Anti-dive &a A-arms - simple as adding spacers to mount?

[Maxhouse97]

Read through this thread here, but was inconclusive on whether you could just add spacers to the front a-arm mount to lower it without messing with the rear a-arm attachment (or I just missed it). Anyone do this? I don't want to cut a hole in the tub for the rear mount.

I believe Craig D did this in his famous 78 suspension rebuild thread, but I didn't see where he explained what's exactly required. Again I'm hoping some simple washers. I PMed him but have t heard back. Thanks.

[Walt Fricke]

Tony - Porsche did this for the Turbo, as you have realized, by raising the rear and lowering the front. You can find the amounts by searching here, and maybe Frere or someone has it in a book.

Easy enough to space the front down the factory amount, but that gives you less anti-dive than otherwise. In theory, you could add what the rear was raised and come out the same. But you'd have a front bar attachment which might be too close to the pavement.

There is also the question of bushing alignment. I don't know just how Porsche dealt with this - maybe the rubber in the street Turbos handled that just fine. You might query Elephant (if that is your car in the picture) to see how much misalignment he thinks his system will accept.

On my coilover track car, I use spherical bearings as the bush so alignment isn't an issue.

You can fake the raised rear by cutting off the protruding sockets for the cross member from the tub, shortening them, and welding what is left back on - this leaves the interlocking feature (recess in the cross member mates with round protrusion on the tub) in place so all the shear stress is not on the 12mm bolt. I can't recall if you need to shorten the bolt, but if so that's easy.

On my first try, my welds eventually failed (you can see how tricky this is if you try it this way), but the redo has held. And nothing failed as a result of not having the self-locating feature functioning.

The procedure in the factory manual for retubbing a 930 (Porsche didn't offer a 930 specific replacement tub from what I deduce)looks like it requires a lot of confidence in your bodywork and welding skills.

[proffighter]

That's my car in the pic...

[Maxhouse97]

Thanks for the thorough explanation Walt. Yes not my car. I'll probably skip this as I'm in the middle of my suspension refresh and don't need another big project.