http://www.garmin.com/aboutGPS/waas.html

pilot and a@p.

dont use it in the air. checked the faa site and it said that has not been implemented in all of north america.

just know that i usually get 7 ft accuracy 95% of the time when i use it. mostly on my bike.

beers

 

I think that using the tach would be very accurate, more accurate than the speedo. I know the speedo in my toyota reads that you are going slower than the one in my rx8

 

my garmin handheld is extremely accurate. whenever I have it with my as I drive it's usually righ taround where the car speedo is. I read that same piece in car and driver sayin gthe 8 was drag limited at 148.

 

Then how did I get 149?

 

Also the faster you go, the less accurate it becomes. I had 131 on the speedo and GPS registered 126

It also probably varies from car to car.

As to the tach, I wouldn't trust the tach with too much accuracy either - I know a guy who had a Apexi SFC in his FC and the rpm's it measured was off by 100-500 rpms from the tach, increasing as it got higher. I'd guesstimate that the tach is probably +/- 250 rpms.

 

from a conservative old cop......115, and nobody around!!

 

Waas is available and it does work. It may not be "officially" blessed by the FAA for inflight use, but I get 9 foot (3 meter) or better accuracy when the WAAS birds lock up.

On my drives I can usually see both WAAS satellites (#35 and #47) locked.

Here is what Garmin has to say about it: http://www.garmin.com/aboutGPS/waas.html

"...Currently, WAAS satellite coverage is only available in North America. ..."

Steve

 

152 mph; down I-80

 

120 indicated...slowed to 90 before passing 2 cops busy with a Trans-Am...whew! Stupid, really.

 

135, thats with the 8000 worth of damage to my 3 week old car some guy from out of town did when he blew through a redlight and nailed my passenger side. I figured if I got pulled over I could tell them I was pissed about my accident!

My poor car is in the shop now getting a new bumper, rear door, rear quarted panel, Rim and tire. A little faster and I would be getting a new car.

 

Only been to 115, but the car felt STABLE. Could've been doing 65 for the way it felt. How does it hold up to the higher speeds? Still rock solid at 130-140?

 

I have been 120+ in a few different vehicles as I am sure a lot of you have. The only one that compared to how my RX8 felt at those speeds was my S2000 which I sold to get my RX8. Honestly, the RX8 felt more stable at every speed.

 

I have lots of data that shows the speedometer is of by 2% high, 1 MPH at 50 and 2Mph at 100. This is compared to the GPS, which matches other cars spedo's perfectly. I also get the same 2% error when comparing it to the ECU speed unsing the CAN Bus. I also have data that shows the Odometer match the speedometer, and it too is 2% off, when compared to the GPS and to the CAN BUS.

MY GPS is WAAS as well.

 

nope,

waas enabled gps reciever, odometer is dead accurate. the speedo is of buy 1.6 mph at all reasonable speeds.

beere

 

It felt like the front was getting light at 128 MPH, so I slowed down.

I was surprised, I expected the shape to hold the front end down.

I was wondering, if you look under the front of the car and see the angle of the radiator, wont the air flow cause a lifting force as describe in this crappy illustration?

 

How long did you test the Odometer for? I went 49 miles on GPS Odometer went 50.

 

HEY! Isn't that the car Homer Simpson designed for his brothers car company?

 

did 3/4 of a tank ~ 230 miles between orlando and naples. mostly straight roads. gps accuracy at 7ft most of the time. at the end of the 230 it was of by .6
of a mile.

as to speed i know it seems to be off by 1.6 from 30mph to about 85. as to faster never looked. i have seen 134 gps indicated but never looked at the speedo.

beers

 

nice wheels randy! if that car had a 600/600 hp, torque it would still not get past 80 with the drag coeficient! whoooooo! j/k my 8 feels more solid than my wrx did at 120 and my brothers s2000. feels like a true roadster at high speeds

 

GPS shows my speedo off by about 0.4 mph across the board.

 

Real happy to hear the 8 is more stable compared to other japanese cars, but it definately finds its match with german opposition. Got my brother's Audi S3 to 250km/h (that's 155+mph) and... that's what stability and low noise levels are meant to be! Police car showed up right after I decided to back down, thank god!

-=My rx-8 got VERY easily to 135mph, didn't want to push it more 'cause it's still new. Two people here in Greece claimed they saw 265km/h(165mph) in the meter. Sounds too much to me=-

 

125 here. Felt stable to me.

 

There shouldn't be enough air hitting the radiator to lift the whole car. The area of the exposed radiator is such a small percentage of the cross sectional area of the entire car that it shouldn't put much upward force on the front end. Actually, cars in general generate lift as they go faster; they're kinda shaped like an airplane wing. Air has to move faster over the top of the car, since it curves, than it does underneath the car, since it's straight. If you look underneath an F1 car, it's clear that they put a ton of design effort into its shape. It's specifically designed to hamper the airflow underneath, thereby causing the air to move faster. As soon as they get the air on the underside moving about the same speed as air over the top, then they can concentrate on creating more downforce with front and rear spoilers. They do such a good job of negating lift and creating downforce that those cars will drive inverted if you get them over 100mph.

 

This car is very stable, and now with the MS suspension and spoiler is rock solid, had her up to 142 (corrected with GPS) the other day, only car on a limited access road... The front and rear were planted solid no wandering, tracked very well... With 320HP this car will easily go into the 170s in six gear... Better than the 996 C2...

 

I know I would take some **** for the crude drawing but I wanted to get the visual effect accrossed.

it just seems with the air flow directed at the angle radiator if might produce some lift. Not enough to lift the whole car, it will lessen the force on the wheels...