is it possible to spin a wheel inside a tire during an autox?
#21
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No.
The sway bar changes roll stiffness by trying to make both sides do the same thing. This is an over simplification, but let's say you turn to the right...
The weight of the car will shift to the left and the suspension components on that side will start to compress.
The sway bar will move up and transfer some portion of that same energy to the connection point on the other side of the car.
So if the inside part of the car wants to lift up, it will have to carry some portion of the unsprung weight to do it.
A super-stiff sway bar will force the inside "side" to take all of the unsprung weight, or at least a larg enough portion to unload or even lift the inside tire(s).
On the other hand, a really "loose" bar will let the body roll without taking to much of the unsprung weight with it and the wheel, brakes, and other suspension components will just "sag".
That "droop" will give the inside tire a better chance of getting some load and some traction.
#23
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everyone has said it already, but I'll echo it.....
Tirespin is very common on a race tire equipped Z cause you are unweighting the inside rear tire. The VLSD is not all that quick to go from open to locked, so you get wheelspin. Blown front shocks that make the front roll more will make it worse. I put the stranoparts bar on my car and it made a world of difference. No more wheelspin and it didn't add any understeer. Win win mod.
Opposite effect: At a local autox, the front endlink broke mid run, meaning NO front bar for the run.....rear wheel was off the ground for most of the run. Spotters said over a foot off the ground!
Just my $.02
JR
Tirespin is very common on a race tire equipped Z cause you are unweighting the inside rear tire. The VLSD is not all that quick to go from open to locked, so you get wheelspin. Blown front shocks that make the front roll more will make it worse. I put the stranoparts bar on my car and it made a world of difference. No more wheelspin and it didn't add any understeer. Win win mod.
Opposite effect: At a local autox, the front endlink broke mid run, meaning NO front bar for the run.....rear wheel was off the ground for most of the run. Spotters said over a foot off the ground!
Just my $.02
JR
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everyone has said it already, but I'll echo it.....
Tirespin is very common on a race tire equipped Z cause you are unweighting the inside rear tire. The VLSD is not all that quick to go from open to locked, so you get wheelspin. Blown front shocks that make the front roll more will make it worse. I put the stranoparts bar on my car and it made a world of difference. No more wheelspin and it didn't add any understeer. Win win mod.
Opposite effect: At a local autox, the front endlink broke mid run, meaning NO front bar for the run.....rear wheel was off the ground for most of the run. Spotters said over a foot off the ground!
Just my $.02
JR
Tirespin is very common on a race tire equipped Z cause you are unweighting the inside rear tire. The VLSD is not all that quick to go from open to locked, so you get wheelspin. Blown front shocks that make the front roll more will make it worse. I put the stranoparts bar on my car and it made a world of difference. No more wheelspin and it didn't add any understeer. Win win mod.
Opposite effect: At a local autox, the front endlink broke mid run, meaning NO front bar for the run.....rear wheel was off the ground for most of the run. Spotters said over a foot off the ground!
Just my $.02
JR
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He sells it, but it is made by Addco I think. It's the same bar that Carter ran, and the same one that Cavanaugh is now running. It's like $130, but non adjustable. In hindsight, adjustability would have been nice. Perhaps he can get the adjustable version, call Sam and ask him. One of the nicest guys goin...
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well i have hotchkis bars front and rear, and i can still go 2 holes stiffer on the front, so i think i'll try that before buying another sway bar.
hopefully this helps till i can get a real lsd...
hopefully this helps till i can get a real lsd...
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#29
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so second from stiffest in front and full soft in rear?
damn, not really looking forward to all the understeer, would i be ok leaving the front as is, and just going to full soft in the rear?
damn, not really looking forward to all the understeer, would i be ok leaving the front as is, and just going to full soft in the rear?
#31
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is it more important to add roll stiffness to the front or remove roll stiffness from the rear?
To reiterate, you will need to really change your driving style to make this work. Brake earlier because the absolute worst thing you can do is come into the corner even a smidgen too fast. And be careful about coming off the brakes too fast. Don't pop off the brake pedal, easy off it and then ease on the gas.
#32
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-Jack the car up on one rear side
-Leave that side in the air with the other 3 tires on the ground.
-Put the car in gear
-Put a torque wrench on one lugnut and test the break away torque (i.e. the amount of tq it takes to make the wheel spin with the opposing wheel on the ground and the car in gear)
-Report back (I think breakaway tq is about 70#ft)
#34
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Originally Posted by betamotorsports
It sounds like you need a big change to get the wheelspin under control. Go full stiff in front and full soft in back. Then adjust from there (stiffen rear first if needed). Bring tools to the next event and make adjustments between runs.
Originally Posted by betamotorsports
To reiterate, you will need to really change your driving style to make this work. Brake earlier because the absolute worst thing you can do is come into the corner even a smidgen too fast. And be careful about coming off the brakes too fast. Don't pop off the brake pedal, easy off it and then ease on the gas.
Sounds like an LSD issue. Try this crude test:
-Jack the car up on one rear side
-Leave that side in the air with the other 3 tires on the ground.
-Put the car in gear
-Put a torque wrench on one lugnut and test the break away torque (i.e. the amount of tq it takes to make the wheel spin with the opposing wheel on the ground and the car in gear)
-Report back (I think breakaway tq is about 70#ft)
#36
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well i am planning on a better lsd (before i even considered mine was going bad), but i want the quaife lsd. but i wanna do some other upgrades (bbk and oil cooler) that i think will provide more benefit to me... the diff will have to wait till late this year or early next year...
#37
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well i am planning on a better lsd (before i even considered mine was going bad), but i want the quaife lsd. but i wanna do some other upgrades (bbk and oil cooler) that i think will provide more benefit to me... the diff will have to wait till late this year or early next year...
#39
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right now, i mostly do autox cause i don't have a bbk or an oil cooler, i'll start doing track days also once i get the those items
i did a couple of track days on the stock brakes (non brembo) with project mu b force pads and fresh motul fluid, and the fade was pretty bad. pedal got really soft and would hit the floor, and i can feel my stopping distance increase with each lap...
i did a couple of track days on the stock brakes (non brembo) with project mu b force pads and fresh motul fluid, and the fade was pretty bad. pedal got really soft and would hit the floor, and i can feel my stopping distance increase with each lap...
#40
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right now, i mostly do autox cause i don't have a bbk or an oil cooler, i'll start doing track days also once i get the those items
i did a couple of track days on the stock brakes (non brembo) with project mu b force pads and fresh motul fluid, and the fade was pretty bad. pedal got really soft and would hit the floor, and i can feel my stopping distance increase with each lap...
i did a couple of track days on the stock brakes (non brembo) with project mu b force pads and fresh motul fluid, and the fade was pretty bad. pedal got really soft and would hit the floor, and i can feel my stopping distance increase with each lap...
As for lap times, the LSD really came into play in the slow, sharp corners (stock power). On the track, it may reduce my lap times by 1 second or so, but I imagine that the benefits on an autoX course would be more substantial.