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Discussion Starter · #1 ·
I was wondering if people have taken their S5 to top speed (track or streets). I was driving home from work the other night (around 1AM) and found an empty stretch of road on a highway in central Illinois (no cars, police, deer, etc.). So I floored the gas and the car quickly got up to 164mph before I had to slow down with a curve fast approaching.

If you have a copy of the US Audi A5/S5 dealer brochure, it states for the S5:
"Top Track Speed: 155 mph*
*Maximum speed electronically limited to 130 mph in the US"

So, first of all, I was definitely going faster than the 130 mph that the US-spec car should be limited to but I was also going much faster (and still accelerating) than the 155 mph that I thought the car would be limited to.

Weird yet exciting! :D
 

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I have heard that the "limited" speed is a bit of a myth... Most cars will go above the limiters where permitted...
 

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...Several people have mentioned the aparent lack of limiter... I can't comment. :D

However, the reason for the limiters on cars that can clearly go faster is not for the road safety campaigners, it's to set limits for the cars design (and ergo it's cost)... if the car is limited to 155mph (std in Europe) then it only needs 155mph tyres, 155mph suspension, 155mph brakes, 155mph aerodynamics... etc. At these speeds, even modest changes, such as +20 mph (175mph) necessitates significant changes (and increased cost) in design and materials. Tyres and suspension in particular.

...So it suprises me that the limiter doesn't seem to limit... I wonder (particularly in the US) if you had an accident in excess of the limit (and lived to tell the tale) whether you could sue Audi for allowing the car to exceed it's design limits? ...???
 

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The car is electronically limited via the ECU and as far as I know is linked to rev's.. Someone can confirm, but I think the speedo is based on wheel revolutions so will generally 'over read' therefore 164mph on the speedo is more like 155mph actual which could be confirmed via GPS if someone has one...

There was a quite a bit of discussion about it Here on the RS246 forum

Jason
 

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im not generally opposed to stuff like this (i've done it), but i cant imagine doing this at night. sounds pretty scary to me...
 

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im not generally opposed to stuff like this (i've done it), but i cant imagine doing this at night. sounds pretty scary to me...
When you are driving at empty three lane highway, there is nothing scary about it. I have videotaped my first top speed run in my A5...I reached 266KPH = 165MPH and there WAS LIMITER.

After mods I reached 165MPH going UPHILL on the highway, once I reached the hill and started going downhilll car still stayed at 165MPH, which means 266KPH and that means that limiter is at around 256KPH....I am not sure about S5 though.......
 

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Remember your reading on the speedo can be +/-10%. And it gets worst if you've changed your wheel size.

I'm not sure how the S5/A5 works, but with a lot of older cars the reading which the limiter took was actually from the speedo, strangely. My supra took it's reading from the speedo, so all it takes to bypass that was to install TSD behind the speedo.
 

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The speedos do tend to be inaccurate. I had a 1.6 FSI Golf hire car last week and my portable sat nav. According to the golfs speedo from as low a speed as 60 mph the sat nav was showing me to do 55 mph, I can only imagine how inaccurate it would be going even to 100 mph.
 

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Discussion Starter · #9 ·
When you are driving at empty three lane highway, there is nothing scary about it. I have videotaped my first top speed run in my A5...I reached 266KPH = 165MPH and there WAS LIMITER.

After mods I reached 165MPH going UPHILL on the highway, once I reached the hill and started going downhilll car still stayed at 165MPH, which means 266KPH and that means that limiter is at around 256KPH....I am not sure about S5 though.......
Yea, I wasn't scared or worried about "obstacles". The road was empty but still enough light to see... and the navi helped me in anticipating the next curve in the road. I've also driven the same route numerous times so I knew there were no hiding places for the police. ;)

I just need to find a track around here that will let me test the top speed.
 

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I was able to get mine a hair under 140 mph on the tollway, before I ran out of clear road. Seems to be not very limited??
 

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+1
defnitely done just over 140. im a dope and accelerated to that speed in 6th gear, so it took FOREVER. had i started in 4th, i probably could have gotten much faster before i saw another car about a half mile up the road.
 

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Unfortunately in New York you may as well assume that there's a cop hiding behind every tree on the freeway, even at one in the morning. But to know that my car may go past 160..wow! May try it one day if I ever take the car out of state.
 

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Someone I know attained a (digital) speedo-indicated 162mph in his S5 at approx 06:30 on a clear A-road. Apparently he too was wondering how accurate this was, and how the limiter, if in fact present, is integrated. One might assume, he thought, that it would share the same data as the speedo?
 

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The car is electronically limited via the ECU and as far as I know is linked to rev's.. Someone can confirm, but I think the speedo is based on wheel revolutions so will generally 'over read' therefore 164mph on the speedo is more like 155mph actual which could be confirmed via GPS if someone has one...

There was a quite a bit of discussion about it Here on the RS246 forum

Jason
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I'm pretty certain that the limiter would utilise the same fuel reduction functions used by the rev limiter... therefore, as Jason says, it is likely to be invoked at certain revs in top gear.

...This does mean that the 155mph is 'theoretical' because changes in the rolling diameter, through wheel/tyre modification, different tyre pressures and a degree of 'balooning' (like dragster tyres) will affect the speed at which these revs are attained... most likely, wider tyres will 'balloon' more, increasing the rolling diameter by quite a few percent and hence increasing the speed at which the lmiter comes in.

:)
 

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I'm just curious to know what the penalty would be in America if you were stopped after doing these sorts of speeds? Presumably the penalty isn't that onerous otherwise you wouldn't take the risk - or would you anyway?

In Australia, which has no decent roads that compare to say the english motorways or french autoroutes, anything over 100mph is likely to ensure a loss of licence for around 12 months - less if your lucky - and a hefty fine. At 160mph I wonder if you might even be jailed.

Oh and someone suggested that if you do more than 155mph and have a crash you might conceivably sue Audi. May I suggest if that happens it should be the other way round! lol.
 

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In many states, speeding more than a certain amount above the speed limit (often about 25 mph over) is automatically categorized as "reckless driving", an offense much more serious than normal speeding. This can sometimes result in immediate suspension of your license. So much depends on the state you live in. But if I were caught doing 155 mph anywhere, I'd expect to not be driving for a few months.
 

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I'm just curious to know what the penalty would be in America if you were stopped after doing these sorts of speeds? Presumably the penalty isn't that onerous otherwise you wouldn't take the risk - or would you anyway?

In Australia, which has no decent roads that compare to say the english motorways or french autoroutes, anything over 100mph is likely to ensure a loss of licence for around 12 months - less if your lucky - and a hefty fine. At 160mph I wonder if you might even be jailed.

Oh and someone suggested that if you do more than 155mph and have a crash you might conceivably sue Audi. May I suggest if that happens it should be the other way round! lol.
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Same here in the UK... over 100 highly likely to have your license suspended... at 150... definate suspension and fine... not sure about jail, but we have a tendency to release murderers, rapists and paedophiles early, to make space in the prisons for real criminals, like people who object to increases in council tax.
 

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Around here i'm not too worried about cops and other cars, i'm more worried about deer and foxes and the occasional turtle.. especially at night..
 

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Discussion Starter · #19 ·
Same here... more worried about deer, etc. I was on an empty road that I've driven numerous times in the past. I'm sure I wouldn't be speeding like that in the middle of Chicago.

Besides, what do expect the penalty to be for driving 164mph? A slap on the wrist? Of course it'll be a massive fine with suspension. I expect that. But then again, that's why I'm driving an S5 and not a Chevy Aveo. I took a risk and I got lucky. Will I take that risk again? Probably not. That's why in my original post, I stated that I was searching for a track around Chicago to really test the top speed.

Hope that helps...
 

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I am not sure how accurate the speedos are but I have GPS confirmed that mine is accurate at 70, 80, 90, and 100 mph--all within 1-2 mph accurate. Therefore, unlikely to be 10% error at higher speeds--I have been past 165mph only once in this car and probably never again. Did not feel any speed limiter but only head wind limited.
 
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