View Full Version : 360 & 430 AFCO Front Spring Installation

03-04-2009, 05:49 PM
AFCO 10” Spring Installation

360/430 Front Spring Installation

I found that my F/E was bobbing a bit and at highway speeds it would in some cases bottom on a high spot on the road. I decided to remedy both problems.

I chose an AFCO replacement spring for the 360 front suspension. It is an AFCO P/N: 23400. See: http://www.afabcorp.com/AFCO_Dynatech_USbrake/merchant.mvc?Screen=PROD&Store_Code=A&Product_Code=23400&Category_Code=hp_coil-over-10.

It is a 400# spring and it measures 10” in height. The OEM spring is 9.5” +/- in height, and it is about 350# in pressure. The P/N: 23400 AFCO is about 15% slightly greater in pressure which gives the front end just a bit more control, less sway, and takes away the slight dip at speeds.

The final vehicle height adjustment process can be done easiest with the shock body mounted in the spring compressor. It can certainly be done with the spring mounted, but it is much easier to do it with the spring compressed outside of the vehicle. See 360 Front Shock Removal.

Have an experienced person compress the springs on a quality piece of equipment if you are not familiar with spring compression. It is a dangerous process for a novice!

Remember that prior to removing the OEM spring one must measure the original location of the spring support collar to a fixed point on the shock before removing the OEM spring. Mark with a small felt pen on the shock body and record the distance on each shock with a digital vernier or equivalent. You are measuring from the bottom of the spring support collar to any point on the shock for a reference point! When installing the new AFCO spring you will then have a reference point to drop the additional required ˝” (8 turns) on the spring support collar.

Since there is a ˝” height difference between the OEM and the AFCO spring, when the AFCO spring is mounted into the coilover the spring supporting collar (measurement) must be lowered by this ˝” amount (8 turns) to equal the original spring distance.

The additional pressure of the AFCO spring will initially raise the vehicle about 1” when the spring support collar is dropped the additional ˝” from the OEM location on the shock body. Remember, however, that springs drop a bit after initial usage, and this will happen with the AFCO springs.

With the spring in the compressor and with the support ring set to the OEM spring distance above-marked, there are approximately 8 additional turns required to lower the spring support ring beyond the ˝” (8 turn) spring differential of the AFCO spring so that the vehicle will settle to factory settings. This is based upon the OEM springs set to the OEM Ferrari ride height. Refer to the Motion Ratio table for height changes per given turns.

See “Lowering A 360/430” for the procedure and preferred tools.

When the adjustment is done with the spring in the compressor, turning the spring support ring is easy.

In review, mark the OEM distance of the spring support ring on the shock body before spring removal, compress the OEM spring, loosen the locking ring and remove, slowly loosen the spring support ring until free, remove the spring, install the AFCO spring and compress, reduce the distance you measured for the OEM spring by ˝” (8 turns) and then set the spring support ring down 8 additional turns from there. Securely lock the two rings, and then slowly decompress the spring.

Check the lower shock support bushings before reinstallation and replace if necessary. This is important as they may knock. They are Ferrari P/N: 157630.

Upon installation of the complete coilover assembly the front body height should be about 4.99” front as prescribed in the “Lowering A 360 or 430” discussion. Check the measurements from below as prescribed by Ferrari, and adjust if necessary.

Remember that springs do need to settle. So initially the above-suggested settings will make the vehicle ride height seems too high, but after 25-50 miles the body will settle to the correct height

If too low (which they should not be) one can always turn up the ring to raise the vehicle. See the M.R. chart for the effect.

See attached Motion Ratio table below.

Note: Motion Ratio 0.80 figures are shown for reference purposes only. M.R. 0.70 is applicable to the 360 & 430.

The AFCO springs in the front make a noticeable difference in front end bob and body roll control.

They are available from:

[size=4]GAT Racing
Attn: Mark
3720 E. Hardy
Tucson, AZ 85716
V 520-325-4462
F 520-323-1429[/size=4]