trail braking
rebump for the confrontational thread resurrected from the dead!
most of these opinions were with the 03/04 open front diff i believe. have these opinions on trail braking and when to use it changed with the inclusion of the quaiffe, ralliart, rs lsds or the inclusion of the acd?
most of these opinions were with the 03/04 open front diff i believe. have these opinions on trail braking and when to use it changed with the inclusion of the quaiffe, ralliart, rs lsds or the inclusion of the acd?
a helical front diff will 'require' you to be on the gas in the turn, when this occurs is still subject to debate and whether or not you are putting more heat into a tire by trail braking is also up for debate on a nose heavy awd car. that said, the helical diffs are wonderous.
Originally Posted by EVOL EDO
rebump for the confrontational thread resurrected from the dead!
most of these opinions were with the 03/04 open front diff i believe. have these opinions on trail braking and when to use it changed with the inclusion of the quaiffe, ralliart, rs lsds or the inclusion of the acd?
most of these opinions were with the 03/04 open front diff i believe. have these opinions on trail braking and when to use it changed with the inclusion of the quaiffe, ralliart, rs lsds or the inclusion of the acd?
Originally Posted by chronohunter
Not to much changes as we had been running Cusco diffs in the front and rear back then. Just to clarify, all lsd diffs increase corner entry understeer to some extent (compared to an open diff). The tighter the diffs the more understeer and the more trailbraking that will be required. ACD also makes understeer worse in some situations (and that's why we are going to start tuning the ACD with a Xede).
Originally Posted by trinydex
how come when i'm on the gas my quaife pulls the car around?
Originally Posted by chronohunter
it's a separate Xede if that makes a difference...
Be in touch soon - it's about to finally go down (or up, depending on how you look at it
).
Originally Posted by chronohunter
because it puts more power to the outside wheel when you're accelerating, it causes understeer on entry though when you are off the gas hence the greater need for trail braking with a diff to compensate. kapish!?!
Evolving Member
Joined: Jan 2006
Posts: 166
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From: California
Just a note for beginners on this board.
The proper sequence you should be learning is
brake, turn, throttle (brake in a straight line, make the turn one motion, throttle after the apex)
This sequence is not car, track or driver specific. It is the safest and best way to learn the line around a track.
Onto thread specifics:
Im late to the thread but even at this point, i would be very surprised if robi doens't get some rotation under braking with the above sequence. In fact without some brake induced rotation/yaw, the throttle part of the sequence means robi would be accelerating straight ahead. Note that rotation under braking can happen very naturally and most experienced drivers dont' even think about the wheel inputs/brake modulation required to make it happen. Rotation under braking means youre trail braking, true threshold braking happens only in a straight line.
-heeltoer
NASA instructor
PS great discussion BTW.
Originally Posted by robi
brake, throttle,turn, I work very hard at that exact sequence if it's slower "in theory" so be it
brake, turn, throttle (brake in a straight line, make the turn one motion, throttle after the apex)
This sequence is not car, track or driver specific. It is the safest and best way to learn the line around a track.
Onto thread specifics:
Im late to the thread but even at this point, i would be very surprised if robi doens't get some rotation under braking with the above sequence. In fact without some brake induced rotation/yaw, the throttle part of the sequence means robi would be accelerating straight ahead. Note that rotation under braking can happen very naturally and most experienced drivers dont' even think about the wheel inputs/brake modulation required to make it happen. Rotation under braking means youre trail braking, true threshold braking happens only in a straight line.
-heeltoer
NASA instructor
PS great discussion BTW.
Last edited by heeltoer; May 8, 2006 at 02:00 PM.
^ very skip barber (going faster chapter 1). that said robi purpose did not want to trail brake because he didn't want to overheat the outside tire. there should be ways to tune around it, but also of course there's ways to drive around it.
Originally Posted by trinydex
how does it cause understeer any more than a normal open diff? dont' they act the same off throttle?
Originally Posted by chronohunter
No, not exactly, all have a certain amount of drag that varies depending on the design. Think of a 1 way, 1.5 way or 2 way all are the same on exit (locked). On decel the 1-way is least locked, the 1.5 is 50% locked and the 2-way is 100% locked. LSDs always have *some* drag on decel and drag=understeer. I"m not saying I'm against them, you need them in certain applications. I prefer using the 1-ways to minimize understeer on cars like the nose heavy evo and as the weight distribution moves back from evo->BMW->911 you can use more decel locking to settle the back on entry (minimize oversteer).
1 way 2 way 1.5 way all have to do with CLUTCH type LSD's and have to due with the cam based engagement (ramp angle and cam shape) the Quaife and other HELICAL style difs lock ONLY under power with a certain set preload on the lightest loaded tire....Hydraulic difs like the "active center" use a complex series of equations to factor in throttleposition steering wheel angle individual wheel speed and g/yaw angle...and tailor the lock up of the clutckes to best transmit the torque to the points which can take it....chrono et. al. PLEASE read your basic texts and understand how these all interact prior to opening your mouth and proving your ignorance to all but the most uninitiated souls....