Noahs944

Welcome. I started this thread because I find old threads are too time consuming to sort through sometimes. The purpose of this is to document special considerations about modifying 924/944/968 cars for off road,

Noahs944

Rear end:
We spoke about this previously. CV AXLES.
Most 930 CV joints that are "plunging" (meaning lengthen-compressing like a slip-joint) are functional up to 28 degrees.
I suspect this would work for a very modest lift (I dunno maybe 4" higher than stock ride height), but when lifting bigger, one of the problems is the cv axle isn't long enough... And the problem with installing a longer shaft is when the cv prop-shaft is compressed to its shortest length (at zero degrees-perfectly horizontal from hub flange to tranny output flange) is it will bottom out. It is recommended that a minimum of 1/4" plunging movement be available at the tightest points (such as max suspension upward travel/downward travel or zero degrees angle).

Today I was beginning research for a solution to the suspension modifications on Wilson, my 88 944. I need to address the CV axles because I might need to lower the present torsion bar ride height, but if I can find a cv solution, than I might retain the present height (measuring 15" from floor to bottom of belly, just in front of the rear tire-this is roughly 7 inches lift from oem).

My goal is to have roughly 8" suspension travel at each wheel.
I measured cv angle at droop (droop is when the weight of the wheel and related suspension is hanging): 32 degrees.
Measured at ride height (vehicle at rest on ground): 22 degrees.
I got a problem. CV axles, like u-joints are weakest at severe angles and failures increase with more engine torque and sudden traction.

Looking at the VW BAJA world, I see many products are available from the good old USA. The Porsche 930 cv is very popular thankfully.
UPGRADE OPTIONS. This gets pricey, but critical.
CV: The CV cages and races can be upgraded to cro-moly and can be super upgraded to 300M metal. https://www.racereadyproducts.com/cv-cages/
You can upsize the 930 to 934 cv joint which is bigger. And there are about 15 variations.
CV propeller shaft: "Sway-away" makes upgrade shafts with longer splines that allow the cv joints to "float". https://swayaway.com/product/axle-se...ong-33-spline/
Edit: this is interesting, company offers a "counter-bore" cut for the CV STAR: https://www.kartek.com/parts/kartek-...-cv-bolts.html

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Noahs944

Depending on the purpose of the build, one consideration is welding the spider gears of the diff (to be fully locked, like a spool or mini spool which don't appear to be available for our cars). An advantage of being fully locked, unlike a LSD is you can drive home on one CV shaft if you break a CV shaft because you were abusing it. An important consideration for TSD rallies.

Noahs944

A solution for cv joint angle correction is to lower the transmission. When lowering the tranny (perhaps 1" is possible by inserting spacers under the body (above the wide steel bracket that mounts the transaxle hanger), the next thing that hits is the tips of the collision hooks on the late model torque tube. You can trim the tips. (careful of sparks near fuel tank). You will need to make adjustments to the exhaust, but from what I am seeing, this is an excellent suggestion to improve angles. As a quick check I compared angles and found its possible to decrease angles approx 4 degrees. In the case of my own car, it has these effects:

ride height was 22 degrees/corrected to 18
full droop was 32/corrected to 28 degrees.
28 degrees is considered the max angle on 930 or the bigger 934 cv joints.
4 degrees took us from a red zone to yellow. This should be acceptable.






These cars respond well to being lifted by suspension, however it's only tire size that will increase the lowest point of the car. Tires that are the most practical "upgrade" are hard to find, because the size is in between small passenger car size and truck size. Fortunately, they can be found to fit the stock Porsche 15 and 16 inch rims. Keeping tire increases to 10-15% is the most practical. Larger than that is going to be wrong for the ring and pinion gearing (if street driven). Larger tires also means more unsprung weight (the suspension will not be as controlled) and the braking distance will be increased.

Noahs944

This week I have determined that unless the rear trailing arms are wider (more space from trans output flange to hub input flange), then Wilson is simply too high & simply should be lowered at the back. I anticipated this but wanted to at least try. The problem is cv angles. So last night I pulled the carrier to re-clock. My goal here is to lower the back half about 1.5" from where it was. This should put the rear ride height around 3+ inches over normal ride height & leave the car nose high. I'd like to try the car nose high like the old 911 rally cars because I think it helps keep the tires down when you get air (but I could be wrong).
Things getting desperate in the garage. My jack stands are not only way too short, but my torsion bar mechanicing skills are improving.

Above: with trans removed & T.B. Carrier removed, I used this muffler to hold up the Torque tube and support engine. Hillbilly me.


Above: Upgrade from the Porsche 930 cv joint (like a VW type 4 but better angles) to the mighty 934 cv joint. Good for v8 power & big tires. I counted on the late 944 cv axle a spline count of 33. Most 934 cv joints are cut for 33 splines. But you'd need adapters or different flanges. Seen here are some crafty 930-934 adapters to change the game, but the problem is that the cv angles will be again compromised, so you'd have to widen the stance (something I don't want to do).

Nut shell: I'm trying to gain as much height as possible while using stock 944 cv axles, this is the most practical/reliable/affordable option for me at this point.

Noahs944

Hey Brothers and Sisters. I hope you are all doing well.
I haven't concluded on what the hardest part about lifting the 944 is, because I haven't successfully completed this task.
My personal goals & reasons for lifting my car Wilson is:
-Looks cool
-Will slow me down on the street... help shape a chill driving spirit while on the street
-Easier for me to get into & out of (especially as I grow older)
-FUN
Now when you think about lowering or raising an automobile, you have a number or image in mind.
My goal, when I started and continued to move forward with the idea, is to raise it 8 inches. That is my goal. I also set a goal of 8 inches wheel travel. That;s not going to happen (not in the rear anyway-because of cv shaft restrictions. It was my intention to "settle" on a rear suspension height (regardless of type of spring used) before settling on a front ride height. Simply stated, my view:
The rear is the master & the master of the rear is the C.V.
One must be willing to compromise, especially on a low dollar budget. Try to re-use Porsche parts whenever possible & it'll be easier to get cheap spare parts. Suspension is what makes our cars so special and we want to have killer suspension in the offroad domain, but with the steering & driving connection of the transaxle Porsche.
So because for me "bigger is better" and I think torsion bar is a better choice than typical rear coilover in terms of durability, I have just changed to 11 inches between these holes (I was at 12.5 before, which incidentally measured 12" when I removed it from the car). I'm hoping this lowers the car 1.5"-2" at the rear and pray the cv axles work.

Hey late model lifters, you have to do some trimming on the forward collision hooks. If you want to decrease your cv angles by dropping the tranny around 19mm.

And I chose to notch the side plate

tempest411

An off-road 944? These cars require enough attention to keep them going on the street, much less the dirt.

Noahs944

Tempest, Yeah ain't that right. Which is why I was so impressed to see a 1980 924 complete a whole 5 hour rally over rough terrain a couple years ago!

tempest411

How close to stock was it? From what little I know of the old VW engine from that time period I'm under the the impression it was a much more robust design, If lacking in the hosepower department. But the suspension isn't the very inspiring for off road use, epecially the hollow front axle on the driver's side. And then you've got a chassis that has nothing guarding the radiator but a flimsy piece of sheet metal. Most cars of any make have a pretty stout crossmember there. One bump and your cooling system is all over the trail!

Noahs944

That's my boy D'Arcy... best navigator I have ever had. He's kind of geeky about rally and that is what I like.

Tempest, you bring up a good point on the rad's exposure... I'll have to check it out. Your comments inspired me to try and find images. And I found them. The 924 is seen here, and it's actually a 4 lug '78 (just like I had, but theirs ran better! LOL-I was so angry at VW/Porsche and my '78 "Gramps" by this point... I turned down a nice 951 to by my 924, that was an error on my part). Anyway, this was a father/daughter team and the conditions were slimy in the mountains of Alberta. It was a thrilling and at times exhausting drive. People sliding off the truck routes and needing to be tugged out (almost happened to us several times. But the our dream team got second place in the Historic cat). Look at the white car, this is stock suspension. It was weighed down. On a trip like this with navigator, 2 full size spares, tools, fuel, emergency items, etc... we might weigh 3200 (car was down to about 2500 lbs with half tank/single race seat & no driver). Wilson weighs about 3000 now before the junk in the trunk.

Noahs944

Hey if anyone isn't familiar with the 924-968 rear suspension, please check out Van Svenson's overview on Youtube. I have a camber issue in the rear I need to sort (but didn't know how), so I searched 944 rear suspension on youtube & Van's video showed up & answered all of my Q's. In fact if someone can post it on this thread, I'd appreciate it.

Noahs944

Some good news/some bad. Bad stuff first:

Had to deal with the body. It was cut the body or buy aftermarket trailing arm or do a lot of fabrication.



Good news: The upper shock mounts that I thought were cracked are in fact NOT!
So I will try to use the oem shock mounts but with a long stroke shock.
Now on to the best news I could ask for: After dropping the rear ride height (measuring 11" as I previously described) and resting the torque tube onto the torsion bar carrier, I freehand measured the approximate drive shaft angle at ride height; It is 10 degrees. That is pretty amazing and makes me hopeful of using stock driveshafts. This angle will get worse as I raise the tranny up from the tube, but it gives me a number to try and stay close to! Oh, and btw, the stock late drive axle c.v.'s might only be good to 22 degrees, not 28 as I stated previously.

Noahs944

A really good option for bigger travel rear shock absorbers comes from a Jeep TJ application, but both the upper and lower bushings need modifying. Seen is a 2.5" longer-than-stock-TJ rear shock looking very much at home using the factory Porsche bolts.
944 cars limit the "droop" or suspension extension with shock absorbers, so if you lift a car and put longer shocks in, then you need a mechanism to limit droop (to avoid cv shafts breaking while you are driving, creating a very dangerous situation).

Noahs944

Couldn't be more pleased because today's present came by surprise.
1.25" Urethane transaxle lowering spacers & longer bolts were able to be used.
Final cv axle angle at ride height: 11 degrees.
Tested angle for droop (FULLY expecting to need to purchase limiting straps), but when letting the suspension droop I measured only 17 degrees. Which is good because I'd rather have reliability than max flex.
Turned the wheel & test for binding at tranny and hub, found smooth operation, with no indication of binding. Checked for axial movement at hub and trans when drooping & found a good 1/4" movement on both sides, which meets our minimum requirement. What can I say? The backend is nearly complete & should prove to be reliable. Total shock travel being used is up to 6" and the cost was very affordable. THANKS to VAN & V2 for the tranny drop idea!

V2Rocket

Noah - my research (and fuzzy memory) recalls that the max TOTAL travel on a 944 CV is 22 degrees - as in 11 up or 11 down, off horizontal.
So if you're sitting static at -10 you don't have much room for droop, unless my info is wrong.