Stiff Front Sway Bar Thoughts
 

It seems that the general consensus is to run a stiff sway bar up front and a soft or no rear sway bar in back.

Is this set up good for any situation or only good for specific ones (ie. track, autocross only)?

It's good for any situation when you turn your car hard.

Smart *** comment aside, the Z will benefit from a stiffer front end with any spirited driving.

Thanks. Yeah I wanna go on full stiff front sway but wanted to make sure it applies to any driving condition either DD, spirited or track.

I just added the Eibach front sway bar, set to the stiffest setting and it's perfect for a daily. It feels like how it should have came from the factory.

I daily a Hotchkis front bar 50 miles a day. I love it whether I am driving to work or going out to play. The cheapest place to get one from is Amazon.

I do both DD and track with the Hotchkis front bar. Love it for both.

So should I just buy an eibach front + spl links and call it a day?

or is there anything to be gained by going for a full set front+rear? are we talking 5-10% difference? I do value the highly stock compliance at the limits on uneven pavement as it's a daily setup.

Thoughts appreciated!!!

I'm probably not the fastest here (only 2 track days so far) but I personally actually like aftermarket front and rear (I use stillen) and strangely I think I may even soften the front (one softer than middle) after first track day with oem coils/shocks and stillen bars set to middle/middle I felt balance was great with just a hint of oversteer (and totally eliminated factory understeer) when pinching a turn. After going powertrix with 12k/11k (keep in mind oem is 7.5k/8.1k) I then felt a touch of undsersteer when pushing it in a turn (but the shocks are awesome and completely kept the car stable in the dip at turn 6 at leguna). So I myself couldn't think I would want no rear bar or even oem but maybe I just haven't gotten fast enough to enter turn super hard or I just like a loose rear.

I think Rusty has a lot of track experience so I would trust him but just thought I would give another opinion.

Front bar is all you need. :tup:

The whole idea is to have a balanced car, or close to it. For DD, the Eibach is fine. You'll notice the difference. Everyone who has changed bars. Doesn't matter which bar. Have felled an improvement. If you have big meat meats/sticky tires, driving style. Then I think you would need the Hotchkis.

My SPL linkage squeaks afterwards if I get caught in the rain. Then I have to give it a shot of oil. Then it's good until the next time. Also to keep your new bars from squeaking. Where the bar bushings sit on the bar. Wrap that area with white teflon pipe thread tape. Then smear grease over the area and inside the bushing. ;)

Any other opinions on this?

About to order soon! :stirthepot:

Front bar only. I have the Hotchkiss but may get an Eibach for lower grip surfaces.

If I already feel the back slipping, will the sways make it better or worse?

Whats the general consensus for spirited street driving?

Currently using Michelin Ps4s 265/35/19 f, 305/30/19 r

Regardless of what type of driving you're doing the answer is "front bar only". For the street, the Hotchkis might be a bit overkill. The Eibach front bar maybe the way to go.

A front bar should help bring an oversteery car back to neutral.

Yeah, you do get a little bit of waddle from the front bar on uneven/bumpy roads with the Hotchkis. I notice it, but I am not taking it off... LOL

So, going with either the Hotchkis or Eibach front bar, what's the pros and cons of each for daily use which may see a track once or twice a year?

Why would I pick one over the other? Price is not a factor.

Depends on how hard you push it on the street.

What Rusty said! I ran Eibach on the street and it was a great improvement over my Nismo bar. It was fine for most everything but I did experience with under steer on the Dragon at speed. I switch to a Hotchkis bar because of that experience and because I was going to track the car. It was another step forward. The only understeer I got on the dragon was because I took the corner with too much speed. I don't really see much difference for most driving on the street for the most part. Oh you need to keep the Hotchkis bar greased up...it creaks a lot more than the Eibach if you don't. I love it matched with a square setup at the track...very predictable and little understeer and the right amount of understeer for my driving style.

Driving style should be a consideration as some people like some understeer...I'm not one of them it scares the crap out of me. I rather have my arse hagging out! :p

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Well I'm probably more conservative than some on here, even though I do push the car from time to time. And honestly, I'd rather have no under or over steer.

A staggered setup is going to promote understeer. The Hotchkis sway bar will help a lot with that and squaring up will get you where you want to be on the street even with a Eibach front bar.

So short of going with a square setup, going with the Hotchkis is probably the best bet?

I think you could get pretty close with the Eibach bar too if you run a tire like ps4s or re-11. The deal is your back tires can and will over power your front tires so running a good wide tire up front will help a lot! The other thing is learning how to brake properly so you aren't over driving the car!

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Go with both Hotchkis bars. Set the rear on soft and see how you like it. Then set it on hard and try again. With my some what over square set-up. I run the rear bar on soft.

I been waiting for to jump in! :D

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Just got back from having dinner with my daughter. :D Catching up on the new posts.

Again, this is pretty much street only, and even though I push the car from time to time, I don't push it to the point of the tires losing grip.

This is all just for some spirited driving, and the fact that I'm headed to the "Dragon" in September and didn't want to go there completely stock, hence the recent suspension upgrades out of the clear blue all of a sudden.

The tires are all brand new with only a 3k miles on them, if that, so those aren't getting swapped out anytime soon. And remember, I live in Florida, so 99.9% of the time, the car isn't seeing any kind of wild curves at all, just the occasional on and off ramp. LOL

Sounds like you want to be talked out of one bar into another.

No, just giving more details about me and the car, that's all.

They're both priced pretty much the same, so money isn't an issue. I just want to buy once. Not buy one, then a few months later think "well, I should have bought the other one...". I don't like "What if?" scenarios. LOL

This is precisely why I was asking about the pros and cons of going with either bar.

I feel like the Eibach bar is enough for the street. My next upgrade will probably be dampers instead of a stiffer bar. Then again I've never ran the Hotchkis.

Think you would be happy with either one. At this point. It's splitting hairs. One is better at the track, and the other is not. Think if you plan on a couple of trackdays/hard street. Hotchkis. If not, go with the other one.

:iagree::iagree::iagree:

Seems that the general consensus on running a stiffer front bar is that it will induce understeer but, why is the 370z the exception and more bar is preferred?

Can someone explain that to me. thanks.

It not to complicated...most cars these day are setup to understeer because when the average Joe or Jane make a mistake and takes a turn to hot the correction to it is hit the brakes. The Z is no different and do to having a staggered tire and wheel setup it is more exaggerated. The increased rubber, traction and power of the rear wheel will overcome the grip of the front wheels and tires. Have more front bar helps combat that condition. This why many, me included run square at the track and still have the biggest bar available up front.

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This is precisely where I'm confused :icon14:

Wouldn't this situation cause understeer and having a stiffer bar induce even MORE understeer?

Not saying you guys are wrong, just wanna know why is this different in the Z?

No...think NASCAR! The setup causes the car to push because there is not enough grip in the front to hold the car in place so even though the wheels are turned the car goes straight. Oversteer occurs when the front of the car turns (has more grip or resistance) and the rear rotates around do to the loss of traction in the rear.

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Great. Thanks Hotrodz

The Z is not the only exception. Almost every car with a greater front weight bias has a larger front bar. The wrong information has been spread over the past decade that the rear bar should be enlarged for a plethora of wrong reasons. In reality the only reason the bars should be increased is if you have a significant increase in torque or increase in weight and or spring rate.

Most cars understeer from either having too much weight on the nose, or not enough at speed, this is why a 50/50 weight balance is ideal or slightly rearward (48f/52r). Under braking and lateral forces, weight shifts forward and outward increasing load on the front tires. Too much load and you overload the tires and lose traction, too little and the tires won't grip. This balancing act is the most critical aspect of design.

The Z has more weight on the front axle, no where near the levels of a Subaru or VW. But combined with smaller tires, you get a loss of traction from tire overload. There isn't anything funky about the suspension design or alignment that would cause additional understeer.

Increasing sway bar size is rather compromising unless you're increasing the spring rate or the amount of lateral load (increased g forces from bigger, stickier tires). Adding a larger bar with the same factory tires will just increase the load on the outter tire and reduce the contact patch on the inner tire. This is no bueno, thus the plethora of complaints of understeer.

Adding a larger front bar will reduce roll as intended with increased lateral load or additional weight (downforce). Increasing the rear bar causes a cross weighting effect that will transfer additional load to the inner front wheel, sharpening steering response and tire grip. The downside being increased instability and increased load on the outter rear tire. The trade offs are vast if you aren't actually increasing tire grip and load capacity.

Lol I was just trying to keep it simple. It is basic physics, weight, friction, force and power. Force=momentum and power=acceleration. I got a C in physics by the way so I'm no rocket scientist lol!

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It also has to do with camber curve. If the camber curve can't keep up with the body roll then you need to reduce body roll. Plus excessive bodyroll is just harder to control.

This is taken into consideration from factory. Thus the oem alignment specifications. Things start to change when you decrease or increase tire grip, IE larger tires, grippier' tires.

Reducing body roll in the form of a stiffer sway bar doesn't reduce camber curve however, in some cases of high load you may be increasing it. You will need to combine this with a higher spring rate to combat compression across the axle. Neither is a great option unless you increase tire traction and tire load.

and the melting pot of tuning begins :stirthepot: