1987 3.2 Carrera Backdate project - Sladeys hotrod

[markm]

It is mighty impressive Mark

[Bootsy]

It is mighty impressive Mark

It is considering he can hardly dress himself

[jtparr]

Mark

great to see the further progress...am doing this remotely being abroad again.... but from memory those pipes also had something to do with the headlamp washer tank reservoir unit...?...

jp

and / or the main screen wash reservoir.....

jp

[jury]

As Bootsy says, sod the conveyancing, get yourself acouple of resto projects!

Nice work mate

[jb]

You are a hero Mark

[Darren65]

In awe of your courage, truly am, absolutely awesome! ......I would inspiring but in truth I'm never getting involved with this shite!

Great to see the progress......really looking forward to seeing this car back on the road.

Well done

[964RS]

Great stuff Mark, well done.

I think your level headedness and calm nature helps you a LOT in work like this....many of us would have kicked $hite out of our cars had we seen what you had and been faced with doing it ourselves.

Not me of course, as you know I'm a hands on genius now, yesterday I sawed a piece of rubber tile (admittedly with a wood saw and it's not straight).

[johnM]

I dont think you could have got where you are without the support of Nige

[Nige]

I'm his muse!

He's done well for a desk wallah

To be fair I only suggested he take it off the road for a longer period as it was obviously a lot sh*ttier than initially thought.

[sladey]

Thanks for the kind comments guys. Yours too Nige

While I was in there I had to take a decision on the torsion bar covers/hole. During the backdate the torsion bar hole was changed to replicate those on a 915 gearboxed car. This looked great but when I later went to do some work on the torsion bars I ended up having to cut the bodywork to get them out. I've never been happy with that.

I'm now faced with the same dilemma again - I go to a big hole (which I don't like) or replicate the smaller one but have to cut the bodywork next time I need to do some work. I don't fancydoing that again so I just pulled the trigger on these


(I've just ordered the kit and the turret strengthening pieces - I'm going to order the springs over here)

By going to coilovers I'm going to do away with rear torsion bars altogether meaning I can do what I want with the bodywork. I may go to no hole(!)

On the coil strength side of things, I don't suppose anyone knows what would be the equivalent of my 25mm torsion bar? Chuck suggests 300lb as suitable for a "fast road/canyon carver" - I like my current setup and wouldn't be changing it if it weren't for the bodywork issues (though the easy change of ride height is an attraction).

Given the general US inclination towards 'stiffer is better' I'm wary that I might be stiffening up my rear end too much. Anyone any idea?

[Lightweight_911]

Mark - I have this information stashed away for some reason:

Front Torsion Bars

18.8 mm = 110 lb/in
21 = 173
22 = 210
23 = 250
24 = 296
25 = 350

Rear Torsion Bars

23 mm = 100 lb/in
24 = 120
25 = 140
26 = 165
27 = 191
28 = 221
29 = 254
30 = 294
31 = 332
32 = 377
33 = 427


It originally came from here:

http://tech.rennlist.com/911/pdf/torsionbars.PDF

[Darren65]

Mark - I have this information stashed away for some reason:

....as you do!

[sladey]

Thanks for that Andy

Those measurements are for a 915 car, but I happened to have a spare 25mm g50 torsion bar knocking about, so I measured that carefully and did the same calculations.

It came out the same! (Actually 138lb/in so roughly 140) (if you want to do the same you have to convert ALL the measurements involved to inches)

That's a hell of a difference to the 300lb/in suggested by chuck! ( bearing in mind that was the softest of the 3 variants he suggested). Mind you that equates to a 30mm torsion bar and they tend to like that size of bar over the pond!

I think I'll go for 160, which should be a very slight increase over stock

Thanks again

[dragonfly]

Tuthills fitted hollow 27s in my SC, keeping the fronts standard, and it seems to work well on road and track.

I re-read the backdate stages of this again last night. It's one of the threads which prompted me to push the button on a 911 purchase, so thank you for that.

[Gary71]

Where are you measuring the spring rate? the actual spring or the rate at the wheel?

The damper is inclined which will reduce the effective rate from the actual spring rate. However it being rearward of the wheel will increase it again so it's not a straight like for like comparison of rates