70 replies to this topic

[Cooperman]

My box standard mpi sits at 100mph with ease, bloke I bought it off said his daughter did some road testing with it and maxed it at the 110mph, like you all didnt think it could, so I decided to test it out myself legally of course and with a proper dash calibrated speedo I hit a ton with ease

 

It was either downhill, or with a strong tail wind, or both, or you have an engine with well over 90 bhp.

It is scientifically impossible for a standard  MPI with c.65 bhp to reach anything over 90 mph in still air on a level road. The power curve, torque curve, drag curve and gearing simply will not allow it.

[tmarmsi]

My box standard mpi sits at 100mph with ease, bloke I bought it off said his daughter did some road testing with it and maxed it at the 110mph, like you all didnt think it could, so I decided to test it out myself legally of course and with a proper dash calibrated speedo I hit a ton with ease

 
It was either downhill, or with a strong tail wind, or both, or you have an engine with well over 90 bhp.
It is scientifically impossible for a standard  MPI with c.65 bhp to reach anything over 90 mph in still air on a level road. The power curve, torque curve, drag curve and gearing simply will not allow it.

No mods on the car what so ever was a flat road no wind etc, I'm as shocked as you just telling how it is, funny how a lot of other guys on here are getting the same results, great little individual cars those mpi's :)

[Tommyboy12]

There are very few on this forum that know anywhere near what Cooperman knows so you shouldnt shun him so lightly. The man has more likely been playing with Minis longer than you have been alive.

[anthonysjb]

the speedos aren't accurate, unless you've verified it by gps it could be any speed

[Cooperman]

Sorry to disappoint you and anyone else, but the speed of any vehicle is governed by the aerodynamic drag coefficient, the available power/torque and the final drive gearing. 65 bhp with the aero-d drag coefficient of the Mini and the high gearing of the MPI will govern the top speed. What people may claim is irrelevant as the real top speed will be around 90 mph, or less with all the additional drag creating features such as the large wing mirrors and wheel arch extensions.

Remember, the original Cooper 'S' 1275 had 75 bhp, low gearing (3.76:1 of 3.44:1), and no wing mirrors or arch extensions and narrow wheels & tyres. It had a measured top speed of 95 mph at which was about where peak power was developed.

A 65 bhp Mini with wing mirrors, etc., will never reach this genuine speed. It is scientifically impossible.

[sonikk4]

I think what we can draw from all of this without it descending into chaos is that unless you have a base line to start from in a set of uniform conditions with speedos verified by calibrated instrumentation then you will never truly gauge a vehicle's top speed.

 

The power to weight ratios, drag coefficient of different cars, tyre pressures, rolling radius of the tyres, gearing etc etc etc all play a huge significant part of a vehicles ultimate top speed.  

 

Cooperman has hit the nail on the head here.

[Cooperman]

The John Cooper 'S-Works' with a claimed 90 bhp had a road-tested top speed of 99 mph.
The Rover figures for the 63 bhp MPI gave a top speed of 85 mph in their sales brochures/literature.
Again, drag increases as the square of the speed. So to double the speed requires 4 times the power. That is why a 34 bhp 850 will do 72 mph, a 998 Cooper with 55 bhp will do 86 mph and a 75 bhp Cooper 'S' will do 96 mph. So the increase in bhp from 34 to 55 give an additional 14 mph, whereas the increase from 55 to 75 only give another 10 mph. You can draw a graph from this to establish what power will be required to do 100 mph and you'll find it is about 90 bhp.
There is a lot of loss of top speed and, indeed, increased fuel consumption, from the later additions of the very wide wing mirrors and wider wheels and tyres. The higher FDR of the later cars does not help with top speed either, although it makes cruising a lot less frantic.
Even moving the front number plate above the front bumper will improve the aerodynamics a bit, as will driving with the windows closed. Acceleration is improved by reducing the weight.

[tomtaylor1994]

Physics aside (and no, I'm not shunning physics, I will be doing a degree in automotive engineering this year), my speedo indicated 110. I'm not claiming the actual speed was 110 (I highly doubt it was anywhere near), but it does make you wonder how inaccurate these speedos are!
This is why I always drive at an indicated 80 on dual carriageways and motorways, as I am confident I am really doing a speed of 70 mph.

[mini93]

241 Km/h 

213 HP 32.3 kgm

 

 

 

 

Hey, thats cool... I did 140mph in mine with more to go... well... In my daily, which isnt a mini either... kinda just as relivent to this post as your shonky video (nice camera skillz)

Edited by mini93, 22 July 2013 - 06:02 PM.

[jonny95]

if you want a car to have a high top speed minis are not the way to go

 

minis at high speeds are awful

 

i fail to understand the desire to do 100mph in a mini

[Hrimfaxi]

MY MINI R TEH FASTEST!!

Agreed with Jonny95 - Mini's are the most fun in twisty lanes/B roads.... and roundabouts.