LSD - How important?
03-05-2009, 01:23 PM
#46
Burning Brakes
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My understanding is that the Quaife LSD doesn't lock under braking, while the Guard's does... is that correct?<
i.e Quaife is a torque biased differential vs "true" LSD offered by Guard.
i.e Quaife is a torque biased differential vs "true" LSD offered by Guard.
Last edited by early_grayce; 03-05-2009 at 01:32 PM. Reason: typo
03-05-2009, 01:34 PM
#47
Rennlist Member
Joe,
For me the biggest issue was comming out of the carrousel, your spot on at 2 and thats where you really notice it the difference in the 964...never had issue with 9 but maybe thats cause I'm slow and underpowered in the 44
...Oh yea I'm up for this weekend, Jim just got done with corner balance/align...my home brewed setup had some wedge I'm sure, and the turbo cooler is on so hopefully I won't be backing out of it for the oil temps....I'll be out Sat morning for both days...gotta wear out these RA1s...
For me the biggest issue was comming out of the carrousel, your spot on at 2 and thats where you really notice it the difference in the 964...never had issue with 9 but maybe thats cause I'm slow and underpowered in the 44
...Oh yea I'm up for this weekend, Jim just got done with corner balance/align...my home brewed setup had some wedge I'm sure, and the turbo cooler is on so hopefully I won't be backing out of it for the oil temps....I'll be out Sat morning for both days...gotta wear out these RA1s...
03-05-2009, 04:30 PM
#48
Race Director
My wheel sping in turn 9 was very dependant on set-up. So much so I could easly dial it out or suffer pretty badly. The carousel is harder to dial out with out mess-up the car elsewhere. However you can adjust the line/technique to help alot.
Come in all the way to the right and slow the heck down with right tires just on the edge of the curb. If you hit it that will upset the car. Slow down alot and then went you are going really slow crank wheel over to use the weight on the nose to get front end to bit and turn it. Done right and you can get just about all the turning done early and you can use the surface change from concret to asphalt to help get the back end around. Then stand on it 3rd gear and unwind. You will be at the bottom of 3rd, but the lack of hp there helps mask the open diff and if you are gentle unwinding through the corner it helps keep the back end planted so you can apply all the hp you do have.
I done that corner in 2nd and 3rd gears. 2nd give you more punch, but has a few issues. This forces an extra downshift from 4th to 2nd instead of 3rd. This costs time and when you rev match you are higher in the RPM band creating more engine braking. This then tend to slow the car down more than in 3rd. So when you get back on the power I at least am going slower in 2nd than in 3rd. So I need the extra power of 2nd just to catch up to the speed I was in 3rd. Of course you are at the meat of the power band in 2nd so you have lots of it. That can be bad due to an open diff can it can also really get the band end loose due to the hp and the tight turn. This then forces you a bit wider taking a greater distance and also forces a shift to 3rd right in the middle of the turn. This can be hard to execute smoothly.
In my experince these factors tend to make it a wash for me on 3rd vs 2nd. I can do either one and still get to the braking point for 9 at same speed at the same time. I perfer 3rd in nearly all cases since it just easier on the car. 1 less downshift, 1 less up shift, less tire wear due to managing the power and more relaxing on the driver since I can stand on it 3rd and just wait for the revs to build rather than really working it in 2nd. Howeve if get stuck behind a car doing it in 2nd the cna slow my entry speed such that we we both get back on the power we are going the same speed. Thus being in 3rd hurts badly. So if I get stuck going in slow I need to drop to 2nd to prevent losing too much ground.
BTW... too little front roll stiffness is a big contributor to wheel spin in the rear. The front end leans over too much and picks up the inside rear wheel. In creasing the front roll stiffness will keep the back end more planted so when you go from no power to power the inside rear has more grip. Of course too stiff in front roll rate has its isse as well so that is where trying to find the right balance between them is key.
Come in all the way to the right and slow the heck down with right tires just on the edge of the curb. If you hit it that will upset the car. Slow down alot and then went you are going really slow crank wheel over to use the weight on the nose to get front end to bit and turn it. Done right and you can get just about all the turning done early and you can use the surface change from concret to asphalt to help get the back end around. Then stand on it 3rd gear and unwind. You will be at the bottom of 3rd, but the lack of hp there helps mask the open diff and if you are gentle unwinding through the corner it helps keep the back end planted so you can apply all the hp you do have.
I done that corner in 2nd and 3rd gears. 2nd give you more punch, but has a few issues. This forces an extra downshift from 4th to 2nd instead of 3rd. This costs time and when you rev match you are higher in the RPM band creating more engine braking. This then tend to slow the car down more than in 3rd. So when you get back on the power I at least am going slower in 2nd than in 3rd. So I need the extra power of 2nd just to catch up to the speed I was in 3rd. Of course you are at the meat of the power band in 2nd so you have lots of it. That can be bad due to an open diff can it can also really get the band end loose due to the hp and the tight turn. This then forces you a bit wider taking a greater distance and also forces a shift to 3rd right in the middle of the turn. This can be hard to execute smoothly.
In my experince these factors tend to make it a wash for me on 3rd vs 2nd. I can do either one and still get to the braking point for 9 at same speed at the same time. I perfer 3rd in nearly all cases since it just easier on the car. 1 less downshift, 1 less up shift, less tire wear due to managing the power and more relaxing on the driver since I can stand on it 3rd and just wait for the revs to build rather than really working it in 2nd. Howeve if get stuck behind a car doing it in 2nd the cna slow my entry speed such that we we both get back on the power we are going the same speed. Thus being in 3rd hurts badly. So if I get stuck going in slow I need to drop to 2nd to prevent losing too much ground.
BTW... too little front roll stiffness is a big contributor to wheel spin in the rear. The front end leans over too much and picks up the inside rear wheel. In creasing the front roll stiffness will keep the back end more planted so when you go from no power to power the inside rear has more grip. Of course too stiff in front roll rate has its isse as well so that is where trying to find the right balance between them is key.
03-05-2009, 05:33 PM
#49
Rennlist Member
Joe, as I expected the corner weights were jacked all over and the alignment was all off too, it was scrubbing half the tires on the thing, so hopefully this takes care of all my excuses...I'll see if I can stay on your tail...(yea right...) see ya sat...
