TTS WHICH QUATTRO SYSTEM?
02-09-2018, 09:21 AM
#21
So, I don't so much care about the loss of control since I'm thrashing my car more than 90% of drivers. I did name my car Lt. Drifts for a reason as the rear gets out like crazy sometimes. But thats ok! The issue im more speaking to is for tighter corners theres a cut in power and that absolutely ruins the performance experience. Especially when compared to the MX5 which i'm aware is a totally different car. Second if I leave it in sport mode and floor it, at most any speed, it downshifts but NOT enough. There is always another gear I could have safely downshifted if I was in manual mode. I've tested it out multiple times. Sport mode will not downshift as much as it can, even safely, when pushed to the floor.
02-10-2018, 10:16 PM
#22
AudiWorld Member
I think it is incorrect to say that torque is “diverted” to the rear. The front axles are always 100% engaged! Torque is not “diverted” from the front to the rear as the Haldex unit engages the rear axles. It takes a Torsen system to do that. No?
Last edited by Jeffc; 02-10-2018 at 11:04 PM.
02-11-2018, 05:10 AM
#23
AudiWorld Super User
It wasn't my quote guys. See link in original post. I agree that it can't be 100% to the rears.
02-11-2018, 07:37 AM
#24
So I suppose there's no way of saying this without sounding like a crybaby but that seems like an awfully lot of work and brain power to get a transmission to do what it should in a sport car. I would expect that manner of computing to be on a Hyundai not a $63,000 Audi. But I suppose this is a perfect example of why car men and women prefer manuals to automatics. Curious though how much you have to spend on a car to get a transmission that shifts like it should. And I don't mean that as an insult but I can't imagine that transmission Behavior would be tolerated with a Lamborghini.
02-11-2018, 08:23 AM
#25
AudiWorld Member
My point is that the front axles are always 100% engaged, but by using the word divert Audi makes it appear that torque can be removed from the front as it is added to the rear. The Haldex system cannot do that. This wouldn’t have changed my decision to purchase the TTS, but it was a surprising revelation after the fact.
02-11-2018, 08:51 AM
#26
My point is that the front axles are always 100% engaged, but by using the word divert Audi makes it appear that torque can be removed from the front as it is added to the rear. The Haldex system cannot do that. This wouldn’t have changed my decision to purchase the TTS, but it was a surprising revelation after the fact.
I loved me some oversteer back when I had a 370z, but I feel like that's sort of like longing for what's technically an unstable driving condition. I've never done racing/track though and I'm sure that would change my tune a bit...
02-11-2018, 05:06 PM
#27
Guys, torque is FORCE. There can be no torque applied to a wheel with zero traction. Regardless of whether it is being driven to rotate. Haldex can have up to 100% torque at either axle since the clutches have them locked together. Torsen applies more force or torque to the rear due to the unequal ratio split of the front and rear output drives. BUT with Torsen a traction loss at one axle causes the Torsen to bind up and direct torque to the other. Even so though, Torsen cannot send 100% to either end. Each has its advantages. I have seen TTs strip the splines in a front CV joint and continue to drive almost normally because the Haldex engages and drives the car via the rear axle. The clue that this has happened is that engine rpm drops to idle when you brake because the Haldex disengages. If you had this happen on a Torsen Car, It would not move. At least not well.
03-22-2018, 03:59 PM
#28
AudiWorld Senior Member
Haldex can have up to 100% torque at either axle since the clutches have them locked together. Torsen applies more force or torque to the rear due to the unequal ratio split of the front and rear output drives. BUT with Torsen a traction loss at one axle causes the Torsen to bind up and direct torque to the other. Even so though, Torsen cannot send 100% to either end. Each has its advantages. I have seen TTs strip the splines in a front CV joint and continue to drive almost normally because the Haldex engages and drives the car via the rear axle. The clue that this has happened is that engine rpm drops to idle when you brake because the Haldex disengages. If you had this happen on a Torsen Car, It would not move. At least not well.
So if I understand correctly, front/rear torque ratio is always the same as the front/rear grip ratio, correct?
Last edited by Yoshimura; 03-22-2018 at 04:01 PM.
03-22-2018, 04:06 PM
#29
AudiWorld Senior Member
So Haldex can only send 100% of the torque to a particular axel only if the other axel has zero adhesion, right? And in this situation, both axel will spin a the same speed. In fact, they always spin a the same speed when they are locked together, right? When both axel have the same amount of adhesion, torque will be distributed 50/50, right?
So if I understand correctly, front/rear torque ratio is always the same as the front/rear grip ratio, correct?
So if I understand correctly, front/rear torque ratio is always the same as the front/rear grip ratio, correct?