New personal best m6 stock with drag radials

[Chrispy]

Originally Posted by trainman

Great times for a 6-speed manual. I have a tip for you to improve the 60' time. The tire you are running is way to tall for your mods(none). The 305-45-18 is 28.8" tall. Since you already have an 18" wheel, I suggest you get either the Mickey Thompson 305-35-18 (26.4" tall) or better yet the 315-30-18 (25.5" tall). These will have the effect of lowering your rear gear ratio quit a bit. I have a CTS V Coupe 6-speed manual and I run an M&H 275-40-17 (26" tall) @ 15 lbs air pressure, and my 60' is 1.54. I have a few more mods than you (10.85 @ 130.89) but I ran that in 2150' DA here in California about a month ago. Your DA on the runs you posted are a contributing factor to the great times ( 3pm run -782', 4pm run -793' and the 5pm run -927') , yes MINUS DA which is great! Try the shorter tire and you will see your 11.60 or even better in similar DA.

I did some calculating for you to show the difference. Your stock tire (305-30-20 is 27.2" tall) with 3.73 gears yields 21.7 mph per 1000 rpm in 4th gear. By using the 305-45-18 drag radial (28.8" tall) you raise the mph @ 1000 to 22.97mph , which is like going to a 3.52 rear end with your stock tires. Using the 315-30-18 (25.5" tall) you would in effect lower your mph per 1000 rpm to 20.34 mph, like having 3.98 gears with your stock tires , which is way better for acceleration. Hope this helps.

Ditto I used those tires on my CTS V wagon 6 speed manual (305/35/18) and went 11.8 @ 120mph with only an Air raid as the only mods. (~2K DA and ~4500 raceweight)

You'll probably hit 11.5-11.6 at 118-119mph with just the tire change if you can hook it.

[dtwolcot2]

Originally Posted by Chrispy

Ditto I used those tires on my CTS V wagon 6 speed manual (305/35/18) and went 11.8 @ 120mph with only an Air raid as the only mods. (~2K DA and ~4500 raceweight)

You'll probably hit 11.5-11.6 at 118-119mph with just the tire change if you can hook it.

Any thoughts on the Hoosier 315/30r18 drag radials? That's what I originally planned on getting until I saw most people ran 305/45 mt's.

[Bolding220]

Good job!!