Input/Advice needed IRS Baja

[Schepp]

Hey guys hoping you can help me decide what to do with my rear setup.
I’m building a 1972 Full nose all steel baja/rally car intended for rough country roads and rough wash board mountain fire roads. The front is done. Beefed up and gusseted 3” lift spindles, Bilstein’s w/ remote resi’s, disc brakes & hook/rod stops. The rear im having trouble deciding on the direction I should go. The catch is I have to use the stock arms as my garage is a single with very limited width. I can barely fit the car inside as it is. I plan on boxing the arms and relocating the shock mounts and tie them into the cage. The car is fully caged front to back.
I have type 2 100mm cv’s and thing flanges, axles & stubs ready to go on.
The question is;
Do I notch the spring plates for extra travel?
Or
Cut off the bottom stops and run limit straps?
This car will not be raced. Just a fun toy to mess around with.
Any advice is greatly appreciated.
Thanks,
Schepp

[Matt Wilson]

Six of one, half a dozen of the other. You could notch the plate bottoms 10mm. Be sure to add heavier springs in the rear, maybe like a sway-a-way 1226. You don't want to be riding on the bottom stops or banging on the top stops. It might look cool in your garage having all that lift, but be miserable driving otherwise. Droop travel is important too.

Other options include rear center adjuster, which is a pan-off mod, or adjustable spring plates. Be sure to put the shock mounts in a strong place, as they can still flex the boxing kit and push it into the stub axle flanges. If you end up using limit straps, you may still want to fab a top stop as well to protect your shocks at both extremes.
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1972 Standard Beetle
1969 Baja Beetle

[DHale_510]

I have a similar car as you describe.
I tried the notch thing, went too far, and it broke both sides at the same time while bombing a washboard road at about 50mph. Granted I notched them too far. Then we fabbed up some extra deep mounts and no further trouble and no limiting straps since the shocks have limiters inside.
I installed the KingKong adjusters and they were useful with the short 28mm torsions that twisted more or less daily but I have not needed them since I changed to longer torsions, Another advantage to the wider arms, they let the tires clear the long torsions. I figure the 28mms are about the same stiffness as 2mm on shorter arms. It doesn't bottom yet rides very good even at rather silly speeds.

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Dennis

[Matt Wilson]

In my opinion, short 28mm torsion bars won't allow quite enough twist angle (only 25.5deg) and it'll feel like riding in a shopping cart. They'll stop twisting prior to full jounce. Which means you'll have lift but the spring plate will be limited in range of motion, and may prematurely break. You'd do better with something slimmer. Do the math, then buy the springs. Stop-to-stop with your setup is about 32deg and anything you preload will subtract from that number. What's your eye-to-eye shock dimension?

You'll of course want to fab your shock mounts on the arms, then assemble the trailing arm without torsion bar. Install an unpressurized shock to get proper extension and collapse to position the upper mount on the cage. You may even consider shock shaft extensions if the rear cage mounts aren't quite where you need them to be. Of course leave yourself some margin to never over extend or collapse the shock.

You may also look for the video that instructs you how to get your CV's (hopefully floating CV's) in the correct phase to make sure you have the most articulation.

Your car is very typical of a Class 11 full body Baja bug sedan. Lots of information out there.
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1972 Standard Beetle
1969 Baja Beetle

[Mikedrevguy]

Am interested in what valving you’ve got in the Bilsteins up front.
I’ve the 7100 with 180/75, and am thinking I’d like a bit softer on the rebound.the FOA COILOVERS in the rear (not sure of valving) and they deflect nice over obstacles whereas the front more bounce over. Not terrible, but is different.
Seems like a similar setup to the Bwajaja, cept I’ve got 3x3 rear arms.
_________________
74 1303 (RevBug): plan for German Look
76 914 with 2260
79 VW Iltis
69 Bwajaja
"The wise speak because they have something to say; while the foolish speak because they have to say something." Plato

Illigitimi non-Carborundum!!

[Schepp]

Hey guys thanks for all the great info. I’m heading towards not notching the plates to retain their strength and going with limiting straps. Is it recommended that I get the weld on kit to lower the bottom bolt location as well? Like I mentioned before I’ll be running the stock arms, boxed. Stock long torsion bars mildly indexed. Still working on a engine cage design that’ll incorporate a spare tire mount similar to the bug pictured above. I don’t have rear shocks yet. That’ll come after I figure out the rear travel.
This is not a class 11 look alike but it does have a fully intact all steel front end. The fuel tank is also stock.
As for the front shocks I was recommended the Bilstein B46-1085R 220/115 due to the extra weight up front. I’m running lift spindles so the stock spring rate is retained.
I’m essentially building the car similar to a class 11. With my own twist. Much of the build has come from all your guy’s info and build write ups I’ve been reading for the last 2 years. I’ve read the Jeff book like 20 times. I’m inspired by Blake Wilkeys class 11 car and many of the other cars on here.
I’m an experienced fabricator and weldor a machinist by trade. I love a good project and challenge. This is my 1st VW. Here’s a pic of the front without the fenders or skid plate.
Any specific shock recommendations for the rear?

[Matt Wilson]

If you are boxing the arms, you'll probably be removing the lower shock mounts and need to fabricate new mounts that put the shock atop the boxing.

Stock springs will lift the car, but I'd be interested in how the rear looks once the vehicle is at full weight. It'll likely be heavier than stock with the cage.
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1972 Standard Beetle
1969 Baja Beetle

[Schepp]

Yea I’ll be removing the lower shock mounts and relocating them. I figured with the added weight to the car and having the spare tire on the back the indexed rear bars would help with that. Not really doing it to lift the car but to be able to handle the added weight. Time will tell if stiffer bars will be needed. For the cage, aside from the b-pillar hoop which is 1-1/2 x .120 hrew everything else is .095 wall.
Weight has definitely been a consideration throughout this build.

[Mikedrevguy]

Thanks for info on the valving.
I’ve got a 69 Bwajaja with all metal front end, gas tank, steel tube bumper
I’ve used the Bilstein b46-0493vw (265/70) and feels harsh IMO.
I’m currently running bilstein 7100 b46?? With 180/75 and these feel much more responsive to the mountain roads I get to enjoy.
Though I’ll admit my litmus test has also included nailing speed bumps at 30-35.
That said, with this valving, I still get more lifting of the front end, as compared to the rear end.
Regarding the rear suspension. Ive got 3x3 with spring plates notched 1”. Running FOA 6” coilovers with their recommendation on valving that I do not recall. They did recommend a 200lb spring, but have since gone with dual springs 350/150 and am happy with how this combo smooths out the speed bump test.
Had I realized that I’d need to cut unto the cabin with even these shorter coilovers, I would have gone with 8”, maybe 10. But these serve their purpose well.
Ive got the rear limited with straps at 21degrees with the race clearanced type 2 cvs to better handle that. .


Link

_________________
74 1303 (RevBug): plan for German Look
76 914 with 2260
79 VW Iltis
69 Bwajaja
"The wise speak because they have something to say; while the foolish speak because they have to say something." Plato

Illigitimi non-Carborundum!!

[Schepp]

I’d like some recommendations as far as valving for rear Bilstein shocks. I’ve read the entire sticky in shocks nowhere in that sticky does anyone state the valve specs of the shocks that they are using.

Also where are you guys buying Bilstein’s from these days? Many of the links/websites from 10-20yrs ago either don’t work or have gone out of business.

Websites like 4wheelparts.com have shocks listed but say discontinued. I know Bilstein still makes them as they still have part numbers listed in their catalog. But where can I order them?

Luckily 4wheelparts worked with me on getting my front Bilstein’s but it took 5 months for them to arrive!
I’d like to not have to wait that long again.

I went ahead and posted the Bilstein catalog link in the shocks sticky for future reference.

Single shock per wheel application. Stock long torsion bars with a mild index to compensate for the extra weight of the engine cage and rear mounted spare tire.

I need a 10” non-reservoir shock.

I’ve been looking at part numbers:
B46-1361-H1 valve: 180/75
AK7110S04 valve: 255/70
B46-0360-H1 valve: 275/78
AK7110S06 valve: 360/80

Please help!!

[Schepp]

@DHale510

Do you or anyone else have some detailed pictures of the backside of how you welded on the lower bolt location?
What thickness of plate did you use?
Did you drill/tap the threads, use a weld-on bung or drill a hole and use a nut?
I appreciate the pics of the outer side. Great reference.

I’ve got 10” rear shocks. I’d like to be able to utilize a bit more of the stroke length then my current travel number which is about 7.5 inches with Type 2 CV’s and boxed stock arms.

The only way to achieve this is to lower the bolt location.
I’ve got some 3/8” plate I was thinking of using for the new lower threaded hole.

Also what are some typical travel numbers you guys are able to achieve with a setup like this? Curious if I’m in the ballpark of what’s realistic.

Thanks,
Schepp