I hear it is drag-limited at 144. I hear it is governed at 148. I raced a charger and was going 146 and had it on a dyno going 148. Not sure what to tell you other than the 144 by car & driver or road and track, or motortrend was wrong in my case. I let off on the dyno cause I hit close to 9000 rpms so just stopped the run. I have not heard of anything proven over 148 yet but, doesnt mean it hasnt happened.

 

There is no limiter (US/Canada models) dyno runs have topped 180mph....

My personal best is 234kph (145mph) on an airport run with a tailwind.

It slowed in 6th, and redlined in 5th.

S

 

The 4-port A/T model does have an electronic limiter though. I wasn't sure at first until I hit 125 and it bounced me back a little....

 

Heheh, yeah I bet that's a fast way to kill a gas tank. I went from delaware bridge to goethal's bridge in an hour (100-110MPH) which completely destroyed my mpg. Pretty sure I was running in 6th, but still, thats running at like 6K rpm or something I think. After the turbo, might change my final drive.

 

Hold on, how did you figure you can go 186mph with just under 230whp??

 

+1........???

 

I'd like to see that math!

Like a good exam - no marks unless you show your work.


S

 

Well yesterday i just hit 115Mph, i was tryin too keep up with my friend in his .....................little bit 'o' street race edited out, and poster warned........S........it felt kinda crazy driving at those speeds. egh i dont want to do that again

 

I believe the MT rx8's have 6 gears so ur top speed in 5th is not ur "top" speed..however everything stock I believe it cuts the injectors/shuts off at 156 or 158 not positive but I think I remember hearing that...correct me if i'm wrong and never ever bread the speed limit we know u did this speed on a closed course...

 

cd= .29
frontal area = 18ft^2

(.29 * 18 * 185.8981^3)/(15*10^4) = 223.5652

That whp. With a proper turbo kit you should be able to push 300 to the wheels, making 186 (redline in 6th) doable.

 

No, the car has acheved 180+ mph on a dyno. There is a YouTube video of it out there. On the road it is drag limited.

I thought the cd on the RX8 was .31. The cd on the RX7 FD was .29.

Reference: http://www.motortrend.com/cars/2007/...ons/index.html
-
Coefficient of drag: 0.31

 

According to Mazda Cd is .31 or .33 I think it was. They have updated on Mazdausa.com and the new one is .3 as the final drive is now the 4.777. That would mean that the new ones would not go as fast. According to the gearing, in 6th, you achieve 19.9 mph/ 1000 rpms. That would mean about 185 when the fuel cuts off at 9300 if you have your tires pumped well too. I am not sure but, the vette has as good Cd or better than the 8 and requires over 400 to the wheels to get to 190. If I am wrong, let me know but, I beilieve it is going to take more than 230 or even 300 to the wheels to top out at 185 on the open road. Unless you have taller tires, or have the computer program that allows more revs, a basic stock 8 tops out around 150 or so on the road and 185 on the dyno. It may hit 186 due to momentum for a short time but, like I said, there are other variables. 235/45 or even taller tires can achieve 186+ on the dyno. I have never gotten my 8 above 146 (ran out of road) and 150 on dyno. My experience anyway.

 

the lower Cd of the 2009 will help the .25 time and speed somewhat but looks as if you have to change gears little more often. Works for me

 

http://www.precisionsite.com/auto-x/tools/ can tell you about the top speed.

 

On the German autobahn with my crappy camera going down a huge freaking hill 175.848 mph

 

one word on that. WOW would be scary at that speed.

 

I hit 155 MPH but when I took the pic I had to let off of the gas bc I ran out of road but I still got 152 MPH on camera!!

 

Not my top speed and havn't topped out the 8' max speed personally cause I can't force myself to go past 120 but the other day on a mountain cuise with the local CO club I hit 96 in third going up hill.

 

this thread has me wondering... how fast can state troopers go?

 

the radio goes fast enough..im kinda wondering how fast im gonna be after the swap with the differant gearing in the tranny....i guess we will see, i wish i had the autobahn

 

i hit 145 in in 5th at 8000rpms on the parkway in jersey. the car def felt like it wanted to go faster but my radar started goin off. havent really tried it again since then

 

Hey guys, with stock springs, shocks and sway bars is not a good idea to go faster than 170 km or 112 mph, you can loose the car in one second, be careful.
manny

 

I hit 143 on I83 before Istarted closing on cars at over 60mphs ,,, once I get the Petit SC Ill go for another run...

 

130 then i got too scared hehehehe i always drive 90 + in 95 (georgia) so is like 20 over

 

one time i strapped rockets to my 8 and went 400 km/h on the freeway. I wouldn't lie. U can ask the 9 mexicans i had in the back.