welded diff ,viscous or locked diff for drifting
04-11-08, 11:34 AM
#51
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With normal, controlled driving, not much is considered dangerous, short of broken axles or wheels falling off.
I guess it's the times when you run spirited on the street, but unexpectedly traffic comes out. I wouldn't want to have a welded diff there. Plus I can't stand understeer or wearing tires faster.
But that's just me.
I guess it's the times when you run spirited on the street, but unexpectedly traffic comes out. I wouldn't want to have a welded diff there. Plus I can't stand understeer or wearing tires faster.
But that's just me.
I'm not going to go through it again so you can keep believing that. You won't know until you drive it, otherwise it's just word of mouth.
04-11-08, 12:02 PM
#52
Except I don't drive "normal", "controlled" or any other variation of it. I drive to the limit on nearly every turn. And I've had numerous drivers come out in front of me and have to perform manuvers to avoid a accident and never had a problem, I live in FL it happens everyday. And the understeer... I'm not going to go through it again so you can keep believing that. You won't know until you drive it, otherwise it's just word of mouth.
I'm not going to go through it again so you can keep believing that. You won't know until you drive it, otherwise it's just word of mouth.Seriously though, it's a shame you're far away, I wouldn't mind sitting in a car with a welded diff to see how it goes around corners.
04-11-08, 12:52 PM
#53
93' Rx7 Widebody
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You truley won't notice it's welded until you try to park your car. Because at low speeds the tires skipping is noticable. Other than that, it's normal.
04-11-08, 02:43 PM
#54
I would if I could do the following but I can't. Take two cars, one with a welded diff, one with an open diff, to a road course and run them around a track on timed laps, see which one has a faster entry speed, etc. I would bet that the open diff car would corner faster than the welded diff car.
I guess on the street, it wouldn't matter as much though.
05-08-08, 03:05 PM
#57
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^^ Eh, Torsens are alright. Definatley better than a viscous. Its all mechanical and it works great until one wheel looses traction completley, then it cannot supply the proper tq to the other wheel (and acts like an open diff and spins only one wheel) and thats it's only downfall really. A clutch type is a better design though.
05-09-08, 12:42 AM
#58
The clutch-type provides more understeer upon lockup when pushed to the limit. It's pretty common to hear that from FD drivers who've switched to the KAAZ LSD's complaining of understeer at entry and exit. In road race, unless you're bouncing off curbs, it's a rarity for you to three wheel.
In autox, that's a different story.
In autox, that's a different story.
05-09-08, 06:38 AM
#59
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The clutch-type provides more understeer upon lockup when pushed to the limit. It's pretty common to hear that from FD drivers who've switched to the KAAZ LSD's complaining of understeer at entry and exit. In road race, unless you're bouncing off curbs, it's a rarity for you to three wheel.
In autox, that's a different story.
In autox, that's a different story.
05-09-08, 10:28 AM
#60
There's a reason why most Mazda RX-7 racers either get the Miata Torsen or the FD Torsen for road race. 
Show me a winning ITS racer who doesn't have a modified Miata Torsen.
The Torsen is a much smoother differential when active, and smoothness leads to quick lap times.
The clutch-type's advantage lies in it's strength, it can handle gobs more torque than the torsen can. If you have a car capable of breaking torsens, you obviously have to go with a clutch type.
However, if your car can coexist fine with a Torsen on it's rear and it's main form of racing is road race, then I would submit that the Torsen is the best diff to use in that situation.
If you're a straight-line racer or you have gobs of power, use a clutch-type
If you drift mostly, definitely use a clutch-type.
If you autocross and your suspension is not compliant enough that it 3 wheels around turns, use a clutch-type.
If you autocross and all 4 wheels are always in contact with the ground, use a Torsen
If you road race, use a Torsen.
Show me a winning ITS racer who doesn't have a modified Miata Torsen.
The Torsen is a much smoother differential when active, and smoothness leads to quick lap times.
The clutch-type's advantage lies in it's strength, it can handle gobs more torque than the torsen can. If you have a car capable of breaking torsens, you obviously have to go with a clutch type.
However, if your car can coexist fine with a Torsen on it's rear and it's main form of racing is road race, then I would submit that the Torsen is the best diff to use in that situation.
If you're a straight-line racer or you have gobs of power, use a clutch-type
If you drift mostly, definitely use a clutch-type.
If you autocross and your suspension is not compliant enough that it 3 wheels around turns, use a clutch-type.
If you autocross and all 4 wheels are always in contact with the ground, use a Torsen
If you road race, use a Torsen.
Last edited by Roen; 05-09-08 at 10:39 AM.
05-09-08, 11:19 AM
#61
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Explain to me this. why arn't torsens the diff of choice for everyone else if they are better for road race? The big names in road race would be all over them if they even shaved .001 seconds off a lap time. So why not? And by most Rx7 racers do you mean Mazda Road race cars or just the average joe who does autocross and roadrace? The RX8's don't use Torsens, so is Mazda making a mistake? I think not.
Last edited by Roen; 05-09-08 at 02:06 PM.
05-09-08, 02:18 PM
#62
Explain to me this. why arn't torsens the diff of choice for everyone else if they are better for road race? The big names in road race would be all over them if they even shaved .001 seconds off a lap time. So why not? And by most Rx7 racers do you mean Mazda Road race cars or just the average joe who does autocross and roadrace? The RX8's don't use Torsens, so is Mazda making a mistake? I think not.
And, I believe mazda does use a torque sensing LSD for the RX-8. Mazda switched from the clutch-type to the Torsen during the FC years. (S4's used clutch-types, S5 Infini IV used a torsen)
Old BMW M drivers always complain about the old locking diffs in adverse conditions. These days, they use a Variable diff, which isn't exactly a clutch-type any more, though it still uses clutch disks.
I would think that The LS engines in the corvettes would have no problem destroying the worm gears in the Torsen, so they have to compromise and use the clutch-type. The big name race cars all produce a lot of power, so it wouldn't make sense to use a torsen.
Most front wheel drive road race cars use a helical diff, which is built in the same principles as a torsen. The 4WD turbo cars that come out use a front helical diff to promote grip and a rear clutch-type for strength. Tell you what, try putting a KAAZ on a Civic and taking that around a road course. Then put a helical diff on and try it again. It'll be a world of difference. FWD cars exaggerate the differences between the two diffs to the point where it's very apparent which one is better for cornering.
It's simple, under a certain power/torque level, the torsen is the only choice to go with. Above that, the torsen can handle the power and you are forced to use a bad compromise and use a clutch-type for it's strength. You're never going to get the linear lockup of a torsen with a clutch-type, there's always a kink between unlocked and locked. If you think about it, this is how a clutch type works: unlocked, unlocked, unlocked, unlocked, locked, locked, locked, locked, locked: A torsen works like this (given traction on both wheels): unlocked, lock a little bit, lock a little bit more, lock a little bit more, etc... It's just smoother, up to a certain power level, then it just destroys itself.
Carbon clutch-types come close to a Torsen, and have the benefit of added strength, which is why most big race teams will opt to go with them. In this discussion, I am only referring to clutch-types as diffs with metallic clutch packs, since carbon clutch diffs are out of the range of the average consumer.
Remember, big name = big money = big power. You'll grenade the torsen before the it even gets through 1 lap. Make a torsen that can handle that power, and I bet you, many teams would switch to it, since then, you'll get cornering grip greater than that of a carbon clutch-type, with increased strength.
However, in the fields where the power levels and rules allow for a Torsen diff, you'll see mostly those types of diffs. Look at NASA PTB-PTE classes.
On a personal anecdote: I had a friend of mine drive my car with a viscous diff, he used to have a clutch-type diff on his car. He was surpised at the gentleness of the lockup and how much earlier he could get on the throttle on my car than his car. He was in the process of switching to a FD torsen diff and was really looking forward to it. I used to own a S4 TII as well, with a working clutch-type diff. As soon as there was any wheel slippage, there was understeer, which I had to power my way out of, which was not fun, nor was it fast.
Last edited by Roen; 05-09-08 at 02:23 PM.
05-09-08, 03:15 PM
#63
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Some decent info. But I want to add that the clutch types are not just "lock" and "unlock". Depending on the springs and clutchs in the pack, it slips kind of like a clutch in a trans. This in turn creates a smooth transition between locking and unlocking. To comment on your personal story: You can't really compare the two (torsen vs. off the shelf anyone can buy LSD) because those are not set up properly for everything (they can't be) and are usually set for drag racing specs. Actual race teams have custom clutch types set up perfectly for their situation. The BMW race cars switch out the clutches after every race due to it slipping over the course of the race and slightly wearing the clutches. Yes, it's a downfall to have to change them out, but you won't have the problem if one wheel looses traction completley like in the torsen and they keep the smootness.
Last edited by FlyinFINN; 05-09-08 at 03:24 PM.
08-01-08, 06:09 AM
#64
do any of you guys know if the s4 open NA diff will fit with a turbo 2 driveshaft to turbo 2 tranny? I have a extra s4 open diff, but dont know if it will fit my turbo 2setup. Will the s4 diffs driveshaft bolt pattern matchup with the t2 driveshaft?
08-01-08, 07:39 PM
#69
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The reason your dumb to run a welded diff on the street is wait for it, rain, snow, gravel, sand, or just dust in a corner. If you think a FC would like to kick out before on dry and clear pavement give it a go on something other than dry or clear. You will be all over the road and could possible(very high chance) wreck and possibly hurt someone. Also a car with a welded diff does not offer the same braking ability of a non welded or LSD equipped car and you do not have nearly the amount of turn in as a LSD or open. Which i must say is ind of important for a low powered car tryin to start a drift, yes you can just cut the wheel to full lock and mash the gas in 2nd but when you are powering you will slide up the track and the car has a greater chance of snap back.
OP if yo are poor/broke/or a regualr cheap *** FC owner just save up the money for this one lil mod and get the S4 clutch type. It is well worth the 75-150$ youll spend on it.
08-03-08, 12:48 AM
#71
oh so ican actualy get the open diff and weld it and get my t2 stubshafts swapped in there... thanks im going this route. Thats the kind of answer i was hoping for.
its best not to worry about running welded on the streets, its really not that dangerous, alot of my friends run it daily, some even delievering food, they drive it in the winter rain np all the time, all it really comes down to really is driver..so chill man
Idrove myfriends s13 with welded it felt really nice oversteer when I gas it , I LIKE it full time 2way lsd. I like it . i like it and will have it haha
its best not to worry about running welded on the streets, its really not that dangerous, alot of my friends run it daily, some even delievering food, they drive it in the winter rain np all the time, all it really comes down to really is driver..so chill man
Idrove myfriends s13 with welded it felt really nice oversteer when I gas it , I LIKE it full time 2way lsd. I like it . i like it and will have it haha
08-03-08, 12:57 AM
#72
I actually wonder how the ATS carbon lsd is for grip driving. It's supposted to lock much smoother than metal plate diff's. Bet it's $$$ though.
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