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Discussion Starter · #1 ·
Hi all,

If anyones interested heres my Dyno printout for the remap Slumpy did for me at Trans Tune

Before = 108

After = 138


 

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Whats the explaination of the two shadow lines, top right corner after 70mph... ?
 

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Sorry for appearing thick, but isnt the flywheel connected to the clutch?

Is this internal drag which at 15 hp seems a bit low.. ?

Just curious... thats all... as well as wanting to properly understand these charts.
 

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Sorry for appearing thick, but isnt the flywheel connected to the clutch?

*<:)>Is this internal drag which at 15 hp seems a bit low.. ?

Just curious... thats all... as well as wanting to properly understand these charts.

Not thick at all good question! The clutch is connected to the flywheel.

It's down to how we set up this dyno. You could have called it Max Power like you see on most dyno's. But we left it with clutch power for the customer to know the area of the engine the power was referring to.

This chart shows what's called a negative run. So you run the vehicle up to full power and at the point the dyno tell's you you dip the clutch and let it free wheel. The dyno can then work out the power lost through the clutch, drive shafts, gearbox and diff. It doesn't measure the drag from the engine. So 15hp is about right for a T5 1.9tdi.

Think of it in another way if you look at an aircon pump it takes between 5-6hp to operate imagine 3 aircon pumps on at once and try turning them by hand. 15hp sounds like more.

The dynojet single roller is a different kind of dyno in the sense that the car sits on top of the one piece roller. You tend not to get as much loss of traction and you get less transfer of power from one side of the diff to the other (lsd makes no odds.). It's good for big power cars as you can be more accurate.
I'm not in any way trying to say it is a better dyno than any ones else it's just different in it's operation. I have looked at alot of dynos and they all have different pro's and con's.


I hope this helps!*<:)>
 

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So are you saying the max power is wheel power (WHP) and the Clutch power is the same as what others claim to be max power (HP) :confused:
That's spot on!T: Isn't as clear as it could be will have to make it clearer on the next ones.
I like to try and give you the power that is actually hitting the ground so it's not misleading. Really hp isn't as important as the torque from the point of view of driving.*<:)>
 
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That's spot on!T: Isn't as clear as it could be will have to make it clearer on the next ones.
I like to try and give you the power that is actually hitting the ground so it's not misleading. Really hp isn't as important as the torque from the point of view of driving.*<:)>
Know what you're saying I need to get mine higher too slow at the mo :D

15hp losses aren't bad I've seen some saying over 40hp yet I was led to believe that 15% is roughly about right T:
 

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In light of the bhp/tight engines vs ones with more miles thread, I had a map and dyno done and friction losses were more around 45bhp.. but this was done at about 5k after a map...

Slumpy, thanks for the explaination...
 
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In light of the bhp/tight engines vs ones with more miles thread, I had a map and dyno done and friction losses were more around 45bhp.. but this was done at about 5k after a map...

Slumpy, thanks for the explaination...

Can't how it makes any difference, the losses are through clutch, driveshafts, tyres etc etc mileage of engine has no real relevance, unless T5 have significantly more losses on theirs :confused:
 
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manufacturers are yes but most dynos are measured at the wheel then have some calculated/guessed figure stuck on top to give the max hp. Like stumpys gives the WHP then a resonoble amount added for losses.
 

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Discussion Starter · #13 ·
manufacturers are yes but most dynos are measured at the wheel then have some calculated/guessed figure stuck on top to give the max hp. Like stumpys gives the WHP then a resonoble amount added for losses.
Thats called the negative me thinks
 

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manufacturers are yes but most dynos are measured at the wheel then have some calculated/guessed figure stuck on top to give the max hp. Like stumpys gives the WHP then a resonoble amount added for losses.
yes, figures are gained at the wheel or hub, then alot of calculations or done to work out flywheel hp. this takes into consideration power loss through transmission.

The reason max hp is quoted at flywheel is beacuse newly designed engines when built go through hours of testing on a rig, which also gives the hp figure.
 

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there seems to be a lot this recently on here,whats going on?[/QUOTE

I dunno, I still love everyone


* disclaimer - this may have something to do with the amount of lager, currently swilling round my gutsI:
 
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