Mike,
Just out of curiosity:

You have seen may different vehicles dyno'd, right?

How do they dyno all wheel drive vehicles? And if you know how much hp loss do all wheel drive cars lose through the drivetrain, or how much power a vehicle loses when it's put in 4x4?

 

Hi Captain,

No, only the rear 2 or the front 2 drive wheels are on the dyno, so no tests are done to check total driveline losses in 4WD, as you'd have to have a dyno capable of doing all 4 wheels, meaning 2 complete sets of rollers, and then you immediately run into the size problem, I.E., differing wheelbase lengths for all the different 4X4 vehicles, etc.

So for any number of reasons, all the dyno work is done on 1 axle only, for lack of a better term.

------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer

 

Mike, I am going to have to disagree with you on this. I have been a long time reader of this forum, and while you may be knowledgeable on superchips, you can't always have all the answers. There are AWD dynos. I had my car, a '91 VR4 dynoed on an AWD dyno. That is the only way you can efficiently dyno these cars, otherwise you have to disconnect one of the drive shafts and then you do not get an accurate drivetrain loss.
Capatain, to answer your last question, I had about a 30% HP loss through the drivetrain with a 5sp. That will jump to about 35% with an Automatic.
Hope this helps.
Thanks,
Danny

 

thanks for the reply both of you.

1badvr4 - how is the VR4, I've been wanting to drive one of them forever. You make me jealous.

 

it's a sweet little car. One of the best cars i've ever driven. And it is an extremely fast car. With only 1 mod, I was able to get it running 13.31 @ 102 mph. That time was with an AutoZone Deutsch Paper Filter
If you are ever in the memphis area, let me know and i'll let you take her for a spin....
Later,
Danny

 

Mike,

Reading the post with interest, yet a little lost with the terms you are using then I come upon a term that I am very familiar with: Eddy Curent.

I am a Level 2 NDT inspector for an NDT contract company. I am also an A&P.

I use high and low freq Eddy current machines almost on a daily basis but I use it to find cracks(It's OK, I have heard all of the plumber jokes) in aluminium aircraft skin and aluminium forgings and castings, Etc.

What I am really curious about is how does a Eddy Current machine fit in to a dyno??

We use Ultrasound and we also perform X-Ray and Gamma Ray radiographs.

Just curious about the application.

Thanks.

 

Eddy Current Dynamometer:

An Eddy Current dynamometer produces braking torque using the principle of eddy currents induced in a rotating metallic disk, immersed in a magnetic field.

Advantages:

Low maintenance
Precise control
Widely accepted in the automotive industry

Disadvantages:

High inertia
More expensive than a water brake

 

http://www.claytonindustries.com/ec.htm

------------------
98 SC/XL/4.2/5 speed/3.08/MoonLight Blue Metalic/Mobil One Synthetic/235.70S.16 Michelin XC LT4/AR-136 Wheels/Chrome Nerf Bars/Bug Shield/Aluminum Tool Box/K&N/Superchip/NOS maybe.

DAMN FLEXING DOOR CRACK!

Ford Engineering, reinforce the curve in the door! The cracks will stop.

 

Hi 1badvr4,

I think you're making assumptions that are not correct, as I never said that those types of dynos didn't exist, my friend.

I just responded to the question I was asked, that all the dyno work I've ever been part of has been on single-axle dynos, and that we don't have loss figures for AWD systems.

Nor do I ever claim to have "all the answers", by the way, and you're always welcome to disagree with me.

I'm glad you responded, tickled pink actually, in addition to getting Captain some info along the lines of what he's looking for, I find those figures very interesting. For example, take these late-model 4.6 V-8 automatic F-150's, you get about a 65 hp loss on a good eddy-current chassis dyno, or 29.54% loss comparing power at the flywheel to power at the drive wheels, roughly 30% in round numbers. Put an identical manual-tranny 4.6 F-150 on the dyno to do the drag-down test for driveline losses, and you see a 32-35 hp loss, at 35 hp that would be 15.91%. In round numbers, the automatic models are absorbing roughly just about double what the manuals are. Same thing goes with comparable Mustang automatics versus manuals, and so on. Automatics have always absorbed considerably more power to operate than comparable manuals, all else being equal.

Given that, it's a bit hard to reconcile only a 5% difference in driveline losses between an automatic or a manual in a AWD application all else being equal, so perhaps you can shed a little light on that for us as well?

It's obvious that you're going to have higher driveline losses across the board in any AWD application, but how does that negate the inherent difference in the amount of power absorbed by automatics versus manuals? I don't see it. Since the 2WD applications are already loosing 30% in an automatic, if we add the additional losses caused by engaging the 4WD system, that still doesn't change the fact that automatics take far more power to operate than manual transmissions do.

Thanks in advance,

------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer

 

Mike,
Sorry I may have come off a little rude. I did get the impression that you said they did not exist, which is the main reason I replied.
Also, I'm glad you say I am welcome to disagree with you, but as a long time reader of this forum, I've learned that if someone disagrees with you, everyone else pretty much canes the unfortunate soul
I have worked with dynos a little, but not enough to make valid assumptions. I can only report my loss with my particular vehicle, which was in the neighborhood of %30 (I will look up the actual number if you like). However I guess that it would be %5 - 10% more loss with an auto, but from what I can gather neither one of us truly knows, since we have never tested an AWD auto on a dyno.
Now, I have seen several runs done with Automatic and 5sp FoxBody Mustangs (I used to be a heavy stanger) and the average driveline loss between auto and man transmission was only 5%. That is the basis for my assumption that you would loose an additional 5%.
But as we know, "all vehicles are not created equal!"
Thanks for your responsed Mike,
Danny

 

Hi 1badvr4,

No problem.

I didn't know if perhaps you might have some insight for us there in AWD applications, given the inherent differences in amount of power it takes to turn an automatic versus a manual. Automatics don't take less power to turn just because they're in an AWD application, automatics have always absorbed considerably more power than manuals all else being equal, usually on the order of double, so that's why I wanted to ask you about that once I saw that you mentioned only a 5% differential.

------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer

 

Hi B777,

Bill Bateman's answer was very appropriate, thanks very much, Bill!

I can't answer exactly *how* it is incorporated into chassis dynos, as we don't build or sell chassis dyno's, we just have vehicles run on them when needed. However, it's funny you should ask at this particular time, as just last night I was reading something about metal detector theory, and it talked about using eddy current in their design, so it seems there are all kinds & sizes of eddy current equipment appropriate to the application.

Yours is obviously a very critical application, searching for cracks, metal fatigue, etc. in the skin of an aircraft, I guess a lot of us here should thank you for helping to keep our airliners safe!

Sorry I can't give you the explanation you're looking for,

------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer

 

There are 4 installations of Dynojet AWD dynos in the states. One in Maryland, one in California, and two that I can't mention. I have had time to tinker with ours, but haven't done "negative HP" tests to determine driveline loses. These are inertia chassis dynos, not eddy current, and they are set up to accomodate every wheelbase on the road. I suppose I could test my truck in 4wd and compare them to the 2wd numbers. The dyno room is always in shambles for R&D, maybe I can sneak in there soon.

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2000 5.4


Magnacharged
- 290 rwhp / 375 trq
- Custom Superchip
- FIPK - fabricated by me
- everything else stock


webmaster@totalperformancesolutions.com

 

Mike,

Just another dyno question. I've seen product tests that use a load to show partial throttle improvements. Does Superchips ever do this during their R&D for chips?

It just seems that a chip such as the Superchip that makes changes at all throttle postitions would show great improvements.

 

Hi Signmaster,

You're exactly right, and yes, they do quite a bit of steady & altering load part-throttle testing & tuning, that's one of their claims to fame, so to speak.

It's common to see that a given application may add say, 16 hp to the peak power output, but at say, 2700 rpm on part-throttle to see a larger gain. There is almost always more room for improvement on part-throttle than there is at WOT, and it makes all the difference in the world in overall driveability, aiding in "point & squirt" moves, etc.

They don't ever publish or advertise any part-throttle numbers, they just share that info with us from time to time.

------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer

[This message has been edited by Superchips_Distributor (edited 02-02-2001).]