Slower? Really? Why is that? And is there a thread on here about how to remove the governor by chance?

 

OK.... im confused here... i know several people are saying it is drag limited and everything but i have a unichip and oz alleg rims other wise stock and i have no problems getting to 155 actually im kinda disappointed it took way to long to get there and i got bored however it felt about as stable as my 350z does at 170. the z however has a full wide body and coilovers. My rx8 corners way faster then the z but i cannot autocross my z because of the engine.

 

ummm... no torque plus increased wind resistance and your disapointed it took long.

Get a Vette!

And stay off the public roads.

 

i was able to do 211 km/h i was in 5th gear at 7500 rpm

 

I'm not good in math, so can you convert that to mph...lol

 

lol, ok

1 km/h = 0.62 mph
211km/h x 0.62 mph = 131mph

 

From the posts made so far, the majority have been with stock 8s. What speeds can be achieved with fi?

 

Probably like 160-170 if you keep pouring it on

 

I have a stock 2007 RX8, which I have had up to 140mph in 5th gear. The speed climb by that point had slowed considerably, and had also begun the full body shake from the wind drag. With more road, I am sure it would have gone 150mph, but 185mph stock simply isnt going to happen on the road. Not without considerable mods.

 

More power doesn't affect the maximum speed. You have to switch to different gear ratios to do that. Although with FI it will be easier to reach the maximum speed.

 

The RX8, on a dyno, can register about 187 mph (Redline in 6th gear). Aero drag and rolling resistance reduces that on asphalt. A member with a stock US spec car, in Germany, was able to hit 155 on a level road. Most will top out at 145 to 155. Mods to the car and the quality of the engine will change that top speed. More horsepower will help overcome the drag, but there are diminishing returns as you achieve higher speeds.

 

I've tapped 151mph once...Felt stable but I got nervous. Fast enough to die, fast enough for me...

 

Moby, maybe I am overgeneralising your statement that more power doesnt affect top speed, but are you trying to say that if I added, lets say, 300 lbs/ft torque to my RX8, it wouldnt go any faster? The RX8 does not have enough power stock to truly top out 5th and 6th gears. There is room for more speed without swapping gear ratios.

 

the front end is hardly aerodynamic, the wind buffer caused by the flat front end causes a huge air pocket to form heading right over the roof.

wash your car and take it for a drive and watch the water on the hood sit in place at 80mph..

it's not a top speed body design, nor does it really have the power to utilize the gearing all the way to redline in top gear. 5th and 6th were more designed for fuel economy than speed, even though economy still sucks it could be worse.

once the wind force gets high enough it simply takes power to push through if aerodynamics lack.

 

Ever wonder what she would do with no air resistance?

 

You can die at 55 mph, given the correct circumstances. 151 just lessens your odds of living should you come to a sudden and unexpected stop.

IMO the 8 is plenty fast, top speed not with standing. At the track I have never been able to achieve top speed. On the road I had it up to 145 in West Texas for a very brief moment. Flat roads no one around, except for cops hiding behind giant tumble weeds. As far as the car being able to achieve 155 is not that great of an accomplishment. My Honda Accord will do 140 with a crappy little 4 cylinder. My escort 130 hp would probably do 120+, but is limited at the factory to 100 due to a not so great selection of 14" tires. I have never felt the need to remove the limiter. My truck is limited to 100 at the factory as well. I have no idea what it is capable of if it were removed? I will have to search around and find out. My point, going 150 is easy. It's going beyond that, that is challenging. Take a look at the Veyron it has a top speed that is 95 mph faster than the 8's. Yet it has 4 times the hp rating. I know this thread is not exactly about this topic and I apologize if it has already been covered. I did not read the whole thing.

 

Your answer was only a couple of posts prior to yours.

 

What people with "top speed" on their brain seem quick to forget is that the RX8 wasnt designed with a high-end top speed in mind. Its *how* the car handles the speed it does have. I cannot remember the publication, but the RX8 was named the 3rd best handling car for under $100,000. And, yes, I have taken it up to 140 in a straight line, but more importantly, I have gone into corners way faster than my brain told me was safe, and the car stuck to the road like it was on rails.

I have friends with Mustangs and Corvettes etc who tell me my car is slow, but what they forget is that they drive cars that cant turn a corner without first wrapping themselves around a tree. The RX8 isnt about top speed, its about handling, Fahrvernügen(yes, I did just steal VWs slogan), and race capability, not drag racing.

 

Enginewise stock 192HP RX-8 except K&N drop in (lol).

Got to 240km/h on a straight road until it started to go uphill, so that's about 150mph.

And before anyone tells me to gtfo the road: I live in Germany, this was on an almost empty road, 3 lanes, no speed limit, nice weather.

 

I hate the truckers on the autobahn...

 

Well, go for a drive on a Sunday, most trucks are not allowed to drive on Sundays

 

Lol, i'm generally there during trackdays.de 's events... When I leave the track i don't really feel the need to speed. It's a long way back home!

 

If you are not mechanically limited currently by the gear ratios then there is no need to change them in order to achieve more speed.

The RX8 is unable to accelerate towards redline stock, so adding more power will increase your top speed as the car now has the power to displace more air.

My old Mazdaspeed 3 for example had more power than it did gear which kept it just above 163 mph. If i had another gear it could climb a bit higher since the power band falls of a cliff at 6,000rpm which is right where it was at when it stopped climbing. It had a CPE TBE, Intake, FMIC, Inlet pipe, BPV, and Cobb AP stage 3 tune but it would have taken a different turbo that could manage higher rpm to get much more out of it. that and a longer straightaway at the track.

I am sure a rx8 with an intake, mid pipe and performance tire with less rolling resistance could eek out a few more KM top speed than a stock car

 

So far I'm at 132mph (212km) and she still wanted to keep climbing.

 

Finally, someone here gets it.