IRS twin spring plates

turboboy Seriously Crusin Dubber

117 posts · joined Sep 2008 · 3 Dec 2013, 7:05 pm

#976854

Hi
I have a buggy with IRS and twin spring plates each side.
As far as I know that was how the 1st ones came out.
Is the any adventage or disadventage with them?
Also are the sharfts the same length as single spring plates?
Cheers

Snap Crackle Bang Seriously Crusin Dubber

146 posts · joined Aug 2009 · 3 Dec 2013, 7:47 pm

#976859

In theory the twin plates should be stronger / stiffer. The single plates make it easier to assemble the suspension. Both can use the same torsion bars. Type 3s continued with the double plates. My guess is they changed to single plates on beetles to save a few $$$.

bajachris88 The international telephone dialing code for Antarctica is 6

6,661 posts · joined Apr 2005 · 3 Dec 2013, 8:16 pm

#976864

Disadvantage of twin plate is you end up with the 'long' torsion bars, and thus can't go to 33'' tyres. 31's are the limit, as 33's rub on the torsion tube cover on the spring plate.

Single spring plates use the shorter torsion bars, and the shorter bars finish closer in, without protruding infront of the tyre tread (hence allows 33 inch tyres)

Strength wise, i never recall hearing anyone breaking a single or dual spring plate. You'd most likely break a torsion bar before that happens (heard that senario a few times!).

I believe the single spring plate, spring plate cover and shorter torsion bars (found in swingers) are a straight swap.

Needless to say, 31's are a great size without going silly, unless you need the extra ground clearance to balance front and have high torque transaxle or engine to suit.

(ô_!_/ô) (ô_!_/ô)
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Craig Torrens 6 times Australian, 7 times State Hillclimb Class Champion

8,040 posts · joined Jan 2003 · 3 Dec 2013, 8:51 pm

#976871

bajachris88 wrote:Disadvantage of twin plate is you end up with the 'long' torsion bars, and thus can't go to 33'' tyres. 31's are the limit, as 33's rub on the torsion tube cover on the spring plate.

Single spring plates use the shorter torsion bars, and the shorter bars finish closer in, without protruding infront of the tyre tread (hence allows 33 inch tyres)

Strength wise, i never recall hearing anyone breaking a single or dual spring plate. You'd most likely break a torsion bar before that happens (heard that senario a few times!).

I believe the single spring plate, spring plate cover and shorter torsion bars (found in swingers) are a straight swap.

Ok, there's potentially some confusing info above.

Factory single and dual spring plates for the IRS (CV double jointed) rear end share the same length torsion bars. As for strength, well Ive never heard of anyone breaking either. The single plate does allow the IRS arm to move around more (camber change) due to flex, whereas the dual setup tends to hold it better.

If you want to run the shorter torsion bar setup (for tyre clearance) then you will need to modify the spring plate from a swing axle beetle to suit the IRS arm. It is not a straight swap, but its a relatively easy mod to do.👍