Kenny Brown Spring Install on 99 Cobra (Updated 2/24/00)
I have a friend in Midland who has an identical 1999 Cobra convertible that is completely stock. He came over and let me take some pictures of his stock Cobra next to mine with the KB springs and AFS wheel/Firestone tires. Here are the comparison photos.
Left, stock, right, lowered.
Left, mine, right, stock. Below, mine with wheels, KB springs.
The pictures above are the "After" shots. The KB Sport Spring Set KBP-85230 (coupe) and KBP-85240 (convertible) consists of 650#/in linear front springs and an unspecified rate for the rear springs. The rear springs appear to be linear, but are larger in diameter than stock. The KB springs are all shorter than stock, and lowered my car approximately 1-1/4" front and 1-1/2"rear, compared to my friends stock Cobra. Obviously, the car looks a lot better lowered!
These
are the rear springs, the top two are the KB springs for the convertible
and coupe, and the lower spring is the stock spring.
Note--I found out after installing the springs that there is a different spring set for the convertible which I should have had but didn't. KB sent me the correct rear springs and I installed them on 1/15/00. There is about 3/16" difference in the free length of the KB rear springs with the convertible having the slightly longer springs . The front springs are the same for the convertible and the coupe.
Installing the Rear Springs
The Ford Mustang shop manual would have you think that a spring install on the rear of the 99 Cobra was a terribly difficult job. Don't even bother reading the shop manual. Here are the steps, for information only. Use at your own risk. Use strong properly located jack stands and a suitable floor jack. Use a good spring compressor, safety goggles, and partake of no alcohol or drugs while working on your car. These steps worked for me installing the KB springs. Other springs may require additional steps, particularly if the springs are longer than the KBs.
1. Raise car and support at subframe ahead of IRS, one stand/side. Leave the jack under one rear lower suspension arm, say the right side, for example, after removing the wheels.
2.
Install an internal spring compressor by inserting the pieces one at a
time through the access hole in the upper spring perch. I borrowed
a good compressor from Autozone. Grease the threads on the long bolt
before installing the compressor. Raise the lower control arm
until the car just begins to come up off the jack stand, in other words,
compress the spring as much as possible with the weight of the car to make
it easier to tighten up the spring compressor.
3. Tighten the compressor until the tool or spring bottoms out.
4. Lower the lower control arm until the shock is fully extended. See if the spring can be pulled out. Mine came right out without removing the lower shock bolt but I have the HAL shocks which may have a little more travel than the stock ones. I don't really know. The most you will have to do is to preload the lower arm slightly and remove the lower shock bolt, then continue lowering the lower control arm until the compressed spring can be removed.
5. Before removing the compressed spring, note the position of the spring in each perch and the location of the rubber isolators on top and bottom of the spring.
6. After removing the stock spring, remove the isolators top and bottom and note the shape of the spring ends, match the new spring top and bottom and install the rubber isolators on the new springs exactly like they were on the stock springs.
7. Install the spring compressor on the new KB spring, and compress the spring enough so that the KB spring and the isolators can be placed in the spring perches.
8.
Raise the lower control arm enough to install the lower shock bolt, then
raise the lower control arm with the jack until the car lifts from the
stand slightly. Remove the spring compressor, passing the tool parts
out the top and through the access hole in the frame.
9. Lower the car back down onto the jack stands, install the wheel, move over to the other side and repeat the process.
I did not have to disconnect the toe-in rod end, sway bar, or either knuckle joint to get my old springs out or the new ones in. Your luck may vary. The total job on the rear took about one hour per side, and much of that time was taken up removing the Air Lift bag from the stock springs and re-installing the air bags into the new springs after they were installed in the car. A tip for those of you who install air bags in their springs, use some axle grease on the bags to make it easier to force them through the coils. They are harder to get into the KB springs because the coil spacing is less.
Installing the Front Springs
The steps here are similar to the steps required for the rear, except that a spring compressor is not needed, at least with the KB spring set.
1.
Raise the car and remove the wheels after placing stands at the subframe.
Lower the car to the stands and place the jack under the lower control
arm on one side.
2. Remove the brack caliper and hang from the fender well hardware so that there is no tension in the brake line.
3. The ABS sensor cable can be left in place but remove one grommet from the loop at the frame rail so that there is plenty of slack in the wire when the lower control arm is lowered.
4. Remove the large nut holding the ABS wiring bracket from the upper strut bolt. Remove the nuts on the two strut bolts.
5. Remove the upper sway bar nut and grommet.
6. Raise the lower control arm slightly to take the preload off the strut bolts and remove the strut bolts.
Note: It was not necessary to disconnect the tie-rod ends for me to get enough lower control arm travel to remove the stock springs and insert the new KB springs. Some people have told me that they had to break the tie-rod ends loose from the spindles to get enough travel to install the Eibach springs. Keep this in mind if you are installing the Eibach springs.
7. Lower the control arm to the full extent of its travel. Note the position of the spring and its isolators before removing the spring.
8. The spring will need to be wedged out of its lower perch, but it will come out without using a compressor.
9. Transfer the isolators over to the new spring. The slip-on isolator on the lower end of the spring is a tight fit since the spring coil diameter is larger than the stock spring. Install the spring in the same position as the stock spring was in when it was removed. Be certain to get the orientation of the spring correct in the lower perch in the control arm. The coil end has to fit in the recess in the control arm.
10. Raise the lower control arm with the floor jack until the strut bolts line up with the strut holes and reinstall the bolts. Torque the nuts down. Reinstall the ABS wire loom at the strut bolt and at the frame.
11. Install the brake caliper and carefully tighten the bolts.
12. Follow the steps similarly for the other side, then get a friend to guide the sway bar down over both bar posts at the same time as the last step before putting the wheels back on. Reinstall the grommet and the nut on both sides.
13.
Install the wheels and lower the car.
14.
Go drive the car, listen for any unusual noises. Be careful of bumps--the
car is lower now, real low if you have a Bassani cat-back system with the
larger diameter pipes.
The front spring install took less than one hour per side. Nothing to it, if you have a floor jack, some stands, and an impact wrench.
The total job, front and rear, took me four hours, including the time to remove and reinstall the air bags in the rear springs. If I had to do it again, I am sure I could do it in three hours or less.
Wheelhop?? Who has wheel hop? Cobras with stock springs and shocks, that's who!! These KB springs work great in eliminating the wheel hop, if you have good shocks to go with them.
With the Hal shocks set at 9 out of 12, 4000 rpm starts with the 3.27 gear result in lots of spin but no visible hop. I could still feel a little hop driving the car, but an observer couldn't see it and the tire patches were smooth like they should be. This is a tremendous improvement. The car is now driveable and enjoyable out of the hole!! I am a happy camper. NOW there is a chance that the car will remain driveable with a 4.10 gear and some sticky tires!
Note, that on 1/15/00, I installed the correct rear KB springs for my car. Kenny Brown was pretty insistent that I put the convertible springs on my car in place of the coupe springs originally supplied. The only difference was about 3/16" on the free length. The difference in car height was not hardly measureable but I guess the car was a little higher after swapping in the convertible specific springs. I love both sets!!