Let the 924S modifications begin...

onZedge · 10:46 AM

I am about to embark on an on-going series of improvements to a bone-stock 1987 924S (well, except for a MSD 6A ignition box, MSD coil and Weltmeister poly A-arm bushings). I still have a bunch of goodies on order, so I'm installing things in a semi-logical sequence as parts come in. I will weigh things that I delete, replace or add as I go. My comments regarding noted improvements are of course going to be subjective. Any comments or suggestions are welcome.

Stock anti-roll control is a 20mm front sway bar and no rear sway bar. Tomorrow's project begins with 26.8mm/16mm sway bars from flash968:

Racers Edge front and rear Delrin bushings, KLA rear drop links, KLA front sway bar brackets, factory front sway bar clips from a 968 and factory eccentric rear sway bar mounting bolt. The bars were not the expensive part, but all the hardware to go with them was:

944kiddo · 09-13-2007, 10:18 PM

cant wait to see the progress come about keep us updated and we love pics

haha

KillerDynoSoar · 09-14-2007, 01:22 AM

What the list of mods you are hoping to carry out?
Nice ARB's I'm gonna go for some used bars from a Porsche swapmeet.

Al

fast924S · fast924S's Garage

Sweett, You let me know what woks best, Im working on the engine now, then suspension, so whatever works good on your 924S I will also do

Dean924s · Dean924s's Garage

If you need any info etc I am running out of things to change on my 924s.

Where do I start. I went fully adjustable weltmeister sway bars and rear torque bars (the springs in the transverse tube), adj Koni ft and rear, Iboc progressive springs in the front, Recaro seats, RJS belts, Autopower bar, Quick Throttle Wheel, Dino steering wheel, Custom shorter shifter (not a short shift kit on the trans) Hy-bred 83/89 motor (wanted forged parts but the better hp of the 89. Ac Delete, custom cooling fan controls. Green paint, black interior (changed from white) VDO pro tach (The stock tack in the pre 85.5 cars is basically useless on the track). 3 Qt Accusump.(after several #2 failures I got smart). The best mod was the struts/shocks, springs and bars. Transformed the car form a ho-hum (but still excellent) street car to what I think Porsche should have done from the start. A car that wants to be put through the cones or on the track doing HPDE days. I never had the hart to cut it up and put the full cadge in it but that is the next logical step.

Best of luck!!!

My car on Clarks

Tam Lin · 09-17-2007, 03:51 AM

Don't forget every 924s out of its teens should consider a slimming diet: bonnet (hood), rear screen, smaller battery, a sunroof not designed to serve as a part-time medieval knight's shield...

onZedge · 09:21 AM

Since I decided to weigh things as I go, I bought this at Academy Sports for $15 (on sale) JUST FOR YOU GUYS. Note the weight of the tubular 26.8mm sway bar with delrin bushings and bigger 968 sway bar clips. The stock 20mm sway bar with rubber bushings and stock clips weighs 7lb 6oz!!

The mounts for the sway bar live ends on a 924S and early 944 are not links like the latter 944s and the 924s. They use a saddle type clamp with a rubber bushing. I could not find poly replacements, so I used the rubber ones. It is important to note the dimension of the live end of the 20mm bar is 16mm and the 26.8mm bar is 18mm. I used plenty of grease on the ID of the rubber bushing and the end of the bar. I held the bushing up to my workbench and pushed the bar in with not too much effort. Note that this dimension is even bigger on the 30mm bar if anybody is considering using that size bar. If your car uses link type mounts for the live ends, consult the PET for other bushing sizes that are available or go to aftermarket suppliers of poly bushings.

I should notice a difference, no?

I used very long bolts for the clips during setup, as necessary, to hold things together loosely before I tightened up all the bolts. Vice grip pliers help getting the final hardware in the holes and started. I had a fittment issue with the angle braces, so I did not install them at this time.

[ON SOAPBOX/] I can't stress the importance of dabbing on some anti-sieze compound to the threads and under the bolt head. This is especially important where steel bolts are used on the alloy enine block and head. It makes disassembly easier and insures proper bolt tension when torqued. I use a torque wrench to tighten every bolt, all the time. [/OFF SOAPBOX] Fasenal has good info on their web site regarding bolt strength and proper torque ranges, among other things.

If you have no rear bar to start with, I highly recommend running a tap through the bracket holes to clean them out followed by a dab of anti-sieze in the threads.

Because I had no rear bar to start with, I went with monoball style end links which were cheaper and more rigid than the factory units. I also had to get the factory eccentric bolt, with sway bar provision, to attach the new bar. To set the pre-load on the rear end links, use a floor jack under each trailing arm and raise them both so that they support the weight of the car and are at equal heights. You should be able to twist either link with the same force once all the bolts are torqued. Before you tighten the monoball locknut, make sure both ends of the link are parallel so they don't bind with suspension travel. I hadn't tightened the lock nut yet in this photo. I did not use any thread lubricant on the threaded parts of the ball ends. That locknut does not have to be very tight, just snug.

Driving impressions:
It corners MUCH flatter than before, but I definitely need stiffer front springs to achieve my desired goal. I did notice a loss of suspension independence (left to right) with the bigger bars, but that's because I need new shocks (on backorder) BADLY. It was wet out, but even with bald..er..racing depth tires, the handling was much more neutral (too much understeer in stock form IMHO). It now is easier to induce more oversteer than it is to induce understeer. I believe the new 200lb springs and adjustable KONI yellows will balance things out nicely.

Weights:
Stock solid front 20mm bar with factory bushings and clips, 7lb 6oz (3.33kg)
968 tubular front 26.8mm bar with delrin bushings and 968 clips, 7lb 0oz (3.18kg)
968 rear 16mm bar with delrin bushing kits, monoball links factory eccentric and mounting bolts, 6lb 2oz (2.79kg)
I'm not sure if the rear bar is tubular or solid. I think it's solid.

moorepower · 09-18-2007, 07:13 PM

Nice pics. I'm in the middle of a similar upgrade to my 24S. I've got a 20mm M030 rear bar, monoball links, and Konis installed on the back. Haven't touched the front yet, though. I'm waiting for my manual rack to get here, then I'm doing the 26.8mm bar and front Konis along with the rack.

Needless to say, the stiffer rear end has "loosened" up the handling of the car. It's very fun to drive, but it feels like it's rolling over onto the outer front wheel under heavy cornering. I'm hoping the bigger bar and the Koni's will take care of that.

Eventually, I know I'm going to need more spring, but I don't want to do just the fronts without doing T-bars also. So, maybe next year.

onZedge · 09-19-2007, 05:56 PM

Mistake 1: I didn't allow the new sway bars to settle in before I tried to put these things in.
Mistake 2: I didn't think about pre-loading the suspension before trying to install these. I had the car up on jack stands.

They actually fit like a glove.

Driving impressions:
Front end is now much tighter going around corners. They got rid of some front end wallow I didn't realize I had. I have to re-learn steering inputs.

Weights:
KLA Front Sway Bar Bracket Supports, 0lb 9oz (0.28kg)

KillerDynoSoar · 10-01-2007, 12:03 AM

Hi there,

How do you preload the suspension when its up on jacks? Do you just use two jacks under each A arm?

I am hoping that the installation of my 26mm front and 18mm rear anti-rollbars goes smooth. My 924-S did come with a rear bar so I am hoping all the hardware will slip togeather nice.

Any other advice to look out for?

Al

onZedge · 10-01-2007, 12:02 PM

Re-read reply #7.

KillerDynoSoar · 10-01-2007, 11:45 PM

Quote:

Originally Posted by onZedge

Because I had no rear bar to start with, I went with monoball style end links which were cheaper and more rigid than the factory units. I also had to get the factory eccentric bolt, with sway bar provision, to attach the new bar. To set the pre-load on the rear end links, use a floor jack under each trailing arm and raise them both so that they support the weight of the car and are at equal heights. You should be able to twist either link with the same force once all the bolts are torqued. Before you tighten the monoball locknut, make sure both ends of the link are parallel so they don't bind with suspension travel. I hadn't tightened the lock nut yet in this photo. I did not use any thread lubricant on the threaded parts of the ball ends. That locknut does not have to be very tight, just snug.

Yep there it is... just what I thought. Sorry was reading fast during my break.

Great info..

Al

onZedge · 07:19 PM

I am tempted to cut one round off the stock 125# springs (to lower the front) and re-install those instead of the Weltmeister 200#ers, since I don't have 25.5mm or 26mm T-bars to match yet.

Any comments about that are certainly welcome. Oh, and I returned that "John Deere Yellow" and bought some "School Bus Yellow". Much better match. I'm painting these because KONI included stickers with the inserts (damn them). Might as well do it correctly.

Techno Duck · Techno Duck's Garage

The balance of the car is not that bad with the 200lb fronts and stock torsion bars. I use the same sway bar setup and its pretty neutral with the way my car is currently set. Just play around with the dampening and adjust your tire pressures.

onZedge · 10-02-2007, 07:24 PM

I plan on getting an early start. I think I will try stock front springs first. Then modified stock front springs. And finally, the 200#ers. I've got all day. I do my own alignments anyway. Setting the camber is a ***** though.

Dave L · 10-02-2007, 07:27 PM

Whats the plan for the car, AutoX, DE, street?

Why do you want to lower the front? One of the first "to dos" on the 944s ( I would assume the 924s is the sames) is to make things level front to back. The Weltmiester springs will lower the front by 1 1/4 inches but Im not sure the rear could be lowered the same amount by just doing the eccentric bolts. My understanding is that by dropping the front you will put more weight of the front and cause the car to push. The fact that your front is stiffer would further accentuate that. I currently have the 250lb weltmiesters with the CS900 spacers to keep things level but intend to replace the Torsion bars and will probably remove the spacers at the same time. I would go with Jons advice and install the 200lb springs but I think it might be a good idea to install spacers unless you are willing to replace the Torsion bars (ideal) or reindex the existing torsion bars.

I have kind of gone down a similar path in upgrades as you have outlined and am still learning. I find the car is balanced now that I added the 19mm rear bar but I also wonder if I have simply adjusted my driving to accommodate the understeer.

onZedge · 11:14 PM

My plan is a DE/Street setup. The struts, shocks, coil springs and T-bars are so worn out that my car actually looks as if it was intentionally lowered. Stock height coils would actually require me to RAISE the rear to match.

In a nutshell: My goal is to stiffen the springs to control squat, dive and roll; use larger sway bars to do the final roll control tuning; adjustable shocks to tune out suspension oscillations to keep the tires planted. Other things like less compliant bushings and chassis stiffening components are part of that goal. I did the research. I have a plan.

Back in the real world, opportunity and budget will dictate in what order and how much time goes into each phase. This is, after all, a daily driver/project car.

Tam Lin · 12:26 AM

Quote:

Originally Posted by Dave L

Whats the plan for the car, AutoX, DE, street?

Why do you want to lower the front? One of the first "to dos" on the 944s ( I would assume the 924s is the same)

Yep, 924S is the same. I have KW v3 adjustable coil-overs all round, and whilst I was happy with the setup the shop that fitted it gave me (still want more caster), they rather unhelpfully dropped the nose and lowered the back on the eccentric bolt only. Took about three sessions of adjustment (the front and rear settle differently due to the weight distribution) to get the bloody thing level. Looks weird, with almost Cayenne front wheel arch gaps, but handles a hell of a lot better.

The long term answer is to bite the bullet and do that bad torque tube indexing thing. And whilst I'm there, fit a 968 fuel tank, an LSD and replace fuel & brake lines. Oh boy.

Dave L · 10-03-2007, 04:31 AM

Quote:

Originally Posted by onZedge

My plan is a DE/Street setup. The struts, shocks, coil springs and T-bars are so worn out that my car actually looks as if it was intentionally lowered. Stock height coils would actually require me to RAISE the rear to match.

I suppose the torsion bars could be twisted but I think that would be unlikely. I would guess that the torsion bar mounts might be in pretty bad shape and twisting if the rear is low. Spring plate Bushings

I would try replacing the rear shocks and see how that goes. I found replacing mine with Konis at 50% stiff made the rear much more "stiff" when I push down on the hatch to bounce the car.

onZedge · 10-03-2007, 08:40 AM

I have new Weltmeister spring plate and T-tube mount bushings. I haven't installed them yet. My dance card is full of Talledega this weekend! BTW - those bushings don't look half as bad to do than most people might lead you to believe. Just tedious and time consuming. Go to rennlist and search "tiki" to find an extreme method of spring plate rubber bushing removal. LMAO