What is the difference between IX & non IX subframes???

[///eMveee]

I've searched extensively and could not come up with a definitive answer...

REAR subframe... I'm aware that the Fronts are VERY different from one another...

I own several e30's both IX & non IX.

Looking under the vehicles they appear to be the same.
I do not see any obvious differences.

However, according to the part numbers, Something must be different.

The part number for the IX Subframe is # 33 31 1 135 546
( and it includes the Bushings)

The part number for the Non IX Subframe is # 33 31 1 135 456
( it also includes the bushings)

I have a spare rear subframe and would like to do a complete overhaul/modification to the subframe before install.

Do you gyus think that the only reason that the Subframes carry a different part # is due to the fact that the bushings in them are different?

I want to install all Polly Mounts and Caster & Toe Adjusters.


And a related question:
Does anyone sell Polly bushings for the IX anymore?

I know that AKG used to sell them but as far as I can tell, they are no longer willing to make them ( I emailed AKG several months back and the reply was not encouraging)

Is there a way to use an existing Polly Subframe bushing to get the subframe where it needs to be? I would like to keep my subframe at factory height.

Do you guys think mounting the 12mm Subframe RAISING MOUNTS installed Upside Down will get me what I'm looking for?

Here are some pics of the mounts I am talking about.

These are the AKG iX mounts that are no longer made.



Stock Factory IX Mounts # 33 31 1 128 990





These last mounts are "12mm Raising mounts" causing the subframe to go UP into the vehicle body some 12mm.
Notice how the "flanges" on these Mounts are different from top to bottom.



I was wondering if mounting these with the THICKER flange up TOP instead of on the Bottom will acomplist the same thing the factory did with the IX Mounts.

I know it was a long post, but I wanted to clarify both questions.

Any input greatly appreciated. Thanx

[///eMveee]

Can't post pics of Bushings.
will try again.

But hopefully my descriptions were detailed enough that some of the Gurus on here will know exactly what I'm talking about...

[///eMveee]

No replies guyz?

[Northern]

Here


TL; DR:

Subframe is the same, part number difference is from bushing.
Bushing is different, sleeve is longer for thicker subframe washer (see link)
Can take any regular E30 poly bush set and make a spacer to push the inner sleeve up into the body.

To lower the car and lose camber in the rear, you could run RWD bushings&Subframe washers, and correct at the diff with one of those offset diff bushings or diff spacer kit.
OR
Run RWD riser bushings with the iX subframe washer, plus use the same spacer to accomplish the same as above.

[///eMveee]

Sweet, Thanks.
Thats what I suspected.
Just wanted someone to confirm.

Do you know roughly how much higher the IX bushing is than the regular e30 bushing?

[Northern]

From what I have written down, it is ~.3" taller because of the different washer.

[///eMveee]

Ah, I see, thanks.
So, the IX bushings places the subframe 0.3" lower/ away from the car body, correct ?

[Northern]

In combination with the subframe "stopper" washer, yes.

[///eMveee]

Thanks for clarifying.
Much appreciated.