Tire and wheel opinions

-
H

haybag

Well-Known Member
Joined
Dec 14, 2014
Messages
192
Reaction score
17
Location
New Hampshire
Just got my 69 Dart on the road this spring and took it to the track this week. Stock magnum 5.9 efi, 833 4spd , 8 3/4 3.23 sg, 14 x5.5 sbp wheels with 205/ 75 tires. Best time was 15.68 @ 93 mph. Obvious traction problems. This is a daily driver that I am keeping mainly as is (probably some engine mods down the road)but would like to get the most out of this combo. Suggestions on rear wheel tire combo? I was thinking 14 x 7 or 15 x 7 wheels. Drag radials or street tires?
 
haybag said:
Just got my 69 Dart on the road this spring and took it to the track this week. Stock magnum 5.9 efi, 833 4spd , 8 3/4 3.23 sg, 14 x5.5 sbp wheels with 205/ 75 tires. Best time was 15.68 @ 93 mph. Obvious traction problems. This is a daily driver that I am keeping mainly as is (probably some engine mods down the road)but would like to get the most out of this combo. Suggestions on rear wheel tire combo? I was thinking 14 x 7 or 15 x 7 wheels. Drag radials or street tires?
Click to expand...

If the primary use of the car is going to be as a daily driver street tires should be your first choice. If you're planning on a decent amount of drag racing, it may be worthwhile to buy a second set of rims and tires for the back. That way you can run street tires on the street for your daily driving duties and run the drag radials at the track. If it was just a weekend car or occasional driver than running the drag radials isn't a big deal, but I'm not a fan of drag radials on a daily. Or mixed tire/tread set ups for that matter.

15x7 with a 4.25" backspace should let you run 245/60/15's if you wanted with the stock spring locations and on most cars that should work without doing anything to the quarter lips. There are some folks here that have managed to get 255/60/15's on the back, but I would caution that you should measure everything before you go that route because on a decent amount of cars, especially the pre-'70 cars that combination might require some rolling or trimming of the rear quarter lip. It depends on your cars body tolerances, ride height, etc.
 
I was thinking of getting a second pair of rims and tires for the rear to just use at the track 2 or 3 times a year. Just picked up a 71 Duster that I will be doing a similar build with but automatic and going to do some mods to a magnum. Would use the same wheels and tires on this car when I want to take it to the track.
 
On my 68 fastback;

What 72blunblu said. I managed to fit 15x8 wheels, can't remember the backspacing. I'll look it up when I get home. I fit some MT Sportsman ST tires at 255/60/15 with only a tiny bit of rubbing on the inside of the wheelwell when I hit large speedbumps with my old beat to hell springs. I completely clear the fender lip. I suspect that problem will completely go away when I get new springs.

Measure everything and do your math several times before you do anything though.
 
Not knowing what your rpm's are at the finish line I'll try to help . A 15"x7"rim with a backspace of 4-4 1/2" is safe . I would try M/T street radial inP 235/60-15 . I am of the opinion that you need a shorter tire to increase your rpm's . Start the "StickyMickeys" @20 psi and go down from there but stop @ 15-16 psi . Street radials don't require a lot (if any) water on a prepped track . good luck !
 
I ran the stock sbp Rallyes with 245/60 14 Cooper Cobras for daily use, and had a set of custom made steelies 15X7, 4.25 back spacing, shod with 255/60 15 BFG drag radials. Ran a mild 360/727, 8 3/4 with 3:23s and an Eaton Truetrac. With the Coopers I went 14.0 at about 97 mph, while the BFGs running about 18 psi would give me 13.8 at about 99-100 mph, difference was all in the 60 foot. Keep in mind that altitude makes a difference as does ambient temperature.
 
You must log in or register to reply here.
-

Back
Top