26mm M3 swaybar install with Powerflex bushings and adjustable end-links. What else to take care of ?

[wertyu78]

I picked up a 26mm M3 swaybar for a whopping $30 yesterday. I'm going to clean it up and paint it this weekend, then install with new Powerflex bushings. Along with the new swaybar I plan on replacing the old/tired swaybar end-links.


I use the car for DD and Autox/technical mountain driving. I find myself having to trail brake the car to get it to rotate. Before I tackle the worn suspension with coilovers, I plan on trying to keep the car flatter through the corner.



1. Are adjustable swaybar end-links really worth it? I don't mind spending the money if it yields me good results. I just don't want to pay for a feature I wont use.

2. I've already replaced my FLCAB's, are there any other bushings I should tackle while I'm in there?

[Ryans323i]

I'm glad you brought this up. I've always wondered about sway bars and adjustable endlinks. What makes the aftermarket ones better than the ones already on our cars?

[BimmerWill]

I'm glad you brought this up. I've always wondered about sway bars and adjustable endlinks. What makes the aftermarket ones better than the ones already on our cars?

Im not sure what the stock size is for our sway bars but I know that the bigger the diameter of the bar the better it responds and keeps the car more evenly planted on the pavement.

I can't say personally how much of a difference it makes but I know of people who swear by bigger sway bars.

Wert,
As far as additional items have you done your Rtabs? I replaced mine with powerflex urethane ones and it seemed to help keeping the rear end mire stable as well as eliminated some unusual tire wear I was getting on the inside wall that was eating through my tires.

Sent from my DROID BIONIC using Tapatalk 2

[wertyu78]

I believe it is 23.5mm for the stock ZHP swaybar. RTAB's will be done soon. I forgot about those.

Im not sure what the stock size is for our sway bars but I know that the bigger the diameter of the bar the better it responds and keeps the car more evenly planted on the pavement.

I can't say personally how much of a difference it makes but I know of people who swear by bigger sway bars.

Wert,
As far as additional items have you done your Rtabs? I replaced mine with powerflex urethane ones and it seemed to help keeping the rear end mire stable as well as eliminated some unusual tire wear I was getting on the inside wall that was eating through my tires.

Sent from my DROID BIONIC using Tapatalk 2

[danewilson77]

M0nk3y (Kyle) has great input here.

[M0nk3y]

Looking at your sig and OP post, it doesn't appear you have suspension modifications, correct me if I am wrong.

The only point with adjustable endlinks is to avoid pre-load from the sway bar. When you lower a car, the endlinks can only rotate with the car so much before it cannot physically avoid pre-load on a bar. When you add pre-load to a sway bar, you defeat the whole purpose...so that is when you need to add adjustable endlinks. If you see yourself getting suspension, get adjustable endlinks. However, my friend and a very knowledgeable guy who works at TCK Racing has his car lowered (E36 M) on TCK DA Coilovers and runs OEM endlinks and does not have any pre-load.

A front sway bar will help level out the front end, but will increase understeer. Tires corner best when they are loaded equally. There is more cornering force the more you load it, but it suffers from diminishing returns. For example tires with 40%/60% load on left/right will generate more overall cornering force than 20%/80%, even though the overall downward force on both tires is the same.

What an anti-roll bar does is resist body roll by increasing the downward load on the outside tire. Generally it corners flatter but with less grip. The only way to combat this and regain that grip is camber, usually.


Lastly, if you really want the rear end to rotate just remove the rear swaybar.

Before (OEM 27mm Swaybar, Toyo T1R Tires)



After: (H&R 30mm E46M Swaybar, Hankook RS3s)

[terraphantm]

I think there's more to it then the absolute thickness though. Otherwise you wouldn't have adjustable sway bars. And then the E46 M3 CSL has a 30.8mm sway bar (4.8mm larger than stock) in the front, and 22.5mm in the rear (1mm larger than stock). I'm pretty confident that the CSL does not understeer any more than a standard M3

One reason I'm hesitant to upgrade beyond my stock sway bars is that the sway bar mounts are weak. I've read way too many cases of those mounts ripping out on the Z4 boards. Admittedly I haven't seen it as much on the E46 side, but still. At that point I'd rather just get stiffer springs


Also for E46s, an option for shorter endlinks is to use E36 endlinks

[wertyu78]

What a great read. I learned quite a bit. I appreciate the reply. I do plan on going with an aftermarket suspension setup in the near future. However, I don't plan on going super low either. I think I'll be fine with OEM endlinks. I'll see how the M3 swaybar works out with new end-links and report back.

Looking at your sig and OP post, it doesn't appear you have suspension modifications, correct me if I am wrong.

The only point with adjustable endlinks is to avoid pre-load from the sway bar. When you lower a car, the endlinks can only rotate with the car so much before it cannot physically avoid pre-load on a bar. When you add pre-load to a sway bar, you defeat the whole purpose...so that is when you need to add adjustable endlinks. If you see yourself getting suspension, get adjustable endlinks. However, my friend and a very knowledgeable guy who works at TCK Racing has his car lowered (E36 M) on TCK DA Coilovers and runs OEM endlinks and does not have any pre-load.

A front sway bar will help level out the front end, but will increase understeer. Tires corner best when they are loaded equally. There is more cornering force the more you load it, but it suffers from diminishing returns. For example tires with 40%/60% load on left/right will generate more overall cornering force than 20%/80%, even though the overall downward force on both tires is the same.

What an anti-roll bar does is resist body roll by increasing the downward load on the outside tire. Generally it corners flatter but with less grip. The only way to combat this and regain that grip is camber, usually.


Lastly, if you really want the rear end to rotate just remove the rear swaybar.

Before (OEM 27mm Swaybar, Toyo T1R Tires)



After: (H&R 30mm E46M Swaybar, Hankook RS3s)

[wertyu78]

Your point is noted. I'll look into the E36 end-link option as well.

I think there's more to it then the absolute thickness though. Otherwise you wouldn't have adjustable sway bars. And then the E46 M3 CSL has a 30.8mm sway bar (4.8mm larger than stock) in the front, and 22.5mm in the rear (1mm larger than stock). I'm pretty confident that the CSL does not understeer any more than a standard M3

One reason I'm hesitant to upgrade beyond my stock sway bars is that the sway bar mounts are weak. I've read way too many cases of those mounts ripping out on the Z4 boards. Admittedly I haven't seen it as much on the E46 side, but still. At that point I'd rather just get stiffer springs


Also for E46s, an option for shorter endlinks is to use E36 endlinks

[M0nk3y]

I think there's more to it then the absolute thickness though. Otherwise you wouldn't have adjustable sway bars. And then the E46 M3 CSL has a 30.8mm sway bar (4.8mm larger than stock) in the front, and 22.5mm in the rear (1mm larger than stock). I'm pretty confident that the CSL does not understeer any more than a standard M3

One reason I'm hesitant to upgrade beyond my stock sway bars is that the sway bar mounts are weak. I've read way too many cases of those mounts ripping out on the Z4 boards. Admittedly I haven't seen it as much on the E46 side, but still. At that point I'd rather just get stiffer springs


Also for E46s, an option for shorter endlinks is to use E36 endlinks

Tires, springs, shocks, and sway bars all absorb energy and the mass of the vehicle during braking, acceleration, and cornering.


Stiffer sway bars reduce body roll and help mid cornering. Reduction of body roll means that mass will be loaded onto the other components, and namely the tires as those are the only points of contact to the actual ground. The tires now have to work harder on the corner end that has less body roll. If you were using 100% of the tires grip already in cornering, and now you are asking the tire to handle 20% more grip due to weight transfer from a stiffer sway bar, the tire will break loose. Because you know, it can't do 120% of the work considering the limit is 100%.

This will create understeer.

Because the CSL M3 has higher performance tires, it can therefore have more corner grip without exceeding its front end grip.

Adjustable sway bars are for different conditions. I can't run 30mm on a airport concrete because it is super grippy and I'll understeer very easily (and I have learned this from experience). On other surface conditions where perhaps my car is too much oversteer (aka last weekend) I can stiffen up the front end by going to 31mm and increasing front grip.


Mounts do get ripped out, but it is an easy reinforcement. Stiffer springs is not the easy solution to reduce body roll, you can actually have negative effects in doing so because you cannot properly load the tires.