Real RS4 top speed?!

Post by **Scotty** » Tue Aug 03, 2004 5:28 pm

That's how I did it when I maxed by APR'ed TT. The needle was off the dial so this was the only solution (I didn't have a GPS speedo then)

p.s. 265kmph = 164mph

Post by **Conti** » Tue Aug 03, 2004 6:31 pm

So, does it work with GPS or with air flow?
I think it can't be air flow, because if you are driving backwards it also tells you the speed!

Post by **TarmacTerrorist** » Tue Aug 03, 2004 7:18 pm

Nige_S4 wrote:Conti, I think jr posted some info after he did a flat out run in Germany with a GPS comparison against the speedo readout. From memory, his speedo was showing 196mph and his GPS was showing 182mph.

The speedo was reading just over 190 at approx 6850 revs and the sat nav was saying 181. I would say we were comfortably doing 185mph.

Sat nav is not that accurate, in runs down bruntingthorpe strip ealrier this year with Tim in his csl we were speed trapped at 161 on a few occasions yet the sat nav was only reading 159 and this was after a 2 mile straight run,

Think it time some of the footage went up JR, youv'e got the tapes mate.

With the car now mapped and a nice cold morning the needle will see the double ton no problem.

Post by **Nige_RS4** » Tue Aug 03, 2004 8:22 pm

Sat nav is not that accurate....

Tarmac Terrorist, please send an email to the US military to warn them of impending doom, as they use GPS (albeit differential GPS) to guide their cruise missiles - their email address is missed.the.target.by.a.mile@hotmail.com

Actually, it can be accurate down to 5m if you have sufficient satellites in view - that's pretty accurate - After all, 2mph at that speed is negligible (just over 1%).

You don't say what technology the speed trap equipment was using, but I'd guess the speedo was reading nearer 170mph on the CSL ??

Post by **TarmacTerrorist** » Wed Aug 04, 2004 8:10 am

Post by **TarmacTerrorist** » Wed Aug 04, 2004 8:17 am

Nige_S4 wrote:
Actually, it can be accurate down to 5m if you have sufficient satellites in view - that's pretty accurate - After all, 2mph at that speed is negligible (just over 1%).

You don't say what technology the speed trap equipment was using, but I'd guess the speedo was reading nearer 170mph on the CSL ??

yes speedo was reading nearer 170.

Accurate to within 1%? I would have been sacked on the spot at my last job had I told them that. I suppose they can make up for it by putting in more explosives.

Post by **paul_j_murray** » Thu Aug 05, 2004 9:53 am

So what is the top speed of an unmodded RS4? I hit an indicated 170mph (on the dial) last weekend in France before traffic dictated that I slow down.

The quality of the toll roads over there was suburb. I couldn’t imagine doing that sort of speed on any road in the UK – too much traffic & too bumpy.

Post by **Conti** » Thu Aug 05, 2004 10:43 am

paul_j_murray wrote: too much traffic & too bumpy.

Never been to Germany???

Post by **Conti** » Sat Aug 07, 2004 5:19 pm

we tested the new speed indication in the air cond.:
I was surprised:
@270 km/h (speedo) the air cond. said: 250 km/h

So, did we never go faster than 300 when the speedo was at 320???

Post by **Scotty** » Sat Aug 07, 2004 6:44 pm

I always assummed that they were fed by the same sensors and would therefore be as accurate as each other. Does this mean thats there are extra speed sensors? i.e gearbox and perhaps wheels?

Post by **Jani** » Mon Aug 09, 2004 7:15 am

The AC channel 17 speed is not from GPS, since it works even with non GPS-cars. That is some speed signal from the gearbox, but it seems to be a bit pessimistic. I'll have to verify the difference with a Garmin GPS that shows the speed. The speedo seems more accurate IMO, it shows maybe 2% more than the actual speed.

I've also wondered how do you get the accurate speed from the Navi+ shown, it must have it. Anyone with information please share.

Unmodded RS4 top speed is limited to 270 km/h. You can test this by removing the speed signal from the ECU -the car won't rev above 6300 rpm in any gear. 6300 rpm equal 270 km/h. Or you can drive it flat out in 6th, won't rev above 6300 rpm

Post by **paul_j_murray** » Tue Aug 10, 2004 5:32 pm

Jani wrote:Or you can drive it flat out in 6th, won't rev above 6300 rpm

Sounds about right. (I just thought it was a shed load of wind resistance holding the car back.

)

Post by **kiwi_mtm** » Tue Aug 10, 2004 7:23 pm

Nige_S4 wrote:

Sat nav is not that accurate....
Tarmac Terrorist, please send an email to the US military to warn them of impending doom, as they use GPS (albeit differential GPS) to guide their cruise missiles - their email address is missed.the.target.by.a.mile@hotmail.com

Actually, it can be accurate down to 5m if you have sufficient satellites in view - that's pretty accurate - After all, 2mph at that speed is negligible (just over 1%).

You don't say what technology the speed trap equipment was using, but I'd guess the speedo was reading nearer 170mph on the CSL ??

Is'nt domestic GPS still intentionally made inaccutrate by x meters compared to Mil Spec. ?

ie to stop you buuilding your home made cruise missle guided with your local electonics store GPS.

Post by **peterb** » Wed Aug 11, 2004 9:13 am

kiwi_mtm wrote:Is'nt domestic GPS still intentionally made inaccutrate by x meters compared to Mil Spec. ?

No. SA (Selective Availability) was turned off some little while ago. Now we all get to work with the same inputs that the military does. Their equipment may be better and they will use differential correction.

Post by **TarmacTerrorist** » Wed Aug 11, 2004 11:23 am

peterb wrote: Their equipment may be better and they will use differential correction.

i.e More explosive

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