[73challengerguy]

okay i have a 73 challenger all stock except for ss springs.....im trying to go with a large dia rim with a small side wall tire....i want the retro look like say widened or higher mag 500 trhough stockton rim co,.....or specialty wheel.......but im not sure what will fit and how big and wide i can go....my car with the ss springs sits extremely higher than stock so i could go with a pretty big rim and tire, any buddy have any suggestions, i dont wanna make a1000 dollar mistake....lol..........i hav measured i can use 4 1/2 inch backspacing maybe?...5 inch.......thanks

[fbernard]

For example, I'm using 19x9.5 on the rear, with 5.25 offset. 19x8.5 on the front, which I originally measured at 4.75 offset (I later went to an AlterKtion and changed the front offset).

Tires are 275/40/19 at the rear, 245/45/19 at the front.

I have ample clearance at the rear (tire is 3/4" away from the springs, and more than 1" fron the quarter panel), and even more up front.

Don't get more than 245 (or maybe 255) on the front tire (aiming for 27 to 28" tire diameter), or the tire will hit the lower front fender on turns (my clearance there is 1/2", but it can not get closer, since wheel movement is impossible in that direction). That is the only critical clearance on the front with big wheels.
275 on the rear is good. You may be able to use 295s with the SS springs, and a staggered set (17" front, 19" rear) might look nice with the rake of the car.

Check your car to make sure the rear end is centered.
I used a Wheelrite tool to measure possible rim sizes, you can get one or do the same with a ruler and some time.


Whatever you do, see the wheels in person if you want to go with enlarged classic designs, as they can be weird or downright ugly). The rallye wheels larger than 15" are UGLY (that's my opinion, sure, but most people I know agree with me on that).

The Magnum wheels look OK up to 17", after that they look kinda funny up close - too much blackout area) ; these wheels have poor brake ventilation (not a problem for a street car though).

[dave-r]

I don't like the larger than stock diameter magnums and Rallye's. They look very strange.

Nor am I keen on wheels bigger than 17-inch diameter on Challengers. They just don't look right to me.

Call me old fashioned but for me you can't beat a nice chrome 5-spoke.

Use one of these spreadsheets to work out what your final tyre diameter will be. Just add in the wheel and tyre size you want to try. It will also tell you what speedo gear you will need with that combo.

http://challenger.mpoli.fi/web/4SPEEDchart.xls is for 4-speed users.

http://challenger.mpoli.fi/web/AUTOMATICchart.xls is for automatic users.

[73challengerguy]

does your car have ss spring?

[fbernard]

does your car have ss spring?

Mine? No, I'm using XHF Mopar Perf springs (not all that good by the way).

[dave-r]

And mine I had made to my own spec.
Plus my springs are almost an inch inboard from the stock location. So I could fit 295-50-15s on 15x10 wheels under there.

SS springs lift the back end a little too high. They are really for fitting slicks which of course would have a high sidewall. The spring rate is higher on the passenger side too. Which is not ideal for handling.

[73challengerguy]

yeah im pretty much straight lining the car.....not worried about too much handling....but im trying to to fit the wheel well as much as i can.....maybe a 16 inch or 17 inch custom mag 500,......from stockton?........the ss do make the car sit up a bunch...although i learned i can adjust down one notch.....in the front of spring to bring the car to the tire....so im trying to figure out what tire size a can squeeze in it?.....with the 16 inch rim.....X8.....with 4 1/2 back spacing

[dave-r]

No substitute for a tape measure. Be sure to measure both sides and check to see how centered the axle is under the car. What fits one side may not fit the other.

[fbernard]

An 8-inch wide wheel will fit with no problem. It gets tricky when you get close to 10. My car originally had 15x10 rims with 295-50/15 tires and they rubbed on the quarters (the tire sides really bulged out, which doesn't happen with bigger wheel diameters).
19x9.5-inch wheels and 275 tires fit like a charm, I'm sure I could have used 10-inch wheels and 295 tires.

The bigger the wheel diameter, the more wheel width is important to tire size. While you can fit a wide tire on a narrow rim in 15" (looks like a balloon), you can't do that in 17" or higher (sidewalls can't bulge that much, they are stiffer).

It's pretty easy to guess the backspace once you know what works, but you still have to measure to be sure.
Starting from the usual 7-inch wheel with 4.5 backspace, add 1/2" backspace for every inch of wheel width.
10 : 5.5 backspace (tire-to spring clearance was getting low on my car with this size)
9.5 : 5.25 backspace (that's what I picked, almost 1" tire-to-spring, 1" to the quarter)
9.0 : 5.0 backspace (more than 1.25" clearance everywhere)
8.5 : 4.75 backspace
8.0 : 4.5 backspace
...

[dave-r]

The 295/50/15 BFG radials I have fitted on the stock suspension using 15x8 wheels with (I think?) 4.5 or 5-inch backspace? But there was only a quarter inch between the inside edge of the tyre and the back half of the leaf spring.

The same tyres on 15x10 wheels with 5.5 inch backspace caught the wheel lip and were hard up against the springs.

I cut and welded the wheel lip and fitted offset spring hangers. That gave me plenty of clearence all round.

The 28x10 drag slicks I use at the track are slightly taller and narrower (about 1.5 inches both ways) than my street tyres but slicks can move around under the arches a lot more so it works out well.

[73challengerguy]

okay guys thanks for the advice im still pulling my hair out though and the wheel company is lost.....they gave up and said they couldnt help me...........see what you two think.....of this ....first thing dave my rearend isnt perfect....im off a 1/4 exactely from the drive side to the pass side...on the backspacing.....(measuring from the brakdrum face to the shortest distance on my leafs)......my rearend needs slid over more to the drivers side.....is a 1/4 inch gonna screw me?...on zeroing in on rim and tire sizing?.....could i offset it with a .025 spacer on one side?........if i decide not to move the whole housing?..........
okay so back to the rim backspacing.....i had my car on jack stands on the housing and on the unibody up front.....at first it looked like i needed a ton of tire to fill the wheel housing....i since put a set of 4 1/2 b.s. factory mopar aluimimum rims..width im not sure of?..but there mounted with a 265 50 15........and with these tires i dropped the car down on the ground off the stands......NOW my car does not have motor in it yet so im sure it will change things to a degree...( i can set my motor in it to put weight onthe front if needed)......but now the car is squattin alot lower on the ground with that wheel combo...so it doesnt look at bad..still i can im sure put a bigger wider wheel combo on......what i want to do is use a 16x8 speciatly wheel rim mag 500 on the back.....16x7 on the front.....
there telling me that in the front there recomending 4.25 b. s......
and the rear 4.50...(stock).....with a 16x8.....and max tire series of 245!????..........this i dont get........i dont understand why if i use a stock backspacing on custom wheel....what am i gaining??as far as a deep dish?
i want to be able to visable see the difference of of rim dish between the front and rear wheels......and im afraid if i go witht there setup i wont be happy....maybe i will?...but its 1,200 dollar gamble......
if im understanding back spacing,......thats only a 1/4 diff b.s.....between the front and rear rims.???.....i want a deep dish look...specially in the rear.....so why couldnt i run say a 4.25 or a 4 inch bs to give me that look in the rear?.........when i try to ask them that they just gave up??? and said we dont understand what you want!!!!
so heres the numbers......with the rims i do have. (4.5 bs) hanging a plum bob from the inside wheel lip......to the front of the center cap on the rim is.....2 1/2 drivers side and 2 1/4 pass side (hence the rearend thing)...this isnt a height issue with these tires cause ther 15 inch on 50 series...but with a 16 inch on a taller wider tire im assuming this measurement is important
now on the inboard side with that tire on,there is a 2 1/4 gap between the rubber and the leaf spring......and im assuming a 1/4 diff on the other side with the rearend centering problem........
with the tires off and just measurein from the front of the brakedrum. to the narrowest spot of the inboard leaf.....driver side is 7 inches in front of the drum down to 6.25 behind....the leafs measure a shorter distance as they head back to the rear of the car?.....and on passenger side its 6 75 down to 6...again cause of the centering of the rearend....
am i asking for the impossible here?......i want the 16 inch look....but obviously want the biggest tire and width i can run...specially in the rear....235 series in the front i think is what i read on here.....and theres a ton of guys running that 15 inch 275 tire that looks great with a stock setup.....but with my ss springs wich i beleive makesthe car sit up higher than stock.......i have this problem,i guess of trying to use a 16 rim and trying to get a deep dish look and fill up my wheel housing???????,.......im going nutso here trying to figure it out......ANY help would be so helpful to me guys......so do you think a 4.25 or 4 inch b. s......on a 16 inch 8 inch wheel.......is out of the realm........of reality.......i see so many people stuffing huge 18 19 inch rubber under these cars.....(not knowing though what it took is the hard part)......i can t figure why i cant get this to work............i know this is a killer long email....but im laying it all out there so anybody that could help me.....would have all the info

[dave-r]

If you want a taller tyre use a different profile. Say a 60 series instead of a 50 series. The width will stay the same.

Yes the springs are not parallel. They are closer to the wheels at the rear.

Like your wheel company. I don't understand your problem. Except maybe you don't have the confidence to just measure how big a wheel you can fit and the consequences of getting it wrong!

I don't blame you there. I would be worried if I was going to spend that much.

Just measure from your existing wheel/tyre how far you can safely go in each direction. Then order the wheels and tyres to suit.

Have some confidence in yourself.

If you are going to the absolute max size possible I would strongly suggest you center the axle under the car. A spacer will not cut it.

But first make sure you adjust the axle bearings first. It adjusts on one side only so get that right first otherwise it might throw things out again.

[73challengerguy]

yeah i now what ya mean.....i just cant seem to get a anwser fromt he company i want to deal with.......i wnat those mag 500s...lol guess just dont understand the backspacing thing....so im nervous about tell ing them to build some thing im not sure about.....seems like each company wants a diferent type of measurement on bs......confuses me.....
thought i could give them those measurement i listed in the email and they could say what would and wouldnt work......but they wont....
yeah i was wondering about that axle bearing thing and if that quarter inch cvould be taken out of the equation with the proper preload on the bearing.....i noticed that on the pass side ...where you spin that washer....i dont know how to set that....so i just put it all together to get the car on the ground..........do youthink dropping the motor init will help narrrow things down too?......

[fbernard]

Understanding measurement is a simple thing, once you know the difference between offset and backspacing.

- Backspacing is easy to measure (depth of the wheel, as measured from the backside, from the wheel lip to the wheel mounting flange).

- Offset is not measured, it's calculated. It's the distance between the wheel mounting flange plane and the wheel center (which is a little weird to calculate, it's not the middle of the wheel).

Some wheel retailers/builders want to know the offset, others want to know the backspacing.

More info here : https://www.rsracing.com/tech-wheel.html

From what I saw on my car, zero offset is best for a Challenger.

You can use the web page below to simulate different wheels and tires (I used it a lot to see equivalent tire sizes and make sure I stayed at the OEM tire diameter) : http://www.bigcustomwheels.com/rt_specs.jsp

For your car, you have two solutions : the lazy way (measure for your wheels on the worst side, the wheel will have a little more clearance on the other side), and the hard way : remove your rear end, grind off the spring perches, and weld on a pair of new ones 1/8" from where the old ones were, being carefull not to offset the pinion angle, so your rear end is centered.
I would take the lazy way out (in fact, maybe I did, but I'm not sure anybody will notice a 1/8" difference between either side on my car!)
That's 3 millimeters deviation on a tire that's 275mm wide.... We're talking 30ish-year old cars here, not space shuttles!

Check out a tire retailer (http://www.tirerack.com is a good place to get really available tire sizes for the tires you want), and make sure you can get the tire you want on the rim you're considering before you buy the wheels.

I spent 6 months doing this, so don't sweat it if you can't make up your mind quick. I originally started looking for Torque-Thurst D's, and couldn't find them in the right width, then I grew fed up with the ubiquitous look on those wheels and started looking at other models.

Then I did what finally led to my choice : I measured what could fit (9.5" rear), and started looking for every wheel in that width, from 16" up. Ended up buying 19" because of tire availability (load rating, speed rating etc.). Finding good tires in 16 or 17" sizes, that match the original diameter, and are not 'truck' tires (good luck finding 255/55R17 tires in any performance series) is a daunting task.

Don't start looking for tires once you have bought your wheels. Choose a tire size first, check that it's available, and then get the wheel that can be used with it.

I limited my choice to the 'Extreme Performance Summer' and 'Max Performance Summer' ranges at Tire Rack :
http://www.tirerack.com/tires/surveyresults/index.jsp

All the good-sized tires I could find in 17 or 16 sizes were for SUVs.
Some 18" and 19" were for cars (mostly Porsches, Ferraris and Mercedes)

(Perceived) Wheel dish is largely subjective, and depends on the wheel design. I have about a 3" dish on my rear wheels (http://www.forgeline.com/wheels/md3p.jpg ), it would 'look' bigger with 5-spoke wheels because of the smooth portion between the spokes (example : http://www.etwheels.com/et/classic5.html )

[73challengerguy]

well the biggest problem with these rim companys that they SUCK.....no one calls you back or faxes what they say there gonna....its ridiculous......im here calling them for help so i can SPEND my 1200 to 1800 dollars....its no wonder the japs are kicking our ass.....american companies are lazy......and they wonder why they go out of business or there business is down..........it really pisses me off ....ive been trying for weeks to get some one that will help me......and take my money..........for example......billet speciallities....never called me back..........stockton wheel.....rude and never returned my call.......Specialty wheel.....they were helpful but finally just said...we dont think we can help you with what you want?.........so then i move on to et wheels........said they were gonna fax me over info and email me pics of diff rims.......never did it.........HOW CAN THIS BE......am i the only guy in the country with a dodge that wants some nice rims!......geez

[72challengerorange]

Take a look at this thread, many wheel and tire sizes listed along with BS.

Tom

http://www.cuda-challenger.com/cc/index ... ic=19470.0

I bet that the wheel co's want you to tell them what sizes you want so they don't get blamed if they don't fit.

[dave-r]

along with BS.

Tom

I am sure it is the truth!


There are a lot of threads on here as well if you search for them.

[73challengerguy]

OKAY GUYS IFINALLY FOUND OUT WHAT TIRES AND RIMS WILL FIT ON MY 73 CHALLENGER......ALL STOCK WITH SS SPRINGS UNDER IT....MY BUDDY LET ME MOCK UP HIS RIMS ON MY CAR.....IVE BEEN PULLING MY HAIR OUT ON WHAT TO BUY AND WHAT AND WONT FIT!.....THESE FIT PERFECT....LOOK AWSOME.......295\45\18 NITTOS 555'S ONTHE REAR AND 245\45\17 NITS ON THE FRONT .....WITH 5.5 BS AND TONS OF DISH IF THATS WHAT YOU WANT,....THATS WHAT I LIKE...FILL THE WHEEL WELL UP PERFECT.....NO RUB.....THE ONLY THING THATS CLOSE IS THE REAR SHACKLE ON THE PASS SIDE, MY REAREND IS SHIFTED OVER 1/8 INCH....SO ITS CLOSER ON THAT SIDE BUT DOESTNT RUB...THE DRIVERS SIDE IS A EASY 1/4 INCH OR 3\4 SPACE ON THE LEAF......WHAT A LOOK THOSE THINGS SCREAM TOUGH......TRY TO GET SOME PICS EVENTUALLY.....HAVE TO ORDER THEM AND GETTEM ON....GOTTA THANK MIKE C FOR LETTING ME BORROW THEM AND TAKING THE GUESS WORK OUT OF THE EQUATION......