Im tempted to pick up 2 for the front of my car. We run an airport and a huge lot here so losing top end doesn't seem like a good idea for me

 

Has anyone considered the Toyo R1R in the 245/35-17 size 23.7"diameter.

 

that would put the top speed of the ap1 at 63.4, the 245/40 puts it at 66.0

I dont know if I'd want to limit my ap1 to 63 mph. Plus the fact that I don't like R1R tires because they don't last long. If you drive a ap2 I don't know that I would even do the 245/40's.

 

I think your numbers are wrong.

 

They actually look correct to me. Unfortunately Toyo doesn't publish revolutions per mile for the R1-R, but using the same revolutions per mile as other tires with the same outside diameter, I get 63.9 MPH in 2nd for the AP1. I think that's a better estimate than calculating Pi*D, since we know that tires are not rigid when they roll.

 

I am considering this size/tire as well, but with me being a co-driver car, I am concerned about over heating them. Hmmm...

 

Hankook needs to release a 255/35-17... Shorter sidewall for less flex, shorter diameter for the AP1's, and no overheating in the southeastern summer with a co-driver and 7-8 runs each!

 

That's where I stopped caring. i would gladly spray all day if I could get 8 runs

 

When the heat is up near 100 and your running that much on concrete, even the Kooks are gonna need a ton of spraying lol, I can imagine practically melting off the toyos lol!

 

Heres the numbers if anyone wants them...



disclaimer- MY numbers are based off the "turn zero" website, if they are wrong, I blame them.

ap1 numbers (9000rpm)
-255/40
1st gear top speed 43.7
2nd gear top speed 66.9
-245/40
1st gear top speed 43.1
2nd gear top speed 66
-245/35
1st gear top speed 41.4
2nd gear top speed 63.4

ap2 numbers (8500rpm)
-255/40
1st gear top speed 39.7
2nd gear top speed 60.8
-245/40
1st gear top speed 39.2
2nd gear top speed 60
-245/35
1st gear top speed 37.6
2nd gear top speed 57.6

Its all about how much are you willing to give up "up top" to gain alittle bit of accl. Me myself, am willing to give up .6mph in first and .9mph in second. Thats it. I think the ap1 is able to hang with the ap2 currently because we are able to have that extra 4mph in first and 6.1 mph in second. If you take away that I feel that the ap1 would just be like a ap2 without the grunt. Everyone seems to be getting hung up on this second gear top speed number and not thinking about the fact they are also talking about taking away valuable 1st gear top speeds. Thats a 4mph range that the ap1 does accl faster then the ap2. Plus the fact that where ap2s would have to switch to second because they are hitting the rev limit we ap1 people could of stayed in first and not had to switch to second. (on a tight course that would have a ap1 first gear area, that is)

all this is course depended ofcouse but it's somthing to think about. Also don't the r1rs have some "they have to be under 60 runs or grip drops off" issue? My kooks gripped down to the wear bars with no issues.

I'm slow though, so none of this matters to me but some of you fast guys might want to weight your options on this one. I wouldn't show up at a lot like blythville with 245/35 on a ap1 if you want to win.


edit- can some smart person do the math and figure out the accl g's pulled for a ap1 with the 3 different sizes in 1st and second gear and then also do the same for the ap2? It would be alot of work (mathmaticly speaking) but would be interesting to see what overlaps and what doesn't. (ap1 vs ap2 wise) Exclude wind, drag, ect. Just uses tq numbers, gearing, 8500rpm for ap2, 9000rpm for ap1, and correct tire hights.