944 aluminum rear trailing arm info

[jmd]

a question about spring plates. Are there simple solutions stateside for this? I have spent 3 months looking for a set of spring plates, and it seems each Porsche dealer I speak to has a different Idea of what I am talking about?! So what I am trying to understand is, what spring plates do I need to get in order to continue the install? In a photo above there is a bright silver spring plate cover... what is this from? also is there a way to ditch my rear torsion bars, as I would like to use coil-overs but still require a springplate / uniball something or other... Anyone have insights for this?

Thank you.
(86 alloy arms on 69 IRS pan -body clearance a non-issue, just want the arms to function as installed.)

[Steve C]

Hi

This is an 944 adjusting tool a friend quickly made up on his lathe from some hex brass.

Steve

[C4 Metal Werks]

With the Early (top) will widen track by 43mm is it possible to use alloy wheels and stock rear fenders?

Originally Posted by Superman

Okay here's the scoop on 944 aluminum rear trailing arms. First off, throw the part number, year, and model out the window. Every source says something different. It's very confusing and I've never figured out the "code" yet. The best thing to do is just look at the arm, there are two versions. In the pic attached the top version is "early" and the other is "late". These are terms I have used and may not apply. Anyhoot, just look for the arch as pointed to in the bottom arm and you'll know this is the wider of the two versions.

Early (top) will widen track by 43mm
Late (bottom) will widen track by 74mm

Credit: pics and info from the book Kafer Tuning by Helmut Horn

[zen]

I'm not 100% on this, but doubt it. If I'm not mistaken, wouldn't the 43mm push the wheel mounting surface out past the fender lip on its own? No wheel offset is going to make up for that. If you went to 1-1/4" wider fenders, then yes, with the right offset you are fine.

[C4 Metal Werks]

That was my thought as well. I will keep looking for a steel right rear control arm.

Originally Posted by zen

I'm not 100% on this, but doubt it. If I'm not mistaken, wouldn't the 43mm push the wheel mounting surface out past the fender lip on its own? No wheel offset is going to make up for that. If you went to 1-1/4" wider fenders, then yes, with the right offset you are fine.

[SilverBullet]

is this 43mm or 74mm per side or for both sides?

[Steve C]

Hi

I measured my 1303 bug which had Type 3 rear drums fitted, then with early alloy arms. I've been told that Type 3 rears give a very small track increase.

Rear track wheel bolt face to wheel bolt face
1303 with Type 3 drums 1405 mm
1303 with early 944 alloy arms 1490 mm

Steve

[evilC]

Our 1303 has 924S alloy arms with 7" teledials on the rear and with a 31mm spacer the wheel sits perfect with +4" wings (fenders)

Clive

[zen]

Originally Posted by SilverBullet

is this 43mm or 74mm per side or for both sides?

Per side. I have late arms with 951 brakes/rotors, 8.5"ET48 wheels and 3" fenders and the wheels nicely meet the fender lip.

[SilverBullet]

I just got the late trailing arms without the bump stops, but when I compared the early and late, it looks about the same! Could it be the rotors that widen the track? Or the early alu arms came with bumpstops and without.

[SilverBullet]

Without bump stops L side: 951 331 513. 8R
R side: 951 331 514. 8R

With bump stop R side: 951 331 514.1R , 951 331 514.0R
L side 951 331 513 1R

I have 1 extra right side with bump stop.
Could it be the hubs, rotors that increase each side by 31mm?

[1303GT]

just for some info,
86 and back 944/951 with non ABS used ET23 wheels, 87 and up ABS cars, the hubs changed to a wider track, and the cars went to et53 wheels, so yes the hubs are wider on the later cars.

John

[SilverBullet]

Thanks John for the info, will set it up soon and will post the difference.
Cheers.
Ric

[Tim]

I have late alu arms (no bump stops) with early 951 hubs and 7" cookie cutter (ET 23). The wheels just fit nicely in the fenders with 2.5" universal flares.

[Bug@5speed(US)]

TIm,

Which fender flares are those.. are they generic, or miata?

Let me know, I have been wanting to do the same, as a way to get around not buying flared fenders.. I thought no one had gone down that road yet..

Any info appreciated
Alex