Thought exercise: 911 dual A arm suspension on a Boxster

[truegearhead]

Let me start by saying I have a very cut up Boxster and a buddy has a 911 rear end sitting around that I could get a deal on... Now for the question: Could you make a 911 dual A-arm rear suspension work on a Boxster which has a McPherson suspension. The lower half of the suspension is the same but the Boxster does not have the upper connection points for the top two arms (links). These would have to be welded on with incredible accuracy or the 911 subframe would have to be adapted and used. Both subframes seem to bolt to the car with bolts that are at least close to the same location and the cross supports appear to be in the same location. An interesting observation: the 996 uses rubber subframe mounts and the Boxster has solid metal mounts. Not sure why.

Lets get out of the way that any improvement would be minimal and there is no good reason to do this. This is typically what I say when starting all my "modifications", and if you've seen my other threads you know I have a high pain threshold for horrible projects with a lot of fab work.

Step 2: how could you make a rear dual A arm suspension work on the front of a boxster....

Here's some terrible shots of a 996 setup and subframe


Here are some equally horribly 986 shots

[itsnotanova]

I think in theory the rear is doable and might give you a slight advantage over the McPherson struts. I was going to use the 996 rear suspension on a mid-engine 911 project I have planned. I bought some solid mounts for mine but I can't remember from who. As for using the rear 996 on the front, I think you'll lose some front braking compared to S rotors/calipers. Maybe even base rotors/calipers too

[Gilles]

truegearhead, you have a unique way to keep us very interested on your projects.. :-)
With the added weight from the twin turbo V8 I think that the double A arm rear suspension would be a great idea, you already have the tube subframe as a foundation and you have great welding skills..

[itsnotanova]

Originally Posted by truegearhead

Here's some terrible shots of a 996 setup and subframe


Here are some equally horribly 986 shots

What transmission is that out of?

[truegearhead]

Originally Posted by Gilles

truegearhead, you have a unique way to keep us very interested on your projects.. :-)
With the added weight from the twin turbo V8 I think that the double A arm rear suspension would be a great idea, you already have the tube subframe as a foundation and you have great welding skills..

Thanks! unfortunately I’m a terrible welder but my buddy that has done all the welding on this car is fantastic. My car actually still has most of its chassis intake. Only the top half of the rear is space frame. The floor, trunk, and some cross bracing has all been removed but the frame rails that the sub-frame attaches too are still there. That being said, I love an evening with an angle grinder.

[986tate]

The new 911 Cup or RSRs have dual wishbone front but it won’t be cheap. What about 928 front?
I love daydreaming about this kind of crap.
Would be cool if you did it

[truegearhead]

Originally Posted by 986tate

The new 911 Cup or RSRs have dual wishbone front but it won’t be cheap. What about 928 front?
I love daydreaming about this kind of crap.
Would be cool if you did it

I didn't realize the new cup cars had front dual wishbones, looks like the new GT3 does as well. I've always been shocked Porsche used such a poor McPherson design. They did a great job of making it work I guess.

[truegearhead]

Here's my very in-depth engineering analysis...aka something I made in paint with some images I stole from the internet. The deal breaker is the location of the green tie in points, if they're in the same location the 996 subframe would work...I think. Give that the control arms and the trailing arms below each support are the same design I would think the attachment points would be in the same location.