Anyone know the rate of a tanabe s13 front swaybar (30.4mm hollow bar)

[a_ahmed]

As the title states, anyone know or know of someone who has measured the rate of the s13 front arb 30.4mm hollow chromoly bar by tanabe?

[a_ahmed]

Sheesh no body by now ?

I was wondering what the stock is and what the tanabe is.. vs the sikky one where they give data.

The sikky 32mm solid bar is 414lbs/inch of deflection. Their tubular test bar which was 35mm with 1/4" wall took 314lbs/inch of deflection. Interesting no.

It's 3 ways adjustable unlike the tanabe chromoly hollow one with my spliced heim endlinks... so I figured this is a descent deal.. and I about to score some properly built progress front heim endlinks... and compliment with my rear progress bar that's soon to come... All three being adjustable it'll let me fine tune just fine and dandy, best of both of worlds in one package.

[a_ahmed]

So I contacted Tanabe directly and guess what specs they told me:

Not a problem. However, the numbers I have are metric, so you'll have to calculate your conversions.
Anyways, here's the rate: 567kg/0.05m

And just for curiousity's sake, here's the rate for our rear bar: 22mm diameter hollow at 277kg/0.05m

How?

If I convert 567kg/0.05m to lbs/inch it comes out to be 635.010682 pounds / inch

MORE than the solid 32mm sikky one???

[BeerBringer]

Hmmm
567kg/0.05m -> 113.4kg/0.01m or 11.34kg/mm -> 24.98lbs/mm -> 634.44 lbs/inch
You did the conversion right but you might be comparing apples to pears.

Are the values specified calculated or messured in a rig?
If so how was it calculated or how was the rig setup.

If they did a hand calculation they might have simplified the problem ALOT.
The geometry of the bar does a hand calculation hard.

Random front swaybar pic:



If the geometry of the bars are the same the only thing that should matter is the diameter of the bar. If space (diameter) is not a problem a hollow bar is always better when it comes of weight.
There are almost no difference in E/G-modulus between different steel materials.

Off topic: Note that the swaybar springrate of 11.34 kg/mm can not be directly compared to a spring you use in your strut/coilover. You need to take the position of the coilspring/swaybar on the control arm into the calculation.

If anyone can get good meassurments (in 3-planes, X Y Z) I might be able to do a simple FEA of different bar thicknesses.

[a_ahmed]

Okay I spoke with this guy from Tanabe again (Michael Gambos Jr.) he is very helpful and we're having a little discussion (he said he might know me from NRR so he might actually be on here).

He told me the stock bars are

front: 365kg/0.05m 408.781127 pounds / inch
rear: 168kg/0.05m so 188.151313 pounds / inch


The sikky test must have been different, ill have to contact them and ask them how they both did the tests so then we can either interpolate the numbers relatively or ask them if they could do the numbers in the same fashion.

Interestingly he seems to have an s14 track car and he is running a bigger rear than front (stock s14 front and whitelines at full stiff rear). The springrates he is running are almost what i am except im 1kg/mm more front biased he is 10 front 8 rear im 10.7 front small difference maybe but whatever.

The numbers he gave me was for the jdm s13 bars (im going to guess they are the same if not slightly bigger i remember reading the jdm rear was bigger than the stock usdm ones).


I will definetely try something bigger in the rear to see how it helps or doesnt help... since obviously i had no adjustability it is something new for me to toy with... I want the car to rotate and transition better... obviously i played with rebound last sunday and i did manage to get some change in the car's handling but it still felt a bit awkward. Well whatever, all this is for sake of some fun experimenting.

[Matt93SE]

Dude... stop jacking with your car and learn to drive it as-is. If you can drive a poorly handling car well, then you can drive a good handling one even better.

[McCoy]

Ahmed, there have been several of us on here running a stiffer rear bar than front and are happy with the setup, progress front bar full soft and rear at middle setting here.

That being said, I think you should just continue to work on your driving and the basics for a bit more, just my personnel opinion though. Heck most of your problems related to over/understeer could be tire pressure related, here is some FREE adjustability that only takes an inexpensive gauge and can be adjusted between sessions with minimal work

[a_ahmed]

lol i didnt say im not working on my driving some more :-/ I am trying to right now go to as many track days as i can before season's over I just keep myself busy with the tinkering part u know i love it :-/ And its kinda fun to make changes you can feel on the car... like last time i fiddled with rebound i could definetely change how the car turned in behaved etc... but yea :-/ Its just for the fun of it. I am not getting it right now just the usual research. I lows on the monies atm, other priorities. I havent made any change on the car other than corner balancing which was very noticable (awesome)

[McCoy]

You're making changes based on what you feel and that can change with having the tire pressures set right, that's all I'm getting at.

[Bumnah]

It's also hard to get consistent with your driving if the car is constantly changing.

[Matt93SE]

it's also hard to get consistent with your driving if the car is constantly changing.

+100000

[a_ahmed]

Okay so wthe guys at sikky contacted me curious about my heim endlinks and while speaking to them i mentioned my deflection findings vs theirs (questioned them). They went and remeasured their stuff and supposedly THEIR measurments are as follows:

Ok, the measurement we posted in the thread is actually for a different measurement.

Bar output is as follows in lbs/inch of deflection:



End hole = 1001

Middle Hole = 1205

Inside hole = 1475

sorry for the confusion. I will edit the thread to be correct.
thanks

LOLLLL 1500lbs/inch of deflection uuuh yeah thats hardcore insanity

[Def]

Any measurements of other bars as a comparison?

[a_ahmed]

unfortunately no this is all i've found out so far, ill contact progress and ask them for their rates.

So so far only the tanabe stuff, the sikky stuff and the stock oem nissan stuff as mentioned above