Lowering 911

[kavadarci]

Hi,
While I'm figuring out how to lower the back of the car with the stock setup (I already brought the front as low as it goes), what is a typical setup used for lowering?
I don't want too much but currently sits like an SUV.

Pics of my other two zermans lowered.
Lol

[Joe Bob]

You have to re-index the torsion bars for the rear. There are many threads on the subject. I bought Swayaway adjustable spring plates. Make the job a lot easier.

[Trackrash]

You don't say what year it is, but it looks like and SC. If so you already have adjustable spring plates. That may or may not be enough adjustment to lower with out re-indexing the torsions.

What country are you located in? Do you have a repair manual?

Wayne's 101 Projects for your 911 is a good book to have as it explains many common maintenance tasks on these cars.

[chrismorse]

To get some usefull advice, we need to know what you have, what your primary objective is, how you plan to use the car, what has been done to the car and it would help to have a rough idea of your budget to get what you want to get done paid for.
Carroll Smith once opined that, "there are no insignificant reductions in center of gravity". He was a legendary, world class racing team engineer, of vast experience and capability, wit and wisdom.
very roughly paraphrasing him, you need to keep the chassis off of the ground and the suspension off of the bump stops, (where the spring rate goes to infinity and the car doesn't handle for sour owl $hit).
Further, if you want the car to really handle, (as opposed to making tumescent trannies gasp at your car sitting on the ground), you need to keep the camber and toe curves "happy" with each other, front to rear and for the tire/wheel set you are running. This is a massively complex project to improve on what just came out of the factory.
Once the car is lowered, it is important, (if you want to really make the car handle) to get the ride height and corner weights squared up.
FWIW, I am going to refresh the suspension components, start with stock 74, "euro" height and get the car corner weighted, because I haven't the experience or knowledge to figure the trade offs going lower.
There are legions of guys saying that they have gone too low, only to raise the car back up and extoll the factory engineering and performance.

There are very experienced owners here who can offer a world of help and advice.

Good luck,
chris

[Tarek307]

Front you can get pretty low with with indexing, the rear you will have to do the torsion bars, i did this job with another rennlist member (more like watched him do it) and its a bit complicated but if someone knows what they are doing its about 3-4 hours to get done.

[kavadarci]

Thank you
It's 76 911s targa.
I want it lowered for occasional spirited driving but mostly for looks.
I have the 10 manual and agree loooks little bit intimidating and not sure if it will be enough.
I just don't like that gap between the tires and the fenders.

Does anyone have a picture of this car maximum lowered with factory suspension?
Thank you.

[Bill Verburg]

Originally Posted by kavadarci

Thank you
It's 76 911s targa.
I want it lowered for occasional spirited driving but mostly for looks.
I have the 10 manual and agree loooks little bit intimidating and not sure if it will be enough.
I just don't like that gap between the tires and the fenders.

Does anyone have a picture of this car maximum lowered with factory suspension?
Thank you.

'76 won't have adjustable trailing arms

If you are going to dig in to the suspension I'd suggest that all the bushes be replaced at a minimum, while in there replace the trailing arms w/ adjustable versions either aftermarket like Elephant sell or oe style like Rennline sells, I went w/ Rennline versions for my '76 C3.

whether or not to go beyond that depends on budget and your standards, Billstein shocks all around and larger t-bars are on the menu for many but not all of us.

Ride height will also depend on use and also may be limited by wheel /tire choices, here's a guide


These are the std from the factory specs

[Driven97]

Lowering the car will make it look good but also likely make it ride and handle worse. 1" of CG doesn't matter if your front roll center is underground, you've got crazy bump steer, and you're crashing off the bumpstops.

A little is ok, but be very, very modest with your lowering for best results.

[kavadarci]

Thank you again for the fantastic info. I checked all the bushings and only the rear sway bar bushings were bad and I'm getting new tomorrow.
If all fails and I get frustrated, a shop here in Toronto can do it for $550, including lowering and alignment.

[kavadarci]

Originally Posted by Bill Verburg

'76 won't have adjustable trailing arms

If you are going to dig in to the suspension I'd suggest that all the bushes be replaced at a minimum, while in there replace the trailing arms w/ adjustable versions either aftermarket like Elephant sell or oe style like Rennline sells, I went w/ Rennline versions for my '76 C3.

whether or not to go beyond that depends on budget and your standards, Billstein shocks all around and larger t-bars are on the menu for many but not all of us.

Ride height will also depend on use and also may be limited by wheel /tire choices, here's a guide


These are the std from the factory specs

Bill, would love to see the setup on your car, can you share few pics?
Thank you.

[Bill Verburg]

Originally Posted by kavadarci

Bill, would love to see the setup on your car, can you share few pics?
Thank you.

My car is so modified that it bears little resemblance to stock
but here you go
This was before the last lowering, I haven't taken any since, it's ~.5" lower now, as D97 noted when lowering care needs to be taken to correct bump steer, for most inexpensive steering rack spacers are fine for this

[kavadarci]

Yes I like that, that would be perfect.
Do you have any pics of the trailing arms?

[Joe Bob]

Consider replacing the T-Bar bushing while you are at it. REAALLY consider the aftermarket adjustable spring plates/trailing arms.

[Trackrash]

What Bill said. You probably don't want to go lower than 25" when measured from the fender lip to the ground on the rear suspension. Personally, I have never been able to make sense of the factory method of measuring the ride height. YMMV.

As already stated, replace your rear spring plate bushings. Do it now, do it once, do it right. If you don't replace your spring plates with the adjustable ones, you will probably regret it. AKHIK.

Here is my car. Lower than reasonable for the street at 24" in the rear. Read my "Garage" for all my suspension mods.


If you list your location, there may be other Pelicanites willing to help. Many of us will work for beer.

[Ayles]

Just went through mine as well. I think it looks perfect though I am not sure of the exact heights at the fender.

Replaced everything... Once you go through the hassle of taking it apart you aren't going to want to put it back together with old parts. You will see the bushings are out of round etc...

[Bill Verburg]

Originally Posted by kavadarci

Yes I like that, that would be perfect.
Do you have any pics of the trailing arms?

Here are the parts I used to redo my suspension, I already had Bilstein hd f & Bilstein Sport r shocks and a rack spacer kit

The trailing arms are from Rennline w/ sport hardness rubber bushes, the front is Elephant rubber bushes, & new ball joints w/ hardware, T-bars are 20/26mm plated & drilled also from Elephant. This is a street car, if it was more track oriented 21/27 or larger would have been used.

New stufff




Old

[ClickClickBoom]

Don't forget corner balance.

[Trackrash]

Bill, what size are those rear tires? Do you ever have a problem rubbing when cornering hard? My rears, 245s, show some rubbing on the oil lines after an autocross even though there is about 3/4 clearance when stopped.

[Bill Verburg]

Originally Posted by Trackrash

Bill, what size are those rear tires? Do you ever have a problem rubbing when cornering hard? My rears, 245s, show some rubbing on the oil lines after an autocross even though there is about 3/4 clearance when stopped.

The older pics are 275/40 x17 on 9.5, the newer pics are 255/40 x17 on 9.5. That's why the car needs to be lowered in this pic it is still at the 235/275 tire height


The mods to accommodate the 275 on 9.5 can be seen here
shaved adjuster bolt heads


and relocated oil line


245/45 x16 on Fuchs 9ET15 should have a ton of clearance all around


here's a comparison of 245/45 x16 on 9" Fuchs and 275/40 x17 on 9.5" wheels, The only thing that allows the use of these tires is the breathed on 993 3.6 powering the car.



I've since settled on 255/40 x17 on 9.5 as the ideal compromise for my purposes

[kavadarci]

What is the brand of the tire on the left? So nice.