Rotational Mass vs Tire Contact Patch

[ye olde rust bucket]

Thinking of hotrodding my Falcon. An expert advised me to get the wheels and tires first and work from there.

Let's say a 600-700 HP street car, aiming to go fast in a straight line.

A: 295/55 x 15 OD 28" Width 11.9" Weight 34lb

B: 29x15 OD 29" Width 14.8 Weight 42lb

They say 1 pound on the tire is like 2 pounds on the frame

Which tire do you guys recommended for the best 1/4 time??

[Motobrewmaster]

Seems to me if straight line is your goal, more contact patch wins.

[Tsaints1115]

Thinking of hotrodding my Falcon. An expert advised me to get the wheels and tires first and work from there.

Let's say a 600-700 HP street car, aiming to go fast in a straight line.

A: 295/55 x 15 OD 28" Width 11.9" Weight 34lb

B: 29x15 OD 29" Width 14.8 Weight 42lb

They say 1 pound on the tire is like 2 pounds on the frame

Which tire do you guys recommended for the best 1/4 time??

I believe the 1 to 2 ratio is static weight. When rotational mass is considered it actually goes up substantially.

[Lonnies Performance]

It depends on how well the car hooks. If it hooks with a 295, then the bigger tire will only slow the car down.
Unfortunately, you do not know this before the car is built.

Are both tires radials?
Is the car an auto or manual trans?
If an auto, it is foot brake or trans brake?

If 6-700 HP, then you may need the 29" tire as a taller sidewall helps straight line traction greatly.
Are you planning a 4.10 gear or similar steep gear?

My gut feel is if you had 500 or less HP, the 295 may be OK, but in your case I lean towards the bigger tire.

[ye olde rust bucket]

It depends on how well the car hooks. If it hooks with a 295, then the bigger tire will only slow the car down.
Unfortunately, you do not know this before the car is built.

Are both tires radials?
Is the car an auto or manual trans?
If an auto, it is foot brake or trans brake?

If 6-700 HP, then you may need the 29" tire as a taller sidewall helps straight line traction greatly.
Are you planning a 4.10 gear or similar steep gear?

My gut feel is if you had 500 or less HP, the 295 may be OK, but in your case I lean towards the bigger tire.

Both Mickey Thompson ET Radial
Thinking a manual
What gears do you guys suggest??

[Lonnies Performance]

Drag Radials are not typically recommended for manual transmissions which tend to work better with a bias ply.
Also a bias tire will likely be lighter, but will have worse handling characteristics.

It all depends on how serious you are about going fast....

Gears are dependent on your MPH, tire height & max rpm for peak power.
A good starting point is to figure RPM at about 10% over power peak at the finish line.

Here is a calculator to help figure trap speed vs. weight & HP

https://robrobinette.com/et.htm?


For RPM vs mph.

http://wallaceracing.com/calcmph.php

[Bigblockscott]

A lot of guys going really really fast on a 28-10.5x15 radial.