Toyota OEM Torsion Bar Spring Rates? (2 Viewers)

[ikellymo]

Hi! I've been reading through forum posts about torsion bars on AHC models and everything else -

1. AHC and Non AHC Torsion Bars Question
2. LC-AHC with armor, difference between torsion bars
3. IronMan suspension VS. Old Man Emu?
4. Lx470 Torsion bars
5. LX vs. LC torsion and spring rates...
6. AHC and adding lots of weight
7. SwayAway TB's on built LX w/ AHC

So apologies if I've missed something, but I've tried.

But does anyone have actual spring rate numbers for 100 series torsion bar options?

I'd love numbers for the following:

Sway Away - 1661

Toyota OEM - 48161-60010, 48161-60010 - HDJ100 (diesel)

Toyota OEM - 48161-60020, 48161-60020 - HDJ100 (diesel) AHC

Toyota OEM - 48161-60030, 48161-60030 - UZJ100

Toyota OEM - 48161-60040, 48161-60040 - UZJ100 AHC

OME

TJM

Ironman

Diameters are also interesting, but I wonder if the variation in Young's modulus between different manufacturing processes requires empirical data.

Also, if anyone knows of more OEM variants than what I have listed, please chime in.

Or if anyone has a link to the TJM bars available in the US.

I'm hoping to put a table together to select TB's based on vehicle weight. I know this is pretty common knowledge for the non-AHC models, but I'd like the table to extend to AHC as well.

Thanks!

 

[JunkCrzr89]

I don't know what the spring rates are, but Sway-A-Way provides what appears to be an easy to use calculator that you could use to arrive at comparable spring rates if you had the measurements from each TB type: Torsion Bar Wheel Rate Calculator - Sway-A-Way | Racing Technology

Hopefully others will chime in with numbers/measurements, as I think this could be a very useful thread (sticky worthy).

 

[ikellymo]

Thanks! Yes, I'm happy to do some math and make a nice easy to use graph if I can get some good data.

 

[GTV]

Bump this up...
I'd like to know as well. I know that 80's used a bunch of different coil springs over their production run, I would assume the 100 series spring rates (front and rear) changed as well as weight went up.

 

[jerryb]

the torsion bar # hasn't changed from 08/2002.
assume different part numbers left and right mean different diameters. BUT idk. mine are 29mm both sides but I never measured length.
below are the numbers for LC from 08/2002 on.
Mine have to be original and both are 29mm left and right. Unknown length.

I'm all about sway aways for 220$ there is an option at 31 and 32 mm on their site. Foe me there's no way I'd jump up 2 or 3mm. Stock for stock I'd buy them though before anything else.
I've beefed up rear end cars with sway aways before. They're good and at reasonable price.

4816160040	SPRING, TORSION BAR, RH	48161	UZJ100 W(ACTIVE HEIGHT CONTROL)	1	05.2005 - ...
4816160030	SPRING, TORSION BAR, RH	48161	UZJ100	1	08.2002 - 05.2005
4816160030	SPRING, TORSION BAR, RH	48161	UZJ100	1	05.2005 - ...
4816260030	SPRING, TORSION BAR, LH	48162	UZJ100	1	05.2005 - ...
4816260030	SPRING, TORSION BAR, LH	48162	UZJ100	1	08.2002 - 05.2005
4816260040	SPRING, TORSION BAR, LH	48162	UZJ100 W(ACTIVE HEIGHT CONTROL)	1	05.2005 - ...

 

[ikellymo]

Interestingly, the Sway Away gas model is 31mm x 45.731inches and the diesel is 32mm x 47inches. I'm trying to figure out the reality of putting them on my partially built LX with AHC (how far out of spec it would be).

 

[nukegoat]

Calculating a torsion bar rate isn't hard since all steel is essentially the same modulus of elasticity afaik

 

[Somebodyelse5]

Calculating a torsion bar rate isn't hard since all steel is essentially the same modulus of elasticity afaik

Yup, call it 28E6 psi and you're pretty much golden for what we need.

I don't know what the spring rates are, but Sway-A-Way provides what appears to be an easy to use calculator that you could use to arrive at comparable spring rates if you had the measurements from each TB type: Torsion Bar Wheel Rate Calculator - Sway-A-Way | Racing Technology

Hopefully others will chime in with numbers/measurements, as I think this could be a very useful thread (sticky worthy).

That calculator is muy bueno. I was about to pull out the books...

 

[l3n0x]

Note: The diesel ones are longer. (so the bars are not compatible between HDJ and UZJ)

 

[abuck99]

Interestingly, the Sway Away gas model is 31mm x 45.731inches and the diesel is 32mm x 47inches. I'm trying to figure out the reality of putting them on my partially built LX with AHC (how far out of spec it would be).

For the comparison data; the Ironman4x4 Torsion Bars (Toyo50) I have in my truck measure 32.45mm diameter.

 

[chudly]

so which are beefiest/least sag/can hold most weight?