LE and Plus speedos do show 180mph.

Mine over reads by about 5% compared with the sat nav figures.

Pete

My speedo is over reading by about 8mph at a true 155 (was reading about 163 - clock only goes to 160, so the 163 is an estimate

LEs, Pluses and very late 20VTs have 180mph clocks

No-one believes me that these things have such a high top end!
Glad to hear that there are some more people that have got to similar figures,
My new L200 has an estimated speed on 100MPH!
SLIGHT DIFFERENCE!

Thats becuase speedo speed and actual speed = upto 10% difference.

The speedo isn't consistent on coupes. Sometimes it reads more over than other times.
Mine under-reads because I have tyres with a larger circumference. At 98mph on the speedo I'm doing 102mph according to GPS. I also have a digital view from my ECU which IS consistent so it is primarily the speedo mechanism that is wrong. I had my old Blitz Power-ID calibrated on a rolling road and we observed at 150mph on the speedo my car was actually doing 155mph
In terms of GPS - in car GPS equipment is not completely accurate and has quite a slow sample rate (so lags) so unless you have something like a V-BOX then at these speeds it is not definitively reliable.

IMHO the best way to work it out without masses of expensive electronics is reading the rev counter and doing the maths to determine what speed you were going. The rev counter only lags very slightly and at the acceleration rates you're talking about at 150mph+ it is almost completely accurate.

But often under-reads by about 100rpm - on one of the ECU's you can calibrate the speedo but I don't recall which

Neil

rev counter is definitely inaccurate - my code reader gives figures that are two or three hundred rpm out (rev counter reads too high)

Barbz has done 180 something in his car which was indicating on his gps!! :o....I was with him!!

WOW!
MAD these Little Italian things arent they!

He would never be that naughty

We should have some big power coops at Jimbo's runway bash, I reckon we could see an official 180+

i will go with the rev counter being inncaurate as i got 6800rpm in top(5 speed box) out of my old coupe with minimal mods.as said no 2 speedos seem to be the same,some are 10mph over at high speed and some are less than 5

Speedos are calibrated by statute at +15%/-0% - that is, they may read fast by up to fifteen percent but they may *not* read slow.

Easiest way to do that on production batches is to make them read fast an average of 7.5%

There's also an issue with most speedos driven by cable in that the mechanism is not linear, so they tend to try for most accuracy at speeds that are legal - 30 and 70 *tend* to be most accurate.

Neil

Maybe not everyones is right then:)
Mine is for whatever reason as my Motec shows more or less exactly the same in a steady state. I accept it does lag when accelerating in low gears but when the acceleration is relatively slow my rev counter is spot on.

I had my fastest top speed run on my Europe trip a couple of years back. It shows on video as reading approx 168mph on the clocks (non GPS), some of you may remember this as part 4 of my holiday video? This was on the Autobahns and I reached this speed three times (sections after Stutgart heading north), but each time traffic or corners haltd progress.
TBH I don't think I would have got much more, as I was two up, with a weeks luggage, in 100 degree heat, only at 1 bar boost (approx 265bhp) and was selling the car three days later!

On a cool winters day at 1.3 bar by myself i would have got more for certain.

Are 16vts originally fitted with rear undertrays? Had to cobble together the front one once after pulling it to pieces trying to reverse out of deep snow [!]
S.