Wil Ferch Where is the calculator?

[mb911]

Wil or maybe someone else can help,

Where do I find the ride hieght and corner balance calculator. I am going to change spring plates and bushings this weekend and need to figure this stuff out. Thanks so much

Ben

[Rot 911]

Go here and scroll down to the Porsche 911 Section: http://vintagebus.com/

[1974carrera]

Here's a link to take you to it:

http://tech.rennlist.com/911/pdf/settings.pdf

[Zeke]

I know more about what's going on here than most because I supplied the parts. Ben, THIS THREAD IS USELESS W/O PICS!

[rattlsnak]

I just used it today when I installed my rear bars. I wont know for awhile if I did it right because the engine is still out

[Wil Ferch]

Sorry for responding late to this....but I see others have chimed-in for me. Thanks, all.

The calculator seems to work well, but it requires accurate "input" data to get good "output"...not really surprising. Total weight, fr/rr weight distribution is key.....

---Wil

[widebody911]

Here is the spring plate angle calculator

http://vintagebus.com/cgi-bin/spring.cgi

And the corner balance calculator

http://vintagebus.com/cgi-bin/balance.cgi

[rattlsnak]

Wil, i used it and came up with a spring plate angle of @18 which seems to be not enough. I know the 31 bars are very stiff, but without the engine in the car, its almost where it needs to be now! (the initial angle was @35)
I used the following specs, weight:2200, droop height:3.2, bars:31, and got 17-18 degrees. Well at least I have adjustable spring plates so it will easier to correct if Im off!

[Wil Ferch]

I'm not going to to do individual situation math checks....

but I will say that if the all the input data is correct ( total car weight....fr/rr distribution which is typically 40/60 for non Turbo....plug in the TB sizes...and assume you're targeting Euro ride height ...about 3.84" spring plate angle droop when car is on-ground).....then...this should all work out to within 1/4" or better of your targeted ride height.

Sure beats guessing and doing this whole mess over 3-5 times !

---Wil

[mb911]

Thanks found it! I will go ahead and tear into it. Anybody now where I can set default for rear alignment when I am done?? Of course I will have it done properly just wanted to know if I could do it myself

Ben

[widebody911]

Originally posted by mb911
Thanks found it! I will go ahead and tear into it. Anybody now where I can set default for rear alignment when I am done?? Of course I will have it done properly just wanted to know if I could do it myself

I just scribed a line where the spring plate met the trailing arm before I took things apart, and matched that up when I put it back together. Close enough for govermnet work, and I was actually only 1/2 degree off on toe and 1 degree shy on camber. I think the eccentrics are an 11mm allen.

Another thing to consider: I installed Elephant Racing monoballs and polybronze bushings last weekend, and I noticed the spring plate bolts were kind of haggard, so I replaced all of the hardware with the exception of the eccentrics. The spring plate bolts and eccentrics are 12x1.5mm I bought slightly longer ones and used nylocks instead of plain nuts. I also chased the threads on the eccentrics.

[mb911]

Good idea thats what I will do.

Ben