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Discussion Starter · #1 ·
so i was reading up on tuning anti-sway bars on mazda6tech:

http://www.mazda6tech.com/index.php?option...5&Itemid=50

so i got to thinking about the sway bar in the rear of an awd. if we go with a thicker bar, then the rear of the car will do more work to eliminate body roll while the front of the car will have more grip and be freed up to put power to the ground since it will be doing less work against body roll.

so i was wondering which part of the car we, as awd cars, would like having the most grip and putting power to the ground when cornering? the rear differential is limited slip if that matters at all while the front is open.
 

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We want the front to have more power getting to the ground. This is what will give us the oversteer we need. Our understeer is caused by the rear getting too much (compared to the front).
 

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Discussion Starter · #3 ·
so whats the benefit of having awd, if any, if you want the front tires to take the load in the corner? im thinking of the acura RL commercial about accelerating the outside tires to help around the corners. since we have a LSD in the rear and we're transfering more weight to the outside with a sway upgrade, would this help handling?
 

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The awd helps push the rear in a straight line and the front in the direction of the turn. With a good sway set-up and the rear lsd, this will cause the rear to yank around to where you want it. This is ideal for handling in quick, last minute cornering.
 

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Sorry, guys, I think you've got this exactly backwards. A FWD car can't oversteer under power because the back end is just pulled along by the front. If you increase power, the front tires start to slip and you go wide of the turn (understeer-the car turns less than expected for the steering wheel input). Adding power to the rear (AWD), depending on suspension tuning, can allow the fronts to do their job of steering, and if the rears start to slip, the rear will go wide, increasing the turning angle (oversteer). So, the more power you can put to the ground in the rear the more you'll tend to oversteer-more power transfer or more sway bar (improving suspension geometry and allowing more power to the ground in the rear) will help. So we already oversteer more than a FWD 6, adding a bigger bar in the rear will increase this, at the loss of stability. A bigger bar in front will regain the balance. Depending what you're doing (auto-x probably want more oversteer, drag racing probably neutral, road racing probably leave it alone, since you can rotate it at high speeed with the throttle or perhaps VERY slight increased oversteer) you'd tune differently... On the street it's a safe balance now.

OTOH, we'd get better turn in, better tire wear and slightly more oversteer with camber adjustable front suspension...
 

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Discussion Starter · #7 ·
oic. in essence, to oversteer, the rear would have to move to the outside of the corner faster than the front, so u need to put more power to the rear.

i got another question. the way our car is setup now, we have oversteer in, understeer out. this is ideal for an awd right? now if we add a thicker rear sway, we will still have the same situation, just more oversteer once we turn in. im guessing once the rear starts slipping, the awd system puts the power back to the front pulling the car out of the spin and giving us understeer. so all in all, we get a faster turning car with the same stability and less body roll yah?
 

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You have it backwards again...

The car understeers in (Its heavy, and turn in isn't the best) and oversteers out (IF you can get the rear to rotate)...

With a larger rear sway bar the rear end will come out before the car has a change to understeer... allowing for a balanced/oversteer in, balanced/power oversteer out...
 

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Discussion Starter · #9 ·
You have it backwards again...

The car understeers in (Its heavy, and turn in isn't the best) and oversteers out (IF you can get the rear to rotate)...

With a larger rear sway bar the rear end will come out before the car has a change to understeer... allowing for a balanced/oversteer in, balanced/power oversteer out...
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stretch and crossbow will disagree with you.

http://forum.mazda6club.com/index.php?s=&a...st&p=735394

from after watching top gear on the ms6. i'll have to agree with them too. it does look like oversteer in, understeer out from the video.
 

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They are talking about throttle out of the corner will tend to oversteer, not what the suspenion will do...

As a driver who has taken the car around a track, on high MPH corners the front plows (understeer) and once the car car grabs again and I turn the wheel well on the gas, the rear rotates...

Go watched that top gear video... 1:10 seconds in, watch the car plow when he trys to turn, and then once it grabs and he applies gas, what the gear come around...

All the rear bar is going to do is minimize the plowing time and start the rotation process earlier...
 

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Discussion Starter · #11 ·
They are talking about throttle out of the corner will tend to oversteer, not what the suspenion will do...

As a driver who has taken the car around a track, on high MPH corners the front plows (understeer) and once the car car grabs again and I turn the wheel well on the gas, the rear rotates...

Go watched that top gear video... 1:10 seconds in, watch the car plow when he trys to turn, and then once it grabs and he applies gas, what the gear come around...

All the rear bar is going to do is minimize the plowing time and start the rotation process earlier...
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at 1:10, the wheels aren't turned in.

at 1:19, oversteer like mad.

at 1:37, understeer in, oversteer out. wiggum, you are correct.

i think stretch was referring to the hammerhead at 1:19, but thats throttle modulation there. at 1:37, jeremy is on the throttle thru the whole turn. he misses the apex because of understeer, but the car eventually rotates and he drifts the corner.
 

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You can soften the front bar to see the effect of a stiffer rear bar. I've done this on other cars while track tuning the bars. Method is adding 2 washers ( 1 per bolt) under each pivot bracket clamp up front. Washer acts as spacer, and loosens grip on the rubber.

I ran a full track day like this on a rwd car, after a last minute/midnite rear suspension upgrade (wider track + lowered + more rear camber ) had me plowing off course on 1st turn at summit point.
 

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so i was wondering which part of the car we, as awd cars, would like having the most grip and putting power to the ground when cornering? the rear differential is limited slip if that matters at all while the front is open.
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To answer the original question, we want the rear to get more grip as it will rotate the car around the corner under power because of the LSD. All this talk about suspension reacting under no load wasn't what he was asking.

with no power, obviously the car behaves like any front engine 60/40 weight distributed car, understeer. throttle on, the car behaves like an AWD with LSD rear, oversteer. counter steer once the back comes out and stay on gas to produce a momentary drift. AWD will correct shortly thereafter. This is very easy to produce in the rain at moderately low speeds.
 

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This is very easy to produce in the rain at moderately low speeds.
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And a hell of a lot of fun!!

It rained here Sunday and spent the afternoon practicing - DSC is a trip.
 

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Discussion Starter · #17 ·


omg, that thing is never getting out of there. (don't mind the lines and numbers, i stole this pic from another thread)
 

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omg, that thing is never getting out of there. (don't mind the lines and numbers, i stole this pic from another thread)
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A cutting wheel (or dremel) will make quick work at getting that thing out of there. Of course, how you get the new one in is still up for debate :D
 

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Drop the diff down.. should give plenty of room. I'm sure there is a way to "wiggle" it in there.
 
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