Muscle Mustangs & Fast FordsHow To Chassis Suspension
Bolt-On Handling for the SN95 Mustang: We Teach an Old Horse New Tricks
We all know that Mustangs have always been great platforms for going fast, especially in a straight line. Unfortunately, the same can’t be said for corner-carving performance. While the latest Pony offering is leaps and bounds better in the handling department, those of us who are fond of the seasoned late-model Mustangs have to settle for either less-than-desirable suspension geometry and atrocious amounts of body roll when changing directions at speed or rolling up our sleeves and bolting in some serious suspension improvements.
We recently did a little bench racing session with our friend Marc Lewis, and we couldn’t help but notice he had a bone-stock 1997 Mustang GT convertible nestled in the garage. We are not one to leave anything stock, so we gave him a little encouragement until we talked him into modifying his wife’s drop top with a few simple bolt-ons. Since the car is used primarily as a daily driver and weekend canyon cruiser, we decided to focus the bulk of our upgrades towards the suspension department to get the Mustang to handle the canyons with ease while still delivering outstanding performance in the occasional weekend autocross session.
Our first order of business was to upgrade our shocks and struts. We gave our friends over at Turn 14 Distribution a call and had a set of Koni Sport Series struts and shocks on the way, along with a set of Eibach sway bars to top off our handling modifications. With the parts ordered up, we headed over to GTR High Performance in Rancho Cucamonga, California, to start transforming Lewis’s bone-stock 1997 Mustang GT convertible.
Follow along as we show you what it takes to place a SN95 Mustang to a whole new level of performance on the track, all the while giving us plenty of ride comfort whether out for a leisurely stroll or a spirited canyon carving session.
1. A set of Koni Sport Series adjustable struts and shocks allow us to dial-in the firmness at each corner for different driving conditions. These shocks feature a twin-tube gas pressure design with a large-diameter piston to soak up imperfections in the road while also offering a firm and surefooted ride.
2. A big hurdle in the handling department of an SN95 Mustang is the factory sway bars, which were really only designed with the street in mind. Fortunately, Turn 14 Distribution had us covered and sent us a set of Eibach Anti-Roll Bars that reduce body roll and increase handling and cornering grip. These sway bars are notably larger in thickness than the factory bars, with thickness of 35 mm and 25 mm front and rear, respectively.
3. We began the disassembly of our SN95 Mustang up front by removing the factory struts.
4. Of course it is worth mentioning that you shouldn’t get too far ahead without noting the alignment of the car in stock form. While you shouldn’t use this as a substitute for a professional alignment, it will get you in the ballpark to at least drive the car over to a shop.
5. With the struts out of the way, we lowered the jack underneath our lower control arms to release the tension on the coil spring. As with any spring removal, always err on the side of caution to avoid serious injury.
6. While it goes without saying, you should clean the spring pocket thoroughly to ensure that any road grime is not lodged between your new spring and control arm. (Note: The spring pocket has a deeper groove to locate the coil spring in the proper place.)
7. Installing the new coil spring isn’t all that difficult, but it does help to have a second set of hands and a large pry bar to encourage the coil spring into place.
8. Don’t forget to install the factory rubber bumpstop on your new strut. You will also be reusing the factory dust boot to help keep road grime or other debris away from the shock shaft.
9. Don’t forget to reattach the ABS sensor bracket to the spindle mount side of your strut.
10. With our front end out of the way, we turned our attention to the rear of the car. We quickly removed the rear shocks.
11. With the rear shocks and quad shocks removed, we were able to lower our rear axle far enough to release the tension on the rear coil springs. As with the front, a second set of hands and a trusty pry bar are the ticket.
12. Pedro Pasoldan from GTR High Performance made quick work of removing the old coil springs.
13. With the springs out of the way, Pasoldan then removed the factory pinion snubber bumpstop.
14. Since we were lowering the overall ride height of the Mustang, we swapped out the factory pinion snubber bumpstop for a lower-profile bumpstop for a little extra suspension travel in the rear.
15. A long extension and a batter-powered impact gun will make quick work of installation.
16. Once the bumpstop was in place, we installed the rear shocks from the body.
17. Gonzalo Topete gave us a hand removing the old sway bar.
18. With the rear lowered down, we went ahead and slid in the new dual-rate coil springs. Note that the smaller end faces the bottom.
19. With the rest of the rear suspension buttoned up, we were able to bolt in the rear shocks.
20. Here you can see the difference in size between our factory rear sway bar and our new Eibach 25mm-thick antiroll bar.
21. Topete went ahead and mocked the rear sway bar in place.
22. Once our suspension was taken care of, we lowered the car onto a set of Race Ramps to put a load on the rear suspension before torqueing all the bolts to specifications. This will prevent bushing bind or preload.
23. Just when we thought we were done, we remembered that Lewis mentioned the steering feel was poor at best. We did a little research and realized that we could upgrade to a factory Terminator Cobra steering rack, which would offer us a more aggressive steering response with slightly better steering geometry thanks to a set of offset Energy Suspension bushings.
24. You will notice the difference between the factory bushing on the far right and the offset bushing just to the left of it. This bushing allows the steering rack to be mounted a tad higher than stock to help correct the steering geometry.
25. Here you can see just how much higher the Terminator Cobra steering rack sits on our SN95.
26. Now that’s a huge improvement from the trucklike stance we started out with! Overall we lowered the car just about 1 1/2 inches in the front and 2 inches in the rear. More importantly, we changed the entire dynamic of the car towards a more performance driving orientation.
27. We didn’t feel it proper to wrap up our modifications without giving the drop-top Mustang a little more help where the rubber meets the road. We ordered up a set of 275/35R18 Falken Azenis RT615K tires to get the most out of our suspension upgrades. This tire features a race-inspired tread compound, a solid center rib to reduce wheelspin, massive sport side shoulder blocks to deliver significantly more grip and cornering response, and a high-tension carcass that increases handling response and high-speed stability.
28. As of this writing, we have only had the Falken Azenis RT615K tires on the car for a short time, but we are very impressed with their grip. The cornering ability is absolutely phenomenal, and we are pretty excited to get the car back out on the track and put the tires through their paces.
29. With all the new suspension improvements, the drop-top Pony is now seeing considerably faster lap times on the autocross track. Body roll is no longer an issue, and thanks to the massive Eibach sway bars we can throw the car into a corner aggressively without fear of losing grip both on and off the throttle.