Learning about 411/412 air-ride and lowering

[stevensjames]

I have been searching the forums for information on lowering and air-ride for the T4s and found some useful information. I have also searched the web and obtained informantion there as well. So, I see many companies like Air-Lift Performance sell DIY air strut kits so that's great. I couldn't find any information regarding the rear though. Not having one to look at in person doesn't help so I am here again asking those that know more than me. I assuming the rear is IRS but is it same as T1s? Would the same lowering procedure be for the T4? If so, I would assume that the air-ride kit for a T1 would also work on the T4. Please let me know so I can expand my knowledge.

[raygreenwood]

There was one person who bagged a 412 a while back. Heard it rode like hell.

The 411/412 is no relation to any of the other aircooled VWs. It has tubular welded trailing wishbones. It is most similar to the Vanagon in layout and construction.

The sedans are also a peculiarly balanced vehicle. In spirited driving they exhibit a bit of the Porsche 911 balance of the rear wantkng to pass the front during braking through curves. Nice work on the sway bars and good rear shocks and lower than stock profile tires greatly helps that.

Outside of that....the rear drive train is heaving and the trailing wishbones are long and the shocks and coils are mounted out at the 4/5ths point of the wishbone opposite the pivot.

This makes for very high leverage. It would be NOT ideal to place bags there. Also the shocks in this position are an active part of driving handling on this car. The car has a high center of gravity like all ACVW. Not a safe practice In my opinion.

The front...is McPherson struts similar to superbeetle but with very long, high leverage control arms. The front end also has a bit of a delicate balance due to the length of the struts and control arm. Yes....I believe there are a couple of companies that make circular strut coil spring replacement bags.....that would be the easy part.

However.....the struts only have a 6.5" stroke range. This brings the control arms and radius arms to their limits and puts a lot of side load on the radius arm eye mounts in the sub frame. Great way to break things fast.

Lastly...if you go to severe lowering or air ride....its going to put enormous pressure on the ball joints which already have undersized springs. Ball joints do not grow on trees for type 4. They have not been produced in about 30 years. I am working on a replacement type for them with a machined housing but that may or may not work.

Proceed at your own risk. Ray

[stevensjames]

Thank you for the thorough information. I always looking to expand my knowledge and this is all new to me. Hopefully others will benefit from this information also