Pics of my new H&R Coilover install on my S4 Cab. (And SS brake lines)
04-21-2005, 10:13 AM
#101
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I hear that. My instructor had me trail braking at my 2nd event...
And have been ever since. Was able to pick up some serious distance, especially coming off the straights...the one place a z06 has me. ;-0
04-21-2005, 10:44 AM
#108
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OK then, here are my thoughts. I can't be 100% sure because I speak from my own experience...
On my car. I have raised and lowered it often to find the sweet spot and keep in mind this is on an <b>A4 and not an S4</b> but since the suspension is basically the same, I think my logic should be good on this.
<b>First, I will address the front.</b>
Because we can not adjust the camber (unless you buy the <b>CPP</b> upper links), by lowering your car you have also increased the negative camber of your car, this is normal. However your camber numbers are different from left to right. You indicated the <b>left was at -1 degree 39 minutes or exactly -1.65 degrees</b> (this is a lot closer to what I would have believed normal for a lowered car) and the <b>right was at -1 degree 55 minutes or -1.92 degrees</b>. Maybe it is just me, but I find the differences between the left and right (<b>0.27</b> of a degree, not minutes) a bit much, the car may have a tendency to pull. You should try to find out why, better yet you should move the sub frame left to right, by unbolting it and to try to equalize your camber and this should also affect your caster.
On the toe you indicated a <b>positive toe (toe in) of 0 degree 10 minutes or exactly + 0.16</b> of a degree per side which is exactly what Audi wants for the front. However, I will suggest something later on.
<b>Second, the rear set up.</b>
Now this is where I may open a can of worms for you. As I stated before, I think you are <b>too low</b>. Your camber in the rear is <b>-1 degree 57 minutes or -1.95 degrees</b>. That is way too much. The rear camber should not be more (as per Audi) than <b>-1 degree 15 minutes or -1.25 degrees.</b> So basically, you are 0.75 or 3/4 of a degree too much on the negative side.
Your rear toe is also too much. You indicated a positive <b>rear toe at 0 degree 15 minutes or +0.25 of a degree</b> (even more then in the front!). Audi recommends a maximum of <b>+0.07 minutes or +0.12 of a degree</b>, that's half as much as the front.
By having too much camber and too much toe in the rear you have succeeded in getting the rear end more planted to the ground, in other words you have managed to have a stickier rear end (read even more understeer). We don't want that, do we?
<b>How to fix this mess</b>.
Well I think you are going to have to raise your car. But before we go that step, you will have to bring your car in for another alignment because before raising it, we want to see if in its actual lowered position, we can dial out some of that rear camber and toe. I'm willing to bet if things are the same as on the A4, that you will not be able to bring the camber back down to -1.25 degrees with a toe of +0.12 of a degree or less. If that is the case, up will have to go the suspension, by how much; it depends on your S4 suspension. Again if the similarities between the A4 and S4 hold true, my guess your rear is going to be somewhere between 25 to 25.25 inches, in other words you are going to have to raise it at least 1/2 an inch. This means you are also going to have to raise the front too. You can leave them equal front and rear or you could give the car a positive rake. This means having the rear end slightly higher than the front by <b>no more</b> than a 1/4 of and inch, 1/8 being very good.
As you can see slapping on coilovers is not that simple. To do it right is time consuming.
Now someone in the tread asked you if you were going to get it "corner weighed". Well I have a very easy answer for you. You <b>don't</b> need that at all. It is even more time consuming and requires more $$$ for nothing, especially for 99% road use. In a perfect world it would be nice to have it perfectly balance, but truth be told, even some pros do not bother to balance their cars if they are within 2% in cross weights. I bet you that if you sat in your car with the weight scale under it, you would not be too far off the 2% mark.
Also for a true corner weight, you need to unload the suspension. How do you do that? You have to disconnect the sway bars, front and rear, adjust the suspension, up and down until the proper numbers are reached. This means one or more corner will now not be equal with the others as far as ride height is concerned. The next step is to reconnect the sway bars, but wait, now you run in to another problem. If the car is perfect at each corner without them being attached, what will now happen when you reconnect them? You've got it, the corner weights are now screwed up. How do you get around that problem you say? Well, now you need to buy adjustable sway bar links so as to not preload the suspension again when attaching the sway bars, as you can see more $$$.
Back to the toe for a minute. I suggest you dial out the toe completely, that's right have the tech set 0 toe both front and rear (if he can). This way the car will be a lot more fun to drive. It will be perhaps a bit less stable in highway conditions but a lot better for tossing it around.
<b>BTW, these are only my opinions and the way my car is set up. These settings may not be good to you for what ever reason and I don't want to be held responsible for your own actions if you decide to follow them.</b>
Hope this answers some of your questions, good luck.
<b>First, I will address the front.</b>
Because we can not adjust the camber (unless you buy the <b>CPP</b> upper links), by lowering your car you have also increased the negative camber of your car, this is normal. However your camber numbers are different from left to right. You indicated the <b>left was at -1 degree 39 minutes or exactly -1.65 degrees</b> (this is a lot closer to what I would have believed normal for a lowered car) and the <b>right was at -1 degree 55 minutes or -1.92 degrees</b>. Maybe it is just me, but I find the differences between the left and right (<b>0.27</b> of a degree, not minutes) a bit much, the car may have a tendency to pull. You should try to find out why, better yet you should move the sub frame left to right, by unbolting it and to try to equalize your camber and this should also affect your caster.
On the toe you indicated a <b>positive toe (toe in) of 0 degree 10 minutes or exactly + 0.16</b> of a degree per side which is exactly what Audi wants for the front. However, I will suggest something later on.
<b>Second, the rear set up.</b>
Now this is where I may open a can of worms for you. As I stated before, I think you are <b>too low</b>. Your camber in the rear is <b>-1 degree 57 minutes or -1.95 degrees</b>. That is way too much. The rear camber should not be more (as per Audi) than <b>-1 degree 15 minutes or -1.25 degrees.</b> So basically, you are 0.75 or 3/4 of a degree too much on the negative side.
Your rear toe is also too much. You indicated a positive <b>rear toe at 0 degree 15 minutes or +0.25 of a degree</b> (even more then in the front!). Audi recommends a maximum of <b>+0.07 minutes or +0.12 of a degree</b>, that's half as much as the front.
By having too much camber and too much toe in the rear you have succeeded in getting the rear end more planted to the ground, in other words you have managed to have a stickier rear end (read even more understeer). We don't want that, do we?
<b>How to fix this mess</b>.
Well I think you are going to have to raise your car. But before we go that step, you will have to bring your car in for another alignment because before raising it, we want to see if in its actual lowered position, we can dial out some of that rear camber and toe. I'm willing to bet if things are the same as on the A4, that you will not be able to bring the camber back down to -1.25 degrees with a toe of +0.12 of a degree or less. If that is the case, up will have to go the suspension, by how much; it depends on your S4 suspension. Again if the similarities between the A4 and S4 hold true, my guess your rear is going to be somewhere between 25 to 25.25 inches, in other words you are going to have to raise it at least 1/2 an inch. This means you are also going to have to raise the front too. You can leave them equal front and rear or you could give the car a positive rake. This means having the rear end slightly higher than the front by <b>no more</b> than a 1/4 of and inch, 1/8 being very good.
As you can see slapping on coilovers is not that simple. To do it right is time consuming.
Now someone in the tread asked you if you were going to get it "corner weighed". Well I have a very easy answer for you. You <b>don't</b> need that at all. It is even more time consuming and requires more $$$ for nothing, especially for 99% road use. In a perfect world it would be nice to have it perfectly balance, but truth be told, even some pros do not bother to balance their cars if they are within 2% in cross weights. I bet you that if you sat in your car with the weight scale under it, you would not be too far off the 2% mark.
Also for a true corner weight, you need to unload the suspension. How do you do that? You have to disconnect the sway bars, front and rear, adjust the suspension, up and down until the proper numbers are reached. This means one or more corner will now not be equal with the others as far as ride height is concerned. The next step is to reconnect the sway bars, but wait, now you run in to another problem. If the car is perfect at each corner without them being attached, what will now happen when you reconnect them? You've got it, the corner weights are now screwed up. How do you get around that problem you say? Well, now you need to buy adjustable sway bar links so as to not preload the suspension again when attaching the sway bars, as you can see more $$$.
Back to the toe for a minute. I suggest you dial out the toe completely, that's right have the tech set 0 toe both front and rear (if he can). This way the car will be a lot more fun to drive. It will be perhaps a bit less stable in highway conditions but a lot better for tossing it around.
<b>BTW, these are only my opinions and the way my car is set up. These settings may not be good to you for what ever reason and I don't want to be held responsible for your own actions if you decide to follow them.</b>
Hope this answers some of your questions, good luck.
