How To - 914 Adjustable Rear Coil Overs, Specifically for Bilstein shocks Options

[tomeric914]

I was looking for details on the interwebs on coil overs with helper springs in particular for the Porsche 914 and found not much at all. There was something pretty close on an Audi forum, but not close enough. I was looking for a cost effective coil over setup that works and found http://shop.a1racing.com who had everything I needed at a decent price.

Zero rate helper spring keep the main spring pressed against its perches when jacking up the vehicle or any time the suspension is fully extended. These helpers are usually needed when running a spring rate higher than 150 pounds (in a 914), otherwise the back end of the car will be too high.

Below is a parts list, visual parts list, and video of how it all goes together. The part numbers listed are specific to A-1 Racing's website.

This is one of many ways to get to an easily adjustable suspension setup. Main spring rate will depend on your driving style and intentions for your car.

Note that part numbers BRP597 and 12460 have been modified slightly to allow for full compression of the helper spring. If not modified, the floater will contact the adjusting nut before the helper spring is fully compressed causing all of the force from the main spring to press against the thin aluminum coupler. The coupler will fail.

The floater / coupler does go on the bottom. Otherwise, the helper and main spring will have no lateral support.

As with any modification, proceed with caution. If you don't know what you're doing, STOP and find someone who does. (IMG:style_emoticons/default/bye1.gif)

Parts List:

12456 - Threaded Coil Over Sleeve 7" (qty 2)
12460 - 2-1/2" Coil Over Adjusting Nut (qty 2)
12470 - 2-1/2" Non-Slotted Coil Over Top Hat (qty 2)
BRP597 - Coil Over Spring Floater / Coupler (qty 2)
PROZ902 - Coil Over Adjustment Wrench (qty 1)
HYPCS100 - Hypercoil Zero Rate Helper Spring (qty 2)
HYP1810B - Hypercoil Main Spring (qty 2) - you must select the spring load




https://www.youtube.com/watch?v=SGIrZ1sJVdc

[tomeric914]

A couple of other details:

- The top hat center hole diameter is roughly 14.5mm which allows it to "float" on the shock absorber piston rod. Some choose not to run helper springs and zip tie or safety wire the spring to the top hat. There are two holes through the top hat specifically for the purpose of wiring the spring to it.

- Once the bottom adjustment nut is set to your liking, there is a nylon tipped set screw that holds the adjustment. Time will tell how well this holds up. Other designs use a split adjustment nut that has a means of tightening the diameter of the nut to the threaded sleeve.

- The body diameter of the Bilstein is 1.975" by my measurement or roughly 50mm. The ID of the threaded sleeve that slips over the shock is 1.993".

- The outer diameter at the circlip on the shock is 2.09" by my measurement. This fits nicely inside the recess of the threaded sleeve which is 2.10". That recess is only on one side of the sleeve for a depth of .590".

- Total travel of the Bilstein rear shock specific to the 914 is roughly 8".