Just wanted to throw this out there. On my drag 928 I just installed a fully adjustable upper control arm that would work great for regular 928s as well. I used them to narrow the tracking width along with building a lower control arm from scratch. Mounting the upper arm involved a couple of small mods to make it work. First was drilling out the mounting holes to 3/4" and using a 1" long 3/4 od x 1/2 I'd spacer to allow the use of 1/2 inch bolts to mount the control arm. Also used a 7 degree tapered reamer to fit the Chrysler style screw in ball joint. The arm comes from a company called Specialty Products Company.
Heres a picture of the setup.
I wound up using 2 different part numbers in order to duplicate the geometry of the factory arm. Then I used the long 5" adjuster on the front and short 3 3/4 adjuster on the back. For a regular 928 I would say a 5" on the back and a 6 on the front would probably be about tight. They cost $150 each plus ball joints were about $25 each. As you can see in the picture the cross shafts are slotted for even more caster adjustment. Website is www.specprod.com start on page 114 of catalog. They also offer poly bushings which would be more appropriate for street use

 

Wow, interesting timing.

I have the exact same setup on my replica Cobra and I've been working on replicating that setup on my 928's.

Very cool to see it will work since I haven't gotten any farther than the planning stages.

All of the parts that make up the arm in my replica are also available from Summit racing.

 

what is the performance benefit over stock?

 

Some of those attachment points seem very thin to me if ever exposed to lateral force.

 

This would give more adjustability especially the negative camber needed at the track that can't be obtained with the stock adjustments.

Having put S4 upper A-arms on I could see this being a better alternative. The cost isn't just the arms but in getting the arms shimmed out as a stock mounting would result in too much camber.

The upper arm sees a lot less force than the lower arm. I'd prefer some of that to look beefier but I'm not sure it's not good enough.

 

Doubtless you know what you are doing but I am intrigued as to why your front supension would need such on a drag monster- much appreciate some enlightenment. I have no clue as to how to set up a drag machine but up front I would expect it spends most of its time in the air given what you have under the hood but then presumably that "big lump" keeps the front end down.

What 1/4 times do you pull?

Regards

Fred

 

The pro-touring guys (first gen Camaros, Chevelles, etc.) have been using the SPC arms for years under some pretty extreme track and autocross conditions and I haven't heard of failures of those arms.

There's a guy named Mark Savitske that's a guru in the pro-touring world and he has some pretty decent suspension articles on his website (geared towards pro-touring, of course). Here's one he posted about A-arms: http://scandc.com/new/node/944

 

Pretty cool!!! Guessing much lower friction. Suspension is surprisingly complicated in hooking up today's drag cars.

 

No worries on strength, as mentioned above lots of cars way heavier than a 928, ie chevelles, novas, etc use these arms in autocross events every weekend across the country.
As to why for a drag car? It was way easier than building arms from scratch BTDT. It's a PITA.
the reason I narrowed the track width, is the car just didn't look right with the skiinnies up front and the big tires tucked in the back. Car has run as quick as 4.46 in the 1/8th (approx 6.80-6.90 range in the 1/4). However after converting back to a street driven machine it should run low 8's in the 1/4 on pump gas. (Although I'll be shooting for a 7.99999999)

 

Wow, that's hauling some ***.

 

I think the "*** being hauled" was left on the line- awesome!

Fred

 

What tranny and rear axles are on the car? I would think the torque displayed would break stock parts. Maybe the axles are strong enough, but the track guys regularly break the input shaft.

 

Very interesting work

 

Definitely not stock drivetrain, Lenco racing transmission and ford 9" with 40 spline axles and spool. Car is tube chassis from the firewall back.