Tire sizing

[Cookeddev99]

So I’m sure someone can help this is my first post in this forum still trying to figure everything out
I have a 1979 Malibu building a budget drag car
Trying to decide what rear wheel backspacing and tires
Want to do a 2 inch lowering spring and trying to squeeze 28x10.50x15s dr
Probably gonna do a frame notch if necessary

 

[Kwik_Cutty88]

You'll probably want to do a frame notch to leave yourself a little wiggle room, and keep the tire inside the wheel well. I run a 15x8 with 4" backspacing, 26x9 hoosier slick (10.5" section width.)

I believe a 28x10.5x15 tire is closer to an 11" section width. I'd so some digging around, this is a very popular topic on the forum.

 

[Cookeddev99]

Thanks kwik cutty
I have a chance to buy all new wheels cheap
Summit drag wheels they are 15x8 with 4.5 backspacing and 15x4 fronts for 175 for all so trying to make those work
I’ll do frame notch and was gonna roll wheel well try and make that fit but idk

 

[motorheadmike]

Get 15x10s with 5.5" BS... should work great with a frame notch.

 

[TURNA]

do all your mods then go to a tire shop with the car this way you don't waste money and buy something that wont work.

 

[Cookeddev99]

Get 15x10s with 5.5" BS... should work great with a frame notch.

Have you ever ran this setup?

 

[Cookeddev99]

do all your mods then go to a tire shop with the car this way you don't waste money and buy something that wont work.

I don’t go to shops no where around me close to look into

 

[TURNA]

You have a car drive it!!!!!

You can do all the mods u want if you buy the wheels and they dont fit it was a waste.

What fits one car may not fit another depending on body mounts suspension wear and or body sag.

That being said with the tire you want (28x10.5x15) a 275/60/15 on a 8 inch rim with a 4 inch backspace should fit with no mods besides rolling the fender lip depending on your rear springs

 

[lilbowtie]

Get your tape measure out and do some measuring for yourself. The backspace of your rim is going to be the distance from the drum face toward your frame. Get the cross section (listed w/ tire info) of the tire you are going to use and subtract the rim size. Take half of that number and add it to your rim backspace and this will be the distance from the drum face (plus clearance) you need. You can figure the distance from the drum out the same way. The biggest tire I could get under my car is a 29.5/9/15 and that's on an 8 inch rim w/ 3.5 backspace. The section of that tire is 11.0 inches. Subtracting that from my rim size is 3 inches and half of that is 1.5 inches. So 3.5 backspace plus 1.5 in = 5.0 inches from the brake drum face (plus clearance) which is the room I need toward the frame. An 8 inch rim w/ 3.5 backspace has 4.5 positive offset plus 1.5 from the tire section = 6.0 inches so this is how far the tire will stick outward from the drum face.

 

[motorheadmike]

Have you ever ran this setup?

Open my wagon's build thread and read.