Top speed in 2nd gear...

[Kiven422]

I've had this car for about 3 years now. I never knew you can hit over 100mph in 2nd gear!

Instead of moving the shifter ahead of time I held 2nd gear till redline and hit over 100mph. Shifted to 3rd right in time before the rev-limiter... Think I may have hit 102 or 103 in 2nd tops.

Maybe 110-115mph is possible with the NICO chip @ 7400RPMs? My car is stock except for a dual exhaust system and the 90-93 factory intake ram-air mod. I think its possible to do a significantly faster 1/4 time this way.

[Q45tech]

Don't confuse real speed with displayed speed.

Assuming a oem 3.538 diff gear and a 90-93 transmission where 2nd gear is 1.544 and oem tires where the loaded radius is__________________ as that depends on tire brand, PSI, and speed [as tires grow and stretch above 80 mph]. 3.538 x 1.544 = 5.4871 x loaded radius ratio to 12.

A tire's static (not moving) radius is only accurate while the vehicle is stopped. A static loaded radius is typically about 44% of the static loaded diameter. As the vehicle speed increases, centrifugal force causes the tire to grow taller. This force will increase the tire's dynamic (changes while moving) radius. At 85 mph, most tires will have a radius that is very close 52% tire's static loaded diameter. That's 8% difference from sitting still.

Every brand and size is different as to internal construction and the cap ply specification to restrict the speed growth!

Then there is the issue of treadwear as from new 11/32 to 2/32 ~ 9/32 is 0.28" which is a change of 3.3% on a 26" tire that alone reduces top speed by ~~ 3-4 MPH with worn tires.

For Michelin 235/60/15 I use 740 rpm/10 at 100 mph which yields 98.7 mph uncorrected............or 103 mph corrected depending.

http://wahiduddin.net/calc/calc_speed_rpm.htm