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You can dyno the Fiat but not the Giulia, can you explain why?
 

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Discussion Starter · #4 ·
Greg, is this possibly due to traction control or do you have it turned off?
Good question. Let me ask you a question. Can you turn the ABS off? Those wheel speed sensors send data to the ECU no matter what you do. Furthermore, it's a "fail-safe" system meaning if the ECU doesn't get the data, it assumes a lot of slippage, which is why pulling the ABS fuse doesn't help.

We have done this with traction control off, it still pulls power. We have done this test over and over and we have been dealing with this issue since 2012. If there was a simple solution then I would have spent about 1/2 the money and bought a cheaper dyno, but there just isn't another way that's practical.

Greg
 

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Discussion Starter · #5 ·
You can dyno the Fiat but not the Giulia, can you explain why?
I wish I could. Greater minds than mine are working on that issue. Here is what we can do. We can dyno the QV no problem as long as the rollers are linked. If they are not linked, the values will be low. We actually did dyno the Q and put up a video the first day the dyno was installed. That was before we knew much about using it, so I'll do it again soon to get more solid data, but at least the Q dynos on this thing no problem.

The Giulia 2.0 is another issue. I think the issue is related to software in the dyno's database, but that's only a working theory. You can rest assured that as soon as we have this figured out for the Giulia 2.0 we will post the data. Hopefully it's not related to a G sensor or something like that.

Greg
 

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"greater minds"
very odd that it doesn't work when linked, and I expect it is very troubling to those greater minds that designed the linked dynos for this very reason.
 

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I wish I could. Greater minds than mine are working on that issue. Here is what we can do. We can dyno the QV no problem as long as the rollers are linked. If they are not linked, the values will be low. We actually did dyno the Q and put up a video the first day the dyno was installed. That was before we knew much about using it, so I'll do it again soon to get more solid data, but at least the Q dynos on this thing no problem.

The Giulia 2.0 is another issue. I think the issue is related to software in the dyno's database, but that's only a working theory. You can rest assured that as soon as we have this figured out for the Giulia 2.0 we will post the data. Hopefully it's not related to a G sensor or something like that.

Greg
Silly question, but wouldn't it be a whole lot easier to use some electronics to replicate the signal from the rear wheel speed sensors onto the front wheel speed sensors? With a little creativity that mechanism might also be able to simulate various amounts of wheel slippage without requiring expensive mechanical devices.

Do these vehicles use tone rings and electro-magnetic pickups for wheel speed detection?

I find it curious that the vehicle did not do something more drastic when the front wheels were completely stopped, such as applying the brakes hard enough that you get almost no power.
 

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Greg, in your professional opinion, are the current manufacturer HP ratings of the QV accurate or possibly more/ possibly less?
 

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Discussion Starter · #10 ·
"greater minds"
very odd that it doesn't work when linked, and I expect it is very troubling to those greater minds that designed the linked dynos for this very reason.
I am sure they will figure it out. I am really leaning towards a software/database issue. The worst case would be to find out that the car has a G sensor or uses GPS data to know that it's not moving. I have never heard of that, so I don't think it's likely. Again, it's a new dyno, so it's probably just software because it works perfectly on everything else we had put on it.

Greg
 

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Discussion Starter · #11 ·
Silly question, but wouldn't it be a whole lot easier to use some electronics to replicate the signal from the rear wheel speed sensors onto the front wheel speed sensors? With a little creativity that mechanism might also be able to simulate various amounts of wheel slippage without requiring expensive mechanical devices.
It would not be easier. Think about it from a dyno operator perspective. In order to pay for a dyno, you must be able to rent out dyno time. Now, lets say you had a device you described. Are you going to jack up every car, remove all 4 wheels, install the signal modification device, put the wheels back on, dyno it, and then reverse everything when the car is done? What if you have 5 cars to dyno in an afternoon?

Now, could this be done? I think so, but nobody has done it yet. I actually describe this procedure in a tech article on the EC site I wrote about 4 years ago. It's actually a bit complex, and you would have to have quite a few wiring harness sets made up for different cars.

I find it curious that the vehicle did not do something more drastic when the front wheels were completely stopped, such as applying the brakes hard enough that you get almost no power.
Think that through for a moment. Would you want the car to apply the brakes automatically just because wheel speed sensor failed? Cars are not set up that way.

Greg
 

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Or, yank the engine and bolt it to an engine dyno.
 

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It would not be easier. Think about it from a dyno operator perspective. In order to pay for a dyno, you must be able to rent out dyno time. Now, lets say you had a device you described. Are you going to jack up every car, remove all 4 wheels, install the signal modification device, put the wheels back on, dyno it, and then reverse everything when the car is done? What if you have 5 cars to dyno in an afternoon?

Now, could this be done? I think so, but nobody has done it yet. I actually describe this procedure in a tech article on the EC site I wrote about 4 years ago. It's actually a bit complex, and you would have to have quite a few wiring harness sets made up for different cars.



Think that through for a moment. Would you want the car to apply the brakes automatically just because wheel speed sensor failed? Cars are not set up that way.

Greg
On the dyno, the thing to compare with is the cost of the new dyno versus an ongoing effort to continue to use your already paid for dyno using a contraption such as I have described. The original concept behind said contraption was to be able to defeat the traction control system on vehicles that lack a traction control disable feature. The problem with the latter is that it needs to defeat both traction control and vehicle stability control and the latter is significantly harder to defeat using this technique.

On the braking issue, many folks have reported that Giulia refuses to spin wheels on snow/ice. Your dyno chart appears to show that this is not due to lack of power (at least for a Fiat 124), so why would that be the case? Perhaps the reports are inaccurate? I haven't gotten my Giulia yet to be able to try it out myself. No snow yet either :-(

I believe that the wheel sensors are designed to allow the computer to distinguish a broken sensor from the wheel not turning.

Using a GPS for speed confirmation is problematic, as GPS reception fades in and out with whatever might be overhead (trees, clouds, buildings, etc). Using accelerometers also has its challenges due to extreme precision requirements and the need for 6 axis measurements to really know what is going on. Many modern systems (such as in airplanes) combine the two.
 

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Discussion Starter · #15 ·
On the dyno, the thing to compare with is the cost of the new dyno versus an ongoing effort to continue to use your already paid for dyno using a contraption such as I have described. The original concept behind said contraption was to be able to defeat the traction control system on vehicles that lack a traction control disable feature. The problem with the latter is that it needs to defeat both traction control and vehicle stability control and the latter is significantly harder to defeat using this technique.
No, it needs to defeat the ABS system, which has traction and stability control mixed in with it. If you think you can do, please do. I would love to see that idea come to fruition.

On the braking issue, many folks have reported that Giulia refuses to spin wheels on snow/ice. Your dyno chart appears to show that this is not due to lack of power (at least for a Fiat 124), so why would that be the case? Perhaps the reports are inaccurate? I haven't gotten my Giulia yet to be able to try it out myself. No snow yet either :-(
My 124 will lay down rubber like a muscle car. I have a video of that on my channel in my limited slip video (with a different tune on it). As far as I can tell the 2.0 Giulia will not burn rubber. You are correct, this has nothing to do with a lack of power. It has way more than enough power.

I believe that the wheel sensors are designed to allow the computer to distinguish a broken sensor from the wheel not turning.
Not in this case it doesn't. The ABS fault light clearly comes on when it's run on the dyno in 2wd mode. It sees a fault in the ABS. Sometimes we even have to reset an ABS fault related code, although it usually sorts itself out just by driving the car.

Using a GPS for speed confirmation is problematic, as GPS reception fades in and out with whatever might be overhead (trees, clouds, buildings, etc). Using accelerometers also has its challenges due to extreme precision requirements and the need for 6 axis measurements to really know what is going on. Many modern systems (such as in airplanes) combine the two.
I think GPS would be a problem too, I am just considering all possibilities. There is a Nissan that uses GPS signals to determine if it's at a racetrack. If not, you don't get full power, so this isn't far fetched. As for an accelerometer, I think they could easily tie that in, but I hope they didn't. Wait, you don't have a Giulia? What are you waiting for?

Greg
 

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No, it needs to defeat the ABS system, which has traction and stability control mixed in with it. If you think you can do, please do. I would love to see that idea come to fruition.

My 124 will lay down rubber like a muscle car. I have a video of that on my channel in my limited slip video (with a different tune on it). As far as I can tell the 2.0 Giulia will not burn rubber. You are correct, this has nothing to do with a lack of power. It has way more than enough power.

Not in this case it doesn't. The ABS fault light clearly comes on when it's run on the dyno in 2wd mode. It sees a fault in the ABS. Sometimes we even have to reset an ABS fault related code, although it usually sorts itself out just by driving the car.

I think GPS would be a problem too, I am just considering all possibilities. There is a Nissan that uses GPS signals to determine if it's at a racetrack. If not, you don't get full power, so this isn't far fetched. As for an accelerometer, I think they could easily tie that in, but I hope they didn't. Wait, you don't have a Giulia? What are you waiting for?

Greg
Your 124 will lay down rubber even with traction control enabled? When I say lack of power, I mean the power was turned off by the computers not that the engine cannot make enough power. Reference the thread about getting the best 0 to 60 time and the need to NOT give it full throttle in 1st gear.

I don't think it would be difficult to make a device to defeat traction control. It would by definition defeat ABS (not necessarily a good thing) at the same time. Maybe this could be tied to the brake lights to fix the ABS defeat problem? However, the "simple" solution would likely cause the vehicle stability control to have an epileptic seizure as soon as you turned the steering wheel while moving. Adding a drive shaft rotation sensor would allow a much better implementation but that is likely complicated and would not help with the stability control issue. To avoid the stability control problems the steering angle needs to be known.

My bicycle uses GPS to ASSIST the speedometer. I can run GPS only, but it all too often complains that it can't figure out what is going on. On the bicycle I am leaning over the antenna, which can't be helping so maybe it would work better in a car. This expensive unit from Garmin is a piece of junk for other reasons though (very long story).

I am waiting for my Giulia to be delivered. I could not find one in stock equipped to my satisfaction; the 2.0Ts equipped with all of the performance features sell pretty much instantly and I didn't want to buy the black one that I found (I strongly prefer light colors). Anyway the car is due some time in Jan. I guess it is on the Hoegh Singapore, and probably waiting in or headed to the perpetual traffic jamb at the Panama Canal.
 

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I can't even imagine what you guys paid for this dyno. My old boss dropped 6 figures on a used Dyno Dynamics AWD dyno, 5 years ago.

Thanks for trying to get this going for us! Eagerly awaiting some good results!
 

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I can't even imagine what you guys paid for this dyno. My old boss dropped 6 figures on a used Dyno Dynamics AWD dyno, 5 years ago.

Thanks for trying to get this going for us! Eagerly awaiting some good results!
Its still stinging....

 
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Discussion Starter · #19 ·
Your 124 will lay down rubber even with traction control enabled?
I didn't say that. As shown in the video, the burnout is with traction control off. With traction control on as soon as it detects tire slippage it stops it via brakes and power manipulation. That's not a factor on the dyno in this video.

I don't think it would be difficult to make a device to defeat traction control. It would by definition defeat ABS (not necessarily a good thing) at the same time. Maybe this could be tied to the brake lights to fix the ABS defeat problem? However, the "simple" solution would likely cause the vehicle stability control to have an epileptic seizure as soon as you turned the steering wheel while moving. Adding a drive shaft rotation sensor would allow a much better implementation but that is likely complicated and would not help with the stability control issue. To avoid the stability control problems the steering angle needs to be known.
I am glad you "don't think it would be difficult". I encourage you to prove it by doing it.

My bicycle uses GPS to ASSIST the speedometer. I can run GPS only, but it all too often complains that it can't figure out what is going on. On the bicycle I am leaning over the antenna, which can't be helping so maybe it would work better in a car. This expensive unit from Garmin is a piece of junk for other reasons though (very long story).
I am sorry to hear about your Garmin bicycle unit.

I am waiting for my Giulia to be delivered. I could not find one in stock equipped to my satisfaction; the 2.0Ts equipped with all of the performance features sell pretty much instantly and I didn't want to buy the black one that I found (I strongly prefer light colors). Anyway the car is due some time in Jan. I guess it is on the Hoegh Singapore, and probably waiting in or headed to the perpetual traffic jamb at the Panama Canal.
That's exciting. I understand the idea of waiting for just the right car.

Greg
 

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I am glad you "don't think it would be difficult". I encourage you to prove it by doing it.

I am sorry to hear about your Garmin bicycle unit.
I either need my car so I can make measurements or I need somebody that can provide me with accurate technical details regarding the wheel speed sensors. There are at least two very different technologies out there and the details of how each is implemented has a lot of latitude (impedances, voltages*, etc). Also some cars do have drive shaft speed or differential carrier speed sensors, and the presence of one would greatly simplify the implementation. There is a major flaw in the scheme though, this disables traction control at the expense of causing stability control to have fits when the vehicle is turned. It would work for a car on a dyno, but not for a car on the road. I don't have a dyno, you do. The steering angle is needed to avoid the stability control problems and that is most likely not available via some simple sensor intercept.

My point with the Garmin bicycle speedometer is that GPS based vehicle speedometers exist, but the only one that I have used does not work well. Between signal loss and electrical noise, the thing bleeps that it doesn't know my speed maybe 10% of the time. Garmin expects the unit to be used in conjunction with a wheel speed sensor. With a roof top antenna a unit in a car MIGHT work better, I dunno. It doesn't seem like a good idea, although there is always this scenario:

"Honest officer, my speedometer was reading 0 MPH".>:)
Don't scoff, my Dad got away with that once while driving his TR3.

* In a tone-ring implementation, wheel speed can be determined by the voltage produced by a single pulse from the sensor and I expect that modern car systems do exactly that. However, the voltage to speed conversion factor is not well controlled from unit to unit so some kind of calibration based on the timing of the pulses should need to be done first.
 
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