Noahs944

1988 944 non turbo.
Want to lower the car a little bit and want to stiffen the suspension. I've never lowered a car before.

I have new Bilstein shocks/struts and 19mm rear sway, 25.5mm front sway.

Have watched Van's really informative video:

Also have Pasha's article for reference, though it's written for the 924:
http://www.924.org/techsection/Suspe...reparation.htm

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Finally Questions:

-If I lower the car 1.25"/31.75mm do I need to shorten the struts to prevent bottoming out? -that is the impression I get from Pasha's article.
-Is 250 lb coil front a good match for 27mm solid TBars?
-Are Torsion bars specific Left & Right? Pasha's article says if you buy used make sure they are marked. The used set of 27mm Tbars aren't marked... should I avoid?
-What main alignment concerns will I have after the car is lowered... (what should I expect from an alignment shop)?
-Are these spring rates a good match for my Bilstein or too much?

Thanks!

ddombrowski

I can answer some of your questions

1 - I know of another 944 team that runs cut front springs, and they do not have problems bottoming out the shocks, but they do have problems on full droop with the springs popping out of the seats. Not sure how tall the springs you are planning on using are, but I'd check it out.

When the car is lowered, I recall something about it putting more stress on the balljoint. We run lowered front springs and adjusted the rear to match and have not had any issues with this, although I did just recently rebuild my front control arms. YMMV.

The rear of the car is sensitive to toe-out. Make sure you adjust the rear toe after dropping the car.

I don't know much about the torsion bars, can't help you there.

As for the spring rates, we use 200lb springs on the front with 200 treadwear tires, turbo front struts and bilstein rear shocks. It works pretty well. I think you'd be fine with 250lb springs on bilsteins.

V2Rocket

-no
-yes, but consider 28mm as well. 27mm might make the car under steer, 28mm might be more neutral/over steer-prone which you can dial out with your swaybars (27 bar + 19mm sway will probably be a good match and a little softer on the *** than a 28mm bar )
- yes torsion bars are side-specific...they (should be) stamped on the end with an L or R. two reasons...the "inner" and "outer" splines are different so you can't install the bar backwards, but the L vs R pertains to the way the bar is made - they are supposed to be "pre-stressed" to make them more springy in one direction. if you put the L bar in the R side you'd be stressing the bar the wrong direction. even the OEM Porsche bars have the L/R stamps on the outer end.
- you will probably want to get a "bump steer kit"
- can't help there.

harveyf

I'll bite. (Things are slow at work today. I haven't posted this much in weeks!)

First, I would read everything on this subject that is on Clarks-Garage website.

Bottoming out: Don't know. You can check in the shop by removing the spring and using a bottle jack to exercise the range of motion but at some point it depends on how big of a suspension compression you expect to experience. Smooth racetrack is more forgiving then pot-holed public roads. That is one reason they add rubber bump stops to the struts, to avoid a hard metal to metal contact.

Using the concepts shown in that video, I am pretty sure you can't lower the rear by more than 1/2" or so. It may already be at the limits. To get a 1" to 2" lower, you'll have to pull and re-index the torsion bars.

To really simplify it, you want to increase the stiffness of the front springs and the rear torsion bars by the same percentage amounts. There are calculators out there on the web that can convert torsion bar size to a spring rate. You are looking for the "wheel rate" not the actual spring rate, although on the front they are pretty close to the same thing. On the rear there are several steps from a torsion bar diameter to a wheel rate but a proper calculator should take this into consideration.

It hasn't always made total sense to me but apparently yes, torsion bars should not be switched from side to side after use in service. Brand new, they can be swapped.

Regarding alignment, you will get some rear camber changes, fortunately in the negative direction, as you lower the rear. So the alignment shop will tell you the camber is out of range. For race tires, this is actually a good thing, as they perform better with some negative camber. But most street tires are set up for very little camber.

JustinL

If you are going through the hassle of changing torsion bars, do the bushings while you're in there. There's lots of great pictures in the build thread in my signature. We basically followed the Spec944 setup for this car as it's a pretty well understood setup to make the old 944 handle pretty well. The first attempt on the rear ride height adjustment landed us in Slammy McSlammerston range. One spline actually changes the ride height pretty substantially. Thankfully the stock ride height adjuster also has a lot of range.

Those spring rates will be fine with the Bilsteins, we use 300lb and it's good.

ddombrowski

We do the same. BTW, I remember coming across your build thread when you had first picked up the car and then stayed off the forums for awhile. I just caught up and saw you ran your first race - awesome. I signed up on the other forum, I'll chime in from time to time to follow your progress.

MistaX

Sway Away's instructions for their torsion bars specifically says if you install them backward they'll break in half. They're only stressed in one direction and designed to twist one direction. They're stamped. The original Porsche ones I removed were stamped.

Wouldn't install ones without being 100% sure the orientation is correct, breaking a torsion bar wouldn't be fun in a corner. If you're going in there, replace all mounts and bushings.

V2Rocket

you can get CHEAP torsion bars from cip1.com.
WAY less expensive than "Sway Away"
since the 944 uses beetle suspension, we can use beetle T-bars...26-9/16" IIRC, look them up on their site.

i have a set of their 26mm bars in my car...nice.

Noahs944

Great suggestion everyone. THANKS. V2... what is your suggestion as an anti-bumpsteer device?

Noahs944

I was considering buying a used set of Sway Away torsion bars. Are they stamped for orientation... like in a way that wouldn't rub off?

The fear of them breaking makes me think buying new is better, but these are being sold from a reputable seller... but yeah, I don't want broken bits

Noahs944

Also, since this car is a daily driver, is Weltmeister about as "comfortable" as can be, or is there a better brand?

924srr27l

Comfort comes from the spring rate not the brand!


I'm using Poly Bronze bushings & adjustable blades 27mm Hollow Elephant Racing quick release T bars (rated 220lbs), which I read might be made by Weltmeister? these are in combo with (190Lb) 2.25 front race coils on converted adjustable platform original strut legs and Aluminium 944 early (short) wishbones.
but of course all on a 2300lb car, so you'll want higher rates.


26.8mm front / 18mm rear ARB and it's good for 3 hour street trips


Although I'm going try a lighter rate front coil set (165lb front) for more movement and less understeer, if it's too soft I'll fit a thicker 20mm rear ARB


This set up allows for easy ride height corner weight adjustability, where we managed to get nearly identical 555 lb's / 255kg on each corner.






















R

MistaX

Sway Away bars have L and R etched on the outside ends in a big font. It's not paint or a sticker, the only way it'd wear off is with a file.

Smaller diameter = more comfortable.

I daily my car with 350lb springs and 30mm bars and I think it's perfectly fine, but I guess I'm a minority around here.

SloMo228

I have 200lb front and 26mm rear and it's a decent combo. I also have a set of 27mm I may install one day but it is a bit of a PITA to do the torsion bars so I'm not exactly rushing to do that job, and in any event I don't know if it would even be an improvement anyway. I have the CIP bars mentioned above, they work just as well as OEM and are far less expensive than other aftermarket brands. They are sold for VW Super Beetles, but the 944 torsion bar setup is the same. You do need to make sure you order the correct length, though. I don't recall off the top of my head but I believe it was something like 26 1/4".

have the Ground Control coilover sleeves, which I heartily recommend - it's really nice to be abke to fine tune the ride height and it allows for much easier corner balancing too. They're not that much more expensive than regular lowering springs and if you later decide to change spring rates, the springs themselves are fairly inexpensive and come in a wide range of rates. As an added benefit, you can lose a couple pounds of weight from the front suspension by cutting off most of the stock spring perch since it's no longer needed, and the smaller diameter springs weigh a bit less than the stock ones.

No real need for coilovers on the rear, there is plenty of adjustment in the trailing arm eccentric.

When you change out the springs and torsion bars, you're going to be basically disassembling the whole suspension, so a full alignment will be necessary afterward. It's also a great opportunity to replace all the old bushings, too. There is enough adjustment range in the stock setup to cope with a reasonable drop of 1-1.5", so no worries there.

I don't know that a bumpsteer kit is necessary unless you're also installing longer balljoint pins, and that's only necessary for more extreme lowering. As long as the control arms aren't angled up after the lowering, you will be OK. Because of the design of the McPherson suspension, having the balljoint higher than the control arm pivots does funky things to the suspension, although I am not qualified to make any kind of explanation as to why that happens. I'm sure there's a highly confusing white paper on the subject somewhere if you want to dig deeper, but that's the rule of thumb and the reason why longer balljoint pins exist.

marc abrams

My wounds was just beginning to heal..............