F35 or not?
05-12-2009, 10:49 PM
#76
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you've contradicted yourself even in the links you've posted
an open differential will turn both wheels at the same speed in a straight line, end of story
05-12-2009, 11:46 PM
#77
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i took the time to read this entire post just because i wanted to see if the point was proven or not, and thank god after 5 pages it has been.
the reason why spools are preffered in rear wheel drive applications is because both wheels will spin equally, no worries about posi traction or open diffs, both wheels will spin equally, and since you'll be going in a straight line, that's a good thing. most of the time, some calculations in the flexing of the differential case (rear wheel drive) will require preloading of one tire, so when the case twists a bit from the torque before applying power to the wheels, the power is balanced.
even with spools, if there's enough torque, the differential case will flex (unless ya got a wicked 4-link) and one tire can be sliiightly lifted off the track, resulting in tire spin and the car taking a quick turn into the barriers. my college professor at my automotive school has been racing track cars for 20+ years, he has told me stories like that on numerous occasions. this can also happen in a situation where one axel's steel has been work hardened due to the constant flexing of the differential and power is applied unequally for so long, that the weaker axel can snap on a hard launch and then say hello to the side wall.
In our cars, open diffs will not make for better launches... as said a million times over, it is for cornering. if for some strange reason track prep was bad, then perhaps you'll spin one tire due to the engine torquing back and then giving more power to our front left wheel... if your intermediate shaft and bracketing was strong enough for the task at hand, as are your axels, then the torque would be split perfectly amungst the tires upon perfectly even traction surfaces at both tires. 2 wheel spin FTW.
Launching the car at a stop light can give u a 1 tire spin condition if there isn't much traction due to the fact that the power delivery is slightly biased towards the wheel closest to the output of the differential, our front left. dumping the clutch in a non-lsd on less than track worthy roads will give u the occasional 1 tire burnout.
and this talk about the tire getting more power because it is slipping... it's not that it gets more power, but yes as some1 noted, power travels along the path of least resistance, aka less traction. in an open diff, power to the wheel with traction will be equal to the maximum power that can be transfered to the tire with less traction. if you're in mud, and you're getting a tiny bit of traction in one tire, you'll apply the same amount of power to the other wheel. on ice with no traction? no power is being applied to forward momentum? no power to the other. slippery rain on a turn with moderate traction, you'll only get to the outside wheel what is possible on the inside.
200HP cobalt SS, NON LSD... you're driving in the rain, take a cloverleaf at 50mph (pretty stupid) and you're inside tire starts to spin. lets do simple, not entirely accurate math... say each tire gets 100HP, (i know i know, let's hope you're not at 5000+ RPMs producing 200HP in this situation!) but now you're slipping a bit and can only put down say 50HP to the inside wheel due to the slippage and power loss, guess what? now only 50HP can be applied to the outside wheel to pull you out of a potentially dangerous situation where you will slide out wide of the turn at hit the guard rail! ouch. if you're mashing the gas pedal, and you slip the inside hard... you ain't gettin any power to that outside wheel to keep your momentum going in the direction of the turn, unless you get off the gas quick and lightly gas out, or stomp the brakes and pray ABS will save you. otherwise you will no longer be powering yourself through the turn and instead... centripal forces > cobalt. also guard rail > cobalt.
point to be made? lsd helps tremendously with cornering, not getting into it since there are many links in this post thus far... also, lsd can be slightly better for launches (<.1 seconds to 60ft) if the track prep or road isn't great, since it makes up for any small imperfections in torque application. don't say you wasted $$ on an LSD... simply whip cloverleafs a bit faster and you'll never look at an open diff the same.
the reason why spools are preffered in rear wheel drive applications is because both wheels will spin equally, no worries about posi traction or open diffs, both wheels will spin equally, and since you'll be going in a straight line, that's a good thing. most of the time, some calculations in the flexing of the differential case (rear wheel drive) will require preloading of one tire, so when the case twists a bit from the torque before applying power to the wheels, the power is balanced.
even with spools, if there's enough torque, the differential case will flex (unless ya got a wicked 4-link) and one tire can be sliiightly lifted off the track, resulting in tire spin and the car taking a quick turn into the barriers. my college professor at my automotive school has been racing track cars for 20+ years, he has told me stories like that on numerous occasions. this can also happen in a situation where one axel's steel has been work hardened due to the constant flexing of the differential and power is applied unequally for so long, that the weaker axel can snap on a hard launch and then say hello to the side wall.
In our cars, open diffs will not make for better launches... as said a million times over, it is for cornering. if for some strange reason track prep was bad, then perhaps you'll spin one tire due to the engine torquing back and then giving more power to our front left wheel... if your intermediate shaft and bracketing was strong enough for the task at hand, as are your axels, then the torque would be split perfectly amungst the tires upon perfectly even traction surfaces at both tires. 2 wheel spin FTW.
Launching the car at a stop light can give u a 1 tire spin condition if there isn't much traction due to the fact that the power delivery is slightly biased towards the wheel closest to the output of the differential, our front left. dumping the clutch in a non-lsd on less than track worthy roads will give u the occasional 1 tire burnout.
and this talk about the tire getting more power because it is slipping... it's not that it gets more power, but yes as some1 noted, power travels along the path of least resistance, aka less traction. in an open diff, power to the wheel with traction will be equal to the maximum power that can be transfered to the tire with less traction. if you're in mud, and you're getting a tiny bit of traction in one tire, you'll apply the same amount of power to the other wheel. on ice with no traction? no power is being applied to forward momentum? no power to the other. slippery rain on a turn with moderate traction, you'll only get to the outside wheel what is possible on the inside.
200HP cobalt SS, NON LSD... you're driving in the rain, take a cloverleaf at 50mph (pretty stupid) and you're inside tire starts to spin. lets do simple, not entirely accurate math... say each tire gets 100HP, (i know i know, let's hope you're not at 5000+ RPMs producing 200HP in this situation!) but now you're slipping a bit and can only put down say 50HP to the inside wheel due to the slippage and power loss, guess what? now only 50HP can be applied to the outside wheel to pull you out of a potentially dangerous situation where you will slide out wide of the turn at hit the guard rail! ouch. if you're mashing the gas pedal, and you slip the inside hard... you ain't gettin any power to that outside wheel to keep your momentum going in the direction of the turn, unless you get off the gas quick and lightly gas out, or stomp the brakes and pray ABS will save you. otherwise you will no longer be powering yourself through the turn and instead... centripal forces > cobalt. also guard rail > cobalt.
point to be made? lsd helps tremendously with cornering, not getting into it since there are many links in this post thus far... also, lsd can be slightly better for launches (<.1 seconds to 60ft) if the track prep or road isn't great, since it makes up for any small imperfections in torque application. don't say you wasted $$ on an LSD... simply whip cloverleafs a bit faster and you'll never look at an open diff the same.
05-13-2009, 12:00 AM
#78
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Your acting like he completely agreed with you..
Your still all on the fact that with the open diff, one wheel spins. Which that is totally false.
sprcrg4life has a very good post as well...
They both have awesome facts.. and indeed are saying the same exact thing.
Your still all on the fact that with the open diff, one wheel spins. Which that is totally false.
sprcrg4life has a very good post as well...
They both have awesome facts.. and indeed are saying the same exact thing.
Last edited by ShortStack; 05-13-2009 at 12:00 AM. Reason: Automerged Doublepost
05-13-2009, 12:09 AM
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Never disagreed with that.
With street tires... you might notice a difference. but the tires will only spin as fast as they can without losing traction.
Are you still arguing that the non G85 Cobalts only spin one wheel?
With street tires... you might notice a difference. but the tires will only spin as fast as they can without losing traction.
Are you still arguing that the non G85 Cobalts only spin one wheel?
05-13-2009, 12:16 AM
#83
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Lol... so what is my car?
It doesnt have an LSD.. but both of my tires spin..?
http://www.rangerpowersports.com/for.../t-188358.html
Theres a whole bunch of people on there too saying that both wheels will spin on a open diff..
If everyone else was agreeing with you, i'd change my mind.. but you are the ONLY one who seems to think an open diff spins one wheel.. doesnt that mean anything to you?
http://auto.howstuffworks.com/differential2.htm
This link is from a actual citable website.
It doesnt have an LSD.. but both of my tires spin..?
http://www.rangerpowersports.com/for.../t-188358.html
Theres a whole bunch of people on there too saying that both wheels will spin on a open diff..
If everyone else was agreeing with you, i'd change my mind.. but you are the ONLY one who seems to think an open diff spins one wheel.. doesnt that mean anything to you?
http://auto.howstuffworks.com/differential2.htm
This link is from a actual citable website.
When a car is driving straight down the road, both drive wheels are spinning at the same speed. The input pinion is turning the ring gear and cage, and none of the pinions within the cage are rotating -- both side gears are effectively locked to the cage.
Last edited by ShortStack; 05-13-2009 at 12:16 AM. Reason: Automerged Doublepost
05-13-2009, 12:19 AM
#84
both of my tires spin when i launch (i have an open diff.) .... are you calling me a liar ??? my car gets of the line just as good as an lsd car. now in the twisties .... that would be a diff. story. an lsd car would take the cake in that race. No one is tryin to be a dick man .... we are just trying to inform you on correct facts with our cars ....
Last edited by Staged07SS; 05-13-2009 at 07:15 AM.
05-13-2009, 12:23 AM
#86
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... You even posted tons of links.. and all of them said that an open diff spins both wheels..
Why dont you read them?
You havent answered my question as to how every single one of us, who all have the same answer.. be wrong?
http://www.off-road.com/offroad/arti....jsp?id=285534
Here is another good one.. This explains the difference between an LSD and a spool..
The spool is what spins both tires at the same speed, no matter what...
an lsd puts more power to the wheel with the most traction..
They are completely different.
Why dont you read them?
You havent answered my question as to how every single one of us, who all have the same answer.. be wrong?
http://www.off-road.com/offroad/arti....jsp?id=285534
Here is another good one.. This explains the difference between an LSD and a spool..
The spool is what spins both tires at the same speed, no matter what...
an lsd puts more power to the wheel with the most traction..
They are completely different.
Last edited by ShortStack; 05-13-2009 at 12:23 AM. Reason: Automerged Doublepost
05-13-2009, 12:27 AM
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A typical open differential will keep the AVERAGE rpm of both axles constant relative to the drive shaft rpm. For example, when one wheel is not turning (0rpm), the other wheel will be turning at 2 times the rpm that it would be if both wheels were at the same rpm - relative to the drive shaft.
In an automobile and other wheeled vehicles, the differential allows each of the driving wheels to rotate at different speeds, while supplying equal torque to each of them. In automotive applications, the differential and its housing are sometimes collectively called a "pumpkin" (because the housing resembles a pumpkin).
EACH WHEEL GETS TORQUE... meaning both wheels spin!
Last edited by ShortStack; 05-13-2009 at 12:27 AM. Reason: Automerged Doublepost
05-13-2009, 12:32 AM
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http://www.superchargersonline.com/content.asp?ID=29
That link actually says it in nice big words...
That wheel will only spin because it is not getting traction. and Since the torque is going to the wheel that is spinning, the little remaining torque is at the wheel with traction...
That link actually says it in nice big words...
An open differential will always transfer the same amount of torque to both wheels when they both have traction.
(+) They are reliable, mechanically simple, and have very long maintenance intervals.
(-) The problem with open differentials is that they will allow all input torque to flow to the wheel with the least amount of resistance. Once a wheel breaks traction and begins to spin, its resistance decreases sharply. It’s a lot easier for the differential to send power to the wheel that’s spinning than it is to get the truck moving with the other wheel that still has traction.
On the street, the right side tire usually spins first because the rotational torque of the drive shaft actually shifts more weight onto the left side tire, giving it more traction than the right.
(+) They are reliable, mechanically simple, and have very long maintenance intervals.
(-) The problem with open differentials is that they will allow all input torque to flow to the wheel with the least amount of resistance. Once a wheel breaks traction and begins to spin, its resistance decreases sharply. It’s a lot easier for the differential to send power to the wheel that’s spinning than it is to get the truck moving with the other wheel that still has traction.
On the street, the right side tire usually spins first because the rotational torque of the drive shaft actually shifts more weight onto the left side tire, giving it more traction than the right.
Last edited by ShortStack; 05-13-2009 at 12:32 AM. Reason: Automerged Doublepost
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