The ultimate differential thread

I believe actually there was some mechanical limitations using race compound tires hence the e diff removal and using a traditional lsd for challenge cars

It doesnt allow enough slip and damages the e diff somehow

 

I added a quaife mechanical to the front of my AWD explorer which already had a LSD rear. Made parking harder at slow speeds but great traction improvement in wet/snow.

 

First off, there are not THAT many cars out there with an E-diff bypass. By far more with an E-diff, and there are also more horribly maintained cars and cars with the dash peeling up, seats worn out with bad paint jobs but a functional E-diff. I think you are under the impression that the only people who have an E-diff delete means the e-diff was broken. I can assure you that is not always the case, my E-diff was 100% fully functional, and still is if I wanted it to be, but I chose to bypass it.

I am in the automotive and racing business, however I am not the expert here on the E-diff system, nor does it sound like you are.

This has got to be a joke? Now you lost all credibility to me.... The last time you drove a little over the speed limit, did you drive to the nearest police station and turn yourself in for the crime you committed?

My car is used for street driving. There is no question a functional E-Diff is better for track use, especially if faster lap times are what you are after. But then again no regular street F430 is in any real racing anyway. Also, unless you are driving very aggressive on the street would you even need the E-diff to come in and notice it.. But again, if driving that way on the street, you would likely want to contact your insurance company and tell them how you were driving so they would likely drop your coverage, am I right?

If I was to ever sell my car, which I am not, I could simply remove my bypass and have a fully functional E-diff if the new owner wanted.

 

Deciding to do an E-Diff delete on a fully functional F430 just doesn't make sense. What are you trying to gain?

I am not in the minority here, I am yet to discover a single experienced automotive industry engineer or Ferrari master tech that thinks its a good idea, not one. Go and ask a Ferrari main dealer if they would do it for you and what the implications would be. Why would you ever want to do that? I guarantee the vast majority of the E-Diff delete cars are because of issues or kludges, if your E-Diff really is functional and you delete it you really are in the minority and I still (genuinely) question why you would want to do that.

There is no point in getting aggressive and attacking me suggesting what I do or don't know. I am just asserting my opinion that its so very wrong to E-diff delete on an F430 (especially if not fitting an LSD to replace it), even more so if it is working correctly. I was under the assumption that no sane person would ever want to delete it unless they faced bills to repair in and decided to botch it before selling it on.

As for the insurance question. I am deadly serious. All modifications to the software on the car which impact performance or safety, including tuning, gated conversions, E-diff deletion, immobilizer and so forth must be declared on the policy. If you have not done so your committing insurance fraud if you knowingly don't declare it and at worst your leaving yourself liable to huge compensation claims if it was discovered in an accident investigation. An E-Diff bypass box behind the seats would be a dead giveaway to an investigator if the case was big enough to warrant a deep investigation (e.g. deaths occurred because the car slid out of control).

 

Why the E-diff is a FANTASTIC addition to the F430 and WHY you should keep it!

In combination with Bosch, Ferrari developed their interpretation of an Electronic Differential and even went as far as getting input to tuning the system from their Formula 1 drivers at the time. It was a big thing for them with a lot of R&D invested and they where very proud of it. It was a pretty advanced system at the time of launch and continuously monitored many of the vehicle's performance factors through a raft of sensors and computers, including:

Bosch ABS Wheel speed sensors : Detecting the speed of each rear wheel.
Bosch Steering Angle sensor : Determining the steering wheel position.
Bosch Yaw rate sensor : Measuring the vehicle's rotation around its vertical axis.
Bosch Lateral acceleration sensor : Detecting the sideways acceleration of the vehicle.
Bosch Motronic Engine management : Providing information about engines current torque, speed and acceleration.

These inputs are processed by a dedicated E-Diff control units software, which implements sophisticated algorithms to calculate the optimal torque difference between the wheels. This torque difference is then translated into a signal sent to the differential actuator, which adjusts the clutch pressure, effectively locking or unlocking the differential. Traditional mechanical differentials distribute torque equally between wheels, regardless of traction conditions so while they can be effective they are less efficient and this difference can lead to wheelspin on the inner wheel during cornering, resulting in loss of traction and vehicle instability.
Electronic differentials offer a significant improvement by actively adjusting the torque distribution based on various dynamic parameters in real-time.

Cooperative Action:
1. Bosch Motronic Engine Management control:

The E-diff can tell the Bosch Motronic system over CAN bus to adjust engine torque to optimize traction and prevent wheelspin proactively.​

2. TCU / Gearbox:

The E-diff can take into account the gear engaged to adapt its operation.​

3. ESP / ASR / ABS / EBD Control:

• ESP (Electronic Stability Program): The E-diff can work together with ESP to enhance stability during critical situations
• ASR (Anti-Slip Regulation): The E-diff can assist ASR in preventing wheelspin and maintaining traction.
• ABS (Anti-lock Braking System): The E-diff can coordinate with ABS to ensure optimal braking performance.
• EBD (Brake Force Distribution): The E-diff can coordinate with EBD to keep maximum stability under harsh braking.

When the ABS detects a potential wheel lockup, it intervenes by rapidly modulating the hydraulic pressure to that specific wheel, preventing it from locking and maintaining traction. This helps to maintain steering control and reduces the risk of skidding. Concurrently, the E-Diff can further enhance this action by adjusting the torque distribution between the wheels.

Depending on the situation and specific control algorithm, the E-Diff may;

Reduce torque to the wheel that is about to lock:
This further assists ABS in preventing lockup and maintaining traction. Transfer more torque to the wheel with better traction:
This helps to maintain vehicle stability and forward momentum, especially during hard braking on uneven surfaces.

Apply a slight differential lock:
This can help to improve vehicle stability and control, especially while cornering under heavy braking.​

4. Shock absorber damping control:

The E-diff can interact with the shock absorber system to further enhance handling and stability.​

The combined actions offers several combined key benefits:

• Improved braking performance: Both systems work together to ensure optimal traction and minimize stopping distance, even on slippery surfaces.
• Enhanced stability and control: By preventing wheel lockup and optimizing torque distribution, both systems contribute to maintaining vehicle stability and control during hard braking and cornering.
• Reduced risk of accidents: By minimizing skidding and maintaining control, the combined action of ABS and E-Diff helps to reduce the risk of accidents.
• Increased driver confidence: Drivers can feel more confident when braking hard or cornering, knowing that both ABS and E-Diff are working to ensure their safety and control.
• Integration and Control: The ABS and E-Diff are tightly coupled with advanced algorithms that adapt the interaction based on real-time data and driving conditions. The ABS and E-Diff are powerful technologies that work independently but link together to further enhance safety and performance. By sharing information over CAN and coordinating their actions, they help to ensure optimal braking, maintain vehicle stability, and provide drivers with greater confidence behind the wheel.

Improved Performance:
By optimizing torque distribution, the E-diff significantly improves traction, especially during cornering. This leads to faster acceleration, improved handling, and shorter lap times and improve road holding.

Enhanced Directional Stability:
The E-diff helps to maintain the vehicle's intended trajectory by minimizing oversteer (improving road feel) and understeer tendencies. This results in a more predictable and stable driving experience, especially in challenging conditions.

Increased Active Safety:
By proactively adjusting torque distribution, the E-diff helps prevent loss of control and potential accidents. This is particularly important when driving at the limit of grip.

Enhanced Driving Pleasure:
The E-diff provides a more engaging and enjoyable driving experience by allowing drivers to push the vehicle harder with greater confidence.

Improved Cornering G-Forces & Reduction in unintended oversteer:
The E-diff progressively locks the differential in proportion to the lateral acceleration and vehicle speed, inducing a slight understeering behavior at the grip limit. This helps to maintain control and prevent the rear end from stepping out without warning.

Stabilization under deceleration:
When the driver lifts off the accelerator during cornering, the E-diff applies a slight lock to the rear axle, stabilizing the vehicle and preventing excessive oversteer.

Maximizing stability and acceleration:
The E-diff locks the differential in proportion to the lateral acceleration, speed, gear engaged, and engine torque, ensuring optimal stability and maximizing acceleration through corners.

Other Situations:
Straight-line acceleration: The E-diff minimizes torque loss due to wheelspin, ensuring maximum acceleration.
Low-traction surfaces: The E-diff optimizes torque distribution to the wheels with the most traction, improving handling and preventing getting stuck.

Underlying Physics:

The operation of the E-diff is based on several principles of physics:
Differential action: The differential allows the two wheels to rotate at different speeds, which is essential for smooth cornering.
Torque distribution: The E-diff adjusts the torque applied to each wheel to optimize traction and handling.
Lateral force transfer: When cornering, the vehicle's weight is transferred to the outside wheels, generating increased lateral force.
Yaw rate control: The E-diff can influence the vehicle's yaw rate by adjusting the torque distribution between the wheels.

 

... And here why I believe deleting the E-diff software on a high-horsepower car like the Ferrari F430 could be highly dangerous.

The electronic differential (E-diff) plays a crucial role in maintaining stability and safety, especially in high-performance vehicles like the Ferrari F430.
Disabling it through a software delete would significantly increase the risk of accidents and potentially lead to hazardous situations. Lets look at why this could be a problem...

1. Increased Wheelspin:
With the E-diff disabled, the car would revert to an open differential, allowing the inner and outer wheels to spin at different speeds.
This would cause excessive wheelspin, especially on the inner wheel during cornering. As the driver applies power, the unloaded inner wheel would spin freely,
losing traction and hindering cornering performance. This can lead to a loss of control and potential spin-outs, especially on slippery surfaces.

2. Oversteer and Understeer:
In high-power vehicles like the F430, managing oversteer and understeer is crucial. The E-diff helps balance power delivery between the wheels,
mitigating oversteer and understeer tendencies. Deleting the E-diff software would remove this crucial control mechanism, making the car more prone to both oversteer (rear-end stepping out) and understeer (front pushing wide) during cornering. This can be challenging to manage, especially for inexperienced drivers, and significantly increase the risk of accidents.

3. Reduced Traction and Stability:
The E-diff actively improves traction by controlling power delivery to the wheels. This is particularly crucial in high-performance cars with significant power output like the F430. Without the E-diff, the car would have reduced traction, especially during acceleration and cornering, making it more difficult to control and increasing the risk of losing grip and causing the car to spin out of control.

4. Increased Wear and Tear on Tires:
With an open differential, the tires would experience increased wear due to excessive wheelspin and uneven power distribution. This would significantly shorten the lifespan of the tires and increase maintenance costs.

5. Reduced Performance:
The E-diff optimizes power delivery to the wheels, improving overall car performance, especially during cornering and acceleration. Deleting the E-diff would negatively impact the car's handling, responsiveness, and overall performance.

6. Specific Dangers for the Ferrari F430:
Considering the F430's 490hp horsepower and rear-wheel drive configuration, the risks associated with disabling the E-diff are even greater.
The car's high power output combined with an open differential could lead to:

7. Sudden and unpredictable oversteer:
The car's rear end could unexpectedly step out during cornering, especially under acceleration, making it difficult to control and potentially causing the car to spin out.

8. Loss of control:
The lack of traction and stability control would make the car more prone to losing control, especially on slippery surfaces or during sudden maneuvers.
Increased risk of accidents: The combination of high power, reduced control, and unpredictable behavior significantly increases the risk of accidents, especially in the hands of inexperienced drivers.


I therefore believe that deleting the E-diff software on a high-performance car like the Ferrari F430 would be a dangerous and potentially hazardous modification.

The increased risks of wheelspin, oversteer, understeer, reduced traction, and instability significantly outweigh any perceived benefits and could lead to serious accidents. In my humble opinion its therefore crucial to maintain the E-diff functionality for safe and optimal performance of the car and other members of the public who just happen to be around when you decide to floor it!

Still want to do it?

 

This is laughable! I just realized you are not in the USA, so not sure how things work in your country, but apparently it is very different from here. I did not read any of your long posts above and I won't because you seem to not know how to handle driving a car with any electronic nannies, so we are very different people.

 

I'll add a section in my upcoming book on Bosch Motronic on the interaction with E-Diff..

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As for 'not knowing how to drive'. How can you ascertain my ability to drive from reading at best a couple of posts? Talk about jumping to assumptions.

Yes I still have (an expired) National B racing license from when I had more time. Back in the 90's I raced an old TRD2000GT Racing MR2 turbo with 504hp Rwd, 1.5 way mechanical LSD , NO ABS, no TC, no nothing and it was absolutely lethal but good fun! I've raced the Nürburgring in Germany using my 360 back in the day and more recently took my McLaren 12C to Portimão F1 circuit in Portugal on open pit lane getting a track time close to the McLaren P1 driven by Chris Harris back in the day (and my car at the time was relatively stock).

Here's what it looks like now, its now boasting Genuine uber rare Factory carbon bodied McLaren parts which I'm soon to be upgrading with Hybrid Electric turbos and circa 800rwhp with "Instant" torque.
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And yes... I'm keeping the E-Diff thanks very much!

 

Still think its "Laughable" ? Read more about the laws in your country;

Consider that since 2006 in USA the law stipulated use the of EDR (Event Data Recorder) in all production vehicles so most F430 will have one (by law).
https://en.wikipedia.org/wiki/Event_data_recorder

Its a legal mandatory requirement and this actually only came into legal force in EU since 2023, so US is ahead of the RoW with regards to logging. From the logged data it would be easy to see if your E-Diff was bypassed because the car would behave very differently and that alone could warrant enough to dig deeper.

 

You win, I refuse to read any of these long bragging posts of yours thinking you know what you are talking about. But my statement still stands, have you yet to go to the police department to ask for a speeding ticket the last time you went over the speed limit since you live very by the book it seems. I honestly think you should turn yourself in, as you know, speeding is against the law.

 

Bragging posts? Oh dear...

If you haven't already figured it out yet there is a lot of valuable information contained within.
Choose to ignore it or not. If you don't want to be informed by all means live in denial but don't say you where not informed.

And it is not going to be you turning yourself in, its your car... Happy Holiday's!

 

....so... switching gears ; just out of curiosity, how can you "upgrade" the E-diff to a mechanical LSD (used in F430 Challenge). Are they available for sale ?

 

They just carried over from the 360...

 

Trev has added a wealth of knowledge to the community, many times for free, and also helped many members for hours and hours, again, many times for free. He has pioneered well respected tunes for many cars and continues to help develop many knew products for the platforms that we all enjoy. Why hate on someone like that? What do you bring to the community? I know I don't bring much if anything at all, other than asking lots of questions. I don't think any of us take his posts as bragging. He was attacked and had to defend himself after you told him he couldn't drive. I think what he mostly posts is just knowledge and opinions shared on an open form like we all do. Even if you don't agree.

On another note, this entire thread has been an interesting read. Thanks for the info everyone and I'm glad I don't have to worry about having an e-diff or not because my car never had one! Haha.

 

Trev where was that article posted and can I get a copy?

 

Please don't throw the word "hate" in there. Hate is a very strong word, and because I am disagreeing with him, does not mean I have any hate to him. Like many things in this world, no matter how good or bad you are, not everyone will agree with you, not everyone agrees on everything, and we are all free to express that.

I still do disagree on the fact that not all E-diff bypass'd cars have E-diff problems, and modifying your car does not need to be reported to your insurance company, and that driving without a limited slip or electronic locking or hydraulic diff like the E-diff is a death wish! If you disagree with my statements, that is ok, like I said, we all cannot agree on everything.

 

Exactly why I did it...

 

1. Quote, "I still do disagree on the fact that not all E-diff bypass'd cars have E-diff problems".
A. I never said ALL but I strongly suspect most have been done because of issues such as botched gated conversions. I was speaking to someone that had done a gated conversion just yesterday evening that 'surprise surprise' had been re-flashed with the incompatible firmware for his car (cross flashed) and it had broken his e-diff within 250 miles. He didn't want to get rid but felt compelled to. This was just because of bad advice. I'm going to help him re-flash his car properly with the correct software for his car (compatible) and get his e-diff working for him.

2. Quote, "... and modifying your car does not need to be reported to your insurance company".
A. I know its not the most interesting reading but review your car insurance policy documentation. I again believe your advice here is against the contract and will inevitably lead to them having the ability to void your contract if they so wish.

3. Quote, "... and that driving without a limited slip or electronic locking or hydraulic diff like the E-diff is a death wish!".
A. Again nobody said it was a death wish, many cars from earlier period had no ABS, no TC, no ESP, no seatbelts, airbags, crumple zones, ziltch. People still survived. The difference is most never had circa 500 bhp through the rear wheels either and most people these days have grown up used to the car ecus 'flattering' their poor driving techniques. I would strongly suggest for the majority of people its a bad idea.

4. Quote, "... If you disagree with my statements, that is ok, like I said, we all cannot agree on everything."
Here here. I fully agree with this one.

 

This is not really a technical compromise that I would personally make but each to their own. I just could not justify deleting a working E-Diff (millions in R&D right here) and IMHO an integral part of the F430 "experience", just so I could run 'blingy' rims.

In fact there are plenty of alloys/rims that run the same rolling radius as the factory so if you want a different style to be individual its still possible, just make sure they are either the same weight or lighter to ensure factory performance is maintained. Again, the same thing for tires. Don't fit heavier tires at the compromise of performance, its something many people forget about and the weight differential can be considerable between brands.

If all you want is plus sized rims (regardless of additional rotating mass it may bring and therefore even worse handling characteristics, worst stopping distances, etc.), like I said this can be re-calibrated for without disabling the entire system. You just have to have someone do it who really knows what they are doing.

 

Having spent considerable track time in my McLaren, which has one of the best E-Diff calibrations in the road car business, especially for track use that I've experienced, I'd say almost everyone, from Novice to Pro driver will benefit from the E-Diff. The car will feel more stable at high speeds, it will corner better and it will understeer and oversteer less making any car with 500+ hp more useable in all situations, particularly if the car is used its was intended. The data log traces show these improvements are considerable and pretty much you gain time "everywhere", its not hearsay, its provable.

I think its quite different of a debate to F1 vs Gated, as its not to say that a mechanical LSD is less "fun", its just going to be slower and less confidence inspiring for the vast majority of drivers. My 360 which is pretty much as close to a "race car for the road" as you can take it without loosing road use, is an absolute blast on the public roads and tracks - with a good old fashioned LSD. Of course it is slower than if it was fitted with an E-Diff but that does not in any way make it less "fun".

As with every innovation, you gain something and loose 'something'. It does inevitably make a car easier to drive and some people let this go to their head, until they get into a track prepped car that has no driving aids at all and spin it on the first corner. The biggest complaint pro racing drivers have is 'inconsistency' when the system is working or transitioning between modes, or adjusting its behavior - most people cannot even perceive this. Its something that has got better with each new iteration of software modelling of the underlying physics modelling.

The majority of people will be faster and more stable in all circumstances with an E-Diff vs a mechanical LSD for the follow summarized reasons;

• Adaptive Grip: Unlike a mechanical LSD, which applies a fixed amount of lock regardless of conditions, an E-Diff can adjust the amount of torque transfer which allows for a more dynamic and responsive handling experience, especially in slippery conditions or during cornering.
• Smooth and Predictable: E-Diff works seamlessly, unlike mechanical LSDs that can be jerky and unpredictable.
• No More Wheelspin: E-Diff prevents wheels from spinning, especially on slippery surfaces or during hard acceleration.
• Stay Stable: E-Diff helps keep your car stable in sudden maneuvers and on uneven roads.
• Less Wear and Tear: E-Diff engages only when needed, saving wear and tear on your drivetrain, making your car more fuel efficient too.
• Safety First: E-Diff works with other safety features like traction control, ensuring your safety.
• Drive Mode Flexibility: E-Diff offers different driving modes for various conditions like racing or wet roads.
• Works Seamlessly: E-Diff integrates smoothly with other car systems for optimal performance.

I think this E-Diff deleting will always be a 'fringe' thing to even contemplate but nonetheless there are many unintended consequences of trying to remove or trick the software in this "hacky" way.

Its a bit like these "o2 extenders" you can buy, in my opinion they are just a plain headache, they give the illusion of working until they don't - too many edge cases where they just won't pass the conditions to trick the CEL from illuminating. They work on some MY cars only because early cars had the diagnostics turned off anyway! Just do it properly in the calibration within the ecu rather than try to trick the software externally.

And to add another recently discussed, trying to 'fool' the Engine Management to thinking your driving in F1 mode when the car is gated converted. This is done by simply by nothing more fancy than playing back TCU CAN messages. This really is a disaster waiting to happen. If you actually understand how the Bosch Engine management really works (that is you've spent years reverse engineering the code) you just wouldn't even contemplate doing it. It could actually lead to catastrophic engine failure as the engine management does a lot more to protect the driver of a manual shifted engine than when a robot with hydraulics is shifting - try to fake it and you loose all those protections. Its a disaster waiting to happen. Again just do it properly first time around. Flash the damn ecu's!

I think the E-diff bypass is in the same camp as these things. By all means spend some time to reverse engineer the firmware, understand the algorithms, improve them and add new sensors, etc. for better modelling but just deleting it and leaving it open diff is just 'ahhhhhhhg'... Hack, chop, hack. Why not just put a black sticker over your CEL light... ? This is just the digital equivalent in my mind.

There is no reason why you should do a delete of the E-Diff if your doing a gated conversion properly in the first place. This is essentially just a hack. As I mentioned earlier I am seeing more of these issue related to people "cross flashing" the wrong incompatible software onto the cars, either as part of tuning where the tuner doesn't really understand Ferrari's properly or is lazy to use a "single file" tune - with the aforementioned consequences or because they have flashed the wrong software for the car as part of conversion to gated. "Well we think it works, sort of", then 250 miles later "E-diff failure" pops up after diagnostics checks have kicked in. As you can tell, I just don't like hacks like this. Do things properly or be doomed to repeat again and again or create 'lemon' cars with 20+ owners who give up after typically trying to spend their way out of the problem and getting nowhere fast.

 

This is where you and I will again disagree, because my car has never been considered "blingy" because I wanted to upsize and run 20" wheels all round. But again, your opinion is just that, it is your opinion and not not anyone else's. Just like I don't like the look of other sizes out there, I am not going to start to name call that style if people like that. Some people don't think before they talk, then wonder why on earth people can disagree or get upset with them....