Sorry I have been so slow to reply. I have been absolutely flat out
at work.

I don't where too much about load cells, other than some different
types and what they do. I don't know enough to recommend one. Try
reading about them on the web and maybe talking to a supplier. This
site has some good info;
http://www.omega.com/prodinfo/loadcells.html

If your torque arm restraining bolt is in tension then you probably
want a simple tension load cell like this one;
http://www.transducertechniques.com/TLL-Load-Cell.cfm

I have added a spreadsheet for you in the files section. You will
notice I typically calculate everything in SI units, as then you
don't have all the crazy multipliers needed to make imperial units
work. For example, if you know the force in N and the velocity in m/s
then you just multiply the together and get power in Watts.

Have a play with the excel sheet and tell me if it makes sense.

Wes

--- In exceldyno@yahoogroups.com, "Todd" <narider@t...> wrote:
> > A load cell is a good accurate way of getting the torque in the
> > roller reading (the hydraulic brake isn't driven through a
gearbox
> > by the roller I assume).
>
> The hydraulic brake is direct drive from the end of the drum's
shaft.
>
>
> > It's easy to set-up if the hydraulic brake is
> > already mounted using a torque arm.
>
> I'm not sure what is meant by a torque arm. There is a tab with a
> bolt going up to the floor of the dyno coming off the mounting
flange
> area of the pump that appearantly keeps it from being spun?
>
>
> > Then you multiply the load by the
> > torque arm radius and you have the roller torque.
>
> I'd have to look but I'm not sure that the mounting arm I speak of
is
> the only thing keeping the brake from spinning, but if it is then
> what you're saying is I could simply measure out from the center of
> the pump to the end of this arm to get the radius, and a load ceell
> opf some sort would mount at this point?
>
>
> > Now just use the torque at the roller and speed of the roller (in
> > RPM) together to calculate the power at the roller.
>
> Speed at the roller is no problem(I currently have that in MPH,
which
> could be converted to rpm easy enough). The torque I have also, but
> it is in PSI, and at any given rpm is different depending on GPM of
> the hydraulic brake.
> IE: TQ=(((PSIxGPM)/1714)x5252)/RPM
> The above(at the HP versus ground speed level) is the formula I
> believe my charts are figured from by the OEM.
>
> So to find GPM(as it's ever changing with psi and mph) is rather
> tough so my first thought was be to put a flow meter in rather then
> try to back figure(as I don't know horsepower in the first place
and
> it is putting too much data in the mix to input).
> IE: GPM=(1714/PSI)xHP (so adding this to the above formula jsut
keeps
> adding more and more room for error that I was hoping to bypass
with
> a load cell.
>
>
> > The roller power will be you vehicle power at the wheels. You can
> > then divide this back through by the engine rpm at any point and
> > get the engine torque.
>
> > These two powers and torques you have are as measured at the rear
> > wheels. Just divide back through by expected driveline efficiency
> > to estimate the power and torque at the flywheel.
> > Did that make any sense?
>
> Absolutley, these last 3 parts I understand very well and would be
> the easy part to have the program do once the data was input, and
if
> I understand correctly you agree that a load cell would be the way
to
> get that data?
>
>
> > Would you like me to give some equations as an example?
>
> That would be great Wes, but more importantly(as I'm not familiar
> with load cells), i'd be curious of what type of load cell I would
use
> (do you have a reccomendation?), and what type of data or reading
it
> puts out(can it be fed into my data-aq system in a 0-5v signal?).
>
> If I could get these figures into my data logger in a 0-5v signal,
I
> can program it to put it out(visually on screen) in any way I want
> via a chart trace or a gauge reading. And my system allows data to
be
> exported to Excel also.. would this be something a program such as
> yours would be able to have inpout to give printouts like a normal
HP
> or TQ versus a MPH or RPM chart as well as an A/F chart via RPM?
>
> Thanks Wes(hope I'm not burning you out or asking stupid questions
on
> this),
> Todd

> A load cell is a good accurate way of getting the torque in the
> roller reading (the hydraulic brake isn't driven through a gearbox
> by the roller I assume).

The hydraulic brake is direct drive from the end of the drum's shaft.


> It's easy to set-up if the hydraulic brake is
> already mounted using a torque arm.

I'm not sure what is meant by a torque arm. There is a tab with a
bolt going up to the floor of the dyno coming off the mounting flange
area of the pump that appearantly keeps it from being spun?


> Then you multiply the load by the
> torque arm radius and you have the roller torque.

I'd have to look but I'm not sure that the mounting arm I speak of is
the only thing keeping the brake from spinning, but if it is then
what you're saying is I could simply measure out from the center of
the pump to the end of this arm to get the radius, and a load ceell
opf some sort would mount at this point?


> Now just use the torque at the roller and speed of the roller (in
> RPM) together to calculate the power at the roller.

Speed at the roller is no problem(I currently have that in MPH, which
could be converted to rpm easy enough). The torque I have also, but
it is in PSI, and at any given rpm is different depending on GPM of
the hydraulic brake.
IE: TQ=(((PSIxGPM)/1714)x5252)/RPM
The above(at the HP versus ground speed level) is the formula I
believe my charts are figured from by the OEM.

So to find GPM(as it's ever changing with psi and mph) is rather
tough so my first thought was be to put a flow meter in rather then
try to back figure(as I don't know horsepower in the first place and
it is putting too much data in the mix to input).
IE: GPM=(1714/PSI)xHP (so adding this to the above formula jsut keeps
adding more and more room for error that I was hoping to bypass with
a load cell.


> The roller power will be you vehicle power at the wheels. You can
> then divide this back through by the engine rpm at any point and
> get the engine torque.

> These two powers and torques you have are as measured at the rear
> wheels. Just divide back through by expected driveline efficiency
> to estimate the power and torque at the flywheel.
> Did that make any sense?

Absolutley, these last 3 parts I understand very well and would be
the easy part to have the program do once the data was input, and if
I understand correctly you agree that a load cell would be the way to
get that data?


> Would you like me to give some equations as an example?

That would be great Wes, but more importantly(as I'm not familiar
with load cells), i'd be curious of what type of load cell I would use
(do you have a reccomendation?), and what type of data or reading it
puts out(can it be fed into my data-aq system in a 0-5v signal?).

If I could get these figures into my data logger in a 0-5v signal, I
can program it to put it out(visually on screen) in any way I want
via a chart trace or a gauge reading. And my system allows data to be
exported to Excel also.. would this be something a program such as
yours would be able to have inpout to give printouts like a normal HP
or TQ versus a MPH or RPM chart as well as an A/F chart via RPM?

Thanks Wes(hope I'm not burning you out or asking stupid questions on
this),
Todd

> Hi Wes, thanks for a decent forum and sharing a very cool piece of
> software. Also hope your feeling well, I just had a open heart
triple
> bypass two weeks ago(the reason I have enogh time to sit on the
> computer for aminuite here and there and how I found this group).
> The dyno I have works fine as it was originally designed, it's jsut
> very labor intensive(its a hydraulic load brake and graphed from OE
> charts via a speedometer and 3000psi gauge). I'll soon be adding a
> PtoE trransducer to feed the pressure info into my data-aq with
> everything else I normally pull trraceces on now, but this still
will
> not give any type of direct HP or TQ readings as hydraulics need to
> have a given GPM at any given MPH or RPM to get HP readings(which
is
> of course a constantly varying formula). I was thinking a load cell
> may be able to help here but I'm not at all familiar with them. I
can
> make what I have work and work well repeatability wise, which will
> allow me any rpm or load figure ability to tune at. But I would
still
> like to have actual hp and ft-lb readings into some type of software
> (Excel would be fine) that I could keep and compare printouts
too...
> and really not suire how to go about this without high cost(which
may
> be the final straw and that's that).
> So, do I have a specific question? No, not at this point.
> Am I trying to learn and create positive conversation for a forum
> like this? Yes, I believe so.
> Can you(or anyone else on here) help? I have no idea, but I am all
> ears and very grateful for good conversation while I'm recovering.
> Thanks,
> TD

A load cell is a good accurate way of getting the torque in the
roller reading (the hydraulic brake isn't driven through a gearbox by
the roller I assume). It's easy to set-up if the hydraulic brake is
already mounted using a torque arm. Then you multiply the load by the
torque arm radius and you have the roller torque.

Now just use the torque at the roller and speed of the roller (in
RPM) together to calculate the power at the roller.

The roller power will be you vehicle power at the wheels. You can
then divide this back through by the engine rpm at any point and get
the engine torque.

These two powers and torques you have are as measured at the rear
wheels. Just divide back through by expected driveline efficiency to
estimate the power and torque at the flywheel.

Did that make any sense?

Would you like me to give some equations as an example?

Wes

> > I've got a hydraulic brake dyno that I;'m hooking my data-aq to
and
> > setting up to record data including rpm, hydraulic ppressure,
mph,
> > a/f, egt, cht, iat, tps, map, bmp, etc, etc. What I'm not
familiar
> > with is tying in a load cell and that could record true torque
rather
> > then hydraulic psi manually converted/mph from hp to tq. ANy
thoughts
> > or experiences with this?
> > TD
>
> Good to see the group looked after itself in my absense. I just had
4
> wisdom teeth pulled out :(
>
> Yes Torque and HP are both different scales. If you want to you can
> right click on the different y-axes and force them to the same
scale.
> Right click > format axis. click on the scale tab. uncheck the tick
for
> maximum and enter a number. Do the same on the other axis. The two
> curves will now cross at 5252rpm.
>
> I am sure I could help with your dyno. the load cell would record
force
> at the end of your torque arm. multiply that by the torque arm
radius
> and you have the roller torque (a rather large value),
> which is your engine torque x gearbox ratio's x gearbox efficiency.
>
> What exactly do you need to know?
> Wes

Hi Wes, thanks for a decent forum and sharing a very cool piece of
software. Also hope your feeling well, I just had a open heart triple
bypass two weeks ago(the reason I have enogh time to sit on the
computer for aminuite here and there and how I found this group).
The dyno I have works fine as it was originally designed, it's jsut
very labor intensive(its a hydraulic load brake and graphed from OE
charts via a speedometer and 3000psi gauge). I'll soon be adding a
PtoE trransducer to feed the pressure info into my data-aq with
everything else I normally pull trraceces on now, but this still will
not give any type of direct HP or TQ readings as hydraulics need to
have a given GPM at any given MPH or RPM to get HP readings(which is
of course a constantly varying formula). I was thinking a load cell
may be able to help here but I'm not at all familiar with them. I can
make what I have work and work well repeatability wise, which will
allow me any rpm or load figure ability to tune at. But I would still
like to have actual hp and ft-lb readings into some type of software
(Excel would be fine) that I could keep and compare printouts too...
and really not suire how to go about this without high cost(which may
be the final straw and that's that).
So, do I have a specific question? No, not at this point.
Am I trying to learn and create positive conversation for a forum
like this? Yes, I believe so.
Can you(or anyone else on here) help? I have no idea, but I am all
ears and very grateful for good conversation while I'm recovering.
Thanks,
TD

--- In exceldyno@yahoogroups.com, "Todd" <narider@t...> wrote:
> I've got a hydraulic brake dyno that I;'m hooking my data-aq to and
> setting up to record data including rpm, hydraulic ppressure, mph,
> a/f, egt, cht, iat, tps, map, bmp, etc, etc. What I'm not familiar
> with is tying in a load cell and that could record true torque rather
> then hydraulic psi manually converted/mph from hp to tq. ANy thoughts
> or experiences with this?
> TD

Good to see the group looked after itself in my absense. I just had 4
wisdom teeth pulled out :(

Yes Torque and HP are both different scales. If you want to you can
right click on the different y-axes and force them to the same scale.
Right click > format axis. click on the scale tab. uncheck the tick for
maximum and enter a number. Do the same on the other axis. The two
curves will now cross at 5252rpm.

I am sure I could help with your dyno. the load cell would record force
at the end of your torque arm. multiply that by the torque arm radius
and you have the roller torque (a rather large value),
which is your engine torque x gearbox ratio's x gearbox efficiency.

What exactly do you need to know?

Wes

I've got a hydraulic brake dyno that I;'m hooking my data-aq to and
setting up to record data including rpm, hydraulic ppressure, mph,
a/f, egt, cht, iat, tps, map, bmp, etc, etc. What I'm not familiar
with is tying in a load cell and that could record true torque rather
then hydraulic psi manually converted/mph from hp to tq. ANy thoughts
or experiences with this?
TD

I understand that part(very common on any dyno printout). Problem I
mention is that horsepower and torque do not cross at 5252rpm, which
they must do for an internal combution engine when torque is figured
in ft-lb's. Oh wait, I see.. the HP and TQ not being equal acropss
the left and right are screwing the rpm cross, Thanks.
TD

> I was fooled too! If you look closer you will see that HP and
torque are not
> on the same lines. HP is on one side of the graph and torque on the
other.
> Both are on the vertical but not graduated the same.
>
> Ron


> > Not understanding why HP and Torque do not cross at appropriatte
rpm
> > on any of the graphs foprmed by the supplied data. Am I missing
> > something?
> > TD

I was fooled too! If you look closer you will see that HP and torque are not
on the same lines. HP is on one side of the graph and torque on the other.
Both are on the vertical but not graduated the same.

Ron
----- Original Message -----
From: "Todd" <narider@...>
To: <exceldyno@yahoogroups.com>
Sent: Friday, July 29, 2005 7:09 PM
Subject: [exceldyno] Bad data


> Not understanding why HP and Torque do not cross at appropriatte rpm
> on any of the graphs foprmed by the supplied data. Am I missing
> something?
> TD
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>

Not understanding why HP and Torque do not cross at appropriatte rpm
on any of the graphs foprmed by the supplied data. Am I missing
something?
TD

Hi All,

I've just added the new version of Excel Dyno.

V2.0 Changes - Quite a big redesign of the entire worksheet. Tweaked
the math here and there to improve the accuracy and fixed small bugs.
Main changes are;
* Changed main sheet layout, added user defined fields for 0-X kph
times, similar with distance. So you can calculate exactly what you
want to more easily.
* Put tyre sizes in with vehicle type, as generally they go together.
* Added toggle buttons to toggle kph/mph units, metric/ imperial tyre
sizes, HP/kW power units, etc.
* Changed the way new engines, vehicles or transmissions are saved to
the list. Also made the lists accessible so people can add, delete and
modify the sheet directly. Just don't change the format of these sheets
or you will stuff things up.
* Added chart resize buttons, to automatically set the chart limits to
suit the vehicle
* Added a rollout time field for the serious racers.
* Changed the rpm range from 2-10K to 1-20K
* The new rev range also makes the worksheet motorcycle friendly. Most
fast bikes will have the acceleration limited by tyre friction rather
than flipping over from wheelstanding. I found some good data on a
Hayabusa and the worksheet seems to be very accurate, but maybe a
little optimistic on the 1/4 mile time (although I have seen high 9s
time slips for stock Busa's). Of course the Excel Dyno is assuming a
perfect rider getting an absolutely perfect launch. Reducing the tyre
friction from 1.0 to 0.9 would possibly more accurately reflect the
point at which wheelstanding would be a problem and gives more
conservative 1/4 mile times.

Have fun guys,
Wes

--- In exceldyno@yahoogroups.com, "Wes" <bajawes@h...> wrote:
>
> Just to let people know that I will be uploading a new version of the
> sheet soon.
>
> I am trying to make it capable of handling bikes as well. I have
> expanded the rpm range to cover 1,000 to 20,000 rpm.
>
> I have added a button to toggle between kW / Nm and HP / ft.lbs
>
> I am changing the way engines are entered, so you basically enter it
on
> the engine sheet and then save it from there.
>
> I trying a couple of things too.
>
> Wes

Hello,

This email message is a notification to let you know that
a file has been uploaded to the Files area of the exceldyno
group.

   File        : /calc.zip
   Uploaded by : baja_wes <bajawes@...>
   Description : Excel Dyno V2.0 - Latest Version!

You can access this file at the URL:
http://groups.yahoo.com/group/exceldyno/files/calc.zip

To learn more about file sharing for your group, please visit:
http://help.yahoo.com/help/us/groups/files

Regards,

baja_wes <bajawes@...>

Hi Wes,
oh fine! I'm looking forward to download the new extended release(s). :)

»Horst

Just to let people know that I will be uploading a new version of the
sheet soon.

I am trying to make it capable of handling bikes as well. I have
expanded the rpm range to cover 1,000 to 20,000 rpm.

I have added a button to toggle between kW / Nm and HP / ft.lbs

I am changing the way engines are entered, so you basically enter it on
the engine sheet and then save it from there.

I trying a couple of things too.

Wes

Thanks for making exceldyno available, I'm very impressed.


I'm trying to model the acceleration of a European Golf GTTDI diesel.
However, these engines start to do useful work at 1500 rpm or less.
Is it possible to adjust exceldyno to start at, say,  1000 rpm?

Regards

trevor7657

I just found excel program on your homepage, looks like a cool
stuff.  When I have the time I will try to fit my cars data into it
and see how it works.  Thanks for sharing

Hinrik



--- In exceldyno@yahoogroups.com, "Baja Wes" <bajawes@h...> wrote:
> Good to get some feedback ;)
>
> I was mainly posting to keep the group open.
>
> Another thing I have to do is add the dead time at the start.
Really fast
> cars get up a bit of speed before they've even travelled the foot
or so to
> trip the timing lights, so I will be adding that.
>
> I probably won't get to anything until the end of the year though.
I've just
> moved into a new house (with no grass / fence / driveway /
anything) so have
> alot to keep me busy.
>
> The lastest version is the v1.1_draft which can be found here;
> http://autos.groups.yahoo.com/group/exceldyno/files/
>
> I've got some plans to make entering modified data easier too.
>
> Wes
> www.offroadvw.net
> baja@o...
>
>
>
>
> >From: Bevan Beattie <bevanbeattie@y...>
> >Reply-To: exceldyno@yahoogroups.com
> >To: exceldyno@yahoogroups.com
> >Subject: Re: [exceldyno] why don't people respond
> >Date: Thu, 25 Nov 2004 02:42:29 -0800 (PST)
> >
> >Wes,
> >
> >   Mate I have used oine of the older version of the dyno, very
useful, run
> >a 2.2 legacy motor in 72 kombi, dyno came in at 16.8 seconds
quater mile I
> >did that and a few around that, heaps cheap[er wya top experiment
with
> >motor combos, might go to 2.5 leagcy, or 4 litre lexus
> >
> >Whats the lastest version
> >
> >Cheers
> >'
> >  Bevan
> >
> >Wes <bajawes@h...> wrote:
> >
> >Just wondering...
> >
> >People post here, ask for improvements, I make them and ask for
> >feedback and then here nothing. Why is that.
> >
> >Oh, and I had to post something to keep the group open.
> >
> >Wes
> >
> >
> >
> >
> >Yahoo! Groups SponsorADVERTISEMENT
> >
> >
> >---------------------------------
> >Yahoo! Groups Links
> >
> >    To visit your group on the web, go to:
> >http://groups.yahoo.com/group/exceldyno/
> >
> >    To unsubscribe from this group, send an email to:
> >exceldyno-unsubscribe@yahoogroups.com
> >
> >    Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.
> >
> >
> >
> >---------------------------------
> >Do you Yahoo!?
> >  Take Yahoo! Mail with you! Get it on your mobile phone.

Good to get some feedback ;)

I was mainly posting to keep the group open.

Another thing I have to do is add the dead time at the start. Really fast
cars get up a bit of speed before they've even travelled the foot or so to
trip the timing lights, so I will be adding that.

I probably won't get to anything until the end of the year though. I've just
moved into a new house (with no grass / fence / driveway / anything) so have
alot to keep me busy.

The lastest version is the v1.1_draft which can be found here;
http://autos.groups.yahoo.com/group/exceldyno/files/

I've got some plans to make entering modified data easier too.

Wes
www.offroadvw.net
baja@...




>From: Bevan Beattie <bevanbeattie@...>
>Reply-To: exceldyno@yahoogroups.com
>To: exceldyno@yahoogroups.com
>Subject: Re: [exceldyno] why don't people respond
>Date: Thu, 25 Nov 2004 02:42:29 -0800 (PST)
>
>Wes,
>
>   Mate I have used oine of the older version of the dyno, very useful, run
>a 2.2 legacy motor in 72 kombi, dyno came in at 16.8 seconds quater mile I
>did that and a few around that, heaps cheap[er wya top experiment with
>motor combos, might go to 2.5 leagcy, or 4 litre lexus
>
>Whats the lastest version
>
>Cheers
>'
>  Bevan
>
>Wes <bajawes@...> wrote:
>
>Just wondering...
>
>People post here, ask for improvements, I make them and ask for
>feedback and then here nothing. Why is that.
>
>Oh, and I had to post something to keep the group open.
>
>Wes
>
>
>
>
>Yahoo! Groups SponsorADVERTISEMENT
>
>
>---------------------------------
>Yahoo! Groups Links
>
>    To visit your group on the web, go to:
>http://groups.yahoo.com/group/exceldyno/
>
>    To unsubscribe from this group, send an email to:
>exceldyno-unsubscribe@yahoogroups.com
>
>    Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
>
>
>
>---------------------------------
>Do you Yahoo!?
>  Take Yahoo! Mail with you! Get it on your mobile phone.

--- In exceldyno@yahoogroups.com, "Wes" <bajawes@h...> wrote:
> Just wondering...
> People post here, ask for improvements, I make them and ask for
> feedback and then here nothing.
> Why is that.

Because "people" are so bad. ;)

Hello Wes,

please excuse that I have't replied.
There were several (poor) reasons:

The first reason was that I wanted to know if/how you calculated the
gradient. Wouldn't like to ask you but I was not sure which formula
you used. It could be that you approximated the gradient/angle with
tan(alp)=sin(alp)=alp in unit arc(?) [rad], not degree[°]. With this
approximation the max gradient calculation of the lower gears would be
far away from reality.
I made my power/torque graph with Streetdyno but under/overrestimated
friction losses, drag coefficient... I had the chance to make a trip
on highway and was dissapointed because the car didn't get faster than
~125km/h, then I had absolutely no time to improve tuning EFI
(airfilter case seems the limitimng factor) so I didn't continue the
gear box project.
Also I was to lazy/busy to type in all parameters, because you
indicated that a seperate car data file isn't impossible.
Honestly I *forgot* the sheet during the last weeks and haven't
continue any calculations and dyno tests.

Today I typed in all my datas an enjoyed the new gradient sheet. Thank
you very much!

Here is my feedback, includes all other features of your ExcelDyno
which  are worth to be commented.

»I had problems with my custom tyre settings. Sheet aborted a 'test
modus' maybe my fault.

»I'd like to put in power for rpm<2000 too, but the cells are
protected. :(

»Is there a way to add new datas based on 'old' ones, for example
light changes in gear box ratios etc. I found only to define lank cells.

»I'd be absolute happy if you could add the power_max graph in the
gradient sheet. It would be an envelope shape (hyperbola), also some
paramters would be fine to see how many revs the engine would make if
I shift up or down.

So this all is only a feedback, please don't think that I ask anything
more. I've forveited all...

»Horst

Just wondering...

People post here, ask for improvements, I make them and ask for
feedback and then here nothing. Why is that.

Oh, and I had to post something to keep the group open.

Wes

Just wondering...

People post here, ask for improvements, I make them and ask for
feedback and then here nothing. Why is that.

Oh, and I had to post something to keep the group open.

Wes

--- In exceldyno@yahoogroups.com, "w00kie98" <w00kie98@l...> wrote:
> Everytime I go to change settings, ie: different drivetrain,
chassis.
> I get an error and the MS error report window and excel shutsdown.
Is
> this a known issue? If so whats the fix?
>
> The spreadsheet looks pretty interesting. Cant wait to try out
some
> of my own configs.

Hi,

Excel does some weird things some times. One guy had a problem where
it wouldn't work no matter what, then when I released the next
version it started working. It's a bit of a hit and miss affair when
you don't have an R&D team looking for bugs. Here's some questions
to help narrow down the issue.

What version of Excel are you using? you will need 2000 or better.

Which Exceldyno did you download? There are currently V1.0 and
V1.1_draft in the file section of this group, try both and see if
they both do it.

Does the expand and compact button work, or does it cause the error
too?

Are you enabling the macros when the sheet opens?

If the macros or forms aren't working, then sometimes it is because
you don't have a full installation of Excel. I have noticed this a
couple of times on peoples computers. Open excel and the exceldyno
workbook. Press Alt-F11. This will take you to the Visual basic part
of excel, you can see alot of how the workbook works in here.
Anyway, once your in Microsoft Visual Basic, go to the top menu, and
go to Tools > References. This should open up a bunch of references
that vbaproject is looking for. You should have the following 5 of
them ticked;
* Visual Basic for Applications
* Microsoft Excel 9.0 Object Library
* OLE Automation
* Microsoft Office 9.0 Object Library
* Microsoft Forms 2.0 Object Library

If those 5 aren't there, then your Excel installation is missing
some components. Tell me how you go :)

Cheers,
Wes

Everytime I go to change settings, ie: different drivetrain, chassis.
I get an error and the MS error report window and excel shutsdown. Is
this a known issue? If so whats the fix?

The spreadsheet looks pretty interesting. Cant wait to try out some
of my own configs.

--- In exceldyno@yahoogroups.com, "ami8break" <ami8@g...> wrote:
> I guess a myth...

Hi,

I wouldn't call any of those things myths, since I have test results
here in a text book showing the effects, but I will agree the effects
are small and for what you want to do can be ignored.

So I think I have figured out what you want. You basically want a
graph of maximum driveable gradient vs vehicle speed for each gear.
And you basically want your overdrive gear to be as tall as possible
while keeping a slightly positive acceleration, just enough to
overcome wind.

Ok, So I have added this chart to the excel dyno, and added a draft
v1.1 version in the files section. Have a look and see if it's what
your trying to do.

I have set all the parameters to my car. I have a very tall 4th gear
set in my gearbox. I selected it for a highway cruising gear. For
acceleration I use 1st to 3rd gear, and then use 4th for cruising.
Our speed limits on the highway range from 100 to 110kph. So it is
perfectly selected for that speed range.

My gearbox efficiency is my estimate. The VW transaxle doesn't seem
to be very efficient, and I think running high angles on the CV
joints like I do makes the efficiency even worse. I need to dyno my
engine to see if I am getting the HP I think I am getting though.

I have ignored rolling resistance, as I believe it is insignificant
compared to the wind resistance (especially at freeway speeds) and
driveline efficiency.

See if the new chart is what your looking for :)

Cheers,
Wes

--- In exceldyno@yahoogroups.com, "Wes" <bajawes@h...> wrote:
> Your spreadsheet is interesting, but after a brief look I am not
sure
> what it is actually doing.
>

Hello Wes,
yes, my layout confuses... :) The range of torque/power and speed/rpm
is very narrow. So you can only see a limited window. And the gears
are not representive for a car, I compared only the longest available
gear ratios for my purpose.

--> modified Excel-file in files section:
I've changed all confusing parameters to values wide out of screen.
Except one gradient of 0.945%.
I changed the range of axes and put in 5 typical gears.
I'm sure you've seen charts like P-v and M-v. 'My' P-n and M-n graphs
are a little bit strange to read. :)

How to exploit the graphs:
The 5th gear is an overdrive because I can't reach high speed in 5th
gear (max=129km/h).
High speed is achieved in the 4.th gear (~135km/h) at ~6300rpm.
This is ~300rpm about max power --> 4.th gear is best on a gradient of
0.945% (reserve, headwind).

> I understand you want to calculate the optium gear ratio for the
best fuel economy while cruising at high speed.

Partially yes. As you describe it's not possible (without a dyno) to
find THE most economic point but petrol engines have a better fuel
economy at high(!) loads (=WOT) and low rpms.

> In order to do that, you would need a complete performance map of
> the engine, plotting brake mean effective pressure in the cylinder
> against the piston speed, with contours of the specific fuel
> consumption at any point.

It's not so complicated (piston speed?) for rough tuning but you' re
right it's not easy to get precise datas. :( One diagramme is enough
to see all what you need. I guess it's called 'mussel (or shell?)
diagramme' but I found not much with Google. A more general
introduction with intesting charts is here:
http://www.ecodrive.org/(en)/newdriving/easytolearn.html
Especially the chart
http://www.ecodrive.org/(en)/images/easytolearn_fig2A.jpg shows that
in each gear the lowest fuel consumption is at nearly
at lowest possible speed. "Verbrauch [l/100km]" is indirect
proportional to mpg ( [mpg] = 235 / [l/100km] ).

> You see the specific fuel consumption changes on an engine. it
> changes with different throttle openings,

I guess a myth...
Carbed engine:
Even at high loads and low revs it makes nearly no difference. Fuel
flow is a function of pressure and flow (Bernoulli equation) in the
carb. If throttle is opened wider velocity and pressure change a
little bit (mass flow is constant) in different directions.
At lower loads the car would accelerate.
Fuel injected engine:
alpha/rpm: Yes
Speed desnity: No at high load because throttle is wide open (manifolp
pressure near atmospheric pressure) and at lower load car would
accelerate.

> different rpm, different ignition and air/fuel mixtures.

I hope ignition and AFR is reproduceable which says this is a
'constant' parameter. ;)

> It is general the best lower in the rev range, with decent throttle
> openings. of course it all depends on the motor.

Another myth... Please read the linked page, I'm sorry that my English
is too poor to find more useful sites. On
http://www.geocities.com/SunsetStrip/4060/consumo.html I found a
chart.

> Without this information I can't see how your figuring out the best
> rpm for a certain speed.

Me too. :)  But I can chose the longest useful gear. For example my
5.gear would be long enough to save fuel and strong enough to get
nearly high speed.
You can imagine the mussel diagramme directly in M-n diagramme or
imagine it in the distorted/streched. Even a longer ratio would not be
too bad.

Benefit of a modified Excel-Dyno sheet would be not to use a too long
gear so that the user is not dissapointed about gearbox modification.

»Horst

PS: I use MegaSquirt as EFI controller and plan to do some Streetdyno
runs with different MAP=const lines --> injected volume (~ms)
multipled with AFR, rpm VE and some constants --> a rough SFC sheet :)

Hi,

Your spreadsheet is interesting, but after a brief look I am not sure
what it is actually doing.

I understand you want to calculate the optium gear ratio for the best
fuel economy while cruising at high speed.

In order to do that, you would need a complete performance map of the
engine, plotting brake mean effective pressure in the cylinder
against the piston speed, with contours of the specific fuel
consumption at any point. Car manufacturers would have this
information, but I doubt you would be able to obtain one for the
engine your interested in.

You see the specific fuel consumption changes on an engine. it
changes with different throttle openings, different rpm, different
ignition and air/fuel mixtures. It is general the best lower in the
rev range, with decent throttle openings. of course it all depends on
the motor.

Without this information I can't see how your figuring out the best
rpm for a certain speed. It will be dependant on the particular
motor. A turbo diesel will be low in the rev range, a 2-stroke petrol
will be higher in the rev range.

But as far as a seperate file for car data, yes I am looking into
that.

I am also trying to learn stand alone visual basic, to see what parts
of the program I could do outside of excel as a stand alone program.

thanks for the suggestions
Wes

--- In exceldyno@yahoogroups.com, "ami8break" <ami8@g...> wrote:
> Hello Wes and members,
>
> I like your Excel-Dyno very much but it's not optimized for my
> purposes (gear ratio setting) for a daily driver. I'm interested in
> economy (5th gear) and best speed.
> If you're interested in an update (I' be very happy and) I would
> suggest to seperate custom car datas in an extra editable xls.file.
> Otherwise I see much work to transfer (typing?) datas.
>
>
> If nobody of the list members is willing or able to giving some
input
> we could discuss off list - if you want. Thanks
>
> »Horst
>
> PS: If you convert units to imperial/US. Don't worry about little
> power and high speed. Car is a deviant of the weak Citroen 2CV. :)

Hello Wes and members,

I like your Excel-Dyno very much but it's not optimized for my
purposes (gear ratio setting) for a daily driver. I'm interested in
economy (5th gear) and best speed.

I've done my high speed sheet with some graphs to find out optimized
gear ratios. I uploaded the file in file section so everyone can test.
"http://f3.grp.yahoofs.com/v1/UE4RQXZkMGHllPZ3PQhg7uZQwWkhse5NG8AJVc6uQq2MB=
_1Sy6kNVcU6oHaOqBwkgHYoVq-5y40V5ms-Wwvfc3zW45G0Jc6T/Ami8-Visa-Motor-Getriebe=
-Ideen.xls"
or
http://autos.groups.yahoo.com/group/exceldyno/files/

Most calculations are based on a fit curve for high speed (optimized
gear ratio).
  v_max=100(1/17*P_max/cw/A)^(1/3)
This formula includes all mechanical friction losses.
In another form:
  P_erf=(v_max/100)^3*17*cw*A
I extended this formula for driving up (and down) a hill:
  P_erf=(v_max/100)^3*17*cw*A+m*g/1000*s/100*v_max/3.6= Force*v_max
with M=P/n*9550
  M_erf=9550*U*3.6/60*[v_max^2/100^3*cw*A*17+g*m/1000*s/100/3.6]
  n_R=v*60/U/3.6=n_Mot/(i1*i2*...iN)
  n_Mot=v*60*(i1*i2*...iN)/U/3.6

acronyms:
v_max......achieved high speed [km/h]
P_max......full power[kW]
cw.........drag coefficient
A..........area [m^2]
m..........mass of car, driver, luggage... [kg]
M..........torque [Nm]
n..........rpm [rpm]
i1*i2*.....gear ratios
U..........circumference of wheel [m]
s..........gradient [%]

index:
max........maximum
erf........'erforderlich'=required
Mot........engine (flywheel)
Rad........'Rad'=tyre/wheel
Steigung...gradient

sheets:
Ueberblick.....only a suitable collection of gearboxes Citroen ever made.
Berechnung.....calculation and input site
P-v............power versus speed graph (v_max is cross section between
                P_erf and the distorted/streched power graphs
M-v............torque versus speed graph (v_max is cross section between
                M_erf and the distorted/streched torque graphs. Power=const
                parameter show gear shifting at same speed
P-n............power versus rpm (v_max is cross section between P_Mot and
                different P_erf graphs. The parameters are 'residual' power
                for different gradients. Not very scientific but it works.
M-n............torque versus rpm (v_max is cross section between M_Mot and
                torque graphs. Some parameters are 'residual' torque for
                different gradients. The other parameters are different
power
                levels also useful for visualizing shift points.
P-n_Tabelle....the rpm/M/P table which was base for it software.

legend:
yellow background....user basic datas
yellow frame.........gearbox ratios (user data)
black background.....each ratio solve with 'Solver' 0.
blue letters.........results


I made my power graph with the freeware Streetdyno and fitted this as
a polynom (Tablecurve). An interpolating algorithm would also work. :)

I'm not the Excel king so some calculations are not very user friendly
and graphs are not perfect. A zoom function would be fine. :)


If you are interested in including the graphs please let me know, I'll
give you all support you need, perhaps I can find an aproximation
graph which includes linear friction losses too.


If you're interested in an update (I' be very happy and) I would
suggest to seperate custom car datas in an extra editable xls.file.
Otherwise I see much work to transfer (typing?) datas.


If nobody of the list members is willing or able to giving some input
we could discuss off list - if you want. Thanks

»Horst

PS: If you convert units to imperial/US. Don't worry about little
power and high speed. Car is a deviant of the weak Citroen 2CV. :)

----- Original Message -----

From: Pete & Liz Wood

To: exceldyno@yahoogroups.com

Sent: Friday, June 18, 2004 2:31 PM

Subject: [exceldyno] Wes; EJ25 power curve

found this power curve on the web. Not sure if the torque agrees with
the one the program calculates. See what you think.

http://www.protekperformance.com/rv7/engine/dyno_graph.htm

Pete

found this power curve on the web. Not sure if the torque agrees with
the one the program calculates. See what you think.

http://www.protekperformance.com/rv7/engine/dyno_graph.htm

Pete

----- Original Message -----

From: Pete & Liz Wood

To: exceldyno@yahoogroups.com

Sent: Thursday, June 17, 2004 4:29 PM

Subject: [exceldyno] To Wes; read only files

what is the password to change the security on the page so I can
change details of torque ETC.

what is the password to change the security on the page so I can
change details of torque ETC.