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

[nike001]

I've been tossing the idea back and forth of getting some upgraded sways (H&R: 28F, 21R IIRC), so these posts are helping my edumacation

[terraphantm]

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.

I never said a front sway bar doesn't create understeer. The point I was trying to make is that there's more to it than absolute diameter. Solid vs Hollow makes a decent difference, as will the overall geometry. I also don't think the CSL's tires are much of an excuse. Yes it does have more absolute grip, but that grip isn't infinite. It will let loose eventually. The real answer probably has to do with the wider front track and generally differently tuned springs rates and dampers. Not that I've personally driven one, but iirc almost all testimony indicates the CSL is a decent bit more tail happy than the standard m3. I know my own car definitely shifted towards oversteer just by putting spacers on the front (need them for winter tires, changing wheels next year)


Anyway, I don't think it's appropriate to get super stiff sway bars on stock springs. The sway bar mounts that point are under more load than intended. You can have negative effects from any suspension mod, even sways. The key is to select components that are well matched to your car, driving style, etc...

[Imola.ZHP]

Instead of creating a new thread, I thought I would just bump this one.

I am on an H&R Sport Cup kit, my car only came down about 0.5" from stock. I am currently running stock end links, but was told I should go ahead and replace my end links as I'm doing the second stage of my suspension re-do (first stage was the H&R Cup Kit). My new RTAB's are installed, my FCAB's are on the way, I'm going to check my ball joints (FCA's) on Sunday. I am trying to determine if I should go shorter on my end links or if its necessary considering the very mild drop from factory.

Thoughts?! Is there anything else I need to do? I replaced FSM's and RSM's when I put the cup kit in. While this car did see some sweet auto-x action back when I first got her, she is just a daily driver now.

Thanks!

[danewilson77]

You have stock endlinks installed with the H&R cupkit? I would stay with those.

[Imola.ZHP]

^ yup, they came off and went right back on, no problems...

[echo46]

Agree, I would also stay with stock.

[Imola.ZHP]

I'm chasing a "popping" noise in the front, I'm pretty sure its my FCAB's, could it be end-links? The research I've done (google searching) says the cup kit doesn't require adjustable end-links. Then I read another thread of a popping issue with the cup kit where adjustable end links were suggested, but it was never updated to say if that cured it or not, that was on a mini too...

EDIT: I'll take them off and see if the noise goes away, that should do the trick, right?

What about tie-rod ends?

[echo46]

About a year ago I had the popping sound in the front. Popping occured at slower speeds and when in reverse. I replaced the end links and the popping disappeared. When I inspected them they were in pretty bad shape. I replaced with Lemforder/

[LivesNearCostco]

I read somewhere that you only get preload on the swaybar if you lower one side more than the other. If both sides are at the same height and swaybar links are same length (or disconnected), there should be no load on the swaybar. If you put more weight on one side (e.g. passenger, or driver eats really big turkey dinner) or lower one side more than the other for corner balancing, then the swaybar will be preloaded. You can use adjustable end links to eliminate this preload.

In the back, adjustable end-links also help prevent the swaybar from hitting things. The stock rear swaybar just squeezes in there so if the aftermarket sway is thicker, longer at the ends (for adjustability), or you lower your car a lot, it may hit the axle half-shaft or lower control arm and you can adjust the end link to stop that.

[danewilson77]

http://www.zhpmafia.com/forums/showt...order-endlinks