Saturday morning at 8.00 am,outside temp was 77 degrees F.
redlined 1,2,3,4 but 5th will only rev to 8,250 good for 133mph.
shift into 6 gear,rpm dropped to 6,750 at 130mph.My car already has 2,200 miles

Well, I hope you are driving somewhere safe at that speed... Maybe it's still running rich and hasn't totally loosened up yet. I'm not going to look at these dyno's or user facts until we get a bunch of people say over 5-6k miles on the car.

My car had a little over 700 miles and I got it up to 136mph. And it seemed that the road was not totally level, I was going up "a perceived" slight incline. Whatever that is plenty fast for me.

I'm more curious as to the horsepower issue than the top speed. Via documented stats this car is electronically limited to 148mph, it's not the engine, if anything, it's the ECU..

Might also be a speed limiter of some kind. That would be a first - no RX-7 had a speed limiter.

Dale

I also got up to 135 and still picking up speed in 5th. I was on a slight decline, so maybe that is helping out a bit.

136mph in 5th

The only time manufacturers put speed limiters on their vehicle is when the vehicle can (gear limited) go faster than the OEM tires allow. What are the standard tires speed rating?

I have read this multiple times about the 8 being "governed, electronically limited" to 148mph.

But ofcourse, I can't find a friggin source to back up my statement! :)

Anyway, maybe I was dreaming but if true, I'm sure somebody could offer to quote a source.

Thanks,
BV

I've seen somewhere from Mazda for maximum speeds for each gear. Here, it stated maximum speeds for gears 1-5 at 9xxx RPM, but for gear 6 the max RPM was only around 6500 - which would put it somewhere around 140 MPH.

Is it true that stock odometers typically overstate speed? If so, the issue might be more serious

The above results seem to match with the dyno results that seem to be missing torque over 6000.

I suspect people will see an extra 10-15 mph at the top end when the mystery is solved.

Brian

Originally posted by Buger
The above results seem to match with the dyno results that seem to be missing torque over 6000.
I suspect people will see an extra 10-15 mph at the top end when the mystery is solved.
Brian
Check out Buger's excellent graph here:
http://www.rx8forum.com/showthread.php?s=&threadid=7976&perpage=15&pagenumber=11

Due to the amount of drag on the car due to wind resistance at higher speeds it takes 8 times as much power to double your speed.

Granted that the RX-8 is down 10% of its horsepower at the upper RPMs, don't expect a car that is doing 136 MPH now to do more than 140 MPH with 10% more power.

I don't know what the coefficient of drag on the RX-8 is but it seems that after 60MPH the car even in the Road and Track / Car and Driver tests had poor performance after 100 MPH.

I think odd-shaped pairly-closed large front air inlets of the car are hindering the aerodynamics.

-Mr. Wigggles

Car&Driver test data

_________________ Top Speed ____ Power

Dodge SRT-4 _______153 mph _____ 215 hp

BMW 330i PP _______ 152 mph _____235 hp

Chrysler Crossfire ___ 151 mph _____215 hp

Saab 9-3 Vector ____ 148 mph _____210 hp

Mazda RX-8 ________ 144 mph _____247 hp

Acura RSX Type-S ___142 mph _____200 hp


The data suggests that the RX-8 tested by Car&Driver has less than 247 hp.

Supercharger,

The coefficient of drag (cd) and the car's horsepower determine top-speed. Those are the two main factors.

I think the cd is higher than other vehicles out there for the reasons I menitoned earlier.

-Mr. Wigggles

doest top speed have to do with torque (i guesse and thus hp...)

ok, maybe im an idiot...this post is pointless i guesse since torque and hp are directly related

i was just thinking cause of this thing this MB guy told me regarding some AMG model..anyway...
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depends on hp, not torque. torque is a measurement of work, hp is a measurement of power, or work per unit of time, different things, different measurements, different units.

a car's hp is simply the torque multiplied by the rotational speed, and converted using a certain number, depending on the units you want.

power (hp) = torque (ft-lbs) * engine speed (RPM) / 5258

or something to that effect.

the hp required to keep a car at a top speed is simply the drag forces acting on the vehicle multiplied by the top speed, converted to hp.

Originally posted by DisneyDestroyer
I've seen somewhere from Mazda for maximum speeds for each gear. Here, it stated maximum speeds for gears 1-5 at 9xxx RPM, but for gear 6 the max RPM was only around 6500 - which would put it somewhere around 140 MPH.
The quoted top speed is achieved in 5th gear, 6th is geared too high. I suspect 5th is geared too low for maximum top speed and you just run out of revs. You really need a ratio somewhere between 5th and 6th to get the best top speed.

I think this is why the quoted top speed is disappointing compared with other cars with similar power (the 8's drag coefficient is actually quite decent, 0.31). This reason behind this strange gearing is to help with fuel economy.

The top speeds people are seeing in the 130's are definitely too low though, and seem to confirm the dyno results.

The whole subject of gearing and hypothetical top speed was discussed last year in this thread (http://www.rx8club.com/showthread.php?s=&threadid=931). Buger ran the projected numbers through CarTest, and came up with the set of cascades below. While they don't match up with the top speed reported in this thread, they do demonstrate the difference in available torque at the wheels in each gear. Top speed is where the "losses" due to wind resistance, friction, etc, match the available torque.

(The cascades also indicate that for maximum acceleration you should take it to the redline in every gear. This is often not the case for other vehicles - see the lower set of cascades for a Mustang, in which the lines actually intersect indicating that the next gear has more torque available before you hit redline in the lower gear.)

To get a better idea of how a car performs, let’s examine acceleration and top speed.


Car&Driver test data

__________________ 0 – 1/4 mile ___ Top Speed __ Power ___ Weight ___ P/W

Dodge SRT-4 ____ 14.1s @ 102mph __ 153 mph ___215 hp ___ 2920 lb ___ 0.074

BMW Z4 3.0i ____ 14.0s @ 99mph ___ 152 mph ___225 hp ___ 3090 lb ___ 0.073

BMW 330i PP ____ 14.3s @ 97mph ___ 152 mph ___235 hp ___ 3370 lb ___ 0.070

Porsche Boxster __ 14.6s @ 98mph ___148 mph ___228 hp ___ 3024 lb ___ 0.075

Mazda RX-8 ______14.5s @ 96mph ___144 mph ___ 247 hp ___ 2940 lb ___0.084

Chrysler Crossfire __14.8s @ 96mph ___151 mph ___215 hp ___ 3111 lb ___0.069


All the above cars have manual transmission.

Some cars are geared for acceleration while others are geared for top speed.
It seems that Car&Driver tested a RX-8 with less than 247 hp.

Mazda RX-8 ________ 144 mph _____247 hp

Probably a headwind more than a power problem. Car & Driver seems too visible for Mazda to send an underperforming car.

Guys,

I don't think the RX-8 is all that aerodynamic and that is its "problem" at high speed. Some of the air intakes on the front are partially blocked or completely blocked. That can only hurt the coefficient of drag.

-Mr. Wigggles

For those who live close to these facilities, you may want to test your RX-8’s aerodynamics.

Full-Scale Wind Tunnel Testing

NASA Langley (Virginia)
http://wte.larc.nasa.gov/facilities/aerodynamics/14X22.cfm?field=1&id=2&fac=1

NASA Ames (California)
http://windtunnels.arc.nasa.gov/

I've removed this post since the calculations in it were wrong and did nothing but add to the confusion.

Sorry 'bout that.

/Elak

My last car, bont stock Millenia S 4AT sustained 145mph+ speed on a desert highway. (top speed over 150mph) The car had 210hp 210lb-ft torque and runs on 16" wheels. The 90-94 designed Millenia had the CD value of 0.29. The car was very quiet at high speed and did feel like it was slicing through wind. (except the tail end design, which caused slight lift and noise at high speed) In the RX-8, the drag on highway and wind noise was much more noteable than the Millenia. Did Mazda really designed this car in a wind tunnel or did they compromise some aerodynamic design for styling?


http://www.datsuns.com/images/aerographbmp.gif

Here is a diagram detailing the relationship between speed and power given the same aerodynamic. Improving the CD figure will lower the slope of the curve. In the case of low top speed of the RX-8, is it:

1) Driver issue (Wrong gear? Inability to plant the right foot?)
2) Engine power issue (215hp?)
3) Environmental issue (100% humidity, 120F?)
4) Aerodynamic (too much drag at that 130mph?)
5) Port Opening issue?
6) Break in period ECU doesn't allow top speed runs?
7) Check engine light? ;)

Cast your votes

OOPS...i posted a dup. of this in the discussion board...

anyway, had the 8 at 145 tonight, dsc completely off

oh, i heard the buzzer too, i still think it needs to be a TAD louder
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had the 8 at 145 tonight,

Did it take a long time to get there? Mine gets to 115 (my current max) quickly, but I would guess that 145 takes a good push.

Originally posted by Elak
Even with 204-207whp I can't see that this car could reach 248mph except in high temperature or low air preassure (alt. high altitude) conditions... Dude, the low air pressure will cause the engine to lose more power than the car will gain from less air resistance.

---jps

Originally posted by Elak
Even with 204-207whp I can't see that this car could reach 248mph except in high temperature or low air preassure (alt. high altitude) conditions. /Elak

Are you talking about McLaren F1 performance here? I think you'll need less than 2,500 lbs and over 600 hp along with a CD of less than 0.29 to achieve that top speed :D

Guys
have any of you been back to the dealer and politely (!) asked WHERE'S MY GODDAM TOP SPEED ?

If it was me and I'd had that experience I'd be knocking down the dealers door, on the phone to Mazda, exposing this in the media etc etc.

This is WAY down on what Mazda claim - and if this is it, they are ripping you off big time - this has got to be illegal surely ??

This is WAY down on what Mazda claim - and if this is it, they are ripping you off big time - this has got to be illegal surely ??


The one thing I know for sure is, doing top speed runs are illegal :P

Not on a track, not in some countries in Europe...
But that doesn't change the fact that if it's meant to do 150mph (or whatever it is) it should do it ...

If it doesn't then you've been ripped off, period.

not very long at all, and it was a SLIGHT incline too, but dsc was completely off, AC running on 2, and it seemed there was more room to go also

if the top speed is 148, with electronic limitation, it will DEFINATLY get there
________
GENETICALLY MODIFIED FOOD (http://gmfoods.info/)

A recent Road & Track article states that the RX8 has a top speed of 148 mph, and that the top speed is Electronically limited.

PS I have had my 1990 Miata up to 120 mph. My car has the 1.6 L engine.

Can some one jack up their car and take the wheels off and then lower the suspension onto a floor jack [ on each side of the car ] so the CV joints are at their normal angles, and then procede to see what the maximum speed achieved in 5th and 6th gear.

Assuming the Rx-8 isn't like the M3, where the engine speed is capped to 6000rpm when the front wheels aren't spinning.

I'll do that tonite J/K

Don't forget to put the lug nuts back on the wheels so the brake rotors will not come off (unless there is a screw/bolt to hold the rotor in place)

Originally posted by MikeW
Can some one jack up their car and take the wheels off and then lower the suspension onto a floor jack [ on each side of the car ] so the CV joints are at their normal angles, and then procede to see what the maximum speed achieved in 5th and 6th gear.



...why not just do the math?? in 6th at 9300 rpm the speed would be 186mph spot on (~300kph).

...why not just do the math?? in 6th at 9300 rpm the speed would be 186mph spot on (~300kph).


math is too theoretical; people need application :D

(edit: sorry, that was a nerd joke about the split between theory and application. I didn't mean anything by it :) )

Originally posted by blizz81


math is too theoretical; people need application :D


...i'm not saying the car would ever touch redline in six without major major work, i'm just saying you can work out whatever speed you want in whatever gear rather easily, with a pen and paper in minutes.

It's funny how people put in their mind that if something is listed as being governed/ electronically limited to 148 that they assume that it's capable of doing that....they might as well have said "electronically limited to 250 mph"?....maybe if we dropped it from an airplane.........

Terminal velocity's only 120MPH :D

On a deserted highway, 3,600' altitude, 242kmh ( about 150mph) according to the speedo, not a GPS.
I did not detect anything stopping/limiting it, but I doubt I could get it to go much faster.

150.. wow.. I guess that's the record.. thought it was limited at 148..

I thought it was limited too, but then bear in mind speedo, not GPS, so probably a few kmh off reality.
BTW, I was a bit nervous. This car NEEDS a chin spoiler if one would do that much.

The 3rd gen RX-7s were ECU limited to 155 MPH. But if you left off the gas a little then back on, you could get pretty close to 160. Don't ask me how I know this ;) I'm sure the speedo could be a bit off at that speed too.

I've gone 110 and slowed down because I dont want to chrash my 2004 car before 2004 even starts

Absolutely flat,
10*c temp,
91 octane,
5th gear,
buzzer going at about 8600revs

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

Why didn;t you shift to 6th??


I pulled 244 on Highway 40 at about 23C.
6th gear.

Took a run down the hillinto a valley, leveled off at 225, shifted to 6th, pulled up to 244 before I hit the climb on the other end of the valley.

Came over the top of the hill at 215.

That is when i discovered just how good the brakes are.

Herd of cows across the road.

I've had mine up to 149, and that's with intake and midpipe and hks legamax exhaust. also i had to let off cause of a semi.

3rd gen RX-7s were definitely NOT speed limited, at least not to anything below 180.

I have in-car camera footage of 165 down the back straight at Sebring (full lap after passing NSX).

I have personally buried the 180mph speedo and have seen radar measured 204 from a similarly modified RX-7. Do not do this without a vented hood. Otherwise there will be little to no steering over 150.

And yes, those are MPH numbers.

Cool.

I've gone 130+ mph while having some fun with a ZO6. ;)

135 on a pass (highway) to show an s2000 owner once and for all the limitations of his little (but strong) vtec. He caught me at a light later and stated that it was pushing all it had and 125 was the best he ever saw out of his car. We had miggled on the highway a couple times but never runs up like this time....

old topic i know, but i remember reading the Cd was a .30, which isnt the most aerodynamic vehicle on the road at all. to answer the previous question... yes torque has 1/2 to do with it, since HP is [(Torque x RPM) / 5250].... the other half is the Cd....

this is assuming the gearing isnt a limitation... and with a theoretical 186mph (btw- Z rated tires are rated for 149+mph.. to answer another question asked before).,.. it can be assumed that the aerodynamics are really causing the lower that theoretical results. either that or give it a LOT more power... but aero's can be easier to fix than adding another 500hp.

135 on a pass (highway) to show an s2000 owner once and for all the limitations of his little (but strong) vtec. He caught me at a light later and stated that it was pushing all it had and 125 was the best he ever saw out of his car. We had miggled on the highway a couple times but never runs up like this time....

sorry man..but i call b.s. on that one.. as a prior S2000 owner myself before trading up to the more creature comfort rx-8...and can personaly verify that the S2000 is no doubt a quicker car. i had mine north of 150 on many ocassion. it is a MUCH louder car at that speed than the rx-8 though. but i must admit i do kinda miss that 4-cyl scream (and kick) after it hit 5,600 rpm and the 2nd cam profile kicked in... *sigh* i did the right thing trading it in right???? :confused:


yeah..i think so... ;)

Saturday morning at 8.00 am,outside temp was 77 degrees F.
redlined 1,2,3,4 but 5th will only rev to 8,250 good for 133mph.
shift into 6 gear,rpm dropped to 6,750 at 130mph.My car already has 2,200 miles

for me it was 138 waas gps. in 5th gear still pulling well. 82deg and high humidity.

the two things that i know about top speed runs in this car. radatior temp is important as is fuel temp. the car knows and adjusts.

also you need to have over .25 tank of fuel or it will throttle back and give a cel.

how do it know???? car is smart.

beers

john stewar

I've seen somewhere from Mazda for maximum speeds for each gear. Here, it stated maximum speeds for gears 1-5 at 9xxx RPM, but for gear 6 the max RPM was only around 6500 - which would put it somewhere around 140 MPH.

umm..my car must be broken then because i've had mine up around 7500 in 6th gear STOCK at 149...i probably would have tried to faster, but my exit was coming up...

I had mine on 143 MPH on 6th. I dont know the tach because I didn't dare look back down,

3 seconds later I hat to brake real hard because of an a-hole post man car that crossed 3 lanes from the right to the left in front of me. Thank god for DSC and not panicking and doing somthing stupid like turning the wheel while breaking that hard. BTW this thing breaks almost like hitting a brick wall even with the ABS fully functioning. Thumbs up for Mazda.

Iherd someware that the top speed was rev limited not aereodinamicaly limited. does this mean that if we fiddle around with the computer and eliminate that nasty rev limiter on the top end we might go higher?

I had mine on 143 MPH on 6th. I dont know the tach because I didn't dare look back down,

3 seconds later I hat to brake real hard because of an a-hole post man car that crossed 3 lanes from the right to the left in front of me. Thank god for DSC and not panicking and doing somthing stupid like turning the wheel while breaking that hard. BTW this thing breaks almost like hitting a brick wall even with the ABS fully functioning. Thumbs up for Mazda.

Iherd someware that the top speed was rev limited not aereodinamicaly limited. does this mean that if we fiddle around with the computer and eliminate that nasty rev limiter on the top end we might go higher?

While I'm sure this car can go over 150mph, in what possible situation would you need to go faster than 143mph???? Seriously...

While I'm sure this car can go over 150mph, in what possible situation would you need to go faster than 143mph???? Seriously...

You just ate Taco Bell from a drive-through, and somethin's a rumblin' down low...

to those of us who've gone 150+ (myself included) do we actually need more speed...and for what application...it took quite a bit of time to get to over 150. I think id rather get up to 150 faster than have a higher top speed.

Did 250km/h (= 156mph) on the German autobahn a few weeks ago.
The car was running 8000rpm in 6th gear and did not want to go faster.
It just kept on running 8000rpm without ups or downs.
To me it seemed like the car is restricted to 250km/h like most european cars.

To me it was fast enough :-)
Rather have fast cornering and faster 0-100km/h.

FYI

135 in 5th w/plenty to spare

same here 6th at 137 and still was goin up.

to those of us who've gone 150+ (myself included) do we actually need more speed...and for what application...it took quite a bit of time to get to over 150. I think id rather get up to 150 faster than have a higher top speed.

Absolutely! In first you hit redline from say 5k much much faster (timewise) than in 4th or 5th. If it takes 3 secs in first then it seems to take 9 in 3rd, 15 in 4th and 30 in fifth. I think 550 HP would be more fun, so can we count on a four rotor version?

i got my top speed on my rx-8 up to 149....but it got really shakey i was going down hill on a major highway.

on one sunny day in the summer on an open and yet slightly windy road, I was able to get up to 149mph before i had to slow down. Well I was a little bit pissed off because i was catching up to cars and since i never drove 150mph, i decided to try it again. Luckily i had a party to dj at in vermont about 1/2hr north of white river junction. On my way home I was going about 80 when i noticed that i was on a huge downward roller coaster hill that was probably close to a mile long. Dropped it to 3rd, redlined it, and the same with 4th, 5th & 6th gears. I was able to hit 153mph near the bottom of the hill before i had to start to slow down for oncoming traffic. As far as what was in my car at the time ...... almost a full tank of gas (probably lost a 1/2 of tank on the downhill), 2 people, a couple of bags in the trunk and a crate of records. It was a great rush and i cant wait to do it again. Oh yeah, one more thing .... once you hit top speed, you do need mod.'s to hit a new higher top speed.

have fun and be safe
speed kills, but it beats going slow
and don't forget .... drive it like you stole it!

i took my rx8 up to 140 mph with ease, Had there been less traffic I could have easily hit 150mph and no semis or G-35s

You guys are all idiots.


The moderators delete street racing threads but leave this crap on the board... go figure...

What is it going to take? Someone to crash and die testing their top speed? :rolleyes:

All this thread is asking is for members to go out and speed on public roads. Brilliant, just brilliant.




Hopefully someday you'll understand where I'm coming from and how stupid this is.

Theres a difference 310. Technically, measuring top speeds 'should be' on a track rather than flying down the highway like some seem to think is quite cool! I am sure I speak for other mods that we do not approve of such foolishness.

I personally have never gone over a 100. It will stay that why until I finally find a local track. I advise others should do the same, and if not, think of the folks that are on the road with you. Its not worth it just to see triple digits.

My thoughts....

Wayne

See Avatar....

Hey you theroletical guys - The drag coefficient is not the whole story. You need to know the frontal area. A 747 may have a CD lower than the RX8, but it takes a lot more power because it is so large. The RX8 has more frontal area than the older RX7s so slower with the same power (but stock the 8 has much more) and poorer freeway mileage.

142 MPH, ran out of room.

When I was still driving the car daily to and from work I would usually hit 124 - 128 MPH on the same stretch in the morning.

Since I had a little wreck with the car (going 10 mph) I feel differently about it now. I won't even give a riced Civic the satisfaction of getting it's ass kicked.

Things change. ;)

147 Mph in sixth... still was gaining... level ground.

I had mine up to 130 in 4th at redline level groud

i like having an intake and loud exhaust and sound polluting at 9k rev on a street next to an outside cafe. they boo me because their ears hurtzors.

156

Ive been about 135 too :ylsuper: it felt like it had more but I let out because it also felt like it was going to take off :Eyecrazy:

I hit 152, about 8500 rpm in 5th gear.

I had mine up to 130 in 4th at redline level groud

At the risk of sounding trite--

HOLY THREAD RESURRECTION, BATMAN!!!

Im more worried about the morons doing 80 in their armored SUV's and mini vans. He poses a larger hazard than me doing 100 in my 8.

Nissan Titan 70 - 0 MPH = 170 feet !!
Ford Excursion 60 - 0 MPH = 167 feet.
Cadillac Escalade = 144 feet
Ford Explorer = 137 feet
Nissan Titan 60 - 0 MPH = 137 feet
Mazda RX8 = 114 feet.


Not to mention the Low chance of flipping over in an 8, which all the other cars mentioned suck balls at.

i feel better about my 8 now

this thread is stupid and need to die!

I would be seriously disappointed with this car if it couldn't even reach 140MPH. Seems like later RX-8s have better top end performance.

I got my old 1994 Acura Integra with 170HP and 8200RPM redline up to 130MPH at least once so it'd be pretty sad if an RX-8 couldnt top that.

I do hope that anyone who attempts to find the top speed of their RX-8 does it in as safe a manner as possible mainly not hitting anyone or anything else in the process.

From what I've learned about the Subaru STI, it would do 155 stock, and if you installed an ECU chip, would remove the limiter allowing for a top speed of around 170.

Now I found this same type of chip for the RX-8's and would assume it would remove the limiter.

http://www.sfxperformance.com/parts/UNI1320013.htm

Anyone here have this?

I hit 152, about 8500 rpm in 5th gear.

I don't believe this, you would be at around 9700 or so, wherever fuel cut out is, you would have hit it. 146 in fifth is 9500.

First off, the car has no speed limiter. I have had it to 185 when the car was on the dyno.

I've done 154 mph in 6th on a long flat road.

As mentioned above, 6th is really too high for top end and 5th is too low. A gear in between the two would provide best top end power.

First off, the car has no speed limiter. I have had it to 185 when the car was on the dyno.

I've done 154 mph in 6th on a long flat road.

As mentioned above, 6th is really too high for top end and 5th is too low. A gear in between the two would provide best top end power.
Um I thought thats because the speed was measured from the front wheels....

On cruise control mine will go 92 MPH.

Fastest I've had it up to is 95. I doubt I'll need to go any faster then that.

The rx8 does have a speed limiter and its at 155 MPH. IT measured by the front wheels. If youre on a dyno, you can go as fast as the rollers will spin, but IRL 155 and your cut off. I havent been able to pass 142 MPH in 5th gear, the car doesnt have anymore pull, but it also could be that arizona only has 91 octane max.

On my trip back from picking my RX8 up in dallas, tx I was upto 110 in 4th gear and it was around 8500 I think. This was in passing someone and I soon slowed down as I don't need a ticket thanks

hit 144 in 6th. Ran out of road.

Sounds like you shifted into 6th too early.

145 taking up 3 lanes of highway while the highway was doing it's little nid-bit of slight curves... I was actually in 6th, still felt like it has some go, but not much

On my trip back from picking my RX8 up in dallas, tx I was upto 110 in 4th gear and it was around 8500 I think. This was in passing someone and I soon slowed down as I don't need a ticket thanks

I can relate with that. My daily drive up 75 to Sherman takes me through Barney Fife alley, The first week I had mine I buzzed 92 so I know it goes at least that fast. Then again I peaked 100 in the CX7 crossing over the Red River once.

I find 144 to be pretty fast. Some years ago I had my 390 HP vette up to 145 at CMS on a track day. 6500 RPM. The big blocks break valve springs much above that so I held back. Besides the front end gets so light in the vette it's downright dangerous above 120 anyway.

The rx8 does have a speed limiter and its at 155 MPH. IT measured by the front wheels.

Anyone have any evidence to support this claim? I don't buy it.

^^ It's bullchit.

^second that. The 8 is only limited by drag. Besides, why on earth would they have a limit at a speed that can't be reached with a stock config anyway?

I would be seriously disappointed with this car if it couldn't even reach 140MPH. Seems like later RX-8s have better top end performance.

I got my old 1994 Acura Integra with 170HP and 8200RPM redline up to 130MPH at least once so it'd be pretty sad if an RX-8 couldnt top that.

I do hope that anyone who attempts to find the top speed of their RX-8 does it in as safe a manner as possible mainly not hitting anyone or anything else in the process.

What facts support "later RX8s have better top end performance"? I have never heard that.

got mine up to 155mph in sixth gear with room to go. but i thought it was a little too fast and traffic was picking up lol.

Yeah I take back my earlier comment about not being able to reach the so-called limit speed of 155.

Anyone have any evidence to support this claim? I don't buy it.


Well the guy a few posts back got to 156. And 156 is more than 155.

So this myth is...
http://www.plowsunlimited.com/images/mythbusters/bustedplacard.jpg

:D:

The rx8 is drag limited @ about 155mph....

ive reached 135 at the most, but this car can hit 155? How long would you have to floor it to reach speeds like that?

ive reached 135 at the most, but this car can hit 155? How long would you have to floor it to reach speeds like that?

when i did my 167 mph run it took just over 7 miles. it did 140 in just over 1 mile.

^ Video or else its just BS

146 in my RX-8 Shinka in 6th. I did it on very deserted highway at 3am and slowed down because I saw a deer.:Eyecrazy:

and I thought it was a cop.:wtf:

148 mph at 6th gear on the autobahn slowed down for some slow 5 series bmw still had room to go

my top speed is 99999999999999 mph

165 mph n will prove with video once the rx8 comes back from mazda.

my top speed is 99999999999999 mph

That's cause your using the gameshark...stop hax0ring

165 mph n will prove with video once the rx8 comes back from mazda.

Wait I thought it was at the body shop...then the mechanic...and now its at mazda? Did they finally feel sorry enough that they took that poor car away from you??

no eviltwinkie. i got the car back from the body shop fri, my a/c isnt working, n my car takes a hell of a lot effort to put it in gear.... but it does it fine with the car turned off........well a/c is electrical issue, n clutch issue is possibly slave master cylinder.

Lookin forward to that vid :lol2:

old thread but.....about 125 on the freeway...i have a friend with an '07...and he's claimed 155. but he said it took a long time.

my 06 rx-8 shinka on the 15 freeway in san diego ,ca at 12 ish am.

153. to scared to keep going took a little over a mile.

I don't know if its stock but heres someone doing 165 on a road.

http://www.youtube.com/watch?v=Jz-QmlPXoD4

The stock renny can't push through the tranny's 6th gear, but I heard from a guy with a turbo that you bounce off redline in 6th at 172.

153mph more than a time or two

120 comes easy/quick, 135 is a lil wait, 145 takes forever, and waiting to break 150 i grew a beard.... but it'll get there

The stock renny can't push through the tranny's 6th gear, but I heard from a guy with a turbo that you bounce off redline in 6th at 172.

sure it can, on a dynoe with no load or wind resistance, lol. theres a vid somewhere that shows 6th gear bouncing at 184ish

i've done 146mph with 4 people in the car on the I5 from LA to San Diego. too scared to go any faster

Lulz, this thread got revived....

GPS verified 156 mph I have hit 167 but I did not have a GPS then and right now I don't have tires that can handle that speed

http://i7.photobucket.com/albums/y271/MUNCHE187/RX8/156gpsspeed.jpg

143 in my 04mt, not enough open road to do more :)

I did 141 mph with out a problem could have gone faster but I let up.

wow, Im surprised this thread isnt getting any flames/closed for street racing lol.

I hit the 148, took forever and a long time, never will do it on a public road again.

That's one reason for an electronic speed limiter interlock.

The stock Dunlop 8090 is ZR rated (149 mph).

The only time manufacturers put speed limiters on their vehicle is when the vehicle can (gear limited) go faster than the OEM tires allow. What are the standard tires speed rating?

Ive only reaches 148 with 4 people in the car..
and a trunk that was soo full.. my car looked lowered!!!

i weighed 220 my buddies all weighed at least 200

i was coming back from chicago in the middle of no where.. up in oklahoma

it took forever though

200 lbs is pretty hard to fit in the back seats, where you going downhill?

sure it can, on a dynoe with no load or wind resistance, lol. theres a vid somewhere that shows 6th gear bouncing at 184ish

Well ok I'm sure I could do 80mph on a bicycle if there was no drag too.

Well ok I'm sure I could do 80mph on a bicycle if there was no drag too.

hehehehe:stickpoke