Unless you can afford a dedicated race car, your daily driver probably doubles as your track toy. Or you may have a weekend cruiser that you take to the track occasionally. Either way, when it comes time for you to go to the track, you don't want to deal with tire changes, major suspension adjustments, or unbolting and removing components.
That is where we've arrived with our '93 LX coupe. We wanted to find a combination of wheels, tires, and suspension that would be street-friendly, but would also work on the track. On top of that, the lowering springs that we have been using weren't helping very much with weight transfer, and it was time for some upgrades anyway.
To recap the recent modifications to our daily-driven Fox, we'll have to go back to the Oct. '10 issue, where we installed a Zex nitrous kit. We went from mid-12-second e.t.'s to 11.79 at 115 mph. Though we were happy with the improvement, tire spin became an issue when launching on the juice.
After adding an Edelbrock Performer RPM II intake manifold in the Dec. '10 issue, we dropped our best e.t. to date of 11.55 at 117 mph, pedaling it out of the hole. Our best 60-foot ever has been 1.69 seconds, and that was before the addition of the nitrous. If we want to get all we can out of the power we're making, we need to improve weight transfer and traction.
So there's no better time to kill two birds with one stone than now. But this begs the question: Which components to change? We want to keep it affordable, but also want to get the most out of our current power level. We want it to perform well on track, but also want it to be completely street-friendly for our 60-mile daily commute.
The answer to our quandary came one day as we were fiddling with Project Repeat Offender in the shop. We stumbled upon the discarded stock four-cylinder springs and sway bar, and a light bulb came on. The idea was simple: use four-cylinder springs all the way around, and use the entire budget for a good set of adjustable shocks, struts, and wheels and tires.
First, we called Summit Racing Equipment for a set of Koni "red" single-adjustable shocks and struts, and an airbag kit, which can be used to essentially stiffen the right rear spring to control body roll on launch. Then, we contacted BMR fabrication for a set of its adjustable upper control arms. Lastly, we called Discount Tire Direct for a set of TSW wheels and Nitto rubber.
Tag along with us as we install and test the new components.
Our rear suspension components...
Our rear suspension components (above) include the stock four-cylinder springs, adjustable upper control arms from BMR Fabrication (PN UTCA014; $219.95 per pair), a Steeda Autosports airbag from Summit Racing (PN SDA-432-40947; $41.95), and a pair of single-adjustable Koni shocks (PN KON-80401026; $98.00 each).
The Steeda Autosports airbag...
The Steeda Autosports airbag kit is easy to install and can be filled easily with compressed air. It helps reduce body roll on launch, allowing the car to plant both rear tires equally.
BMR Fabrication supplied us...
BMR Fabrication supplied us with these adjustable upper control arms. Sold as a pair, we opted for the set with polyurethane bushings. They are also available with spherical bushings (PN UTCA015; $329.95), but we recommend those for race-only applications.
Because of the offset of our...
Because of the offset of our new rear wheels, Summit Racing also supplied us with Eibach 30mm wheel spacers (PN EIB-904300053; $159.95).
While still on the ground,...
While still on the ground, we removed the upper shock mounts inside the trunk.
Once supported in the air...
Once supported in the air...
...we removed shocks.
Then, we supported the rear...
Then, we supported the rear axle with pole jacks.
We then removed...
...the stock upper control...
...the stock upper control arms.
Now is a good time to inspect...
Now is a good time to inspect the torque boxes. It is common to see fatigue or damage in high horsepower applications, or after using slicks or solid-mount control arms. Ours checked out okay.
We used the stock control...
We used the stock control arms to adjust our new uppers to stock length.
BMR provides lubricant for...
BMR provides lubricant for the bushings.
We lubed the bushings and...
We lubed the bushings and installed the upper control arms using the stock hardware.
The stock four-cylinder rear...
The stock four-cylinder rear springs are obviously taller than our previous lowering springs, allowing room for our hefty 275/40-17 drag radials to come. The taller (but lighter) springs will have more stored energy at ride height. This will help improve launches.
We then installed the airbag...
We then installed the airbag into the right rear spring and put the four-cylinder springs in place.
With the Koni shocks adjusted...
With the Koni shocks adjusted to the midpoint of their range, we bolted them in place and mounted our wheel spacers. Being lug-centric, these spacers are NHRA-legal.
Up front, we went with the...
Up front, we went with the same four-cylinder springs, Koni single-adjustable struts (PN KON-87101272SPA1; $209.95 each), and the sway bar off the same four-cylinder coupe.
We removed the stock front...
We removed the stock front sway bar, which weighs 20 pounds, that's 10 pounds more than the four-cylinder example. We opted to test with no sway bar on front for now, but may install the four-cylinder one if driveability is affected severely.
We then installed the new...
We then installed the new struts and springs. Use care when installing the front springs-it is easiest to use a spring compressor.
Then we mounted the strut...
Then we mounted the strut to the stock upper strut mount using provided hardware. These struts can be adjusted using the provided knob on the top of the strut. We adjusted ours to the midrange-good for street use. We will adjust them later at the track.
Discount Tire Direct supplied...
Discount Tire Direct supplied us with this set of wheels and tires. We went with TSW's new Nurburgring wheels-7.5-inches wide in the front and 9-inches wide in the rear.
We chose 235/40-17 Nitto NT05...
We chose 235/40-17 Nitto NT05 tires in the front and 275/40-17 Nitto NT05R drag radials in the rear.
With everything bolted on...
With everything bolted on and tightened up, we headed to Bradenton Motorsports Park in Bradenton, Florida. Once there, we didn't have to bolt on or unbolt anything. We adjusted the rear tire pressure to 14 psi, aired up the airbag to 30 psi, set the front struts to full loose, opened the nitrous bottle, and headed to the burnout box. The first pass yielded the best timeslip ever for our LX coupe, a 11.49 at 117 with a 1.62-second 60-foot, with no tools required.