912 outlaw project

[Lightweight_911]

28mm rear torsion bars

That combined with an 18mm anti roll bar must have been scary in such a light car !

I would imagine you'll have a lot more fun driving the car now.

Say hello to David from me.


PS - (another) nice-looking house ...


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[Darren65]

Great move Chris, now you'll actually be able to drive that thing!

Cool looking neighbourhood.

[neilbardsley]

28mm rear torsion bars

That combined with an 18mm anti roll bar must have been scary in such a light car !

I would imagine you'll have a lot more fun driving the car now.

Say hello to David from me.


PS - (another) nice-looking house ...


.

Can someone explain why this is bad? Is it because the back end of the car is too stiff with a wider torsion bar?

[Gary71]

Massive roll stiffness at the back of a car relative to the front leads to oversteer. Its not like a SWB (or any early 911) needs any more help with oversteer!

Also with so little weight in this car it would have been almost rigid which won't help traction on anything less than a perfectly smooth track.

[Bruce M]

Also, for interest.

Torsion bar Spring rates increase by the fourth power of the diameter change. So small increases in diameter rapidly increases the spring rate.

Increase from 23mm to 28mm = (1+((28-23)/23))^4% increase in spring rate (all other factors being equal). Which works out as 220% increase or 2.2 times.

Roll bar change from 15mm to 18mm is a 207% increase in stiffness (Spring rate).

[964RS]

Front torsion bar - 18mm

Rear torsion bar - 28mm

Holy crap Batman! There must have been no flex at all in the car. Bet it's a world of difference now....

Americans seem to really like huge torsion bars for some reason

[Gary71]

Also, for interest.

Torsion bar Spring rates increase by the fourth power of the diameter change. So small increases in diameter rapidly increases the spring rate.

Increase from 23mm to 28mm = (1+((28-23)/23))^4% increase in spring rate (all other factors being equal). Which works out as 220% increase or 2.2 times.

Roll bar change from 15mm to 18mm is a 207% increase in stiffness (Spring rate).

Pretty much solid then in a 850kg car

[hot66]

Think Ive got some 23mm ! front torsion bars in a cupboard that came with the rsr front struts I bought from mikes rsr rep

[jury]

Also, for interest.

Torsion bar Spring rates increase by the fourth power of the diameter change. So small increases in diameter rapidly increases the spring rate.

Increase from 23mm to 28mm = (1+((28-23)/23))^4% increase in spring rate (all other factors being equal). Which works out as 220% increase or 2.2 times.

Roll bar change from 15mm to 18mm is a 207% increase in stiffness (Spring rate).

So what you saying ?

Live and learn, live and learn...but scary when you think about it!

[sladey]

28mm!!! I've got 25s on mine and it weighs quite a bit more than yours

Great to have it sorted though - that's a big part of the fun - getting it to be perfect for you

Edit:- No I haven't - I forgot I went to coil overs at the rear. It's been a long day....

[johnM]

Great result Chris seems like the right way forward.

[hashman]

Go on, admit it Chris, you just wanted to be driving sideways round as many corners as possible didn't you!
The door straps look like a more resolved solution, are they proving better?
As always, you provide an interesting read,
keep having fun.

Karl.

[Tony]

Have run 18/27 torsion bars on a 1000kg 911 for over a year now - beautiful!
18/28 in a 912 that light should at least be interesting!

Tony

[jury]

Been awhile since I had a tinker.

There had been some chat about LED headlights, at which I chirped in on...

viewtopic.php?f=1&t=52440&p=486077&hili ... ts#p486077

On the few occasions I have driven the car in the dark it is noticeable that the lights are pretty woeful. Bulbs, Relays and outputs have been checked and are good, the only other possible reason was that I had painted the buckets Black (I wanted a look similar to the black scoops on a 904/906) and maybe the light wasn't reflecting around.....who knows

So this weekend I got everything together and made a MOD.....I had previously done some research and worked out that early sealed beam units, later H4's and early Beetle headlight parts are all interchangeable.....well sort of, alittle massaging is needed.

I ordered some complete but cheap Beetle repro units from CIP1 in California, along with extra wiring pig tails and seals, whole lot came to $90. Then after bit of research I found a company making similar units to the LED Truck-lite units mentioned in the above thread...but at half the price.


Current setup...








Repro Beetle units...






LED units with H4 compatible connector. A transformer is also supplied should you experience any flicking (repro Beetle retaining ring shown) ...




I had planned to use the already fitted buckets but even with some persuading the new LED units and retaining rings wouldn't fit. I ended up painting the Beetle buckets, and blanked off the running light hole. It is still bit visible and I may either go back to revise the blanking plate, or, refit the running light fitting and bulb...



Everything put together:
-Beetle Bucket
-LED sealed beam unit
-Beetle retaining ring
-Porsche chrome ring
-Beetle glass




Ready to fit. The tabs on the retaining ring stick out little bit more vs the originals and the unit wouldn't fit ! This may be because the fiberglass wings have a substantially thicker Bowl compared to standard steel wings.....but, alittle bit of Dremel work and the new units slotted in.


Best thing is that the new LED units are black, this in combination with the black bowls and retaining rings gives look a lot closer to the 904/906 I was originally looking for...and the early glass is much more date appropriate for the car.





And...they work !! Blimey they are bright, and the light is instant !


Dipped...



Full beam...






Will need to level and adjust, but over all very pleased with the result


Cheers
Chris

[sladey]

Cool work Chris