help how to make a car ati roll bar

[whensparksfly]

any of you making your own car anti roll bar i am very interested to know what process you all use . cold beading the bar or heat treating the bar and what material you use.

 

[brightspark]

any of you making your own car anti roll bar i am very interested to know what process you all use . cold beading the bar or heat treating the bar and what material you use.

there made of spring steel tortion bar

 

[hotrodder]

2 Books to buy... Competition Car suspension by Alan Staniforth and Engineer to Win by Carroll Smith. Both cover various types from the production car bent lump of solid bar through to adjustable blade hollow tube competition styles. Physically making 'em is the easy bit, working out spring rates not so much but Staniforth talks you through the process of designing suspension pretty much from the ground up. Engineer to win begins by taking you back to school with some basic chemistry and then applies that first to basic metallurgy and applies the metallurgy to racing cars in general, pretty much all aspects of them- materials, design, fatigue (why things break) etc

Not the best material (Smith explains why) but plenty of aftermarket 3 piece bars are made from 4130, better ones from 4140 or even 4340. Unsurprisingly i'm talking about Americans, 4140 is en19 and 4340 is en24.

The numbers are bound to be wrong 'cause i've plucked 'em from the top of my head but hollow bars offer something along the lines 90% of the springrate for 50% of the weight? Whatever, they're a LOT more efficient than solid.

For a given rate diameters and wall thicknesses depend on length of the thing and the 'effective' length of the levers plays a large role too. Effective length is perpendicular to the working portion of the bar not the actual length when the ends of the bar are only bent 45°

If the car in question is popular enough for Eibach, Bilstein etc to produce uprated bars and the like for it i'd just buy them (unless you really want/need hollow adjustable bars), almost certainly cheaper than making 'em

 

[711jrp]

That's an excellent recommendation of reading material, the Carrol Smith book was one of a series of three if I recall correctly and all worth a look. Another good bedtime read is Race car vehicle dynamics by Douglas Milliken that'll give you a headache if anything will.

 

[chevy2]

I've made several antiroll bars,
Usually from 4130/chromemoly,
done 3 of them using 1" x 0.065" wall tube with the blade length around 5-6" long,
Bar length plays another big part, as they get longer they become weaker and require more diameter for the same gain,

They often take some trial and error on each application to find the sweet spot,

Another trick if you want to make one from solid bar as opposed to tube and assuming it comes apart is to make the bar diameter bigger than you need and then keep removing material on the lathe from the entire centre part of the bar gradually making it weaker,
As i said they often require trial and error,
Heres one i did recently.

 

[hotrodder]

Another trick if you want to make one from solid bar as opposed to tube and assuming it comes apart is to make the bar diameter bigger than you need and then keep removing material on the lathe from the entire centre part of the bar gradually making it weaker,
As i said they often require trial and error,

That is a neat trick. Both bars on my daily driver were made a similar way but tapering the ends (levers). As it's a big wafty barge i guess the idea was to give it a progressive rising rate in roll