OcUK Rolling Road Day 22 @ Viezu & Caffeine and Machine (Warwickshire) - Saturday 1st December 2018

Tbh I’m still confused by the numbers. Printout showed 241whp for mine. Normally these are around 12/15% drivetrain loss. So even then it would put it around 280-290 at the flywheel.

Yet on the tv monitor when the run was occurring we saw 315-320..so I’m just confused by it all lol.
 
Vita said:
Tbh I’m still confused by the numbers. Printout showed 241whp for mine. Normally these are around 12/15% drivetrain loss. So even then it would put it around 280-290 at the flywheel.

Yet on the tv monitor when the run was occurring we saw 315-320..so I’m just confused by it all lol.
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Same with mine, it showed around 390+ on the screen, 294 @ the wheels on the printout and 367 @ the crank on the corrected figure that the technician showed me.
 
Frozennova said:
There seems to be about 10% difference between the live readout during the run and the crank corrected figure so far
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Damn, so my MX is probably at 110 - 115HP after all. :(

The Viezu manager guy assured me that the figure in the corner of the screen is correct and calculated for each car and that the printout would show whatever that number went up to. :p
 
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I’m curious to see my actual numbers. The car is meant to output 275 so I was shocked at the 304 or so it put on the screen.

Some are slightly dynoing at slightly less (some as little as 250 or so) so I’d be curious to see what I get through.

10% seems to be about bang on (273 or so by my mental arithmetic)
 
It’s not a maha so any flywheel figure will just be the operator putting his finger in the air.

Go off the wheel figure, if it’s a manual and RWD or FWD add 10-12% to wheel power put you roughly in right area.

If auto with torque converter probably around 15%

If AWD upto around 20%

Of course not most accurate way of doing it but that’s all the operator will be doing essentially.
 
Bit peeved if thats the case.
Made me excited over nothing.

I got 93 at the wheels, which is a completely useless figure for me. I wanted to know what it made at the crank, and was assured by James that the figure I saw on the screen was that value, and furthermore that there is a different calculation taking place depending on the car, and he claimed that their dyno is incredibly accurate. I assumed that the printout would show that value.

Drove 3 hours to the dyno, admittedly more for a day out than to find out what the car made, but the joy of a dyno day is seeing the car on the rollers and then being handed the printout telling you the power it made, in a format which actually means something. (In the UK, BHP...)

I saw a probably incorrect value for BHP on the screen, and was then handed a piece of paper with WHP on it which was labelled as engine HP, told to email him if I want BHP, and will now be waiting for that until at least tomorrow, and even then according to what you are saying, the figure will probably still be wrong...
 
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Not as simple as adding a percentage as the mustang dyno under reads up to 20% compared to other dynos (even if other brands also read wheel power). Imho only usage of the dyno yesterday was to see the graph curve and recognise where improvements may be made to improve lower or high rpm torque or to improve issues where there are severe dips.
 
Although, you say the dyno under-reads by 20%?

I took the 93WHP and added 20% (93 * 1.2 = 111.6)

Then took the 111.6 and added 12% to roughly account for drivetrain loss (111.6 * 1.12 = 124.992)

And 124.X is what was shown on the screen during my run...
 
Acme said:
Although, you say the dyno under-reads by 20%?

I took the 93WHP and added 20% (93 * 1.2 = 111.6)

Then took the 111.6 and added 12% to roughly account for drivetrain loss (111.6 * 1.12 = 124.992)

And 124.X is what was shown on the screen during my run...
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Maybe for your car but many cars did under read. Are you sure yours is completely standard BTW?
But my main point is that this is only useful if you use the same dyno and under very similar conditions to measure power before and after mods.

Or, as I mentioned, to see the graph (for example now I know that I need to do mods to hold torque at high RPM, for example a downpipe/sports cat etc.). Anything else is just speculating.

Just my 2p from my 25+ years of experience modifying cars.
 
Less of the speculation - as you all know the graphs I should be getting should include wheel and calculated flywheel bhp.

Although I've not watched any of the footage back yet, I think they may have been doing coast down figures as my car was left to spin back down by itself.

This is normally done to get your transmission losses.

So, until we know, we don't know. All being well I'll get and share all the graphs we want to see tomorrow :)
 
As far as I'm aware, all it has is a cone filter and a cold air pipe. Other than that its stock. Unless someone has advanced the timing and/or de-catted it in the past. But its meant to have 115!
 
ScoobyDoo69 said:
Less of the speculation - as you all know the graphs I should be getting should include wheel and calculated flywheel bhp.

Although I've not watched any of the footage back yet, I think they may have been doing coast down figures as my car was left to spin back down by itself.

This is normally done to get your transmission losses.

So, until we know, we don't know. All being well I'll get and share all the graphs we want to see tomorrow :)
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Fair enough. What I was just trying to day is that different dynos give different readings so not to lose sleep over it :cool:. Curious to see results tomorrow nevertheless :)
 
Just to add: my car peaked at 336 at the crank hp on the screen momentarily. I await the graphs at least I’ll have better understanding and can pass it on to the tuner. They have the same mustang dyno so can see if anything is amiss.
 
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