Good advice. Don't want to end up in one of those "OWNED" pics
Getting back to your original point (stiffer springs)- The JIC setup is more of a track suspension than the Tein's and has a firmer spring rate than the Tein setup so I'm sure the JIC controls the body roll a bit bettter.

 

So this is why Nismo made really light and small swaybars to go with their stiff sport suspension...


right!? no?


krinkov ...you russian? ukrainian? polish?

 

Since I just put the Cusco's on, I'll give my $.02.

I like what they do on my STREET car, that is tracked occasionally.

I bought Carroll Smith's books back in 1975, and he knows his stuff. Correction....I just read he passed away recently. Sad.


I like bigger bars because they increase wheel spring rate when needed, as in cornering, yet I can still maintain a reasonable street ride comfort. On a track only car, suspension balance is best addressed with spring rates, leaving the sway bars for fine tuning. Lowering ANY wishbone suspended car will NEED BIGGER BARS IF THE SPRING RATE IS NOT INCREASED! The actual roll center to center of gravity distance increases drastically, increasing the "leaver" length. Sorry, I am not an engineer, but Carroll's books along with Paul Van Valkenburgh's books explain it a lot better.

 

Your last Avatar was better failsaf3!

 

krinkov,

Most of your points are correct. Two things though.

1) I think you know this and it probably just didn't come through very clearly but sway-bars do not affect total amount of weight transfer. Weight transfer is determined from 3 variables: cornering force, height of CG and track width. What sway bars do is they affect where the weight transfer occurs. I.e. if you had a car that transferred 500 lbs at the front and 500 lbs at the rear and you stiffened the front bar you may end up with 700 lbs of weight transfer in front, 300 lbs in the rear. If you increase both bars by equal amount, you will still get 500/500 but your rate of weight transfer will be changed and your suspension compression will decrease.

2) Sway bars really are analogous to springs except for the fact that they have no effect when both sides of one axle are deflected equal amounts. As such, there really isn't a way to say when more bar is too much unless you know more about the spring rates, damper rates and suspension geometry. For example, a car that is undersprung/overdamped can probably benefit from more bar (although it may still be undersprung in longitudinal response). So what I'm saying is that it is not necessarily true (or false) that adding more bar to an aftermarket-upgraded car will reach the point of diminishing returns. Its just not feasible to say that since it depends on those other factors as well. I don't know enough about the various coil-over systems available for the Z yet to comment on how they feel in terms of spring and damper rates. One other point: the reason racing suspension design favors setting up the car with an optimal spring/damper package and then going to bars for small handling balance adjustments is because race-car designers have much more room to design exactly what they want. For people like us, setting up a street car for track use, it is much harder to get the optimal spring/damoing rates without the adjustability of stiff bars. I'd love to order custom springs and dampers but I would need the full engineering specs of the suspension before I could make educated decisions - of course if I could get that, I would be set, I have a full copy of Reynard Kinematics on my computer that is great for suspension design and simulation.

I personally like bars because they are a cheap way to adjust handling balance on cars that are not purpose-built racers. I have had great success with bars in my previous car and I think as long as you know what you are doing, they can be very helpful.

I hope this made some sense, I typed it in a stream of consciousness manner and have not proof-read.

Jason

 

After a glorious day at Blackhawk Farms, I still maintain the bigger anti-sway bars work.

See my other thread:

https://my350z.com/forum/showthread....threadid=32837

I've been thinking a lot about the feathering, and I'm leaning towards a shaved tire. Much less tread block to squirm. Should be a lot quieter too.

 

So, it seems to me if people want their car to be more neutral with less understeer, they should get a stiffer rear sway, and leave the front alone. Does anyone sell just the rear? Cause that is what I want to achieve.