Jump to content
Sign in to follow this  
blueekb

TT1,2,3 tire size question

Recommended Posts

blueekb

TT1,2,3 rules state this:

 

Non-DOT approved tires = -0.5(CTSC EC-DryContinentals see App. A)

Size 10.5” (267mm) to 9.6” (244mm) non-DOT approved = +0.3

Size 9.5” (241mm) or smaller non-DOT approved = +0.7

Size 275 to 250 (DOT approved) = +0.3

Size 245 or smaller (DOT approved) =+0.7

 

But there are two examples given with tires sizes that are larger with no penalty?

 

Example: 2006 Chevrolet Corvette Z06, with OEM transmission, on DOT approved 345 size

tires, weighing 3000 lbs, with 375 peak rwhp:

3000/375 = 8.0 (TT2)

 

2003 Dodge Viper Comp Coupe, with OEM transmission, on non-DOT approved

345 size tires, weighing 3600 lbs, with peak chassis dyno power of 642rwhp:3600/642= 5.61, minus 0.5(non-DOT's), plus 0.4

(3600 lbs or greater) = 5.51 (TT1)

 

Are these just old examples left over from previous rules? My understanding was that 275 was the largest tire I could run in TT3 and there isn't even an option to run a larger tire correct? Or am I missing something where I can run the same size that came OEM? I've seen people run 305 and larger in the past and just wanted to clarify. Thank you.

Share this post


Link to post
Share on other sites
ILIKETODRIVE

You can run larger than 275. However, there is not an adjustment in PTW for doing so.

 

3000/375 = 8.0

There is no adjustment for tires bcuz DOT 345 width (larger than 275)

There is no adjustment for weight bcuz 3000lb-3299lb (adjustments for lighter and heavier than those weights)

Share this post


Link to post
Share on other sites
blueekb

Ok I get it now. Running a smaller tire can get you more H-W ratio. Not sure why I was confused lol.

Share this post


Link to post
Share on other sites
Clavette

Yeah, I have to run 245's because I need the +0.7 WT/HP adjustment to meet the new 10:1 in TT3.

 

Denis

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...