Drag Racing Tech - Drag tire comparo question...




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LOnSLO
01-17-2005, 11:02 AM
Ordering new tires in about 2 weeks. Thought I'd go for the optimal tire for me, instead of just throwing on the old 28 x 10.5's. Here's the 3 sizes to compare:

1. 28 x 10.5
2. 29 x 10.0
3. 30 x 9.0

Assume these are standard sidewall, soft compound tires. Everything the same just different sizes. I'd like some suggestions.
My combo just for reference: 408 with over 300 shot, 6 speed, right at 3300 raceweight.


B18B1LS1
01-17-2005, 05:00 PM
I'm partial to the 30's! But I would think with your power level and tranny the more contact patch the better.

LOnSLO
01-17-2005, 09:04 PM
I'm partial to the 30's! But I would think with your power level and tranny the more contact patch the better.
That's what I would think, but I'm leaning toward the taller tire since I'm hitting the tires so hard now.


PRAY HRD
01-17-2005, 09:17 PM
correct me if i'm wrong, but there is not likely going to be much of a difference in the amount of contact with the pavement as the taller your tire gets, the larger it is front to back. and compared to the smaller diameter tire with a greater width, you lose some of your front to rear contact but make it up in side to side. so mathmatically, the only real difference that will be realized with these 3 tires is the way your car will react to the difference in the final drive ratio as it goes through each gear. smaller tire = more gear numerically. just the opposite with the larger tire. you will pull some gear out of the car with the taller one. so my final annalysis is that the tire you should be looking for is the one that will give you the appropriate rpm as you pass through the traps. hope that helps you some.

later,
Dave

next
01-17-2005, 09:32 PM
Much like Dave said, I'd focus on the effect is has at finish line rpm and make the choice from there.

LOnSLO
01-17-2005, 09:49 PM
I can use any gear that I have, and I have plenty of sets laying around. That's not the issue. I want to figure my tire first, then gear accordingly. It makes sense to me that the 30" tire would help me get going, as there is a little more "cushion" to take the hit of a 8000 rpm clutch dump on the spray. Any thoughts on this? Or am I just as well off with the 28 x 10.5?

next
01-17-2005, 10:30 PM
The smallest tire you can get to hook, the faster you'll be. From what you're describing though, sounds like the 30" would be a good place to start.

B18B1LS1
01-18-2005, 06:35 PM
If your going to run sometime soon you can borrow mine and see what you think.

LOnSLO
01-18-2005, 07:42 PM
If your going to run sometime soon you can borrow mine and see what you think.
Appreciate that Jeffrey.