FYI Only: Quattro IV, EDL, Torsen, and Haldex
01-25-2000, 04:22 AM
#22
Guest
Posts: n/a
Disadvantage of the center torsen is a racing situation.
Picture a car plowing the front end through a tight, high speed turn. The Torsen will try to send the torque to the front wheels since they will be spinning more slowly than the rears. Unfortunately, this is the opposite of what's needed in the situation. Sending more torque to the front will just aggravate the understeer situation.
If anyone is in the Massachusetts today, it's a perfect time to go test this at slower speeds.
If anyone is in the Massachusetts today, it's a perfect time to go test this at slower speeds.
01-25-2000, 06:57 AM
#26
Guest
Posts: n/a
Re: They're using quattro IV in the Motorola Cup cars.
Yes, this is true.
First of all, I was referring to the Touring Series where Audi takes the "Unfair Advantage" slogan from and attachs it to their street cars. There are no real similarities between the two - drivetrain, front/rear suspension, and even the engine. This is Audi's marketing department at work.
Also, the Motorola Cup, by definition, has OE restrictions which do not allow for one-off's, specials, or customs. Hell, they race Hyundais, Civics. With the likes of BWM, Chevrolet, Porsche and Lexus teams, rest assured that this slogan will not be reused.
Regards,
Bob
96 A4QM
86 4KCSQM
First of all, I was referring to the Touring Series where Audi takes the "Unfair Advantage" slogan from and attachs it to their street cars. There are no real similarities between the two - drivetrain, front/rear suspension, and even the engine. This is Audi's marketing department at work.
Also, the Motorola Cup, by definition, has OE restrictions which do not allow for one-off's, specials, or customs. Hell, they race Hyundais, Civics. With the likes of BWM, Chevrolet, Porsche and Lexus teams, rest assured that this slogan will not be reused.
Regards,
Bob
96 A4QM
86 4KCSQM
01-25-2000, 07:35 AM
#28
Guest
Posts: n/a
Strongly disagree: "Torsen bite" is a worthless myth...
I saw this tripe on the Qlist. This is not a personal issue between us, I just want to squelch this rumor. The dynamics of racing, as well as reality keep it from happening.
First, Bob is exactly right, easy as pie to fix by altering the lock up rates/ratio (not the same but ok for this disc.). No competent engineer would ever be caught by this.
Second, a good portion of this group track/autocross races under many different conditions, NOBODY has ever complained about it here. The qlist is infected with people with gen1-3 q's overcompensating by saying that the gen4 q is somehow dangerous. I have both a 4000q and a A4 and have never had a problem with either in any condition. They do drive differently.
Third, the reason why it doesn't happen is that the weight transfer coming out of the corner is either nearly neutral (with race springs) or on the rear tires (stock springs). Torsen transfer to the end with MORE traction, in this case the rear, (never the front). If your weight is on the front you will oversteer to the outside IN ANY CAR.
Torsen by DEFINITION is not rotationally sensitive (as is the Viscous Coupling design), so it doesn't matter what the F:R differential speed is, just torque.
First, Bob is exactly right, easy as pie to fix by altering the lock up rates/ratio (not the same but ok for this disc.). No competent engineer would ever be caught by this.
Second, a good portion of this group track/autocross races under many different conditions, NOBODY has ever complained about it here. The qlist is infected with people with gen1-3 q's overcompensating by saying that the gen4 q is somehow dangerous. I have both a 4000q and a A4 and have never had a problem with either in any condition. They do drive differently.
Third, the reason why it doesn't happen is that the weight transfer coming out of the corner is either nearly neutral (with race springs) or on the rear tires (stock springs). Torsen transfer to the end with MORE traction, in this case the rear, (never the front). If your weight is on the front you will oversteer to the outside IN ANY CAR.
Torsen by DEFINITION is not rotationally sensitive (as is the Viscous Coupling design), so it doesn't matter what the F:R differential speed is, just torque.
01-25-2000, 08:00 AM
#30
Guest
Posts: n/a
Re: No arguments here, but edl info added...
> The edl speed cutoff that you describe (accurately)
> as a safety feature is not to be misconstured as a negative
True, it's part of an off-the-shelf traction control program. It works, it's a known quality, other manufactures use this cut-off speed, so why not stick with it. Why re-engineer, test and open yourself to liability issues. Agreed.
Regards,
Bob
96 A4QM
86 4KCSQM
> as a safety feature is not to be misconstured as a negative
True, it's part of an off-the-shelf traction control program. It works, it's a known quality, other manufactures use this cut-off speed, so why not stick with it. Why re-engineer, test and open yourself to liability issues. Agreed.
Regards,
Bob
96 A4QM
86 4KCSQM