I see several claims of top speed approaching 150. Is this for real? What is your experience?

Somebody did mention 150, seemed a bit high to me. Anyway there is an entire thread devoted to this subject.

http://www.rx8club.com/showthread.php?s=&threadid=8656&highlight=136

personally, Ive only been 110
I dont want to chrash my 04 before 04

Originally posted by mikeb
personally, Ive only been 110
I dont want to chrash my 04 before 04

Yes, crashing is not good.

Maybe you can try in 2005 instead?

I personally have been 135. Fast enough for me in uncontrolled environment!

150 musta been downhill or something cause the thign is limited to 148

ive been @ 145
________
Public auto insurance dicussion (http://www.insurance-forums.org/public-auto-insurance/)

Yes, 148 is top speed - electronically controlled.

143 MHP for me!

Had some left but the road started to get short.

Vince

65 so far. i'm still breaking it in. :D

...130mph, but out of road too.

a back road i hope :cool:

136mph for me... 4am, center lane on a 6 lane divided hwy. My passenger thought we were doing under 100. Hard to tell without any "traffic flow" I guess... all the Smokeys must have been refilling their thermoses and getting a fresh dozen at Dunkin Donuts or Krispy Kreme. No signals reported by my V1 for miles.

So far -
Absolutely flat, (we have a lot of it around here!)
10*c temp,
91 octane,
5th gear,
buzzer going at about 8600revs

= 230 kph. (143 mph)
.
.
.
:D :D :D doc

If any of you guys crash, please try to hit with the *back* part of the car, I have use for a cheap renesis engine from the salvage yard. ;) ;) ;)

Better try one of the 3 RX8s that got damaged during a train derail, (otherwise I only heard of one crashed RX8).

Originally posted by Irish_in_a_RX8
Yes, 148 is top speed - electronically controlled.
Really? It seems a strange speed to limit to.

I saw a report in a UK car magazine about a year ago which said it would have a 155 mph limited top speed. Many high performance cars in Europe (particularly German cars) are limited to 155 (it translates to something exact in km/h). I guess, at that stage, Mazda thought they could get the RX-8 to go that fast and it would need a limiter to keep it below 155.

But who limits cars to 148? Does that mean that in Europe we are limited to 146 (our specified top speed)? I don't believe this car has a limiter.

yep, 155mph = 250 km/h

It was a silent agreement among auto makers to limit their cars to this "reasonable speed" .

BMW M5, Audi RS6 etc are good for 200+ mph, but I don't think the RX-8 would be able to go much beyond 150 mph - if at all.

RX-8 in 6th gear: 4000 rpm = 80 mph
--> 8000 rpm = 160 mph

Then subtract some for additional drag.

Max speed in 5th gear: 145 MPH
Max speed (electronically limited): 148 MPH

I certainly think it would go all the way up to the rev limiter in 6th without the governor. Look for that governor to go bye-bye once the engine re-tuners come out!

Only had mine up to 100 MPH so far....and that's not very hard to do!

I got mine up to about 137 mph in 5th gear about 2 weeks ago. And it had a lot more in here so it felt. Hard to believe its maxed at 145 I doubt that or have a hard time believeing it. I could have swore it could get up past 150. But this is all based on what I felt was left in the car. I mean I dident even get it in 6th!

Originally posted by o_town_racer
Max speed in 5th gear: 145 MPH
Max speed (electronically limited): 148 MPH

I certainly think it would go all the way up to the rev limiter in 6th without the governor. Look for that governor to go bye-bye once the engine re-tuners come out!

Only had mine up to 100 MPH so far....and that's not very hard to do!
Limiter in 6th? 186 mph? Never!
It doesn't even get there in 5th as that would be 157 mph.

Just reporting on what I have read....haven't had the opportunity to test it out for myself yet.

So does this mean if you take out the speed limiter how fast would it reach then?

I can't say how fast it would go without the governeor. That would be a RPMs versus drag equation. Realize that it takes considerable horsepower to overcome drag when you get to speeds over 150 MPH. For example, the stock C5 Corvette coupe can get to 178 MPH. That is in 5th gear, not 6th, and it is drag limited, not RPM limited. If you increase the horsepower, the speed increases. Since the Vette has a bit better aerodynamics than the RX-8 and more HP, I would assume that even without the limiter the RX-8 would top out around 160. That's just my guess....we'll have to wait and see. I'd be interested in hearing from anyone who has been able to defeat the governor and let it rip.

As I have said, I really don't think there is any limiter/governor. It is not mentioned in any Mazda product literature that I have seen or in any tests that I have read. If you know different, please post the link....

Why would Mazda go to the expense of adding a limiter to limit this car to 148 mph if it could do over 150? To make it look bad against its competitors?

By the way, I assume you guys all have GPS equipment or similar to get speed readings (or you are working it out from the revs)? You can't rely on speedometers - they always overread, often by quite a lot at these sort of speeds.

http://www.technosquareinc.com/350z.htm

Read the above. Nissan put a speed limiter in their ECU. I think it might be common.
Won't know until Aftermarket ECUs show up.

I apologize to everyone out there. My numbers were a bit off. I found the following on Car and Driver's web site from their review of the pre-production RX-8. Their top speed says 150 MPH. I know that I read 148 somewhere, but can't remember where. So I will defer to the experts at C&D.

http://www.caranddriver.com/article.asp?section_id=19&article_id=1790&page_number=2

MAZDA RX-8
Vehicle type: front-engine, rear-wheel-drive, 2+2-passenger, 2+2-door coupe
Estimated base price: $27,000-$28,000
Engine type: two-rotor Wankel, aluminum rotor housings with iron liners and end plates, Mazda engine-control system with port fuel injection
Displacement 80 cu in, 1308cc
Power (SAE net) 207-247 bhp
Torque (SAE net) 159-164 lb-ft
Transmissions 6-speed manual, 5-speed auto
Wheelbase 106.3 in
Length 174.6 in
Width 69.7 in
Height 52.8 in
Curb weight 3000-3050 lb
C/D-estimated performance (247-hp 6-speed):
Zero to 60 mph 6.3 sec
Zero to 100 mph 16.5 sec
Standing 1/4-mile 14.9 sec @ 95 mph
Top speed (drag limited) 150 mph
Estimated fuel economy:
EPA city driving 19-20 mpg
EPA highway driving 28-30 mpg

Originally posted by o_town_racer

http://www.caranddriver.com/article.asp?section_id=19&article_id=1790&page_number=2
[..]
C/D-estimated performance (247-hp 6-speed):
Zero to 60 mph 6.3 sec
Zero to 100 mph 16.5 sec
[..]
EPA city driving 19-20 mpg
EPA highway driving 28-30 mpg

I'm confused now. This is a C&D article dated October 2nd. (Today). The Zero-to-xx numbers are different now. Didn't C&D do this test drive with the 8000 rpm clutch drop and make a 0-60 in 5.9seconds? Wasn't that the result of the preproduction model?

So now they come up with a new article with revised 0-xxx numbers.. but what about the EPA fuel rating???
28-30 on the highway - what???

Can someone explain that to me?

It's getting off-topic, sorry.


Edit:
I just realized that the article is from January 2003. Their web site displayed 10/02/.. simply today's date.
My apologies.
The mpg rating is still strange and I must have confused something about the 0-60 in 5.9s sprint. I have the flu. Maybe that's the reason.

-Peter

still breakin in in the 70s

I was approaching redline in 6th when I hit 143... so I'm pretty sure it's not electronically limited. It's just geared out to about 150. If you wanted to push redline you'd probably hit 148-150. Of course, I could be misremembering and I was actually in 5th.

6th gear is 20 MPh per 1000RPM. (Example 60 MPH= 3000 RPM)
So, 6th should technically be capable of 160 MPH at 8000 RPM, well below redline. So it is either drag limited or electronically limited.

You must have been in 5th.

Oops, makes sense. I guess an electronic governor is likely then.

I did, however, notice that the car pulled to that speed a lot quicker than I had anticipated. I was pleasantly surprised.

my rx8 ms front end cf hood,wing and the short ram intake

NOTICE: For those with the 4AT, please have your PCM, ECU, and TCU flashed at your nearest Mazda dealership.

On some 4ATs, the TCU kicks a signal to the ECU prematurely.

On mine, it manifested itself as an artificial limiter at about 94 mph. I floored it and it just wouldn't go any faster. Needless to say, it surprised the hell out of me as I launched through 70, 80, and 90, then lurched to a sudden stop in acceleration!

He'd mentioned that a few RX-8's have a bad PCM flash and that it's "no problem." Uhhhh...YES IT IS! I don't know how prevalent this is, but I just wanted to let everyone know.

After having every chip in my car flashed, I took it out and breezed through 90, 100, 110, ... and got scared at 112 when I blew by a parked Virginia Sherriff. (oops). Luckily, he must have been in a good mood (more likely asleep) and didn't chase me.

This is the second time that I've expounded on this, but I wanted some confirmation or denial from other 4AT owners.

Thanks.

I got mine up to 145mph and it felt like it had more to give, but I have been told that 155mph is the maximum due to a limiter. :)

122 mph, and I too ran out of clear road ahead ...

230 kmph = 142.915374 mph

long stretch of highway in alberta...only car on the road...ran out of highway or might have gotten it faster.

one thing I've thought about...what would happen if you got it to like 140 mph and then used cruise control to increment by 1 mph? Would it accelerate to 150 (or 148..whatever) faster this way?

Car and Driver tested the top speed of the RX-8 when they compared it to the G35 and Cobra. The top speed of the RX-8 is drag limited at 144MPH. C&D tests the car going in both directions, then they take the average. So yes, you may get the car to go faster than 144 with a tail wind, but going the other way it would be slower. The average of both is the most accurate. The top speed of 144 is reached at 5th gear. A shift to 6th gear maintain the same speed. The car does not have enough horsepower to reach an average higher top speed.

999mph....thats as high as the speedometer goes. :eek: :p

i hit 121 about a week ago. was still accelerating nicely, but I was rapidly running out of road. Took the pic with my phone for my avatar. kind of scary having to take my eyes off the road for a second or two to get the pic, but provided a heck of an adrenalin rush.

Does anyone have any idea what the top speed of the the AT might be? I drove for about 5 miles at 95 on a Tpk with traffic and it still felt like there was plenty of acceleration at times.

I think I have an answer to the question. As you can see from my profile I do live in Germany. I do have the American spec RX-8 which does have a little bit more HP than the euro spec 8. Actually I should say had and RX-8 since I've recently posted (today) that I totalled my 8. Anyway, its not limited to a certain speed but, a certain RPM. When in 5th gear it will cut out at 9500rpms which is right at 155 mph or 250km/hr. I notice above 150 its takes a long time to get it any faster from there. I say it stays around 153 to 155 at top pegged out speed. Now if I do get it up to that speed and there is a some down hill autobahn ahead...I've switched into 6th and actually hit 160. I don't think it can do more than that. I was really pushing the 8 and it any slight incline presented itself...the 8 would drop in speed. I did not have a spoiler...just rotary accents and the chrome mazda wheels. Everything else is stock oh, and the gt package. So no canzoomer or mazdaspeed mods at all. I hope this answers all the questions about top speed. I've pushed the 8 many many times to accumulate 20000miles in just a under a year shy before totaling my 8 a few days ago. So no need to bother reaching these speeds unless you are on a track or the autobahn which is still risky. These are all speedometer recorded so no gps or what not was used. I hope this answers all the top speed questions.

Sorry about your loss...... my 4AT has a lot of bolt-ons and seems to be electronically limited to 125 mph. I have the M-flash, K&N Typhoon cold-air intake, rx7.com midpipe, Magnaflow cat-cack, 8mm Racing Beat (ultra) spark plug wires, Royal Purple synthetic in tranny and rear. The car was made in 01/04 and is fully loaded besides navigation and 6-CD changer. I have minor appearance mods but no body kit other than all the factory options. It gets to 100 mph reasonably quick, then slow from there to 125 mph then electronically governed rev limiter or something..... anyone similar experiences? Secret part of M-flash possiby???

...Last Saturday (Oct 23), with radar detection on, south of King City on highway 101 in California. I ran out of space but reached.......140 mph on speedometer. I had more left but ran out of road; it felt great to finally have a chance to go that fast.

Keep the street racing stories off the forum, please.

about..120mile/h... around 7 rpm with the top gear..!! hm... I think it's the top speed of me.. haha ... so danger when driving fast...!!

Update - made about 132 in my same stretch of road last week. 45 degrees F temp, no wind, 5th gear ... no idea of RPMs

i have a vid of one on dyno doing 184 mph

BFD, that's meaningless in the world of moving air.

heres the 184 mph dyno

Right back at ya..It illustrates its capable of that speed provided you have the power to push it ... Ignorant people suck

I hit 130 last weekend.

Disco-D

blue eyes YOU NEED ANOTHER AVATAR...OR MAYBE EXPRESS YOUR OPINIONS ON A FORD FORUM.. AHH MAKES SENSE NOW YOUR TAINTED

i JUST THOUGHT THAT THE MAJORITY WOULD LIKE TO SEE THAT NUMBER ON THE 8'S INSTRUMENT PANEL..OH AND IT SOUNDS COOL TO

I've taken mine up to 110. Didn't run out of road, but rather nerve. I got VERY paranoid about the possibility of getting pulled over at that speed.

At that speed, it was still quite smooth and obviously had quite a bit of power left to give. I'm happy with the performance.

Right back at ya..It illustrates its capable of that speed provided you have the power to push it ... Ignorant people suck
Right back what at me?
All you're statement illustrates is redundancy.
blue eyes YOU NEED ANOTHER AVATAR...OR MAYBE EXPRESS YOUR OPINIONS ON A FORD FORUM.. AHH MAKES SENSE NOW YOUR TAINTED
Why do I need another avatar? why would I go to a ford forum? aren't I close enough being on forum for a Ford owned car? Tainted by what? intelligence...guilty.
i JUST THOUGHT THAT THE MAJORITY WOULD LIKE TO SEE THAT NUMBER ON THE 8'S INSTRUMENT PANEL..OH AND IT SOUNDS COOL TO
Fantasies always sound cool. ;)

I didn't expect such a violent reaction out of you. Sorry if I came across as a jerk, it was not my intent. I keep seeing this number thrown around like it proves something, it doesn't.

Violent??? Your choice of words is dramatic .I never expected a BFD..I never stated that it could hit that speed on the road ,rather on a dyno.. I said (i have a vid of one on dyno doing 184 mph)you responded(BFD, that's meaningless in the world of moving air.)Now who's being abrasive ?? Please lets try to get along...We share an interest its obvious..No need for rude responses and bickering..Your apology about comming of as a jerk is accepted..I'm sorry that you took my response the way you did..Didn't know that Ford actually owned mazda ,or that the Rx-8 is a Ford product...Hmmmmmmm????

Oh and i'll add that if the air was blowing through the shop bay at 184 mpg it would still do 184 on the dyno ..this is in response to your coment ( BFD, that's meaningless in the world of moving air.) now thats funny!! ... That poke I made at your avatar was warranted.. I do like fords (mustangs) especially the new ones..But man these are two very different cars and I am glad to not have the ford emblem on my 8 ..I respect the history and individuality this car possesses .ie rotary powerplant/body styling the whole thing except for emmissions..

mazda is indeed owned by ford...atleast partly correct?

I hit 135 on a country road and didn't feel it would be prudent to push it any further. I doubt I'll ever find out the top speed.

Who cares if Ford owns 35% or whatever of Mazda. I actually did some research before I bought my 8 and am happy to say that Ford had no INVOLVEMENT at all, other than to perhaps give the ok.

The 8 was designed in Japan and produced in Japan. I'm happy.

BTW, the top speed is in 6th gear and some people have talked about getting in the high 150s, one of them on the Autobahn. I've personally only been about 149 MPH (240 KPH).

That poke I made at your avatar was warranted.. I do like fords (mustangs) especially the new ones..
My avatar is a BMW :p

Strange first post I know, but I've read most of them here doing my research for my pending purchase of an 8, and have to say that "happy there was no Fordinvolvement" seems mighty strange. Why is that? To say reliability is an issue seems strange, they're all I own, and being they own a portion of Mazda is the only reason I even consider buying it, as it's "in the family" . Just my thoughts after lurking for 2 weeks. Great forum guys, lots of useful info for helping with my decision.

70 mph. I never drive faster than the speed limit.

Was able to do 140 in 5th this past weekend with a little bit left in 5th gear, was quite impressed got there faster than I thought it would.

Got up to 125 or so every lap at Memphis Motorsports Park a few weeks ago...it's accelerating pretty slowly by that time, but then again the windows were down. Get's pretty windy at that speed. Probably would accel. much better without the aero drag of having the windows down, but we were running a DE event with the Mid-south Porsche club. I have no doubt it will do the posted 148mph with enough road.