact patch...I know it is hard to tell, but it is an attempt

    [​IMG]
    [​IMG]
     
  16. VoodooBoss

    VoodooBoss Rick Moderator

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    All good information and yes I have camber plates set at -2.1 degrees. So it sounds like buying another pair of 18x10.5 PF01's with 38mm offset is the easiest route for me since I already have a set. Although not a big consideration for me personally the ability to rotate the tires is a plus.

    So Neema a 3mm spacer was all that was needed? Did you have any rubbing on the inside of the front fender? Also are you going to Sonoma this weekend? I'll be there Sat morning with Moto aka Ron. You met him last year.
     
  17. Black Boss

    Black Boss TMO Addict

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    I'm sure there are others with more experience who should comment, but my experience is that the fronts wear out first and the rears heat cycle and get greasy first. Not sure that swapping front/ rear buys as much as swapping fronts left/ right, plus running staggered gets you more rear grip and helps with traction and reducing the point at which the rears get greasy.

    Just one theory....?
     
  18. neema

    neema TMO Race

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    Yes, just a 3mm spacer. There is a tiny bit of rub on the fender liner but only at full lock. I bought some roush steering limiters ($10-15) to try, but the rubbing is so minimal that I'm not that motivated to install them. If you go with the Enkeis, use your rear wheels/305s for a test fit and see how close the tire gets to the strut. Even if you don't go with Enkeis, your rear wheels can give you a good reference point for other brands/sizes.

    I wish I could make it to Sonoma but I have to get some work done as well as spend time with my dad this weekend. Soon...
     
  19. VoodooBoss

    VoodooBoss Rick Moderator

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    Yep I'm going to do that tomorrow when I swap my street tires back on.

    Both Andy and I will be at the Mini Nats @ Sonoma on Sunday August 3rd.
     
  20. Fat Boss

    Fat Boss TMO Addict

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    I've tracked at the Nor Cal Shelby Club Mini Nationals twice now and it's a great event. Kinda crowded but with awesome cars, mostly Fords. Wanna get your doors blown off by a Fairmont? Check.. Wanna run with a cobra driven by Bob Bondurant? Apparently check..

    BTW- Rick if you want to try a regular GT rear bar I have one that I'll give you.
     

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