In order to make rear sway bar little stiffer did anyone tried drilling additional bolt holes? Please share your experience, does flat portion of bar have enough room for additional hole or did you have to press it first? I like to increase rate of my rear sway bar by 10-20%. Thanks

 

hummm...can the bar handle the extra load without breaking?

 

thats gangsta as hell..lol....i dont think that would do n e thing...n never heard of that....please let me know if that works....thanks...

 

just go buy a set of sways...last thing you want to do is ghetto rig your car and have the sways snap on your cheap ***...then you will be posting with: I made a cheap sway bar adjustment and it totaled my car thread!

 

I know, I know.
See I have been waiting, for a while now, on 350evo rear bar to be in stock.

I am OK with my current suspension, revised 350Z springs and front bar with Tokico D-Specs, it’s just that at high speeds front is starting to plow in curve. Perhaps slightly stiffer rear bar wont make a difference for my understeer if my front tires are already at limit, BUT, I have this spare (350Z) OEM rear bar and looking at Stillen pictures made me thinking.

Rear sway bar rate:
OEM 385
350evo 378, 490, 607
Stillen 412, 581, 654

https://g35driver.com/forums/attachm...1&d=1149111407

 

Looking at the oem rear bar I have off the car in my garage, it looks like one could drill another hole. However, I'm not sure you'd be able to have enough room to seat the nut/washers on the bolts and have moved back enough to have really effected the lever arm distance.

Since I believe your considering a rear bar only mod. I'll caution you on that. Tuning at the limit behavior is fine, but are well dialing into the sweet spot of marginal whole car tire contact patches? Your likely only working with a small area of the inside tread, especially on the front tires.

 

Gsedan35, thank you very much for reply, you are absolutely correct that there would be no enough room for the bolt nut/washers on the bar without pressing it first.




Currently I have –1.2L and –1.3R camber on front and –1.7 on rear. Without front camber kit I don’t think alignment can give me any more. I ordered infrared pyrometer and in two weeks will see how tires contact patch looks like on the track.

Gsedan35, I am not sure I understood last two sentences of your post - please explain. Thanks

 

The right angle twist [torque] arm portion of sway bar is the lever.
If the arm length is 12" [to center of hole] adding a hole at 11" = 12/11 or 9% stiffer..............usually bars are 50-75% as stiff as spring [ the real at wheel/tire- ROAD INTERFACE] stiffness so a 9% stiffer rear bar added to 100 pound springs = up to 4.32% total stiffness increase at the interface.

Obviously a shorter lever arm say 6" and a 5.5" added hole results in the same number.

Sometimes oem bar are only 1/3 of the spring stiffness, sometimes you run into older cars without a rear sway bar period.

Since the springs are roughly set to equal the weight ratio: the front and rear sway bars [as installed and coupled to suspension thru rubber bushings] should also be equal in ratio to the springs/sprung weight to maintain a NEUTRAL ROLL STIFFNESS.............this is never the case in oem designs to build in some progressively increasing UNDERSTEER for safety......the problem is the front tires are the weak link and increase in slip angle with progressive increases in side load.

Make the front tires stronger [via increased load index] and avail yourself of half the numeric increase [% load index in pounds] as a reduction in understeer as slip angle decreases.
MUCH MORE EFFECTIVE than increasing the tire load [washout] with a stiffer front sway bar or springs.

 

The load index of my PS/2 tires far exceed the load they see, so I don't see how making the front tires "stronger" will help. Making them stiffer by adding air (increasing PSI) I can intuit would help, but just changing to a wider tire with a higher load index does not seem to make sense to me (other than increasing the contact patch to reduce understeer).

Can you clarify what you mean by "stronger". Do you mean stiffer sidewalls?