993944S2

I have myself totally confused. I have collection of what I think is late and early banana arms. The arms are easy to ID as they have the ABS parts. However, it looks like what I thought were early arms are the same length. What is the actual difference between late and early? It looks to me like the aluminum casting is the same but the hubs are different lengths? Are there exact part numbers for late vs. early? Any help is appreciated. I'm totally confused. Thank you.

MAGK944

Not quite sure what you are referring to, if it's the rear control arms the difference between the early (up to 85.5) and the late (85.5+) is that the early were made of steel and the later were made of aluminum. So it's very easy to determine if they are early or late.

The rear control arms are "banana" shaped and go from the torsion tube carrier to the wheel stub axle and hub. Is that what you mean? There is another arm back there that is sometimes referred to as a banana arm, it goes from the torsion tube carrier to a chassis mount and is the same on all cars. People sometimes remove the last banana arm that I described when they fit coilovers struts at the rear. Also don't confuse early cars with early offset, the late offset cars started in 1987+

If you have an S2 then any aluminum arm will fit, and anything from 85.5 onwards will be aluminum.

993944S2

Sorry. I have a SP2 race car. It has steel, rear trailing arms. All of my wheels are for early off-set. I want to stay with early offset. I purchased a set of early offset aluminum trailing arms, and I also aquired a set of late off-set arms. I am talking about the banana arms. I am running a combination of t-bars and coilovers. My problem is I can't clearly see the difference between the early and late offset aluminum arms.

MAGK944

Like I said, that's because iirc there is no such thing as an early offset or late offset rear aluminum control arm, all the aluminum rear control arms will fit any car early or late. Unlike the front, the offset at the rear is determined only by the hub. So, if you purchased your arms complete with stub axles and hubs fitted, the difference in the hubs will determine if they came of an early or late offset car, not the arm.

Either way though both arms will fit your car if you use the early offset hub, so you have a spare

V2Rocket

as Mike so perfectly explained, the difference in offset with the aluminum arms is entirely in the outer hubs - everything else is identical.
however do note that you will need to swap the spring plate as well as the trailing arm in order to switch your steel-arm car to aluminum, as well as the parking brake cable.

alum arm early offset hub:




alum arm late offset hub:

993944S2

Thanks Guys.

wildcat077

Don,

You'll need to get the later axles as well , they are 3 inches longer than the early ones ... 20 inches versus 17 !
That's what i had to do with mine ... i junked the early rear arms for the later aluminium ones so i could run coilovers and
get rid of the torsion bars.

993944S2

Thanks Phil.. I'm still somewhat confused. I might just be thick. The pictures of the different hubs above help. What may be adding to my confusion is I bought what I thought was an "early arm, which included the stub axle and the hub. See pictures below. The one on the right is the one I ordered and was told was "early". However, the hub looks like "late" and matches the other examples I have.
Phil, if the banana arms are the same, as long at they are aluminum, and the only difference is the outboard length of the early vs. late hub, then why is a longer axel needed? Unless the angle of the arm, where it connects to the torsion tube is different, I can't see why different axles are needed. Don't get me wrong. I totally believe you, but I want to understand. Thanks everyone.

MAGK944

Don, you need longer axles like Phil said when you go from steel to aluminum arms. Again it's not an early to late offset thing, it's a steel to aluminum thing.

944 life would be so much less confusing if they changed to aluminum arms at the same time as they went late offset, or even if they waited until the end of a model year to change things. Unfortunately the fellows at the factory had a warped sense of humor.

993944S2

I feel stupid. Of course. It's the steel vs. aluminum. Thanks Mike. My pictures do show the two different offsets, right?

MAGK944

Yes, your aluminum arms are identical. However, one of your arms has an early offset hub assembly (from an 85.5 to 86 car) and the other has a late offset hub assembly (from an 87+ car). Buy yourself a pair of 85.5+ spring plates, handbrake cable and axles and fit those aluminum arms with the early offset hubs already.

wildcat077

Don,

If you have any questions regarding turning your early SP2 car into a more user friendly
"later" equipped version, feel free to PM me ... i'll be more than happy to help.
I converted my 83 SP2 car which was a total early " frankenjunk " machine from the PO into a somewhat more solid and safer version of a race car !

V2Rocket

the picture comparing the arms is an awesome, perfect reference pic for future posts.
thanks.

993944S2

Where do you guys buy your axels? Thank you.

MAGK944

Last set I bought were GKN Leombro from autohausaz.com, I think lindseyracing.com also sells that brand. Never been a fan of the other (cheaper) brand of axles out there due to hearing of issues with them, though I've had no experience myself of using any of them. LR also does their own "racing" axle version which looks very well made but $$$'s.