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Over the years I have really only ever had problems with side gears or pinion gears never crown wheels and pinions, THE RDU has no side gears/pinion gears, I doubt there is going to be many problems, the crown wheel and pinion will be fine. The clutches will be fine up to a point then will slip but I doubt they will explode or anything like that, they have ben using clutches in auto trans for years, his tech will be fine, so much hearsay, I call bulls!t.
 
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The only problem I have with this is the 3-4 page arguments over a Spool vs Diff and how it went no where( I think I enlightened many on what a spool actually was). Many people refer to the rear end as a diff, this is common in the automotive industry. From and engineer though, that is kind of a tough one as you should be emphasizing the differences of the RDU compare to other systems especially working for FP.
I wouldn't have a problem with it if he made an offhand comment like "yeah we changed the floor pan for the diff" but when he's actually talking about the specific part he should know what the darn thing is called. It's like saying the turbocharger has a flaw but calling it a supercharger.
 
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Damn, all these Ford Performance (Mazda) and GKN employees (NASIOC) posting everywhere but here, lucky competitor's car forums get all the people that designed the Focus RS's tech. Someone go check on the Golf R forums to see if Raj Nair is there talking down the RS.
 

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30+ passes at the track with 400whp and on a full set of drag radials with no issues yet. We have been even launching it in drift mode from time to time which is near full rear lock and again no issues. Car has been making that power for almost a month now.

If the rear diff is going to break, we are going to be the ones that break it. Remember the rear diff is only being used if there is wheel speed error so the transmission is taking the brunt of the torque. The RDU always has an initial pressure lock and then tapers off as it reads multiple inputs and realizes it is not needed. It is a reactionary system, so it is only being used when it needs to be.

Also, I work for the company that makes the O-rings that go into the rear differential. I also am contracted by the company that supplies the aluminum for the casting to point and say "uh huh, yes right there". So, I know a few things... Also, I go to the Ford dealership sometimes and they know me by name.

:)
 

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30+ passes at the track with 400whp and on a full set of drag radials with no issues yet. We have been even launching it in drift mode from time to time which is near full rear lock and again no issues. Car has been making that power for almost a month now.

If the rear diff is going to break, we are going to be the ones that break it. Remember the rear diff is only being used if there is wheel speed error so the transmission is taking the brunt of the torque. The RDU always has an initial pressure lock and then tapers off as it reads multiple inputs and realizes it is not needed. It is a reactionary system, so it is only being used when it needs to be.

Also, I work for the company that makes the O-rings that go into the rear differential. I also am contracted by the company that supplies the aluminum for the casting to point and say "uh huh, yes right there". So, I know a few things... Also, I go to the Ford dealership sometimes and they know me by name.

:)
Sorry if I missed it in the other thread, but what are the mods on the 395/380 car? Filter + WG + BPV + E30? Stock turbo?
 

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Remember the rear diff is only being used if there is wheel speed error so the transmission is taking the brunt of the torque. The RDU always has an initial pressure lock and then tapers off as it reads multiple inputs and realizes it is not needed. It is a reactionary system, so it is only being used when it needs to be
For the 62nd time, differential throttle inputs trigger the AWD, there doesn't have to be wheel speed error. And again, it's not reactionary, since it doesn't NEED wheelspin to activate. The car CAN, WILL, and DOES send tq to the rear end under conditions that would never induce wheelspeed error (e.g., 20% throttle in 4th gear). Also, even in cruising there's a small amount of tq being provided to the rear end. The only time I see zeroes for pressure is off throttle out of gear. Unfortunately I don't have my 3-4th gear low throttle trace on this computer, but here's 3rd gear WOT from a roll. No chance of wheel spin. The 3-4th is showing similar things.

sport.PNG

You can see there's tq commanded and applied at the rear end even where wheel slip would not occur. The diff is being used 90% of the time, even if it's under low load. It's not only triggered with wheelspin, and it's definitely not reactive. It's proactive.
 

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For the 62nd time, differential throttle inputs trigger the AWD, there doesn't have to be wheel speed error. And again, it's not reactionary, since it doesn't NEED wheelspin to activate. The car CAN, WILL, and DOES send tq to the rear end under conditions that would never induce wheelspeed error (e.g., 20% throttle in 4th gear). Also, even in cruising there's a small amount of tq being provided to the rear end. The only time I see zeroes for pressure is off throttle out of gear. Unfortunately I don't have my 3-4th gear low throttle trace on this computer, but here's 3rd gear WOT from a roll. No chance of wheel spin. The 3-4th is showing similar things.

View attachment 45546

You can see there's tq commanded and applied at the rear end even where wheel slip would not occur. The diff is being used 90% of the time, even if it's under low load. It's not only triggered with wheelspin, and it's definitely not reactive. It's proactive.
My MPG's agree with your statement that the AWD is constantly under some torque, even when cruising and low throttle. :)

I believe I recall that the only time it will completely 'disengage' is under constant throttle, going absolutely straight, for an extended period of time.
 

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For the 62nd time, differential throttle inputs trigger the AWD, there doesn't have to be wheel speed error. And again, it's not reactionary, since it doesn't NEED wheelspin to activate. The car CAN, WILL, and DOES send tq to the rear end under conditions that would never induce wheelspeed error (e.g., 20% throttle in 4th gear). Also, even in cruising there's a small amount of tq being provided to the rear end. The only time I see zeroes for pressure is off throttle out of gear. Unfortunately I don't have my 3-4th gear low throttle trace on this computer, but here's 3rd gear WOT from a roll. No chance of wheel spin. The 3-4th is showing similar things.

View attachment 45546

You can see there's tq commanded and applied at the rear end even where wheel slip would not occur. The diff is being used 90% of the time, even if it's under low load. It's not only triggered with wheelspin, and it's definitely not reactive. It's proactive.
Have you done any dataloging during LC? I'm waiting for my OBD cable to test it myself. I'm wondering how much lock the clutches see, I seem to get front tire spin no matter what mode or variation of settings I use. My experience with AWD tells me this system heavily neuters RDU power at launch.
 

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Have you done any dataloging during LC? I'm waiting for my OBD cable to test it myself. I'm wondering how much lock the clutches see, I seem to get front tire spin no matter what mode or variation of settings I use. My experience with AWD tells me this system heavily neuters RDU power at launch.
I'd agree with that, but in the FSM, it even states engine power is limited in 1st and second, likely since you've got a 3.231 GR with a 4.06 FD; that makes for some nasty Tq multiplication in the lower gears.

I experience lots of wheelspin on a LC parented launch, but when I manually do it, I see much less. It feels quicker. but I have no data to back it.
 

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For the 62nd time, differential throttle inputs trigger the AWD, there doesn't have to be wheel speed error. And again, it's not reactionary, since it doesn't NEED wheelspin to activate. The car CAN, WILL, and DOES send tq to the rear end under conditions that would never induce wheelspeed error (e.g., 20% throttle in 4th gear). Also, even in cruising there's a small amount of tq being provided to the rear end. The only time I see zeroes for pressure is off throttle out of gear. Unfortunately I don't have my 3-4th gear low throttle trace on this computer, but here's 3rd gear WOT from a roll. No chance of wheel spin. The 3-4th is showing similar things.

View attachment 45546

You can see there's tq commanded and applied at the rear end even where wheel slip would not occur. The diff is being used 90% of the time, even if it's under low load. It's not only triggered with wheelspin, and it's definitely not reactive. It's proactive.

@Cam wins argument by using Science!!!! +1 Cam
 

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Adam and I have "chatted" about this before lol. It's because engineers and calibrators just cant get along EVER :)
We are working on a custom tune at high altitude for 91 and e30 tune. The Cobb OTS tune is pulling a lot of throttle to prevent overboost. I should have my tuner hit you up.
 

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Please log launching and see which conditions are better for launching, sport, track or drift?

I haven't done any crazy testing like that. Theoretically 100% (minus tq loss on driveshaft) COULD be transferred to the rear if the front tires were slipping and creating no load.
 
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My MPG's agree with your statement that the AWD is constantly under some torque, even when cruising and low throttle. :)

I believe I recall that the only time it will completely 'disengage' is under constant throttle, going absolutely straight, for an extended period of time.
Could be nice if there was a 'Comfort' mode you could put the car in that would prevent the rear from engaging unless slip was detected. Would be good for highway cruises. Maybe the MPG benefit of a mode like this is so minimal as to not be worth the programming time.
 

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Sorry if I missed it in the other thread, but what are the mods on the 395/380 car? Filter + WG + BPV + E30? Stock turbo?
See below

I believe it's the W400 package he sells.. With e30 tune.
Exactly.

For the 62nd time, differential throttle inputs trigger the AWD, there doesn't have to be wheel speed error. And again, it's not reactionary, since it doesn't NEED wheelspin to activate. The car CAN, WILL, and DOES send tq to the rear end under conditions that would never induce wheelspeed error (e.g., 20% throttle in 4th gear). Also, even in cruising there's a small amount of tq being provided to the rear end. The only time I see zeroes for pressure is off throttle out of gear. Unfortunately I don't have my 3-4th gear low throttle trace on this computer, but here's 3rd gear WOT from a roll. No chance of wheel spin. The 3-4th is showing similar things.

View attachment 45546

You can see there's tq commanded and applied at the rear end even where wheel slip would not occur. The diff is being used 90% of the time, even if it's under low load. It's not only triggered with wheelspin, and it's definitely not reactive. It's proactive.
Forehead + Palm. I can't understand why you keep reading what I type in a different context?

Here is what I posted:

If the rear diff is going to break, we are going to be the ones that break it. Remember the rear diff is only being used if there is wheel speed error so the transmission is taking the brunt of the torque. The RDU always has an initial pressure lock and then tapers off as it reads multiple inputs and realizes it is not needed. It is a reactionary system, so it is only being used when it needs to be.
Not needed as in "not full clamp load"

It is reactionary in every sense, if you have a different meaning then so be it. Like I said above the RDU always has initial pressure lock (due to throttle input/torque request) then tapers off (unloads, depressurizes) when it makes it's checks and sees that full torque/clamp load is not needed. If full clamp load is needed and the rear needs to assist it will continue to supply pressure and increase torque capacity/reduce slip.

In no case is full torque being applied to the rear wheels as mentioned, again there is initial lock as it needs to prepare for torque to come on, it would eat it's own face if it tried to clamp once the front wheels are spinning so there is ALWAYS going to be clamp load with throttle input but if it stays driven depends on multiple things including wheel speed error.
 
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