Will this tire fit?-the insanity of this question

[RebekahsZ]

This question is posted repeatedly on this forum and I have an illustration that show why the question has only one answer-gotta try the wheel/tire on to know.

 

So I've burned up my 26x8.5 Mickey Thompson slicks and I'm in the market for some new ones. The day before I'm about to order from summit, a well meaning good ole boy says-"I gotta a brand new set of 26x9 Hoosier slicks you can have for $200." We'll why not, that's less than half price for a tire and only a half inch (1/4" per side) wider and I have plenty of room between my strut and the tire and between the tire and the fender lip. So a deal is made, someone gets paid and I'm feeling pretty good. Get tires mounted, screw them to rim and give them a trial fit. Damn! Even though the section width spec only differs by 0.4", the paper-thin sidewall bulges and rubs on the strut.

 

To get a tire that specs 1/2 wider on my car, the following work was required:

1) aluminum offset LCA bushings which requires:

2) remove and reinstall exhaust system.

3) adjust camber plates

4) 1/8" spacers (thank goodness I already have long studs

5) trim 1/4" off the lip of my fender arch

6) increase ride height/preload 1/2"

7) lower spring seat and jack tire into wheel well three times to ensure clearance then reset ride height

8) watch old video of car launching to see how much car squats on launch.

9) inspect Z31 turbo axles to ensure no axle bind.

 

Wish I had just replaced with same tire and spent the money-I'm whooped! Even if you think a tire will fit, you never know till you bolt it up. This little 2-night experience has solidified my decision to do BAMF flares this winter.

[Namor]

With a new car this is fairly easy question to research and answer because of the uniformity between 1 car to the next.  That isn't the case with our Datsuns.  Suspension components, age, vehicle weight, and any specific clearance issues unique to your car will have to be considered (just like your exhaust.)  You should be able to figure out the wheel specs fairly easily though.  I do also think this problem is exacerbated by use of drag slicks.  I have heard the variances between 1 tire to the next is larger with drag slicks, that could be BS I was told though.

[Phantom]

I would've thought they would fit too.  I'm running 225/50-16's which are 8.86" wide tires and I have about 1/8"-!/4" per side clearance.  Guess a little website perusal to get section width on the tires would have been good foresight.

[RebekahsZ]

Specs were thoroughly perused in advance (you ninny!), which is the whole point of this thread.  When squeezing 10lbs of stuff in a 5lb bag, the difference between fitting and not is a very slim margin.  Even after doing research, the only way to know if a tire will fit is to buy it and try.  Looking forward to some BAMF flares before spring.  I want to run a 10" tire next year-still spinning off the line.

Edited August 31, 2013 by RebekahsZ

[Phantom]

Heck - having looked at the section width specs I wouldn't have tried to fit either tire - unless I put in coil overs and got room in the wheel well - and then remeasured everything to ensure the wheels centered the tires on both sides perfectly and then I would have wanted 1/4" clearance on both sides just because.  Obviously that's why I'm running street tires and only go to the track to play -not to compete.  

I know the 36 year history of my car and know that it has never been in an accident.  That said the wheel well clearance is not the same on both sides of the car.  Oops.  Did something move over the 36 years or is it maybe possible the manufacturing tolerances that Datsun was using would allow +/- 6-10 mm on the centerline alignment? Guess we'll never know for sure but person after person will pay the price.

[RebekahsZ]

Have done all the above. Tires fit into fender at full bump. Lots of work to preserve the stock fender. Abandoning that soon. Too much damn work everytime I change shoes.