How fast can an E89 go? Part Deux!

[sars]

So I've had a little time during a wet lunch to put pen to paper and reacquaint myself to Massey, Bernoulli and Mr Watt! When B21 put the above graph together I thought he's got an answer after a fashion and in a round about way, so: -


This is an amalgamation of two well known formulae derived from Bernoulli and Watt, there are limitations to the theory based on low Reynolds number, where inertia of the fluid is ignored, but for our Zeds it's simple enough. Though it does ignore rolling resistance, friction of bearings etcetera.

For my car the theoretical top speed not limited by gearing with a Cd of 0.35, frontal area of 2.2 m2 and 250kW, is 79 m/s or 178 mph

 

[B21]

So I've had a little time during a wet lunch to put pen to paper and reacquaint myself to Massey, Bernoulli and Mr Watt! When B21 put the above graph together I thought he's got an answer after a fashion and in a round about way, so: -
Screenshot 2022-02-15 172604.png

This is an amalgamation of two well known formulae derived from Bernoulli and Watt, there are limitations to the theory based on low Reynolds number, where inertia of the fluid is ignored, but for our Zeds it's simple enough. Though it does ignore rolling resistance, friction of bearings etcetera.

For my car the theoretical top speed not limited by gearing with a Cd of 0.35, frontal area of 2.2 m2 and 250kW, is 79 m/s or 178 mph

Splendid..the sim suggests 175mph..now that you are on a roll could you do a time, distance to top speed model please ?

 

[Argyll Andy]

So I've had a little time during a wet lunch to put pen to paper and reacquaint myself to Massey, Bernoulli and Mr Watt! When B21 put the above graph together I thought he's got an answer after a fashion and in a round about way, so: -
Screenshot 2022-02-15 172604.png

This is an amalgamation of two well known formulae derived from Bernoulli and Watt, there are limitations to the theory based on low Reynolds number, where inertia of the fluid is ignored, but for our Zeds it's simple enough. Though it does ignore rolling resistance, friction of bearings etcetera.

For my car the theoretical top speed not limited by gearing with a Cd of 0.35, frontal area of 2.2 m2 and 250kW, is 79 m/s or 178 mph

Ahhhh, but are the blue ones faster Sars? oke: :rofl:

 

[The.Analyst]

So many variables in this, wind, incline/decline etc etc. One quiet early morning on a suitable rd I had my 23i up to over 140mph! My 35i on MHD stage 2+ is still pulling really hard at 140mph!
Shall we all arrange a track /drag strip (for cars not clothes lol) day???

The initial launch is very hard on the cars and it’s difficult to master a good technique, been to a few of these only to see people with fried clutches and broken transmissions..a more boring version which reflects more accurately the capabilities of a 300bhp+ cars is the dash from 60-120 mph..that way initial launch techniques don’t matter as much and saves destroying the transmission.

Very popular amongst the guys with large amounts of power to deploy and more representative of how torque impacts the acceleration as well as brute power.

Saves running off the end of the runway too.

You can do it discreetly using Dragy to compare folks in different locations.

 

[john-e89]

So I've had a little time during a wet lunch to put pen to paper and reacquaint myself to Massey, Bernoulli and Mr Watt! When B21 put the above graph together I thought he's got an answer after a fashion and in a round about way, so: -
Screenshot 2022-02-15 172604.png

This is an amalgamation of two well known formulae derived from Bernoulli and Watt, there are limitations to the theory based on low Reynolds number, where inertia of the fluid is ignored, but for our Zeds it's simple enough. Though it does ignore rolling resistance, friction of bearings etcetera.

For my car the theoretical top speed not limited by gearing with a Cd of 0.35, fronteal area of 2.2 m2 and 250kW, is 79 m/s or 178 mph

Yes yes yes that's all very clever yadee yadee....but do you shag on a first date...?

 

[Scubaregs]

Yes yes yes that's all very clever yadee yadee....but do you shag on a first date...?

Only ever done that once, never again.

To be fair the restaurant wasn't that good anyway so a life ban was of little consequence.

 

[flybobbie]

Interesting article;
https://aia.springeropen.com/articles/10.1186/s42774-020-00054-7

 

[Pondrew]

Yes yes yes that's all very clever yadee yadee....but do you shag on a first date...?

:rofl: :rofl:
I do!!

 

[john-e89]

Yes yes yes that's all very clever yadee yadee....but do you shag on a first date...?

Only ever done that once, never again.

To be fair the restaurant wasn't that good anyway so a life ban was of little consequence.

...and I'm banned from Tesco's....it was while she was bent over the freezer looking for scampi...

 

[Nanu]

Would love to but the wife won't let me try

 

[Pondrew]

This is an amalgamation of two well known formulae derived from Bernoulli and Watt, there are limitations to the theory based on low Reynolds number, where inertia of the fluid is ignored, but for our Zeds it's simple enough. Though it does ignore rolling resistance, friction of bearings etcetera.

FFS sars he doesn't need any encouragement :headbang:

 

[Scubaregs]

...and I'm banned from Tesco's....it was while she was bent over the freezer looking for scampi...

I think it's great you've given the little guy a nickname.

 

[Pondrew]

..and I'm banned from Tesco's....it was while she was bent over the freezer looking for scampi...

Was it the smell that turned you on?

 

[B21]

Interesting article;
https://aia.springeropen.com/articles/10.1186/s42774-020-00054-7

Very interesting article…it confirms that fitting a spoiler and diffuser was the right thing to do…nice find :driving:

 

[sars]

[ref]Argyll Andy[/ref], did you see anywhere within that equation for a car colour coefficient multiplier oke:
[ref]john-e89[/ref], The chances of you getting lucky on a date is proportional to the mode of transport in which you pick me up for that date, I’m thinking that a mobility scooter might not quite do it :lol:

 

[john-e89]

[ref]Argyll Andy[/ref], did you see anywhere within that equation for a car colour coefficient multiplier oke:
[ref]john-e89[/ref], The chances of you getting lucky on a date is proportional to the mode of transport in which you pick me up for that date, I’m thinking that a mobility scooter might not quite do it :lol:

Fear not fair wench....I have other means that'll take thee verily breath away....

 

[john-e89]

...and I'm banned from Tesco's....it was while she was bent over the freezer looking for scampi...

I think it's great you've given the little guy a nickname.

I call him 'Languoistine'.....bigger....ish....than a prawn, smaller...much...than a lobster.

 

[Scubaregs]

I don't know mate, pretty sure that codpiece on your armour is marked "xxxxs"

 

[craig3.2]

Anyhoo,I have nothing to prove.
If Peter wants to continue his Willy waving contest.....then,let him


Dont worry Craig - I know yours is longer mate Its all that haggis pal x
[/quote]

Aye Mark,
Must be from all the exercise, chasing all those haggis about the place for my dinner,haha :rofl:

 

[craig3.2]

So many variables in this, wind, incline/decline etc etc. One quiet early morning on a suitable rd I had my 23i up to over 140mph! My 35i on MHD stage 2+ is still pulling really hard at 140mph!
Shall we all arrange a track /drag strip (for cars not clothes lol) day???

Now that wud be gud ,Z4 v Z4,
Quite like a bit o drag miself

Looks like you had fun that day ,Moz

What did you get it upto,speed wise,and were you racing others,or just doing timed runs etc?