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I am curious just how the stock E Diff does work in R mode? The reason I ask....I tried a burn out in a straight line on clean good surface when I first got the car and noted that it would light up both tires leaving equal length skid marks. If one wheel was first spinning, does that wheel get braked a bit and shift power to the other wheel or is it just chocked back. If that were the case I would think you would feel the actual power cut and it would be very obvious as a pause in acceleration or the car would not continue to burn rubber with both tires. I figure there must be a computer doing very fast transfer of power as needed as one wheel spins faster than the other...but in a very fast manner so each tire can maintain an equal speed to the other tire.

I don't know if the Giulia and Stelvio Quads use the same type of an E diff but do remember that a couple of early examples on those Quads had an issue of the E diff stopping working after some hot laps on track as it overheated. I wonder if that might be the case on the 4C for those tracking their cars mentioned at one point the inner tire would spin. The Wave Trac would be an answer but wondering if our E diff as is might negate the Wave Trac as it would work before the Wave Trac could engage and lock up as some others mentioned in posts above.
The double wheel spinning is different - that is ASR not the Q2.
This is the description of the ASR system (title is on the bottom of the previous page of the manual):
Font Screenshot Number Document


And in RACE, this is disabled along with the ESC.
(Again, the title that this is what happens in RACE mode is on a previous page of the manual)
Font Number Document Screenshot
 

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Lets say for arguments sake that the wavetrac does lock, both wheels spinning… the “e-diff” will interfere, I fear. I suspect it will brake both wheels. The guy who said it won’t/doesn’t may only drive in race mode and it has been suggested that race mode disabled or diminishes it effect.
I did not see race mode when I was passenger. I fear that you are chasing ghosts on suspicions not made on the basis of observations, but too critical thinking.
 

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Discussion Starter · #23 ·
Maybe. Maybe the wavetrac locks up and E-diff stays out of it. I will still be happier KNOWING it’s disabled for certain. I’m going ahead with the wiring hack so it’s gets disabled in all modes.
 

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They lie. It isn’t “distributed optimally between the drive wheels”. An open differential can only drive one or the other wheel and that’s hardly optimum. I think they meant as well as possible with an open differential.
Okay just to clear this up.
What you refer to as the "e-Diff" is actually the ABS that is going in and breaking the inner wheel.
So in short.
When you go into a corner and turns around it and have the load on the outer wheels and go on the throttle. Then the inner wheel has little load and the open stock diff always takes the easy way out. That is to put the power to the inner wheel and that starts to spin.
From the wheelspeed sensors the signal goes to the ABS unit. saying that three wheels are rotating at the same speed and the inner rear wheel are spinning faster than the outer wheel rear wheel. Then the ABS is going in and braking the inner wheel to reduce the speed and trying to match the outer wheel. When this happens a higher moment in going into the diff from the inner wheel and then putting some of the power to the outer wheel.
That is all that is happening. In Race mode, this threshold is bigger than in Dynamic and Normal mode. So that is why you feel the inner wheel is spinning more in race mode as it takes a longer time until the ABS starts to work in race mode.

Then you can fall into another situation with TC if you are driving in Dynamic mode and the ABS is braking the inner wheel a bit and both tires are starting to spin then the TC goes in and cuts the engine as the ECU/TCU also have the wheel speeds and saying that the rear wheels are spinning faster then the front and cutting ignition partly until the rear wheels are withing the slipping angle set in the TC control of lets say 5-10% what is quite normal on a sports car.

Then you have another situation when the ESP is cutting in when you have a slide and the gyro in the ABS is sensing strange stuff and comparing to the wheel speed sensors and it goes in and breaks one or more wheels both front and rear to stabilize the car.
Same here in Race mode the threshold is larger and it allows more slip until it goes in and corrects. In Dynamic and Normal mode this happens earlier and more notable when you drive on the limits. .

When you have the WaveTrac diff in the car this doesn't happen with the "e-diff" as the inner wheel will not start slipping or spinning as the diff puts the power to the other wheel much faster then the "e-diff" starts to interact with the car and starts braking the inner wheel. this happens within a slipping angle of around 2-3% and the "e-diff" starts breaking the inner wheel much later.
So with the WaveTrac diff in the car, the "e-diff" will never work anymore.
 

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Maybe. Maybe the wavetrac locks up and E-diff stays out of it. I will still be happier KNOWING it’s disabled for certain. I’m going ahead with the wiring hack so it’s gets disabled in all modes.
You will not be able to do that as that is coded in the ABS unit.
But you can remove it by disconnect the wheel speed sensors in the rear but then you will disable the ABS unit completely.

I have been working with ABS logic and real E-Diffs so I know how it works.

But I like that you are questioning it if you don't understand as it is complicated stuff.

And if you still don't believe me then go ahead and continue your search, you will learn things on the way and maybe understand some of the logic in the end.
 

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Discussion Starter · #26 · (Edited)
It’s not at all complicated. I completely understood how the e-diff /Q2 works about a year ago when 4Canada informed me.
I’m just not convinced by your conclusions and opinions. Perhaps you misunderstood since English is a foreign language to you.
I believe there is a way to disable it and If successful I will share when it’s done.
 

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It’s not at all complicated. I completely understood how the e-diff /Q2 works about a year ago when 4Canada informed me.
I’m just not convinced by your conclusions and opinions. Perhaps you misunderstood since English is a foreign language to you.
I believe there is a way to disable it and If successful I will share when it’s done.
Have you tried your 4C out on a skid-pan to give you an idea of how much effect the electronics has on your lsd ? There’s a marked difference in the activation thresholds of the e-dif in the various modes on the standard car and the skid-pan clearly demonstrates this (my first-hand experience). I would think it would be less noticeable with your lsd….. Have you given it a go?
 

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Discussion Starter · #28 ·
Have you tried your 4C out on a skid-pan to give you an idea of how much effect the electronics has on your lsd ? There’s a marked difference in the activation thresholds of the e-dif in the various modes on the standard car and the skid-pan clearly demonstrates this (my first-hand experience). I would think it would be less noticeable with your lsd….. Have you given it a go?
Not under repeated controlled conditions, no. I’m planning a trip to a local track where they hold drift events. I want the e-diff completely disabled in all modes because I have a locking differential and the possibility of it interfering is sufficient cause for doubt that I would rather disable it by feeding the same wheel speed sensor feedback to both inputs which will ensure it never intervenes.
The thing I’m more interested in evaluating on track is the Wavetrac, in all 4C driving modes. I can’t do that if there’s a possibility the e-diff interferes. The e-diff is for open diffs. It’s no longer applicable in my 4C.
 

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....I want the e-diff completely disabled in all modes because I have a locking differential and the possibility of it interfering is sufficient cause for doubt that I would rather disable it by feeding the same wheel speed sensor feedback to both inputs which will ensure it never intervenes....
Good luck @FLORO, I think that @Niklas is correct when he says you are going to run into trouble with the ABS logic.
That's rather tricky to achieve (disabling Q2 by feeding dummy speed signals) without running into problems with the ABS and possibly the ESP as these systems are all integrated.
I admire your tenacity to want to have the Q2 disabled in all modes - it must be achievable. I think the answer may lay in the software rather than interrupting hardware signals, and that is waaay above my pay grade.
There are plenty of dedicated track cars that remove the ABS module altogether, or replace it with a proper track system where the braking bias can be adjusted.
One way to test if the ESP/ABS/Q2 is really interfering with your diff would be to pull the fuse on the ABS and test drive it (I haven't tried this and you may find that the Alfa Technicians may prevent you from using Dynamic and Race modes, so this may not work). If it does work, placing a switch in that circuit should allow you to have it enabled for road use and disabled for the track.
You may well be able to drive faster without the ESP/ABS/Q2 being available with your Wavetrac diff, but you will also be without the nannies to step in and try to save you if you over-cook it. That's probably not an issue for a pro driver, as long as the risk/reward factor is understood.
Cheers,
Alf.
 

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It’s not at all complicated. I completely understood how the e-diff /Q2 works about a year ago when 4Canada informed me.
I’m just not convinced by your conclusions and opinions. Perhaps you misunderstood since English is a foreign language to you.
I believe there is a way to disable it and If successful I will share when it’s done.
Like your passion to try to find a solution.
Im sad to tell you that is not my conclusion and opinion its the fact how the ABS unit works that is hard coded software in the ABS unit.
There is ways to get the wheel speed signal in to a own programmable ecu unit with your own software and put some logic to them on how different speed sensors will have different outputs that is feeding the ABS unit information.
For an example that you are manipulating an external giro sensor and that some ABS units have a speed limit built in to them and that you can then manipulate the wheelspeed sensors to be able to have the ABS unit to work in higher speeds in real life than the ABS unit thinks it is going for an example.
But this i really tricky stuff because you will run in to ha whole can of worms of other things that will happen.
But if you are and advance electronic engineer and software engineer to be able to manufacture your own pcb boards and software programs then you are looking the wrong directions as you would be a great catch for a lot of big automotive companies.

And well I'm quite good at English as I write and speak that almost every day in my work, might have some typos and the auto correct changing the words some times on the phone but thats life. Don't have time to read and correct everything I write all the time but I think the message are there if your read between the lines a bit.

What you can to is as I said to disconnect one wheelspeed sensor and everything works as normal except you will not have the ABS unit working, ABS, ESP and the Q2 disable and you will have the telltale in the dash. But the DNA will work as normal.
Connect it and the telltale will dissappear after you start rolling with the car. But you will have a faultcode in the system as pending and you can remove it if you have some OBD reader that can remove it. But the system will work as I have done this many times for various reasons.

The thing is also if you have an LSD diff that one works a bit differently and can because of different discs, ramps and preload give you different amount of slip with different amount of torque load in the diff. And then the Q2 system can go in and work but then I would say that the LSD is not working that good.
With the Wavetrac this will not happen.

But I wanna give you for trying and I will be happy to hear your conclusion in the end.
Its mindsets like your that changes things and I like that alot and I'm exactly the same. But just in this case I would not put my energy as I have been working with this to much already.
If you wanna change how it works the buy a proper race ABS unit instead and then the Q2 system is gone and you can program the slip on the ABS and ESP.
 

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Discussion Starter · #31 ·
No, you should be able to just give the same wheel sensor feedback to both wheels sensor wiring inputs. It’s not complicated. Q2 gets involved when it sees different wheel speeds.
The Wavetrac has to rotate cams to lock. That means there’s travel that has to be completed. That means it’s not instant. That time delay will vary depending on speed and load. There is every chance the Q2 could get involved before, during or after the Wavetrac locks IF the Q2 allows it to lock.
English is a very nuanced language. Context, tone and inference are often beyond those who speak it as a foreign language. Translation apps don’t work well either in this regard.
 

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Discussion Starter · #32 ·
Good luck @FLORO, I think that @Niklas is correct when he says you are going to run into trouble with the ABS logic.
That's rather tricky to achieve (disabling Q2 by feeding dummy speed signals) without running into problems with the ABS and possibly the ESP as these systems are all integrated.
I admire your tenacity to want to have the Q2 disabled in all modes - it must be achievable. I think the answer may lay in the software rather than interrupting hardware signals, and that is waaay above my pay grade.
There are plenty of dedicated track cars that remove the ABS module altogether, or replace it with a proper track system where the braking bias can be adjusted.
One way to test if the ESP/ABS/Q2 is really interfering with your diff would be to pull the fuse on the ABS and test drive it (I haven't tried this and you may find that the Alfa Technicians may prevent you from using Dynamic and Race modes, so this may not work). If it does work, placing a switch in that circuit should allow you to have it enabled for road use and disabled for the track.
You may well be able to drive faster without the ESP/ABS/Q2 being available with your Wavetrac diff, but you will also be without the nannies to step in and try to save you if you over-cook it. That's probably not an issue for a pro driver, as long as the risk/reward factor is understood.
Cheers,
Alf.
ABS and ASR are a price worth paying. I hate both.
 

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ABS and ASR are a price worth paying. I hate both.
Drivers aids are for softies, real drivers don't need them.... until they need them.
When you have finished modifying your 4C, you will have to put a warning sticker somewhere on the dash that's reads "Caution-this 4C can bite" so that nobody mistakes your car for one of those standard softcore 4C's. Keep us posted on developments - we used to rely on @Call me Al for this sort of fun.
Cheers,
Alf.
 

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Discussion Starter · #34 ·
Drivers aids are for softies, real drivers don't need them.... until they need them.
When you have finished modifying your 4C, you will have to put a warning sticker somewhere on the dash that's reads "Caution-this 4C can bite" so that nobody mistakes your car for one of those standard softcore 4C's. Keep us posted on developments - we used to rely on @Call me Al for this sort of fun.
Cheers,
Alf.
Will do. I mean about the sticker :)
 

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I like what you are doing @FLORO - the group gains knowledge from people like you that are willing to challenge what is accepted as the norm and push the boundaries of what is possible with these cars. :)
 
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Discussion Starter · #36 ·
I like what you are doing @FLORO - the group gains knowledge from people like you that are willing to challenge what is accepted as the norm and push the boundaries of what is possible with these cars. :)
Thats me. I may succeed and blaze a trail but I might fall flat on my face. Either way, I’m sure it will be entertaining :)
 
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