Front tire help

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Sully_PA

Sully_PA

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Looked through threads a bit but didn't find a definitive answer ...I have a 76' Dart swinger that I have 255/60/15's on the back and was thinking I'd like to go 245/60/15 on the front...I have large bolt pattern disc's on the front and the wheel is 8" wide with 4.25" back spacing ....Anyone? If not whats the biggest you think i can do with that setup? thanks for anyone's input ...
 
15x8 with a 4.25" backspace?

You'll be lucky to get a 215/60/15 on there if those are your rim specs. Even a 215/60/15 would stick out a little further than the 275/35/18's I'm running, and they don't clear by much.

A 245/60/15 is 26.6" tall, which would pretty much make it a no go just on tire height alone. Next is the width, on an 8" wide rim you'd need 5" of backspace to get a 245 inside the fenders. Unfortunately you can't run that much backspace on a 15" rim because you run into the UCA's and brakes. With a 15" rim you're limited to about 4.5" of backspace in the front. Maybe a little more, but not much.
 
Thanks .....right now it has 205/50/15's on and they a ridiculously to small with no side wall ...need to fill that wheel well ...
 
Maybe a 225/60-15. Better bet is a 215/65-15. Both are around 26" tall. A 7" wheel with 4.75" or 4.50" backspacing would be almost perfect. I think that 8" wheel with only 4.25" backspacing you are trying to use is a real problem... everything is pushed outboard too much.
 
So I'm looking at this right now

P215/65R15 (95 T)

UTQG: 440 A B
Performance Rating: T
Load Index: 95
Load/Ply Rating:
Load Capacity: 1,510 lbs
Overall Diameter: 26.00"
Tread Depth: 10
Section Width: 8.40"
Tire Weight: 22.00 lbs
Maximum PSI: 44
 
I ran a 245/50-15 on an 8 rim for a while. 24.6 on the calculator.I moved it in 'til the steel wheel hit the '70 ball joint. I even trimmed the BJ for clearance. I still had to trim the sheetmetal so I could turn it to the steering lock. Note that the early BJ is smaller than the 76.My ride height was quite a bit lower than stock. IIRC the K was 5.75 from the ground-plane.
Point is, maybe your 76 wheel opening is a little bigger, and maybe your ride height is a little higher.If so than maybe you can make it work. But if you don't absolutely need an 8" wheel, the 7 is way easier to fit. A 235 fits in there easy.
 
I want to stick with these rims if I can as I've never seen this style before....going to paint the centers black ....Just got the whole drive train conversion done and would like to get the tires sorted ...here's a pic

33nxgya.jpg

2gsoplg.jpg

295g8eg.jpg


I'm trying for this look ....these rims look very close to the ones I have

oh8osl.jpg
 
The rim is the problem. You just don't have enough backspace. A 235 is really the safe max for a 15" rim, not because of the tire, but because you can't run enough backspace to keep it inside the fenders without hitting the upper ball joint and UCA. And even a 235 needs more backspace than 4.25" on a 15x8" rim.
 
72bluNblu said:
The rim is the problem. You just don't have enough backspace. A 235 is really the safe max for a 15" rim, not because of the tire, but because you can't run enough backspace to keep it inside the fenders without hitting the upper ball joint and UCA. And even a 235 needs more backspace than 4.25" on a 15x8" rim.
Click to expand...

Thanks .....guess I should go with the 215-65 R15 as its pretty much the same width as the 50 ....just 26 high .....I'll measure it all up again when I get home ...235 would have been nice :)
 
I know you're looking at 15s, but I must mention that 235/60-14s on 7 inch rims fit really well. They calculate out to 25.1 tall. They rub nowhere. And the extra rubber has come in handy for me many times. My car is fairly low, IIRC the K is 5.75 to 6 inches off the deck. The rear is also lowered but carries 295/50-15s. Just tossing that in.

I really like those Turbine style wheels. I seem to remember those on a powerwagon
 
.....that sounds good too ....I already have the 15's and a set of 255's on the back so I'll stick with em' for now ....do you have a pic AJ ?
 
Won't 70's be to big? most are 27" ...the P215/70R15 26.7 tall with an 8.7 section width.....
 
Kinda depends where your ride-heights at. But yeah 27 might be a bit tall. It also depends on the look that you are after. Also bear in mind that if the tire you choose gets too far away from the design tire height, this get's to affecting the scrub radius to the point where the steering becomes "nervous". This also happens with rims that have a different offset from factory. A 1/2" offset, and/or a 1" tire diameter change is hardly noticeable. Hardly. This cannot be corrected by any alignment changes. Increased tire pressures may reduce the sensitivity, at the expense of tire life.
 
gotcha ...The 235 is 26.1 and a 9.2 section width.....so I'm thinking, now since I can't have a fat a tire with the 8" 4 1/4 BS I'm leaning towards the 215/65/R15 as it's 26 high and that will give me another 1 1/2 inch to fill the well with while keeping the 8.4 section width of the the 205/50 that's on it now ..... Sound like a good plan?
 
Don't forget only half the tire height goes up to fill the well, the other half goes down to raise the chassis. Unless you lower the chassis by some amount which sooner or later will get you into ride quality issues . And of course with any change in ride height, a trip to the alignment rack is recommended. A change in ride height usually affects the camber,the toe-in,and the scrub radius, which affects tire life, and/or steering feel.
 
Thanks AJ ! .....that 1 1/2 was half it's actually 3" total :)
 
Sully_PA said:
Thanks .....right now it has 205/50/15's on and they a ridiculously to small with no side wall ...need to fill that wheel well ...
Click to expand...

then explore a 60 or 70 series tire....my 2 cents is why a wide tire on the front...I run 215's by 60 and they look great with a wide tire in the rear
 
69_340_GTS said:
Maybe a 225/60-15. Better bet is a 215/65-15. Both are around 26" tall. A 7" wheel with 4.75" or 4.50" backspacing would be almost perfect. I think that 8" wheel with only 4.25" backspacing you are trying to use is a real problem... everything is pushed outboard too much.
Click to expand...

I'm running a 215/70/15 on a 7 " rim with 4 1/2" back space , gives the car a real nice stance!


View attachment 10365918_870382286322677_510096629334429037_n.jpg

View attachment IMG_0667.jpg
 
Well ....I did explore the 60 and 70's but I'm running an 8" wheel with 4.25 backspace ...so the though was to run with the same section width as the tire I have on now 8.4 to be sure it would fit...If I could run the 215/70/15 with the 8.7 SW I would run that... Appreciate the input ..... Nice cars by the way ....jtkaaa07 glad you posted your pic I was just looking at 6 pack scoops today....AJ thanks again
 
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