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An other bosch fla 203 conversion  

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(@ivanro_jo)
Member

@walter hi mate  yes i am spanish, where are you from ? is it possible that you have a video on youtube with a golf mk2 on your  hub dyno?

 

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Posted : 12/04/2020 8:09 pm
(@walter)
Member

yes! from Madrid!

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Posted : 12/04/2020 9:10 pm
ivanro_jo liked
(@ivanro_jo)
Member
Posted by: @tutuur

Settings work way better then what I had before. Still oscilations a little bit but atleast it responds to differences very well 🙂

 

At 0 load it will always display around those values, however full on there could be a difference of +-10nm, ah well, its just a tool in the end.

hi again mate i forgot to mention that i even changed default 10 hz to 15 hz and it makes a big difference, try and hope it solve you problem.

 

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Posted : 15/04/2020 9:03 pm
(@tutuur)
Enthousiast

Interesting to know, I’ll give it a try 🙂

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Posted : 21/04/2020 5:49 pm
(@ivanro_jo)
Member

BTW, for making a dyno graph which kind of option do you use? i have noticed that plot looks different if i choose power sweep or just brake off, with brake off plot is smoother and look more accurate (brake minimum is set to 0,3v no idea if with brake off it is still wroking on  minimum.)

 

What do you think?

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Posted : 21/04/2020 9:33 pm
(@admin)
Member Admin

Can you post the two graphs? If the results differ then the MOI might be wrong. Of course assuming the car's engine actually outputs the same in a fast or slow sweep. 

For the smooth vs not smooth, this may be due to noise on the load cell. Our Bosch FLA had the load arm bent a bit to one side and did not move completely freely, causing some errors in the calibration. Once this was fixed the noise is very low in either mode. 

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Posted : 21/04/2020 10:49 pm
(@ivanro_jo)
Member

Here you have comparison with brake off and power sweep.

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Posted : 22/04/2020 4:04 pm
(@admin)
Member Admin

There are a few things there. The gear ratio seems different? End RPM and peak come at different locations. Is it the same Noise filtering? 

If the gear ratio is really the same and you just stopped the run a bit earlier on one of the runs, then the MOI or load cell calibration is off. We have done exactly the same test in our FLA203 dyno and the curves overlap pretty perfectly. 

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Posted : 22/04/2020 10:31 pm
(@ivanro_jo)
Member

@admin

HI thansk for answer, yes the ratio is same i just changed from brake off to power sweep i stopped run before becouse dyno was braking engine too much so rev didnt go high than those, after a few seconds i pushed up foot.

could be problem of pid brake?  moi was turn on and load cell calibration shows ok...

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Posted : 22/04/2020 10:36 pm
(@admin)
Member Admin

My guess is load cell calibration or MOI. But if you send me the raw log files plus your saved options then I can take a look. Send to jostein@yourdyno.com

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Posted : 22/04/2020 10:44 pm
(@tutuur)
Enthousiast

Just to let you know, your pid settings with 15 Hz work great. Thanks for that!

 

regarding your issue, is it a turbo engine? The difference you see could have lots to do with loading. Also if it has slip on the loaded run the rpms and so torque output will differ aswell. If you want to verify your settings like this it’s best to use a relatively low power n/a car.

 

what MOI do you have set? Just to rule that out. Think Jostein is at 10,7, but that was tested with a kit car with small wheels and bike engine. I’ve tested it with a Clio 197 on 17” wheels and ended up at 11,5

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Posted : 27/04/2020 9:48 pm
(@ivanro_jo)
Member

Great to know it happy to help you with brake!

on the other hand no idea why i am not able to make a good run for testing moi and  yes it was a turbo car, 1.8t 225 hp

So you always use moi of 11.5 on your runs? i am using 10,7 and with brake off power look quite accurate, not with brake... 

 

i though moi was independent of engines or wheels, just a dyno value.

 

thanks

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Posted : 28/04/2020 12:22 am
(@walter)
Member

Try to calculate again MOI of your own dyno and post dynosheet if you did it correctly.

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Posted : 28/04/2020 12:31 am
(@tutuur)
Enthousiast

Moi incorporates all rotating mass, so wheels, discs, driveshafts, flywheel, crank, rods, pistons all matter.

I dyno various cars and I have not checked it for all of them. The Clio 197 I’ve used is about medium of what I do.

The method Jostein has shared for calculating MOI won’t work with a turbo’ed car, as they are sensitive to load.

try my MOI and see if it’s closer. You’ll always see a difference especially on a turbo’ed car, as when doing inertia you’ll have load compared to a 1st/2nd gear run, while when using the brake with a ramp rate of 300rpm/s it’ll be more likely a 4/5th gear run

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Posted : 28/04/2020 12:19 pm
(@walter)
Member
Posted by: @tutuur

Moi incorporates all rotating mass, so wheels, discs, driveshafts, flywheel, crank, rods, pistons all matter.

I dyno various cars and I have not checked it for all of them. The Clio 197 I’ve used is about medium of what I do.

The method Jostein has shared for calculating MOI won’t work with a turbo’ed car, as they are sensitive to load.

try my MOI and see if it’s closer. You’ll always see a difference especially on a turbo’ed car, as when doing inertia you’ll have load compared to a 1st/2nd gear run, while when using the brake with a ramp rate of 300rpm/s it’ll be more likely a 4/5th gear run

it's more like when you want read crank hps (inertial/drivetraing losses reading is needed), you need to run close 1:1 to engine, normally is 4th gear for 5 speed cars and 5ht for 6 speed cars, of course if you try another gear you could see different readings, when you try to see whp readings, it's really close in any gear. ive test some months ago about whp and was almost same whp in 3 or 4 gear for example... im pretty sure i have dynosheets when i did some test about.

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Posted : 28/04/2020 12:29 pm
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