Crazy torque reading?

bman575
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Crazy torque reading?

Postby bman575 » Thu Feb 15, 2018 6:38 pm

Hey guys, first post here! I've had my hawleye for a bit over a year now and loving it. anyway, it was tuned by Got it Rex at the end of 2015 by the previous owner, and I am curious about this torque reading. it seems that the kw went from 73awkw to 156kw and the torque went from a max of 3500 to 6500 N which i think is meaning 350Nm to 650Nm. Now from only having the 3'' exhaust and the tune this seems impossible. any help translating this dyno chart? hmmm

Thanks in advance!!

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Delivan
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Re: Crazy torque reading?

Postby Delivan » Thu Feb 15, 2018 7:08 pm

Dyno charts can be a bit tricky.. especially when the color coding is hard to see ..Looking at the 6000rpm area it looks like it has gone from 128ish kwatw which is normal ish to 156 kwatw which is also about right for a good exhaust and a tune.. The torque is usually in NM not just N ..
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bman575
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Re: Crazy torque reading?

Postby bman575 » Thu Feb 15, 2018 7:25 pm

Thanks mate, yeah i thought it would have been the pink lines as kw and red as torque, rather then the bottom two being for torque and top two for kw. still not too sure what to make of the other lines then, as for torque it couldn't be able to reach the 600's though, could it? i tried to research if there was a N reading for torque, but everything just points back to Nm..
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mv75
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Re: Crazy torque reading?

Postby mv75 » Thu Feb 15, 2018 8:10 pm

I read it as;

Peak power: 156kw @ 7800rpm
Peak Torque: 130nm @ 6000rpm.

bman575
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Re: Crazy torque reading?

Postby bman575 » Thu Feb 15, 2018 8:39 pm

If it was 130Nm wouldn't that be too low for after a tune as the stock Nm would be under 100? And what would you say the right hand side numbers under the N are?

Thanks for your responses guys! :cheer:
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mv75
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Re: Crazy torque reading?

Postby mv75 » Thu Feb 15, 2018 8:59 pm

The right hand numbers look like another cross reference for rpm.

Either way, that print out sucks and is pretty much just trash. Throw it in the bin and ask them for a real read out or interpretation.

bman575
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Re: Crazy torque reading?

Postby bman575 » Thu Feb 15, 2018 9:02 pm

Thanks guys, I plan to get into some mods over the next 6 months or so, so i will take it with a grain of salt and go by my next tune printout.

Thanks though guys, appreciate it! :bowdown:
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Delivan
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Re: Crazy torque reading?

Postby Delivan » Thu Feb 15, 2018 10:38 pm

mv75 wrote:I read it as;

Peak power: 156kw @ 7800rpm
Peak Torque: 130nm @ 6000rpm.

Are you sure... I think you will find the 156kw at 6000 rpm.. I don't think it would do 7800 rpm.. :lol:
'09 Impreza Charcoal Hatch Auto
'03 WRX Pearl Red Bug Sedan
'02 WRX Silver Bug Wagon
'98 WRX Blue Club Spec Evo 2 with 2.5 lt
'99 WRX White Sti Version 6 with 2.5 lt
'98 Mitsubishi EVO 5 (kept in the basement)

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Re: Crazy torque reading?

Postby mv75 » Fri Feb 16, 2018 2:37 am

But peak power wouldn't be at the same spot as peak torque either. If it's a 2l engine it can rev out to that. I reckon to message or call got it rex and ask them. :)

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05-RSX
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Re: Crazy torque reading?

Postby 05-RSX » Fri Feb 16, 2018 8:37 am

RHS is "tractive effort"

The tractive effort is obtained by multiplying the torque by the total ratio of the power train and dividing this sum by the rolling radius of the driving tyres.
T = (TE x r)/(1000 x R)

Where:
T= Motor torque in Nm
TE = Tractive Effort in N
R = Overall gear reduction including both axle and transmission
r = Rolling radius of loaded driving tyre in millimetres

    Example:
    TE = 5400
    R = diff ratio X gear ratio (eg 3.45 diff x 1.00 Auto 3rd gear = 3.45)
    r = 326.60 mm (18" rim/ with 235/40/18 tyre combo)
    T = 510NM



Your power went from ~130kw (stock) to ~155kw (tuned), which are both pretty typical.
Tractive effort went from 3800N to 5200N, which you'd have to run the maths on to convert to Nm. Again, I'd suggest fairly typical. Big difference down low with the TD04 spooling hard early, then tapering differnce as it runs out of flow
You'll just have to check which gear they did it in (3rd vs 4th) and apply the gear ratios for each. Make sure you get the AUDM ratio (different to US) - maybe check your manual for this.
Final drive (diff) on that year is 4.444.
Rolling radius is ballpark 320mm (for OEM/OEM-ish sized tyres)
Campbell.
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Delivan
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Re: Crazy torque reading?

Postby Delivan » Fri Feb 16, 2018 10:32 am

The 2 highest lines are related to kwts.. the numbers across the bottom of the sheet is the rpm.. The 2 lower value lines represent torque which is peaking around 3500 but it is a pretty useless chart.. I find that if you ask the tuner for kwt values and torque values they will do a sheet with the terms you are interested in and can relate to. If you don't ask, you will end up with a sheet that has stuff that doesn't mean a lot to us normal plebs..also ask them to put what gear they used for the test. The gear is an important thing to know... Dyno numbers doen in 3rd gear will be different to ones done in 4th.. If someone says..."ah yeah, but mine has 200kwts with the same mods as yours" BUT his tuner did his in a different gear, that explains why same cars have different results.. Also I would stay away from any tuner that runs an unbuilt engine at 7800rpm to get dyno readings...LOL...
PS...I am not sure what turbo an 06 has but if it is a td04, then that explains why it is running out of puff .. If you decide you want more..start a collection of all the goodies and put them all on at once and then get a retune. It is too expensive to get a tune every time you add something and you can't safely add anything without getting it tuned and never try to get more power by asking them to up the boost.. What you want at the end of the day is a car that makes good power with little effort. That way it will last for many years. My blue (2.5l) one makes 180+ kw on 16p...It could easily be wound up to make 200 at 18-19p but one day I would probably break something..
Last edited by Delivan on Fri Feb 16, 2018 4:43 pm, edited 1 time in total.
'09 Impreza Charcoal Hatch Auto
'03 WRX Pearl Red Bug Sedan
'02 WRX Silver Bug Wagon
'98 WRX Blue Club Spec Evo 2 with 2.5 lt
'99 WRX White Sti Version 6 with 2.5 lt
'98 Mitsubishi EVO 5 (kept in the basement)

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05-RSX
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Re: Crazy torque reading?

Postby 05-RSX » Fri Feb 16, 2018 1:11 pm

Where's everyone getting 7800rpm from?
Campbell.
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mrjarrodcthompson
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Re: Crazy torque reading?

Postby mrjarrodcthompson » Mon Feb 19, 2018 2:30 pm

Not sure why people are saying this isn't a useful dyno - as this is an *extremely* typical dyno graph and as useful as any (trust me I've done dozens of dyno's lol)

In this instance the RPM, Power and Tractive effort are measured at the wheels (as opposed to an engine dyno or hub dyno) - so the tractive effort (N) on the graph is the wheel torque that has actually been measured (influenced by gearing, final drive ratio and RPM). Incidentally, this is probably the figure Tesla used when sprouting their new Tesla Roaster as having over 10,000 newtons or torque.

Yours has some really nice gains - with close to a 40kw increase in the mid-range. Car must drive a heap nicer!

At the end of the day, dyno's are really only a tuning/comparison tool. Next time you get a tune/dyno, multiple things might be different - the dyno hardware, software, parameters used, ambient temperature, even your tyres - so you can't really compare one dyno to another accurately.
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Hayden282
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Re: Crazy torque reading?

Postby Hayden282 » Mon Feb 19, 2018 3:31 pm

My 2011 WRX got tunes to 152kw at the wheels with 580nm of torque so that sounds about right! :)
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mrjarrodcthompson
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Re: Crazy torque reading?

Postby mrjarrodcthompson » Tue Feb 20, 2018 8:24 am

Incidentally - assuming you have a Hawkeye with stock sized wheels, by my calculation:

Tractive Effort: 5,200 (as per dyno sheet)
Gear Reduction (R) = 3.7 (MY06/07 Diff Ratio) * 0.972 (Got it Rex will dyno in your "1:1" gear, i.e. 4th) = 3.5964
Rolling Radius (r) = 312mm (assuming stock 215/45R17's)

T (Nm) = (TE x r)/(1000 x R) .... so

(5200 x 312) / (1000 x 3.5964) = *** 451Nm ***(at the wheels)

PS. Hayden282's 580nm would be corrected for flywheel.
MY 11 WRX Sedan

# EJ257, Forgies, ARP Studs, VF52
# Flexfuel and a very long list of bolt-on bits.
# Tuned by Warwick @ Got it Rex

Sandown 1:26.2
Winton 1:48 in a 1992 Toyota Corolla :-)

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05-RSX
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Re: Crazy torque reading?

Postby 05-RSX » Thu Feb 22, 2018 7:57 pm

WRXs used a 4.444 rear diff until at least 08 in Australia.

It was in the US they used 3.7s, 3.9s, etc.


Also, I believe the Nm calculated is flywheel Nm (as it takes into account the gear ratio - you wouldn't need to if you were converting to Nm atw).
However it doesn't account for drivetrain loss (~25%).
Campbell.
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