Rims and tires

Just got the bad news that Grrretchen's transmission won't be done until mid-April.

Will have to wait more than 6 weeks to get the AOD tranny with the wide gears and the 10.1 launch ratio...

So...

Started looking forward to the next modification of Grrretchen (for those not in the know, she is my 1976 Ford Country Squire wagon that is being...uhm...transformed)

Currently she has some sedate 235/75 R15 tires on 15" rims. Ordinarily that wouldn't bother me too much, except: she can't get disc brakes on the back with those itty bitty wheels. As per my usual exuberance I go "in for a penny, in for a pound."

Here is the plan then:
- 18"x9" rims with the 5x5" bolt pattern.
- 235/55R18s on the front
- 295/45R18s on the back

This'll make the odo read about 1.3% lower (this is the speeders equivalent of setting your clock a little forward to avoid being late) This means that when the odo says i am doing 60mph, i will really only be doing 59.2mph.

Two questions:
- anyone foresee a problem with putting nearly 12" wide tires on the back of the wagon (from a wheel well perspective?)
- am i completely insane for going with two different tire sizes on the wagon and +3 sizing the wheels just to get some larger disc brakes on my 4,800lb road missile?

Bonus question:
- Any thoughts on these rims for Grrretchen? http://www.olddogwheels.com/product_p/u104.htm

 

Rim size is a little off. 235s should be on closer to 8" wide rims, 8.5" at the most, 295s should be on 10" or so wide rims. The combo sounds nice other wise, those wheels look god on just about any American car.

Mike

 

235s will fit on 9s. As will 295s. But i get your point.

Those rims are available in a good variety of widths -- question is, how will it look. The only vehicle i ever owned with different sized front and rear tires was my '93 vette. not sure how it will work on the wagon...

 

http://rimsntires.com/specs.jsp?item=Wheel-Tire size comparer&sw1=235&ar1=55&bd1=18&rw1=9.0&et1=7&sw2=295&ar2=45&bd2=18&rw2=9.0&et2=7&text1=Front&text2=Rear

 

That's a cool site, I'll have to put that in my favorites.

I know they will both fit, and look ok, but I bet you will feel a bit of a wiggle in the rear from the bulged out side walls.

Mike

 

Go in for a pound, not a few schillings!

In for a penny, in for a pound eh?
How about those rims in 20x8 front, and 20x9.5 rear with
245/45-20s on the front
275/40-20s on the back

The 20" tire sizes are more readily available, and that usually means cheaper, and more easily replaceable if you need to use the road hazard warranty. It would also mean that an indicated 60 m.p.h. would be 59.63! Not to mention that you could run the biggest brakes you wanted! Good luck!

P.S. If you go to tirerack.com, 9.5-11" wide rim is recommended for 295/45-18. 9" wide rim would really be pushing it! I would not go narrower than the minimum recommended.

 

You wouldn't go up to 295 on the rear? I just need a boatload of traction with the amount of torque i have...

 

Was looking into it -- i don't think those specific wheels are available at that size with the 5x5 bolt pattern

 

295s

Because of the shorter sidewall, the 275-20s have almost as much tread width as the 295-18s. If you want short-tall, fat-skinny on the tires, the possibilities are endless. I seriously try to stay away from tires sizes that are hard to find if the car is going to be seeing ANY road duty at all. I have found that these tires all have the same diameter.
245/45-20
275/40-20
315/35-20

If you really want the car to stick, the 315s will put over 11.5" of tread on the ground. All those sizes, you can get 50k mi. tires, or 10k that stick like glue! If you went w/the 275/315 combo, you could run 10.5" wide rims all around. If you went with the 245/315, then I would suggest 20x8 front, and 10.5" wide in the rear. The section width on the 315-20s is only 3/4" wider than the 295-18s you originally talked about. Put the rear axle on jack stands, and with an old broomstick, 2x4, angle iron, whatever bolted to or ratchet-strapped to an old wheel that will bolt up to the car (without tire), you can get some pretty accurate measurements that will determine what will fit. Then you will know what kind of offset/backspacing you will need and go from there with rim shopping! There are several complete kits out there that you can find to change the rear over to disc brakes. 13" or 14" rotors would easily fit!

 

Try this link http://www.mhtwheels.com/pdf/specs/U104-6%20Standard1.pdf It shows the 20x8 and 20x9.5 in 5x5.0

 

I personally like the different size front/rears - makes the wagon look more aggressive. My wheels are 17x7 front and 17x9 rear, tires are 215/50 front and 275/40 rear. This was a +3 from the orginal tires/wheels and my wagon rides great on them, however I do get a very slight tire rub parking sometimes if I have to go to full wheel lock. No biggie in my opinion and it hasn't hurt the tires because it's at parking lot speed. Happy wheel/tire hunting!

 

I found another link. http://www.mhtwheels.com/wheel.cfm?cat=739 These are the U.S. "Indy" mags in 18" & 20" sizes in widths up to 15" wide! Yeah, the 295 wide 18's on 10" wide wheels, or the 245/45-20 front on 8.5 wide and 315/35-20 on 12" wide wheels.....that would look sick! If you have boatloads of torque, the traction of 315's would snap your neck! Can't wait to see what you go with!

 

A couple things to remember here. First, metal is heavier than air and rubber, so going too big increases your unsprung weight to the detriment of handling and braking. Second, check carefully for the load ratings of the tires. A lot of the very low aspect ratio tires have single ply sidewalls, and very low weight ratings. I've seen them AT their max rating with the car sitting still.

 

Tire load rating

235/75-15 load rating of 105 standard, 108 xl
295/45-18 load rating of 108 standard
315/35-20 load rating of 110 xl

All looks pretty comparable to me! The larger wheels may be a slight bit heavier, but the original point of the larger wheels was larger BRAKES, and enough meat to handle the torque. I was the one that originally brought up the idea of the 20's, and they both have their pro's and con's. For that year of wagon, and the power, the 18s would prob be best imo. It's all up to the owner's preference and how the car is going to be used. I just wanted to put info out there because when I was searching for non-stock size wheels/tires for my car, I decided on the 225/50-17s because they are an extremely common tire size, and I was able to get $200 tires used w/90% tread only 2yrs old for $30 each!

 

Really, i am just looking for some wheels that will allow for good sized brakes and that won't cost me an arm and a leg to replace te tires. I don't really care for the 'new' look in wheels/tires. However, i am willing to make an aesthetic sacrifice if it means improved performance.