I suck at math, so I'm looking for a math whiz to help me ...

I just got some Kumho Ecsta V700 tires for the Lightning ("won" the bidding war on CRX driver Marshall Cone's certificate for free Kumhos ), and I want to know how far my speedo will be off with them. Since I have to haul the cones for this weekend's NASA autocross, I may have to drive on them since there probably isn't room for 100+ cones, timing equipment, PA speaker, fire extinguishers, jack, loaner helmets and a set of Lightning rimz/tires in the bed.

Anyway, stock tires have a diameter of 28.4" ... the Kumhos are 24.6" (how to lower a truck by 4" in under a half hour ). Gear ratios are:

1st - 2.71
2nd - 1.53
3rd - 1.00
4th - 0.71
Final drive - 3.55

Will I be staring at 4,000 rpm at 80 mph like the SE-R?


[Modified by slowSER, 7:25 PM 12/13/2001]

 

My answer is that due to the Bling-Bling! factor you shouldn't be cruizin' at more than 35MPH so you should be fine . . .

Pimp Away!

 

LOL

 

Yo, I only gots da stock "L" wheels for da sticky tires, so I ain't goin ta be bling-blingin to much. I could see if it wuz rollin on sum chrome polished dubz or sumpin.


[Modified by slowSER, 9:01 PM 12/13/2001]

 

Leave it to a psych major , (28.4 - 24.6) / 28.4 = 13.4% high, so figure that over your normal rpm's Pat.

 

I can't help you on the gearing issue, but let it be known that I think Pat is a CRAZY BEEEYOTCH. You are the first person I have heard of to have r-compounds tires on a Lightning that is their "tow vehicle".

Let's all be rational for a moment... you might be a racer if... YOU HAVE RACE TIRES FOR YOUR TOW VEHICLE!

 

Ooo, found this: http://www.4lo.com/4LoCalc.htm

 

or this: http://www.syty.org/old/calculator.html

 

Let's put it this way. Lowering your overgrown hairdryer with R tires STILL won't be enough to beat a box on three wheels with no tach...

Andy

 

also http://www.miata.net/garage/tirecalc.html

 

Maybe 1.9"?

 

As long as the much-celebrated Lightning's inertial guidance system isn't upset...

 

Look at the first line of my first post.