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Re: VWvortex R32 Stock Dyno Numbers (eiprich)

Quote, originally posted by eiprich »
I spoke with Anthony (95GLX) and he has dynoed his car as well but on a Mustang AWD dyno.
-Rich

My dyno was 189.6 whp at 5500 RPMS and 214.7 LBFT at 3000 RPM's. I have the numbers correct, have to check the RPMS once I look at the sheet which is down in the car! (corrected) Car would not pull past 5500 rpms on the Mustang even though HP was still going up! 4th gear pull so I don't think it was hitting the speed limiter unless they were in 5th. What rpm does 130 MPH come at in 5th?
The VW spec book rates the car at "241hp at 6250 RPM" and "236 ft. lbs. at 2800 rpm." Manual 3.3, page 4!
This was an AWD Mustang Dyno at AWE, dialed at 3400 lbs, 1600 miles on the car, exhuast valve open!
Weird that I have the most tourque out of these three dyno's using a full load and all 4 wheels!
Rich and Jamie, how many miles on the clock with your dyno sessions, did you find the speed limiter, what gear, what RPM?
Anthony



Modified by 95GLX at 6:08 AM 3-17-2004
 

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When I read Jamie's post about the torque split, my thinking was simular to what Ian said. The Haldex unit essentially just reacts to what it is presented with, so to have 90% front- 10% rear torque split is most likely a result of the load that the dyno is providing.
 

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Discussion Starter · #23 ·
Re: VWvortex R32 Stock Dyno Numbers (95GLX)

Quote, originally posted by 95GLX »

My dyno was 189.6 whp at 5500 RPMS and 214.7 LBFT at 3000 RPM's. I have the numbers correct, have to check the RPMS once I look at the sheet which is down in the car! (corrected) Car would not pull past 5500 rpms on the Mustang even though HP was still going up! 4th gear pull so I don't think it was hitting the speed limiter unless they were in 5th. What rpm does 130 MPH come at in 5th?
The VW spec book rates the car at "241hp at 6250 RPM" and "236 ft. lbs. at 2800 rpm." Manual 3.3, page 4!
This was an AWD Mustang Dyno at AWE, dialed at 3400 lbs, 1600 miles on the car, exhuast valve open!
Weird that I have the most tourque out of these three dyno's using a full load and all 4 wheels!
Rich and Jamie, how many miles on the clock with your dyno sessions, did you find the speed limiter, what gear, what RPM?
Anthony

Our car has a little over 1,000 miles on it now. At 211 lb-ft we're in the same ballpark but I'd just chalk up the differences in dynos, conditions and individual cars.
 

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Discussion Starter · #24 ·
Re: VWvortex R32 Stock Dyno Numbers (Daemon42)

Quote, originally posted by Daemon42 »
So there's two ways to look at this.
1. It's a quirk, perhaps even a flaw of the Autopilot mode of the dyno because of the way
it tries to match speed at all 4 wheels at once. Might see if one of the other modes
would avoid the issue. They'd undoubtably see the same thing running say.. an
AWD Porsche with its viscous coupling to the front (no center diff), and it could
be even worse because a VC always allows *some* significant slippage (has to, to keep
the fluid hot and viscous). There may be a setting to allow a larger rpm difference.
Make sure the R32 uses it.
2. Or one could argue that this test represents a more accurate representation
of what Haldex is really doing in the real world switching between AWD and FWD
as it speeds up. Except that it most certainly is not running a 50/50 split in 4th gear
on the highway if you roll on the throttle at 2000 rpms. Too much traction at the front
for that, no rpm difference between input and output shafts at the Haldex unit, thus
no significant rearward torque transfer. 1st and 2nd gear.. yes.. 4th.. no
That's my take at least. Might want to run it by the dyno operators, or even Dynopack
and see what they think. Just tell em that Haldex needs a small rpm difference
between input and output to maintain lock, and see what they say.

Ian, thanks for the insight and here are a few thoughts.
Number 2 of the above is whole heartedly more realistic in terms of measuring real-world horsepower to the wheels wouldn't you say? On the street you're not going to have a difference in rotational speed unless you were turning or on a slippery surface (wet, ice, snow, etc., etc.). So unless we're looking to try and force the haldex system to stay at a 50/50 split (assuming we can do that) and do a dyno run to determine what kind of power the car puts down when there is no traction front and rear (a "snow" dyno run so-to-speak), our current scenario more accurately captures what happens in real life. Even then it isn't exactly capturing that either as most of us that might accelerate hard on a dry surface *might* get some power transfer to the rears as the fronts break traction, but as the car continues to accelerate it won't have a speed difference between front and rear and will move power back to the front wheels. Essentially that's what happens on this dyno. At the start of the run, the Haldex electronics see a "slip" condition of the front wheels spinning at a different rate than the rears and immediately locks up the clutch pack so that all four wheels are now spinning. From there it is like you said, the amount of difference in rotational speeds reduces and the Haldex correspondingly reduces the amount of lockup on the clutch pack.
So the new questions are:
1. Does the amount of driveline loss through a Haldex system change as the amount of rotational speed differences decrease or increase? Short answer is yes, as there will obviously be more work involved in turning a full load rear wheels vs. a partial load rear wheels. So...
2. What is the amount of parasitic loss (or what is the scale percentage) when the Haldex system is not seeing a difference in rotational speeds ("at rest" if you will).
I have some contacts at Haldex and will try and see if there is any way to clarify this but I don't expect answers to be easy to get as I'm sure the individual programming for VW and Audi is proprietary and different than say, Volvo which uses different programming. We'll see.
Either way, we have some plausible explaination for what is going on and in the end the numbers are just what they are. Again, trying to extrapolate driveline loss would be near impossible and quite frankly not important to us here as we want to now measure differences we see when we make modifications to the engine.

And who says you can't find a good discussion on Vortex anymore?

-jamie
 

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Re: VWvortex R32 Stock Dyno Numbers (Daemon42)

If the Haldex is capable of activating with 1-2 rpm difference in wheel speed, could this fact be related to the VW recomended "extra" 10psi of air pressure in the rear wheels. The rear wheels have less weight to support and more air pressure than the fronts, which I am sure makes them turn slightly slower than the fronts. Even at high speeds on the highway in a straight line. Could this difference make the Haldex engage more quickly at higher speeds, especially in even a little turn where the fronts may slip just a bit?
If that's true, trying air pressures like 32 front 48 rear might make for some interseting fun.
 

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Re: VWvortex R32 Stock Dyno Numbers (sveda)

That's an interesting theory about the tire pressures. Could be true.
I know what happens when there's only 32psi in the rear as that's how it
was delivered to me from the dealer. Pretty much nothing. The rear end
stays glued to the pavement and the car understeers noticeably.
ian
 

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Re: VWvortex R32 Stock Dyno Numbers (gti_fan)

Quote, originally posted by gti_fan »
Why would the flapper mod increase horsepower on the top end? With RPM's over 3500 the flapper is open anyway. Logically there should only be a sub-3500 RPM improvement.

Ya, you'd think so wouldn't ya, but now EIP's dyno run and Jamie's both have
shown that there's a reproduceable *power* gain above 3500 rpms due to the mod. EIP's
theory is that it just never gets fully disabled running in stock mode. One would have to
watch the valve directly while it's on a dyno run (imagine being directly behind the exhaust
outlets while it's doing a 30-100 mph dyno pull at WOT..
) to confirm this.
ian
 

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Re: (Dyno-Comp)

Quote, originally posted by Dyno-Comp »
Anyone know if there is a "Dyno Mode" setting that can be actuated with a VAG tool? I know a Dyno mode exsists with Mercedes

Yes I believe there is. A search of the 1.8t or Mk4 forum will probably turn up more info.
Something like "logging block 120" springs to mind.
And there's probably a spreadsheet available on the VAG-COM website.
ian
 

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Re: (Daemon42)

Interesting numbers. Since we have seen mustang, dynojet and dynapack numbers - it would be great to have AMS run an R32 on the MAHA dyno. Here is an excerpt on how the dyno calculates drivetrain loss.
The inherent beauty of a dyno system like the MAHA LPS2000, is that after it has measured the wheel horsepower, it measures the resistance of the entire drive train from the clutch to the tires So instead of dynoing a vehicle with a reported 200HP and measuring only 150HP at the wheel, and ASSUMING that 50HP was eaten up by the drag of the drivetrain and wheels The LPS2000 actually measures the drag loss during the coast down phase.
More info here at AMS's site
http://www.advancedmotorsport....n.htm
 

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Re: ([email protected])

Quote »
Number 2 of the above is whole heartedly more realistic in terms of measuring real-world horsepower to the wheels wouldn't you say? On the street you're not going to have a difference in rotational speed unless you were turning or on a slippery surface (wet, ice, snow, etc., etc.). So unless we're looking to try and force the haldex system to stay at a 50/50 split (assuming we can do that) and do a dyno run to determine what kind of power the car puts down when there is no traction front and rear (a "snow" dyno run so-to-speak), our current scenario more accurately captures what happens in real life.

Except that there are no wheels on the car, and as Ian said above there is a considerable amount of intertia there.
Quote »
The inherent beauty of a dyno system like the MAHA LPS2000, is that after it has measured the wheel horsepower, it measures the resistance of the entire drive train from the clutch to the tires

If the dyno run is an acceleration run the above technique will not "recover" the intertial losses during acceleration, so I guess it would be closer to flywheel power, but not quite.
 

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Discussion Starter · #33 ·
Re: (ValveFloat)

Quote, originally posted by ValveFloat »

Except that there are no wheels on the car, and as Ian said above there is a considerable amount of intertia there.

What I should have said is that what we are seeing on the dyno is more like what we would see on the street where the front wheels may initially slip on a hard launch and the Haldex clutch locks up 50/50 and when rotational speeds equalize (or go below the minimum rotational difference) the system reverts back to FWD as it did on the dyno.
So yes, I shouldn't have said it is a more accurate in terms of measuring power to the wheels. It is more accurate in terms of what happens on the street and therefore what is being read at the hubs. Unless you put the car on a zero cofficient surface (ice for example) you aren't likely going to keep the system locked up in a 50/50 arrangement for long so making the dyno run that way wouldn't be a realistic assessment.
That make sense?
 

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Re: ([email protected])

Except nobody does a "hard launch" in 4th gear at 40mph where a dyno pull is started.
For AWD cars it is best to use a mechanically linked dyno like a Mustang since it is the only dyno that can actually simulate real world conditions. You will see the exact performance a car really is putting out on the road at those speeds using a load type mechanically linked dyno.
The MAHA I believe is also a mechanically linked dyno but since it does not read in HP and Ft/Lbs there is a whole new can o'worms for the correction factor.
 

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Quote »
It is more accurate in terms of what happens on the street and therefore what is being read at the hubs. Unless you put the car on a zero cofficient surface (ice for example) you aren't likely going to keep the system locked up in a 50/50 arrangement for long so making the dyno run that way wouldn't be a realistic assessment.
That make sense?

http://****************.com/smile/emthup.gif Yup

And really, what you said earlier about using the same type dyno to show what you have gained with changes to the car is really the key anyway.


Modified by ValveFloat at 8:14 AM 3-18-2004
 

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Re: (bmxvr6)

Quote, originally posted by bmxvr6 »

The MAHA I believe is also a mechanically linked dyno but since it does not read in HP and Ft/Lbs there is a whole new can o'worms for the correction factor.


The MAHA creates its own correction factor based upon the individual car. IMO that would be the most accurate. I don't know enough about it though to really understand how it works. Apparently though - it has been accurate to 1-2 hp on determine HP on stock cars.
 

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Re: ([email protected])

All the load based dynos that I know of can be calibrated to each indivdual car. That is how load based dynos work.
The operator comes into play during operation of the load type dynos to get the most accurate data. Since so many factors need to be taken into cosideration the results can be very different from a dynojet type dyno where they do not require much setup and are very similar from unit to unit.
 

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Re: (bmxvr6)

Regardless I am happy Jamie is playing with his R32 and for what he is using the Dynapak for I am sure it will serve him well.
Lets see what kind of power you can make with that thing and also how happy VW is that you are voiding that warranty soon!
 

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Re: (bmxvr6)

Great discussion everybody! This makes for some good background info on dyno functionality.
Ian, thanks for taking time off at JPL to chime in.

Quote, originally posted by bmxvr6 »
Lets see ... how happy VW is that you are voiding that warranty ...

I don't think he's particularly concerned about that...
 
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