elitesrock2
Well-Known Member
trying to figure out what the biggest tire from the DOT slick area i can fit under my stock wheel tub 69 dart
largest rear tire on stock wheelwell 69 dart
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mopowers
Well-Known Member
If you do the simple 1/2" offset of the springs a 275/60/15 will fit. You've got to nail the baskspacing of the rim though.
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RPMagoo
Just An Old Motorhead
-- Agree with mopowers. -- Here's a 68 Dart, that I built, I believe the spring off-set was 3/4". The wheels were modified Mopar 8" steelies, with a 4" backspace and 275/60-15" BFG Radial T/As.
I did the spring off set kit and a set of factory 15x8 rally wheels and got 275 60 15s
gold68dart
Well-Known Member
Stock wheel wells, stock spring location...I fit 255/60R15 on a 7" steelie with 4 1/2" backspacing. It is very tight but it fits
255 is pretty much the max for Dart's with the stock spring location and stock wheel wells, and those won't work for everyone without trimming or rolling the quarter lip back for clearance. Some cars can, some can't and the backspace has to be pretty much perfect. I wouldn't even go quite as far as saying a 245 was a sure bet for everyone, but it's definitely a safer bet with everything in the stock locations.
275's are the max with the 1/2" spring offset, and even those sometimes require some quarter lip trimming/rolling.
gold68dart
Well-Known Member
True! I had to trim off about 1/8" on the passenger side because I was rubbing when the car would lean around turns but the driver's side had a good 1/2" clearance and required no trimming.
Yup, it's pretty common for the rear axle not to be perfectly centered between the wheel wells. They're not usually off by more than a 1/4" or so, but even that's more than enough to make tire clearance on one side a problem.
And even the wheel wells themselves can be off by a little, on my '71 GT the axle is centered but there's an extra 1/8" in the width of the drivers wheel well compared to the passenger side, it's just how it's assembled with the quarter, wheel tub, frame rails etc. Not a big deal if you're ok with trimming the quarter lip a little to even things up, but if you don't want to trim anything at all you have to be careful.
And even the wheel wells themselves can be off by a little, on my '71 GT the axle is centered but there's an extra 1/8" in the width of the drivers wheel well compared to the passenger side, it's just how it's assembled with the quarter, wheel tub, frame rails etc. Not a big deal if you're ok with trimming the quarter lip a little to even things up, but if you don't want to trim anything at all you have to be careful.
leblanc
member 2883
BUT will it fit with a 10''-12'' rim like that tire should have???
A 275/60/15 shouldn't have a 10-12" rim. Recommended rim width for a 275/60/15 is 7.5" to 9.5". Tread width on that tire is 8.9", section width is 11".
There should be ~12" from quarter lip to the stock wheel tub on a Dart, and with a 1/2" spring offset that distance is the limiting factor. So, a 10" rim would work, as thats 11" wide (outside to outside). But that's the max. But for a 275/60/15 any recommended rim width will work with a 1/2" spring offset.
Now, if you're talking about running 18" rims, a 275/35/18 is supposed to have a 9" to 11" wide rim. So, an 11" rim wouldn't work, but you could still run 275/35/18's on 18x9's or 18x10's, and that would work fine.
harrisonm
Well-Known Member
Does anybody know of a link to a video or pdf instruction file on how the spring relocation kits work. I have looked at pictures of the kit, and I can't picture how it installs or how you get an offset.
The 1/2" offset or the full 3" spring relocation?
The 1/2" offset just uses the stock mounting locations, but the spring hanger is offset from the mounting studs so it moves the springs a 1/2" closer to the frame rail. The rear shackles then have an offset to them that does the same. Here's an article on installing an offset kit (mopar performance's incorrectly named 3/4" offset, it only moves the front hangers over a 1/2")
Installing Offset Hangers & Shackles - Mopar Muscle Magazine
The 3" relocation moves the spring hanger inside the frame rail, moving it a full 3", and does the same with the shackles. The rear frame rails have to be sectioned to do this. And, you need a mini-tub otherwise there's no point, the 1/2" offset makes the stock wheel tubs the limiting clearance. Here's some instructions on the 3" relocation
Move Your Springs
Here's a video on the 3" relocation.
The 1/2" offset just uses the stock mounting locations, but the spring hanger is offset from the mounting studs so it moves the springs a 1/2" closer to the frame rail. The rear shackles then have an offset to them that does the same. Here's an article on installing an offset kit (mopar performance's incorrectly named 3/4" offset, it only moves the front hangers over a 1/2")
Installing Offset Hangers & Shackles - Mopar Muscle Magazine
The 3" relocation moves the spring hanger inside the frame rail, moving it a full 3", and does the same with the shackles. The rear frame rails have to be sectioned to do this. And, you need a mini-tub otherwise there's no point, the 1/2" offset makes the stock wheel tubs the limiting clearance. Here's some instructions on the 3" relocation
Move Your Springs
Here's a video on the 3" relocation.
mopowers
Well-Known Member
You're kidding, right? A 275/60/15 on a 12" rim??? LOL
leblanc
member 2883
My 255/60's ride on an 8'' rim so 275's should get at least 9-9.5 right...
According to the tire chart I use a 275 is ideal for an 11'' rim but will squeeze on a 9.5, the wider the rim the better your handling and even tire wear will be. A narrow rim promotes wear in the center only, unless you lower the tire air pressure but that ruins the possibility of good cornering.
A 9.5" rim is the MAXIMUM width rim for a 275/60/15. Those are straight off the tire manufacturer recommendations.
An 11" rim is not ideal for a 275/60/15, it's not even recommended.
Like I said earlier, if you were talking about a 275/35/18 it would be a different story because of the much shorter sidewall. But even in that case the recommendation is for a 9"-11" wide rim. The rim should be roughly the same width as the tread width, not the section width, unless you're talking about a very low profile tire. Not sure what "chart" you're using, but something isn't right.
roccodart440
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10.4" section width with offset shackles.
9.65" section width with stock suspension.
340 demon 72
Well-Known Member
Can the rear offset hangers be used without doing anything to the front hangers??
Why? You wouldn't gain much wheel clearance, if any, because the spring would still be pretty much the same distance from the tire at the front of the wheel.
Yes, you could, but it would change the angle of the springs so you would still have to move the perches, or at least angle them to match the springs. You'd have to do the hardest part of the spring offset, ie, moving the perches, and get little to no extra space out of it. If you did nothing to the perches all you would do is side load the rear segment of the springs, probably too much to even get the shackles installed. And even if you angled the perches to match the rear shackles the spring eye wouldn't be parallel to the front spring eye bolt, so, you'd be putting a significant side load on the front bushing. And after all of that you'd probably only gain an 1/8" of clearance to the spring in the front. You'd have more in the back because of the angle, but it would hit in the front so you wouldn't be able to use the extra space created in the back anyway.
leblanc
member 2883
340 demon 72
Well-Known Member
So will be the max tire size and rim offset for a 72 demon with stock wheel Wells and stock location of the springs I'm going with 15 in wheels 8 in wide
So? Something on the internet is inaccurate. There's a lot of bad info out there.
It's a generic calculator, and based on all the graphics I would say it's biased to modern, low profile tires, which 275/60/15's are not. My information is coming directly from what's recommended by the tire manufacturers for that size tire. Sure, the calculator might get you in the ballpark, but you still have to check the specs for the tire you're actually installing. I could post a dozen calculators that would all have different numbers. Look at the specs for BFG T/A in that size.
BFGoodrich Radial T/A
That's a totally different car. What will fit on a '72 Demon with the stock springs is totally different than what will fit on a '69 Dart. Send me a PM and I can get some more info from you so as not to derail this thread.
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340 demon 72
Well-Known Member
Sorry for the demon question in the dart chat!!!
mderoy340
Well-Known Member
the BFG hockey puck chart shows the 255/60/15 tread width wider than the 275
The Pep Boys Futura Sport tires are pretty good for a street tire. Cooper Tire makes them. I've even run them at the track walking the car out a few feet and ran .3 of normal.
I run 255/70/15 29" diameter for the street and 255/60/15 MT drag radial 27" diameter at the track on my 67 dart 1/2" relocate.
The Pep Boys Futura Sport tires are pretty good for a street tire. Cooper Tire makes them. I've even run them at the track walking the car out a few feet and ran .3 of normal.
I run 255/70/15 29" diameter for the street and 255/60/15 MT drag radial 27" diameter at the track on my 67 dart 1/2" relocate.
scampman
68 dart gt guy
hello, I have a set of 14x7 cragars and want to do the same thing basically. small tires on front and max out tires on the back. I believe the rims are the standard backspace. sure could use some help here. thank you brian
BBP or SBP, and what rear axle? Stock spring locations?
The "standard" offset on the 14x7" Cragars is probably going to be your limiting factor. A lot of those cragars have a negative offset, most are zero offset at best. And either of those situations will keep you from running the widest tire possible even with SBP rims and the stock spring locations. To be certain we'd need to know the backspace on those Cragars.
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