What speed was i doing????

recently i was bombing along the ahem "private test track" motorway
in my w reg alfa romeo 146ti. it was about 3am and there wasn't a car in sight. i had my satnav on in the car. i decided to max my car out and hit the go pedal and held it there mercylessly. i reached the limiter and just before the revs were backed off I looked down and the speedo said i was doing just under 150 mph then the limiter came in and knocked the revs back down to 7k the speedo dropped to like 140-145ish (hard to see at that speed!) Great i thought my car will touch almost 150. not bad for a 2 litre.
when I got in I took my satnav out the car.
I checked the travel statistics as mine records a lot of info.
it said the max speed i acheived was 156 mph.
now i've had my satnav from new and never lent it out. I have used it in other cars but never anything capable of going that fast.
I've checked the official statistics on my car and it says the top speed is 131mph.
it is modified but the gearbox and rev limit have not been touched.
So what speed was I actually doing?
I happend to mention this to a couple of work mates and one of them just laughed and made a comment about me being towed by an evo.
Any comments or opinions would be apreciated.

So... your speedo said you were doing it, your rev counter said the engine was doing it, the sat nav agreed... I spose you were doing 150 then. Its way above what the true maximum really is but as the old saying goes, downhill with the wind behind you and anything is possible.
Now just guessing but that is how you got your name, right?

yes 99% of the time I'm a pretty sensible driver, sometimes give it a bit at lights and coming off roundabouts etc but generally perfectly safe. and then ocassionally when someones annoyed me or something inside me triggers it, the red mist comes down and i go nuts !!!

Originally Posted by TwinsparkCrazy

yes 99% of the time I'm a pretty sensible driver, sometimes give it a bit at lights and coming off roundabouts etc but generally perfectly safe. and then ocassionally when someones annoyed me or something inside me triggers it, the red mist comes down and i go nuts !!!

What like saying the contents of this thread is far fetched ??

I can't remember the exact figure, but the limiter in fifth is slightly over 150mph. Your not the first person I've heard claim hitting it either. From my own experiences in my 145 Cloverleaf, I can belive with a decent downhill stetch it would be possible.

150 from a standard QV?? One thing to say to that- Bullsh1t

I have owned a couple and the most I have ever managed was 130mph on a slight downhill stretch, and they simply wouldn't go any faster.

My Fiat Coupe struggles to do much above 155mph and thats with 110 bhp more, and taller gearing.

On a private local runway BTW.

Originally Posted by symonh2000

150 from a standard QV?? One thing to say to that- Bullsh1t

I have owned a couple and the most I have ever managed was 130mph on a slight downhill stretch, and they simply wouldn't go any faster.

My Fiat Coupe struggles to do much above 155mph and thats with 110 bhp more, and taller gearing.

On a private local runway BTW.

A bit stronger than what I said Simon but along the lines of my thinking - I must be losing my touch

Originally Posted by symonh2000

150 from a standard QV?? One thing to say to that- Bullsh1t

I have owned a couple and the most I have ever managed was 130mph on a slight downhill stretch, and they simply wouldn't go any faster.

My Fiat Coupe struggles to do much above 155mph and thats with 110 bhp more, and taller gearing.

On a private local runway BTW.

Crit hit the limiter in his and I've been only a whisker away in mine. Like I said though you'd need a downhill to do it, mine is out of steam showing 140 on the flat.

Originally Posted by chrisd_b

A bit stronger than what I said Simon but along the lines of my thinking - I must be losing my touch

Jim145 the fastest I ever got was 135 out of a 146Ti on a downhill stretch. The 145 had a bit shorter gearing IIRC and wouldn't do much above 129 on the same piece of track.

Many people run 145's with the wrong size tyres 195/50 R15 instead of the correct 195/55 R15 as they are cheaper. That might affect the reading a bit, and mean you are going slower when the rev limiter comes in.

Easy chaps, TwinsparkCrazy was asking a question not boasting.
It is quite common and easy to exceed stated maximum speeds when you do what he said he had done. We are not talking of holding it down for a mile and a half on a runway either, more like 5 mins on a motorway at least, ie 10 miles or more. His choice.

Originally Posted by symonh2000

Jim145 the fastest I ever got was 135 out of a 146Ti on a downhill stretch. The 145 had a bit shorter gearing IIRC and wouldn't do much above 129 on the same piece of track.

Many people run 145's with the wrong size tyres 195/50 R15 instead of the correct 195/55 R15 as they are cheaper. That might affect the reading a bit, and mean you are going slower when the rev limiter comes in.

I can only comment on my own car, running standard wheels and tyres will easily show 145mph on a short downhill stretch. I would hope you would know me well enough by now Symon to know I'm not in the habbit of making things up!
On a good downhill motorway stretch I know if my 145 was nailed it would be onto its limiter.

I do believe you Jim, its just I hadn't manage to get that sort of speed out of any of mine, even with quite a bit of trying.

I did have a burn up with a Renault Clio 172 on a dual carriage way though and he only just managed to edge ahead of me, so the QV is far from slow as you well know.

I concour with that mate, a pal of mine has a 172 Cup. I expected it to demolish my 145, but from 40 - 120 it only pulled a car lenghth - we were both quite suprised!

Aren't speedos legally allowed a margin of error of +10%, and usually set to indicate fast as a default? Mine always seems to be around 5-10% fast compared to my sat nav.

Still doesn't answer where the 156mph sat nav bit comes from - seems totally out of the question.

Originally Posted by Seabadger

Still doesn't answer where the 156mph sat nav bit comes from - seems totally out of the question.

Oversize wheels will increase the top end speed. The OP hasn't specified the tyre size he's running so it's possible to get a higher top speed if a larger then OEM diameter has been fitted. Maybe it's running on tractor wheels

Sat nav is pretty accurate so if it said you where doing 150mph then you where doing 150mph. Also, you hit the limiter in 5th so you must have hit some serious speed. no doubt about it.

Out of interest, what mods have you done?

What's the top speed in 5th at the rev limit with standard wheel / tyre combo? No matter what mods he's done, if he hasn't changed the gearbox or limiter, if he's running standard wheels and tyres he can't go above that. It's a 19% increase over what you'd expect, which is pretty unusual. I suppose a 7inch difference in the circumference could change the gearing enough to do that.

As for sat nav being accurate, I can only speak for mine, and whilst it's generally accurate, it has been known to give slightly mad readings, albeit when I'm stuck in traffic and it shows me as still doing 20mph.