Stiffening The Rear Sway Bar

[altezzaclub]

I thought I might have a go at stiffening the rear sway without rushing off to Whiteline or similar.

 

Has anyone clipped a second sway bar on below the stock one and hooked it up? I figure on making a double mount on the diff then using a pair of heavy little coil springs under tension at the chassis end between the two bars. That way the first sway bar works with the second adding more and more tension as the springs stretch.

 

Any ideas?? Is there a Corona one or similar that a wrecker might have that is stiffer anyway??

[Reaper_Mobb]

I have no idea, but if its not for the rode can you just get out the welder and "supplement" the current one?

 

like i said i have no idea if its possible, just an idea

[SLO-030]

I hope you don't mean welding another swaybar to the original one Reaper?

 

Sway bars are infact springs. Which are made from spring steel. If you go welding it with anything other than Stainless rods and don't temper it. it will become brittle from the heat and eventually crack.

 

As for clipping a second swaybar in. apart from being a bit crude, it has worked before. Just make sure what ever you use to hold the two together is plenty strong.

[350dream]

If you go welding it with anything other than Stainless rods and don't temper it. it will become brittle from the heat and eventually crack.

 

Stainless rods??? is spring steel iron free????

not sure bout welding but,

if you want to bend spring steel all you have to do is heat it up so it is cherry red all the way through, bend it and let it cool, don't chill it

Edited September 13, 2009 by 350dream

[altezzaclub]

Ah- I knew that much... If you weld spring steel the weld is stiff and the spring steel next to it is flexible, so it breaks at the weld. I'll do some planning and see what people say.

 

The maximum strength of a sway bar can only be the weight of the wheel and bit of diff it carries, as after that it picks the wheel up. I'll pop the stock one off and measure the torque deflection on it. I've got a couple of other sway bars lying around.

 

Putting a stiffer one on the back of the Altezza gave pin-sharp turn-in and wiped out the trace of understeer it left the factory with.

[Evan G]

ive made a topic showing a eb sway bar fitted in my rear of my ke55

[philbey]

Stainless rods??? is spring steel iron free????

 

Can't have steel if you haven't got iron.

 

Spring steel is high (>0.6%) carbon, so welding it as Ryan said will cause it to go brittle and crack as it cools. You'll also mess with the temper.

 

Altezzaclub, this was pretty common upgrade back when there wasn't a huge selection of aftermarket swaybars available at the drop of a hat. Look through a few old fast fours mags from the early 90's you'll probably see a few.

 

I just did a very quick dirty calculation that will give you some food for thought; adding a swaybar will double the stiffness of the front, whereas swapping a 20mm swaybar for a 28mm sway bar (with all other geometry the same) will be 4 times stiffer.

 

If you want to swap to a swaybar from a different car with different geometry, let me know, I can work out the change for you.

[altezzaclub]

Thnakyou Mr Philbey Sir, I have been wandering around the wreckers today and for $15 I can go and unbolt an early Celica one. The rear end looks identical except it has a 15mm diam sway bar to replace my 13mm stock one.

 

I will put them both on the workbench, fix one and add a weight to the other, then measure the deflection. It should roughly agree with the % increase in stiffness you are just about to calculate for me!!

 

It will be a shitload easier than adapting two together and will take out some understeer I'm sure! The front I plan to leave stock.

[philbey]

Send me the dimensions of both swaybars, we'll see if the numbers meet up with the practical execution.

 

For example, the rear swaybar should be a U shape; send me the arm lengths, as well as the actual torsion section length, of both bars

 

or, if they're the same dimensionally, I'll just put it into my spreadsheet.

[altezzaclub]

Not only that, will take photos! The bar is bolted to the diff housing, the arms face forward, and it has a semicircular dip in the crosspiece to allow it to go under the diff. That must make the twist along the bar as it goes across the car rather odd.

 

Give me a day or two!

[SLO-030]

if you want to bend spring steel all you have to do is heat it up so it is cherry red all the way through, bend it and let it cool, don't chill it

 

More like. Heat it, Bend it or do what ever with it, whilst still red hot quench it in quenching oil (not any old oil), then temper it.

[Taz_Rx]

Sort of an idea I was toying with.....

 

Why not just get another rolla sway bar, cut the ends off it (where it attaches to the chassis) and then use some clamps to hold it onto the existing one. Now the bit I was interested in - If you clamp it all the way around the sway bar then you'll nearly have twice the stiffness. However if you bring the last clamps (up at the ends you cut off) back down the car towards the diff your basically reducing the seconds swaybars effectiveness giving you an adjustable sway bar system!! :lolcry:

 

I'll draw a panit pic if you don't know what I'm trying to say.

[snot35]

I've you decide to go the dual bar method, I have pics of a setup removed from car in the shed, if you like :lolcry: From a KE55 I believe

[jason12]

Id be keen to see some pics of the ke55 double swaybar setup. Haven't looked at the swaybars at all on rollas but to do it to r31s isn't too hard and gives good results...

[rob83ke70]

this is the ke70 we are talking about? let me know if you want a hand with anything, I'm accompanying kylie to bathurst this weekend for a khanacross but other than that i normally am up for anything on a weekend.

 

the ke55 has an aftermarket rear swaybar (installed so long ago nobody knows anything about them) which is 14mm diameter, and the stock front swaybar, the rear bar makes an incredible difference to oversteer/understeer and just how the car handles. bigger swaybar on the ke70 would do the same sort of thing as adding one on a ke30/55 i would imagine.

 

I never got the hang of driving my ke70 well :lolcry: didn't have it long enough.

 

Robert.