I have 2500 miles on my RX-8 and I have only had it up to a little over 100 mph. It felt very stable. I live in Atlanta so traffic is usually heavy. Also, I am more afraid of the ticket than the high speed. (Assumming road conditions good).

Once I topped out 4th gear on my stock 3rd Gen. RX-7 (Which should be between 145 & 150). Also, I once drove it on a trip from Dayton, OH to Knoxville, TN averaging at over 100 Mph.

When I compare the two cars, the handling feels simalar to me. The RX-8 seems just slightly softer in suspension (not necessary bad after you own the car a few years and drive it daily). The power seems to be a little less but broader.

I would not be suprised if it did 160. Unlike the old twin turbo, the RX-8 has a very flat powerband. This would allow the car reach top speed without being sensitive to perfect gearing when compared to a car with a peaky torque.

 

pfft...wives, always slowin us down :P j/p a good number of us would be dead without them.

142 for me, 4 passengers, level road, warm air. ran out of road and ***** :D

 

I got mine up to 148 then I started slowing down since I'd never gone that fast before. I was both grinning from ear-to-ear and shaking at the same time!

It was on a pretty level road, maybe a very slight downhill but very level. I have no upgrades (exhaust, headers, intake, etc) so I did it on stock. Does anyone who have aftermaket performance enhancements intalled on their car gone 175 or higher? Would it be possible to reach 195 on the 8 with a good intake, headers, and exhaust system or would you need more (maybe turbo if it does come out for the 8)?

 

Hell Doccable, you and I were routinely touching 120 MPH on that recent run down to Denver. :D

Best I've seen so far was 145 MPH also. Ran outta road (didn't think taking the upcoming 90 degree turn at that speed would be a good idea ), but the car had some go left in it and it felt pretty good and stable.

 

DD:D Hehehehe
Somehow this seems appropriate:

 

i think we max out via gearing at 187 or something...it is very obtainable however.

 

Care to explain how 187MPH is "very obtainable"?

 

Just got a chance to be on a very clear road yesterday. The max speed was 239 Km/h. Can't go beyond this. In fact, the RX-8 dropped its speed to 238 Km/h after I kept pushing the car. 240 would look nicer but what can you expect when it's 238 as the top speed in the manual.

 

I hit 143 MPH yesterday, there is a rev limiter on sixth gear, right at 7200k. It wouldn't go above the 7200 line, even though I had pedal space left - I tried. I don't know yet what it'll top out at, I really wasn't trying...

 

I hit 123 before my rectum became so tight a cat couldn't scratch it!!
Also came up on a 4 runner at that speed and was afraid to change lanes. Very stable, you just don't want to hit a deer at 100+.

 

Yes, 6th is limited, but 5th isn't... :D

 

With just stage one 160's has been proven (https://www.rx8club.com/showthread.p...threadid=18480)

stage 2 is a few mph faster. i think once we see some forced induction, we'll have to open the tranny to avoid redline in 6th. what i meant by obtainable is that when compared to some other cars that can't touch redline in 6th gear even with FI applied, I believe that with work the 8 can.

 

I've hit 130 so far and loved every second of it ! My old '69 Mustang will do it too, but not without white knuckle drama and a scary scream from the tired old 351 V8.

The RX8 is just so increadibly smooth. It's like it was meant to run high. I plan on really topping this succer out soon. The Nashville Speedway is nearby and I can't wait to spend a weekend zooming around that brand new track!

 

Ok on the American spec rx-8 the top speed on a 6 spd mt with a just the GT package is 151mph. Thats 243 kmph. I have an american spec 8 here in Germany and did this speed on the autobahn numerous times. The tach pegs out at right around 9200rpm.
I don't have any mods at all. Its completely stock well, gt package, tinted windows and Mazda chrome wheels.

 

I don't have any intention on running over 100mph in our public roads here, but I have done 110mph. I didn't realize how fast I was running because aside from the fact that I was late on an appointment, a blue Celica GT-S and an old Porsche were pacing me. I guess they thought I was racing them when in truth, I was just late.

As for stability, it felt like I was running 50mph on my Solara :D 100mph on my boat-car felt scary.

 

You forgot to shift from 5th to 6th gear! Redline in 5th gear is around 240 km/h, NOT 6th gear.

Regards,
Gordon

 

I don't know about all this 180mph crapola. With stock gearing, 6th gear will give up about 19.5mph/1k rpm. At 9k rpm that works out to about 175.5 mph...but this doesn't take drag into account. Maybe, maybe it'll get 155-160 with no head wind, but I think that's about it assuming there is no rev limiter WHICH there is. I have personally seen a Formula Super Mazda in a test/tune and it is rev limited to 8500rpm. (This is a stock 13B with a header that gives it about 248hp according to the owner (Velocity Motorsports). The car was getting 170+ on the straight at Roebling Road. This car weighs in at over 1,000lbs LESS that an RX-8. So, someone tell me how they can get 160-180 out of a stock 8. I've seen 135 on mine and backed off not wanting to get caught again!

 

I hit 130 Coming back from Galveston. It only felt skittish when I changed two lanes and hit a bump in the road. If I drove like that regularly I would hope one of my friends would have me comitted.

 

I had my rx-8 to 155 mph, I weigh 130 lbs and had only a quarter tank of fuel. The car handeled very nicely. A sales person from the dealership told me, on personal time, that the 8 will do 160 mph but I don't see it unless going slightly downhill. Another sales person called me a lier and said that all cars in California can only legally go 144 mph by state law, either way I love this car and was very impressed on a recent trip to the beach on highway 58 (has 1st gear and 2nd gear hairpins and high speed sweeping turns, this road has it all). Very impressed with this car and have no regrets on my purchase.:D

 

More crapola. California doesn't restrict car speed capability. The manufacturer does at it's discretion, eg. Benz restricts all its AMG cars to 155mph; other are restricted to 130mph. As i nderstand, Mazda has limited the 8 to 148mph. You may get a little more on a downhill, but the engine isn't doing it, gravity is. Of course there are individual variances that may account for some abberations among cars. I'm sure you got one of the fastest though!:p

 

I found out today that in comparison to a GPS unit, my speedo is 3 MPH faster than the GPS. This was consistant across the board from about 20 - 140 MPH:D on the speedo. I'll be heading back out later today to kill a few more bugs and conduct further "scientific" studies on the differences...

 

Hit 160mph or 250km/h on Saturday I think the rev limmiter cicked in at that speed.
The road was quite flat

 

nice to know it's consistent at least. I plan to try corroborating your results with my gps. although it may be a while before I work up to anywhere near 140! (I'm just picking it up this afternoon)

 

236.5 km/h by the Japanese in a oval test track... myself - 160 km/h. I am a good boy

 

My drivers licence is a bit oo important for me to get caught doing over 100Mph but i have found myself at 110 without meaning too. At some point in time (probably late at night) i will run the car up on a clear patch of road but the conditions will have to be right..

On that not I have anchored the brakes at 110 Mph on a test track. This car does stop.