My 996 cup is SLOW - speedo accuracy?
05-27-2018, 10:24 AM
#17
If you have stock 2003 cup gears, 5th is a 32/35 (1.094) ratio, and a 8/32 (4.0) ring and pinion. With the standard 680 tire, 8000 rpm (stock redline) in 5th is about 146 mph, 7500 is 136. My guess is your 135 is accurate from watching the video - seems like around 7500 rpm or less.
06-01-2018, 03:09 PM
#18
I have the same on mine, a 2003. Speedo crawls past 180kph.
On a fast track I am at 220 entering the braking zone where my previous 6cup (an 05) had 240 reading on the VBox...
As my toplaps were 1,5sec faster with the "slower" car I was not to worried.
But just for peace of mind I checked 2 videos next to each others and the 2 cars perform with little difference.
I also ran a GPS in the slower car and the GPS speed difference between the 2 cars was only 2 to 4 kph.
I run more wing in the 2003...Standard Michelin N2 tyre sizes on both cars.
Just strange !
On a fast track I am at 220 entering the braking zone where my previous 6cup (an 05) had 240 reading on the VBox...
As my toplaps were 1,5sec faster with the "slower" car I was not to worried.
But just for peace of mind I checked 2 videos next to each others and the 2 cars perform with little difference.
I also ran a GPS in the slower car and the GPS speed difference between the 2 cars was only 2 to 4 kph.
I run more wing in the 2003...Standard Michelin N2 tyre sizes on both cars.
Just strange !
06-02-2018, 09:25 PM
#19
RL Community Team
Rennlist Member
Rennlist Member
Thread Starter
I have the same on mine, a 2003. Speedo crawls past 180kph.
On a fast track I am at 220 entering the braking zone where my previous 6cup (an 05) had 240 reading on the VBox...
As my toplaps were 1,5sec faster with the "slower" car I was not to worried.
But just for peace of mind I checked 2 videos next to each others and the 2 cars perform with little difference.
I also ran a GPS in the slower car and the GPS speed difference between the 2 cars was only 2 to 4 kph.
I run more wing in the 2003...Standard Michelin N2 tyre sizes on both cars.
Just strange !
On a fast track I am at 220 entering the braking zone where my previous 6cup (an 05) had 240 reading on the VBox...
As my toplaps were 1,5sec faster with the "slower" car I was not to worried.
But just for peace of mind I checked 2 videos next to each others and the 2 cars perform with little difference.
I also ran a GPS in the slower car and the GPS speed difference between the 2 cars was only 2 to 4 kph.
I run more wing in the 2003...Standard Michelin N2 tyre sizes on both cars.
Just strange !
06-03-2018, 02:24 PM
#20
So the speedo in your 05 was more accurate than the 03...very odd! I was only going by the digital speedo on the day but should check the analogue read out next time to see if it coincides. You’d think it would. The other 996 cup at the track with me was shifting slightly earlier with his 7300 rev limit so I’m not too worried. I’m ordering the motec gear so I can access my data in future.