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.

https://www.rx8club.com/showthread.p...&highlight=136

 

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

 

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

 

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).

 

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!

 

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.