"Dyno" results

Post by **jtbo** » 10 Apr 2006 12:57 am

http://www.janiervast.com/gallery/d/181 ... o360gl_veh

You need to change extension to .veh file so you can use it with powerdyn, import vehicle function, I messed something with upload...

Weight is bit more than manual says, that is because driver + extra stuff is needed to add there (toolbox etc, and I'm not too light or small either

)

I think that values are close, but not just 100% right, weight is mostly what I think is bit wrong, but it is not too important as long as one keeps variables around same between changes to engine.

Puma racing had some in-depth detail about dyno testing and how there is not even single rolling road that would show you how much power engine has, those are mostly usable for measuring changes...

Post by **Chris_C** » 10 Apr 2006 01:21 am

Thats great, cheers mate!

Post by **Chris_C** » 11 Apr 2006 04:34 pm

Just been to maplins to buy the bits (I left my goodies box at uni

) £1.99 exactly

I am changing the resistor values, I don't trust the ones they give (a 33k resistor and 25k pot means you can get between 0 and 5V outputs, and the 0.2max you need to really only use the last bit of the pot)

I'll see if mine works (in between getting it started...) and post up the values I'm using.

Post by **jtbo** » 11 Apr 2006 04:43 pm

Hehe, I had no proper pot available, but I had 100k pot, man that is hard to adjust

Post by **Omar** » 11 Apr 2006 05:19 pm

good result

Post by **jtbo** » 11 Apr 2006 05:29 pm

Omar wrote:good result

Thx

Oh yes, need disclaimer

Use multimeter to check voltage to be around 50mV range before you fry your recording device, it can and will fry your equipment if not checked that Voltage level is correct.

http://www.zelscope.com/
Here is trial version of oscilloscope software, it takes signal in same way as powerdyn, you just connect your probe and then you can see spark graphically drawn to your laptop screen, it is just like oscilloscope, just not capable of as high frequencys.

I have older version of software that was freeware, if there is interest I could upload it, even it has less features and it is rather simple.

Here is sample pic from idle, signal is taken from lm1815 output and it should be square pulse but something is not working, but that we have discussed in other topic

Post by **Chris_C** » 12 Apr 2006 03:20 pm

Right, well, I've got some results, not to convinced by them though. 16.2 sec quarter mile with an 8.5 sec 0-60 in a 1.7 anyone?

That must be down to parameters, but hey, I have a pimp as jack socket in the top of my glovebox now, so I just hook my recording device up to the glovebox, and away it goes

I'm off to measure if my gear ratios are the same as Jani's, I changed weight and tyre sizes, but I am carrying around a few sheets of mdf and a blueline interior atm (don't ask...)

Anyway, initial pictures:

Bigger version at : http://www.ecs.soton.ac.uk/~clc202/fake/fake1stgo.JPG

Fake compared with Jani's

Bigger version at : http://www.ecs.soton.ac.uk/~clc202/fake/FakevsJani.JPG

As I said, tweaking needed... 120bhp 1.7 would be nice though. Any ideas what my wiggle past 4500 is? Apart from a cock up on recording?

EDIT: Higher res versions added

Post by **Dexter** » 12 Apr 2006 04:11 pm

The pictures is bad , small.
It is poorly visible

Post by **Chris_C** » 12 Apr 2006 04:35 pm

I've just changed the first one, I had the wrong diff ratio in, so it was giving me 20 more than it should. Still looks like it is running high, but hey, good enough for playing with now. I'll chuck some higher res picture up when I get back.

Post by **Dexter** » 12 Apr 2006 05:34 pm

2 jtbo
Could you give me a foto of cable from computer to engine?

Post by **jtbo** » 12 Apr 2006 05:37 pm

Yes, you need to change gear ratios weight and all according to car spec, also wind and downhill affects to measurement.

You should have 3,64 diff and gears same as mine, maybe drivetrain loss is bit less, mileage affects to that and many other things.
Drivetrain loss is what I used to tweak when other values were right, I adjusted it so that it looks approx correct torque.
When first tuning is ready one should not tweak it anymore.

Of course temp and all enviromental values should be adjusted according to test weather.

Example from rolling road, when they sell you k&n and show curves before and after, it is often that for after curve ambient temp value is set higher so dyno shows more power

That is why I'm usually saying that dyno curves are not precise, they show change to power pretty well but it is just impossible to measure true power output on rolling road, it is always more or less estimate.

Also what gear is used is making quite a lot of difference, so many variables to handle

According to finnish manual 1,7l specs are:
80hp(60kw)@5700rpm
131Nm(13,3kpm)@3200rpm

Weight 983kg/1002kg 3dr/4dr&5dr with fuel tank empty, need to calculate a bit, driver weight must put there too.

But I think that drivetrain loss is one to change, if you put it 0% then you get wheel power, not engine power. My value is taken from one race 360 that had it measured, but I'm not sure if that is still correct for my car

Post by **jtbo** » 12 Apr 2006 05:39 pm

Dexter wrote:2 jtbo
Could you give me a foto of cable from computer to engine?

I try to get one tomorrow if it is not raining, there is actually more than one cable, there is this probe thing and then cable/wire to renix, but I take many photos

Post by **Chris_C** » 12 Apr 2006 05:50 pm

Thanks for that Jani, I guessed mine was a 3.64, and I guessed the box was the same as yours

I'm going to try a few plays now with the drivetrain losses, thought that could be it, and I have a few more bits of data here too! I love having cables hooked up!

Dexter, I have taken a quick photo of the one I made, http://www.ecs.soton.ac.uk/~clc202/fake ... resize.JPG

Red wire to renix, blue wire to ground, and jack socket to the recording device.

Post by **Chris_C** » 12 Apr 2006 06:05 pm

Right, just did another play, 0% drivetrain loss. I get max bhp at 5700 (but I think due to aliasing, not due to actual power) but the secondary max point is at 4800 with 83bhp.

Max torque is at the revs specified roughly, 3100, but gives 143Nm.

Seems a bit high on torque, I'll have more of a play with the new data, also all done in second gear. I've gone from not trusting a word this thing was coming up with to being more than happy for my £1.99

Ok, it's never gonna show true power, but as you say, all the time you use the same parameters, you can at least see whats been changed with a mod.

Great Stuff! Well happy me

Post by **jtbo** » 12 Apr 2006 06:14 pm

Oh yes, idea why this works is simple, as we do know time and we do know rpm change it is possible to calculate power when we know few facts from car. Same way as it is possible to calculate power from 1/4 mile time

We have tested my friends Honda Civic (yes with ricer bodykitstuff), we got pretty close numbers from that one too, but it needed just right values and road that was not downhill, this had huge effect, easily 30hp.

I would be interested to look recorded wave file of yours and fiddle a bit with settings