Lowering my 1986 944 - Torsion Bar Delete or Not?
 

I read and read and read on this topic, honestly the more I dig the less confident I feel in which direction I should go. Sorry in advance for the wordy post, I'm just very thorough!

I plan to lower my car around 2 inches. This is a task I will be doing myself at home to save on labor costs. My goal is to find an affordable and diy solution.

This car is only a daily driver, no track usage. With that in mind, I would love something that's still comfortable (enough) for every day driving. its got the M404 package and stock everything else as far as i know.

First option: If I delete my torsion bar and go full coilover, what else do I need to take care of for it to be ready? I have read torsion deletes require a more solid bushing in the torsion housing but is there anything else i need to replace? What spring rates should I be running then? I see a lot people run around 200-250 lowering spring rates up front to keep a comfortable "stock like" feel. If I delete the torsion bar though and go with a higher spring rate, does that mean the 200 needs to go up as well to balance?

If i go this low i don't want my fender to come down on the tire and rub, how do i prevent that? stiffen the damper setting on my struts or stiffer spring rates?

second option: If I keep my torsion bar, install aftermarket struts like Bilstein or Koni and reindex lower is that all I need to do to achieve a lower stance and desired ride quality? Like the scenario above, My main concern in the back is making sure I don't go over a bump or dip and my fender comes down on my tire and tear it up. It was coming down on my tire sidewall with spacers in the rear on stock suspension for reference.

3rd option: keep torsion bar and add a coilover system. This is the scenario I most struggle with. It would seem I still have to reindex to lower, also does the adjustable coilover system actually allow me to adjust up/down or is it simply just adding another spring on top of the torsion bar spring rate? I ask these questions with scenario 2 in mind, which is most cost effective then having to buy a full coilover for the rear if that lowering function is still done by the torsion bar.


TLDR My goal is to be able to lower my car around 2 inches, while maintaining a comfortable (enough) ride quality. Do I re-index the torsion bar and add struts or delete my t-bar and go full coilover on all 4 corners? If so, which coilovers/sleeves & struts don't sacrifice comfort the best and are affordable?

If one is lowering one of these cars to extremes, one problem you will encounter:

It is very hard on rear axle c.v. joints.

The geometry of these cars for comfortable street use is pretty much involving torsion bars. If it will never see the track, what's the point of removal ?

What type is your suspension now ? I would decipher your codes and find out if it's a base, M404, M456, or M030 car. Does it already have a sport shock, sport spring set up ? What do you have for torsion bars already ?

the car is M404 and all stock suspension/torsion (i suspect). I am not saying I should remove them, because I'm unsure what direction is best for me. If I can re-index lower and add some upgraded struts/whatever else i need in the rear and see no big change in ride quality, that seems like the cheapest/most straight forward approach. Aside from having to deal with re-indexing of course :o

Is it possible to achieve a 2" drop by reindexing the torsion bars? I didn't think that was possible without removing them all together.

I'll give you a good reason not to use coilovers. The rear shock mounts was never meant to hold up the back of the car.

If you enjoy the ride quality, I think you should leave the car at stock ride height. If you lower it, I think you should increase the spring rates - front and back - so you don't risk bottoming out the suspension all the time. I'd use the "SP1" setup, which is Koni adjustable struts in the front with 300 lb/in springs and Koni adjustable shocks in the rear with 30mm torsion bars. Kits are available from Paragon Products. This will make the car lower and stiffer, but ride quality will suffer.

on a street car that sees anything other than brand-new perfectly-smooth asphalt i wouldn't run spring rates any more than 200#.

i have 200# front springs and 26mm bars (~190lb rate) and it's right at the limit of street comfort (IMO) and most roads around here are pretty good, some highway expansion joints excepted.

that said, i don't see how it'd be possible to run a 944 on the street lowered 2" - i got away with ~1" in front for a few years but scraped on every driveway in southern CA until i raised it back to stock height - no problem ever since.

I believe that increasing diameter of front sway bar moves towards or increases understeer depending on the current car balance. Increasing front spring rate with same diameter front sway bar moves towards understeer or increases understeer depending on the current car balance

simple rule - stiffen one end (springs, sways, etc) and the other (softer) end will have more grip (relative to stock) which determines your over/understeer tendencies.

i had the 200# fronts with stock t-bars (paired with 25.5/18mm sways) and the car pushed like an Audi.
when i finally put the 26mm (~190#) t-bars in the back, the thing turned into a carving knife.

my F/R springs are much more balanced now and the sways are more oversteer aggressive than the factory ever offered (IIRC the 18mm rear only came with a 27 or so mm front bar, the 25.5 normally came with a 16? rear).

I notice you revised your first post and included that it has the M404 suspension. This is incorporating the standard torsion bars from Porsche ( if still stock ) and utilizes most likely a 20 or 22.5 mm front sway ( if still in it's original state ). It is one step up from the base 944 in handling and comfort and promotes a limited handling advantage over the base 944. It IS better though and does give the car a less roll prone position on apexing.

Most of my 944s are either M456 or M030 suspensioned cars and I understand your perspective from the one stock M404 car I do own. It has a 22.5 front bar and an 18mm rear bar. If you are looking for an advantage in handling thru lowering, I may suggest with your 404 optioned car, to seriously consider a more aggressive alignment change with attention paid to adding a bit more caster and about 2 to 2.5 negative camber.

I can't help you with the lowering ideals you are choosing as I don't know if you are searching for a certain 'look' or a certain handling advantage by giving your car a lower center of gravity. You most certainly will experience problems with dragging the front valance and scraping other bits on speed bumps and driveways. To me, the risk of damage and constantly slowing for problems on the street ( with unaware drivers following ) isn't worth it. I have to be quite careful with my lowered M030 - 951 and the two 944s set up for the track if I drive them on the street.

By altering your car's stance, you will introduce another level of paranoia to your daily street driven ride. Weigh those options carefully as these cars are supposed to be all about the fun, the enjoyment of driving. I see more limitations than advantages here for a street driver if dropped as far as you are thinking and changing your torsion bars. If we were talking about a track warrior or weekend canyon carver, a different thought process may be in order towards lowering.

YES,
truth.
Re read this post above and consider your next move carefully. Best wishes with your enjoyment of this car. They really ARE great just the way Porsche built them, and it only costs money in exponentially "more spent for marginal, progressive returns".

I am probably just missing something but I noticed this on clarks page a week ago, and then obviously here as quoted...
He starts by saying a 30mm sway, but then the next line he says you may prefer the 26 sway over the 27? But the 27 sway was never mentioned prior, and I do not recall ever seeing a 27mm sway listed anyplace? So is he really talking about the sway bar or is he actually referring to the torsions, just made a typo? I believe he meant torsion bar as then the next sentence he talks about 28mm to induce a more oversteer.

Thanks V2! That simple rule helps quite a bit.