Almost 21 Century Suspension

Or at least it’s what all of the popular cars are wearing these days.

What am I talking about?

Coil overs of course.

I had the fortunate opportunity to drive a BMW M4. I’m sure there are other, better handling cars out there but the M4 was enough to make me think about how the Mustang with its ancient suspension will ride and handle.

The Mustang on the day we headed to California from Ohio, see the road sign in the background? Also, check out the ride height.

I don’t have either the wheels or tires anymore but I sort of remember the tires being 15 inch 78 series. The last thing on my mind was how to make the car handle. My focus was getting the car to go down the road in a straight line.

After the drive in the BMW, we’re talking several years into the Mustang build and already making arrangements to get the suspension parts to duplicate that of a 1969 Boss 302, even with new springs, we’re still talking about a combination that’s over 50 years old.

The BMW has a suspension system that is voodoo to me. It has three levels of firmness and who knows what else. There is no way I could make a 50+ year old car handle like this three or four year old design from Bavaria.

I was looking into finding shorter upper A-Arms in an attempt to decrease the track width of the front end. Why? Boss 429. I was following up on different theories about A-arm length. All other Mustangs vs the Boss 429. Some are saying the Boss used shorter arms, others have said they’re all the same.

I did find that certain tubular A-Arms can be adjusted to a shorter length. Continuing my journey down the bunny hole, I discovered a company, Street or Track out of Detroit.

I had toyed with the idea of coil overs for the front of the Mustang for a long time but it was starting to lose out to the possibility of bagging the car instead…until I began to dig deeper into a very cool air bag system and the parts list and ultimately, the cost. Hooo-Boy.

I had always been under the impression that a coil over was not possible on an older Mustang with shock towers, not without a bit of slicing and dicing that is. Street and Track was advertising a bolt in system for the front. I went in search of reviews and found a couple of articles outlining the installation of the ST front suspension and they were pretty positive. To tell you the truth, I couldn’t find any bad reviews at all concerning Street or track. The fact that the owner, Shaun, often runs a Mustang with his suspension on it on the track helped convince me that this was something worth looking into.

Ok, to be honest, I didn’t do much more searching. I was impressed with the way the system was put together and all of the positive reviews worked on me plus that knee jerk, spoiled brat side of me said, “I want IT!”

So I bought a Street or Track system…or two.

Street or Track on the left front. Also performed the Upper Control Arm drop which comes highly recommended (Boss 302 Chassis Modifications book) and I forget why. Didn’t cost me anything to do.

Street or Track has a conversion to put coil overs in the back of the Mustang. It’s more of a system really. The coil over shocks replace the leaf springs. The thing that got really got my inner brat going was the mention of a Three link and Watts link. If I were focusing on building the car for the quarter mile, this is not the control system I would look at but being that I’m interesting in going around turns occasionally, the 3-link probably is the choice to make short of converting the car to IRS. Pan hard bars never felt like a well thought out design. Although the Watts link is a slightly more complex design, it just makes more logical sense to me.

Unlike the front system though, the rear kit will require some welding.

I don’t have a lift so no bitchin photos of the underside with everything bolted in but I have the ST site catalog picture.

Referencing the not so sharp picture above, the cheesy red pointers are drawing your attention to the subframe that bolts to the rear frame rails forward of the rear end. This is the upper control arm mount. The center of the mount bolts through the transmission tunnel hump just under and to the rear of the rear seats.

The blue cheesy pointers are for the Watts Link center section sub frame. Same as the upper control arm frame, this frame bolts to the rear frame rails but aft of the rear end.

It just so happens that I found a video by Street or Track on the installation of their 3-Link. I wish this had been available a couple of years ago but the instructions that come with either kit are pretty good.

When I decided on the suspension upgrade, I was positive that the car was only months away from hitting the road. Two years later and the car is far from being ready. It’s torture not being able to see how this system performs.

I don’t expect BMW M4 performance but if I can be somewhere between the stock Mustang and the M4, I’ll be a happy camper. Another reason I went coil over? Ride height adjustability without affecting the ride.

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