I'm finally getting my auto tranny and adding a limited slip to the back. I am running 285-75/r16's and while they are not yet square, they are octagonal and ready to change. I am going to try making some runs down at the drag strip and was wondering what size tires some are running. Should i get a new set the same size, or go a bit smaller with a less aggressive tread pattern? Does dropping down to a 265 size make any difference? I was hoping to find something that felt a bit better at higher speeds. 100mph is a bit shakey with these.
Ron

 

Are you wanting to change the tires out at the track for racing tires, or are you wanting a "run what you brung" tire that will stick better?

Changing the tires at the track is a pain, but it really does help a lot. With boosted launch and a limited slip in the rear, slicks can shave .5 sec or more off your time.

I ran brackets with a friend in a Fox body Mustange. We changed out the rears to slicks at the track. On the street tires, it would go best to a 13.68. On slicks, it was usually low 13s, but once ran a 12.99

I think on a truck it would make a bigger difference, especially with a little ballast in the rear.

If you don't want to change out tires, I'd recommend sticking with the 285 size. When you air them down a bit, you'll have a bigger contact patch.

The problem is that everything you want in a truck tire is the opposite of what you want in a race tire. A truck tire needs stiff sidewalls that support lots of weight and air pressure. A race slick has really soft sidewalls so they will "wrinkewall" and increase traction at launch.

So, the ideal is swapping the rears for actual slicks. Short of that, I'd run the lightest load rated tire I could get away with in a hwy pattern and drop the air pressure down to 25psi or so.

If you need E-rated tires for towing or something and don't want to swap tires at the track, then you just have to live with the lower traction, knowing that your truck is 4-5 tenths faster with sticky rubber.

JMO

Justin

 

What width wheel are you runing?

 

I don't know. They are the stock wheels that came on my 92. I'm not looking for slicks, just wondering if the 285's are going to hurt. I guess I should just try it first. The tires are a bit out of round, but in good shape otherwise. Not going to set any records, but would like to break in the 12's just once.

 

Ron...I went with 285/65R18's for daily driving and racing...about 32.5" tall. Most guys around here that run fast...like 12.99 and faster...run a 265/85R16 or equivalent, around a 31.5-32" tire. They seem to still hookup, and don't hurt the times.

If your running 285's, and they don't feel good, go down to 265's...if they feel fine, run them I've seen guys running down into the 11's on 285's!

Chris

 

Where are you taching at the traps? If you still have some rpm left, drop down a size. If you're redlining it through, then maybe a bigger set would be the ticket.

 

Also what gears are you running? The rim may be a bit skinny for a 285. If you got a wider rim or stepped down to the 265s it should be ok and have no problem with a shake.

 

i lost about 3 tenths going from a 265 to a 285.this is with 3.55 gears in an auto..........bama