911 lowering ~ ride height questions

[911 tweaks]

Hey guys...it has been a long day to say the least...so I will get to the point...

I am trying to set the front ride height on a 1976 912E...
I have Wayne's book and here are the #'s I come up with and the car looks like an off road buggie...HELP...Alignment appt tomorrow at 12 noon...
1. running 15x7 cookies which measure 12 3/16" to the center of the wheel = 307.5 mm
2. euro ride height 108 +/- 5 mm = 4 1/4" +/- 3/16"
3. to achieve this "euro height", you find the difference between wheel deminsion & 108 mm...right???????????????????????????

So, 307 - 108 = 199 mm = 7 7/8" = dead on euro spec. RIGHT ?????????????????????????????????

Now, it is my understanding that I turn the torsion bar cap BOLT till the center of the cap, which has a dimple to mark its center, is 7 7/8" off the ground and viola I am at euro ride height. Just one problem, there must be a good 3" between the top of the tire and the bottom lip of the fender...this must be wrong as it looks like a dune buggy = WAY TOO MUCH GAP BTWN TOP OF TIRE & BOTTOM OF FENDER EDGE...

What am I missing here guys...HELP...
THx,
Bob
ps...I do have the car level as I put 1" spacer under rear wheels which makes car perfectly level from my water gauge measurement...new Bilstein sport shocks all around...new turbo tie rods...2/3 full gas tank...spare in trunk...I drove the car around the block 2x to make all shocks feel rite at home & to bounce the car a bit...

[Shaun @ Tru6]

Bob, not sure if this is a help all, but I'm running 23.8 inch ride height on the rear, 24.5 inch height on the front on 7x15 cookies. Here's what it looks like.

[911s55]

Shouldn't you guys be watching the NBA finals?

Tweaks what year is your car and size tire you are using?

David

[juanbenae]

if it's too high remove the wheel, jack up the a-arm to get another t-bar spline and reset the in the new spline. it may take a time or two to find what works, but it will.

safe jacking, car secure, yada-yada-yada....

[911 tweaks]

Shaun...are you tallking fender lip to the ground measurements...??

911s55...just woke up from watching the finals...who won this game...:: I am running 205/60R15 on 7x15 cookies...

car311...I am able to get the visual result with the t-bar covers as is now...I previousley had them so that the center of the torsion bar covers were ~ 4.5" off the ground...then I read Waynes 101 projects book...if my above math is correct & I set the caps height per euro spec, I am at the opposite end of the caps' adjustment and front looks like a dune buggy w/ ~3" space above tire to bottom of fender edge...what am I doing wrong here...?

Thx, Bob

[stlrj]

You have to add 108mm to your wheel center at 307mm to give you the height of the torsion bar center from the ground, which should be 415mm.

[911 tweaks]

...I have been racking my head on this and I tripple checked EVERYTHING...

1st mistake is the wheel center measurement, with wheel on car which is VERY IMPORTANT, IS 280MM...not the 307 I thought...

stirj...that is not possible to ADD to the wheel center...look at Waynes book of 101 projects, pg 145-147...I will subtract the factory spec from the wheel spec and this is the distance the center of the adj cap is off the ground...

So now I have 167 - 172mm and the car is still too high...pleanty of adjustability on the cap bolt...

I am running out of time here...I might just punt and pick a height.. :-)

Bob

[Shaun @ Tru6]

Bob, I think you are way overcomplicating this.

My measurements are from ground to arch.

Set gross height per car 311 and use adjusters to dial in. It's important to set the initial adjuster arm angle given your gross height so you can go up or down and end up with adjusters somewhere in the middle. I like to bring the car up from a low ride height.

It may take more than around the block to settle the front suspension BTW.

[Reifle]

tweaks - just completed my suspension overhall! My '77 911S ride height was 25 + ins. in the front and rear (American settings apparently). I installed new shocks in the front (Bilstein) with turbo tie rods and the leveling kit for the rack. At the rear are a set of new Bilstein sport gas shocks (original were the Boge Hydraulics). Now after the car has settled for about 2 weeks and driven constantly the car sits at 24 ins front and 23 1/2 ins rear. (from the ground to the bottom of the fender lip) Let me just say WOW! What a difference in how she handles now! Just the best improvement I have done to the Porsche! My next thing to do is check into running a lowerer profile tire - I am running 205/60/15 all round. I would like to run 205/50/15 front and maybe 215/50/15 rear. I hear that this is a very good set up for the car. I have not taken photos of it yet but it looks great!

[nesslar]

Shaun,
I like that ride height, shows just the right amount of "air" over the rubber. Your car sits nicely, and with the 15s, it gets you low enough, I think.

[stlrj]

Originally Posted by 911 tweaks

stirj...that is not possible to ADD to the wheel center...look at Waynes book of 101 projects, pg 145-147...I will subtract the factory spec from the wheel spec and this is the distance the center of the adj cap is off the ground...

Uh...right. Just wanted to see if anyone was paying attention!

Good call Tweeks!

[stlrj]

Originally Posted by stlrj

... what most are calling Euro height on this board is actually about 2" lower than actual European height.

http://forums.pelicanparts.com/newreply.php?do=newreply&p=5386799

[Joe Bob]

Then you need to corner balance and align.......ride height adjustment on the rears is REAL f-fun....best to invest in adjustbale spring plates.

While yer in there, consider new rear bushings. I STILL remember the smel burning the old piece o'crap ones off......

Unless it's just a grocery getter............

[SAM DACOSTA]

After corner balancing my 1990 C2, the finished ride height is;
(F) 24" and (R) 23 1/2" with all measurements taken from ground to bottom of fenders. The car has been tracked subsequently and the difference is WOW. The alignment, camber and toe settings made a huge difference on the track.

Here's what the car look like now;

[javadog]

Bob,

If it helps, I've never gotten the factory "math" to work on the front ride height. I don't know where the error is but something isn't correct about the procedure.

JR

[BSNMOE]

Just wondering when you are checking ride height are you checking with full tank of gas? 1/2 tank? The reason I bring this up is on my 73 911 with 21mm front/26mm rear torsion bars with a full tank my front end is 1/4 in lower. This also raises the rear a little. Then with a 1/4 tank the front lifts higher and the rear gets a little lower. I use 1/2 tank to measure then make adjustment. Then I get a full tank of gas and make sure you have fender clearence in the front.

[911 tweaks]

Thx everyone for your input...I will post pics later today after I go take some shots...
What I did was set the front to 167mm off the ground to the center of torsion bar adjuster cap...running 15x7 cookies w/ 205/60 R 15 tires...
At this time I was unwilling to "open" up the rear suspension till the fall when the entire suspension will be re visited...just want to get the car on the road and drive it the rest of the summer...fender ~ tire gaps are a bit high but I can live with it for a while till more funds become available...

Hi JR...you are correct about the factory math...basically with the front being set @ 167mm this leaves ~2" gap between top of tire and bottom edge of fender...which looks still too high but it will have to do for now...car all aligned and handles great...just a bit high...

stlrj...you may be on to something because when I lowered the front to ~ 1" gap for tire/fender, the torsion bar cap center was just about 2" lower than the "euro spec"...interesting...

[stlrj]

At 167mm below wheel center means you are slightly over 2" below Euro, which is what our eyes are comfortable seeing.

[Shaun @ Tru6]

Bob, you have any luck today with the rain? I dropped the motor out of my T just in time.

Looking forward to the pics.

[911 tweaks]

well...here it is...not as lowered as some have posted here or as I wish it was, but, reality being what it is, I did not want to open up the rear suspension as for one reason, the rear spring plates are the non adjustable ones & due to mileage on car, 157K, I am sure the bushings are shot and other things as well...you should of seen the shocks I removed...1 of the front shocks was some type of hyrdauloc type as it looked like a regular front shock/strut, BUT, is had no outer metal tube...!! When I unscrewed the shock it was like pulling out some kind of primitive bicycle tire pump looking thing...I'll post up a pic of after the car pics...