[Editor’s Note: This article originally appeared in the October 2000 issue of Grassroots Motorsports. Some information may have changed. All text has been left as it originally appeared in print.]
Modifying a Honda CRX, or any other popular car for that matter, is much like ordering a pizza. With a simple phone call to one of a zillion …
Our Patient
Andrew Waldman of Pittsburgh, Penn., joined us at Road Atlanta with his 1990 Honda CRX Si that he wields in CSP autocross competition. While the proven recipe for CSP is· an older first-generation CRX, this is Andrew’s daily driver, and the improved amenities of the later car make it more viable as a dual-purpose car. Instead of blindly picking up the phone and calling any number of suppliers that would have been happy to sell a complete package of parts, Andrew picked and chose what he wanted for his Honda on his own. The result is a pretty typical list of mods for a regional- or divisional-level CSP Honda that is not trailered to the event site.
The suspension consists of Ground Control threaded coil-over adjusters ·with 375 lbs./in. front springs and 500 lbs./in. rear springs, while I 3×8-inch Duralight wheels wrapped by 225/50-13 Hoosier A3S03 tires supply the grip. Tokico lllumina adjustable shocks control the suspension, while a collection of upper and lower suspension braces keep the chassis flex to a minimum. A stock front antiroll bar is used in conjunction with a Suspension Techniques rear bar. The drive line is relatively stock, sporting only a header, cold air intake system and a Quaife torque-sensing limited-slip differential.
Doctors in the House
Say the words “win” and “ARRC” together, and you’ll probably get the response “Tom Fowler.” With numerous wins, pole positions and fastest race laps earned at the American Road Race of Champions in both Volkswagens and Hondas, Tom and his OPM Motorsports shop have become synonymous with well prepared race cars. Tom agreed to lend his expertise for our day of tuning at Road Atlanta.
We also had Heath McMillan on hand, the reigning SCCA Solo JI National Champion in CSP. Heath drives the popular and proven first-generation Honda CRX, and he credits a lot of his success to Tom and OPM Motorsports. Knowing what the car should be doing is part of what makes a fast racer, and Heath agreed to drive our test subject and communicate any weak points back to Tom.
Round One
After familiarization runs were taken, and times had stabilized, Andrew, Heath and CRM’s Per Schroeder each took five timed runs on the test course, which consisted of several sweepers, a few offset turns and a four cone slalom. They then reported back to Tom how the car felt, and where they thought it could be improved.
The Honda felt very dicey during the first set of runs, as drop-throttle oversteer, instability under braking, and a good amount of understeer while under power all hampered the car’s times. The CRX could not be comfortably tossed into the corner without the rear trying to pass the front.
Round Two
Tom quickly came up with several ideas for how to make the car more stable under braking, while also preventing the car from understeering while under power. The first change was to the rear toe. On some cars, zero rear toe can be used to coax nose-heavy cars into handling with some semblance of neutrality. However, the already-nimble CRX works better with a touch of rear toe-in. Tom dialed in 1/16 of an inch.
To keep the nose from washing out under power, Tom suggested that the front anti-roll bar be disconnected. This was quickly accomplished by disconnecting one side for testing purposes. Since Andrew was running coil-overs with 375 lbs./in. springs, the extra wheel rate added by the front anti-roll bar was not needed, and the bar was picking up the inside front tire, preventing full power from reaching the ground.
The behavior of the CRX was completely different during the second set of runs. Turns that required early and straight braking were now much easier to navigate, with later braking-and even some trail braking-now possible. This allowed much more speed to be carried through corners, and thus increased speeds on the next straight.
Disconnecting the front anti-roll bar allowed power to be applied much earlier in a turn, and the best line through each turn was much easier to maintain. Long sections of the test course could be navigated under full power, drastically decreasing times.
The results from the set of runs show that, on average, the times dropped half a second on a 19-second course, a drop of 2.6 percent. If this doesn’t seem like a lot, consider that 2.6 percent of 60 seconds is around 1.5 seconds. That’s not too bad for about a half an hour of labor.
Round Three
At this point, we decided that the car would benefit from some fine-tuning. Having just installed the coil-over suspension, Andrew hadn’t yet corner weighted the Honda; he just made sure the ride height was properly set.
Not surprisingly, given Honda’s attention to detail, the CRX had very good initial weights, with the left front being about 35 pounds heavier than the right, and the cross weights about five percent off. With some quick wiggling around under the Honda, Tom had the crossweights within 2.5 percent of each other, which is pretty good for a streetdriven car that hasn’t had its comfort and convenience options yanked out in homage to the god of speed.
The third set of runs were not as breathtaking, as we learned an important lesson about testing: never trust the weather to stay constant. A cold front moved in to the Road Atlanta area, and the air temperature dropped 13 degrees after our second round of tests. The asphalt’s temperature dropped considerably as well.
With temperatures now in the 50s and no heat in the tires, the once hooked-up CRX was a handful again. The front tire temperatures were struggling to break 100 degrees, while the rears were barely above ambient. Hoosiers really like to be run at 140 degrees or more, so the grip was less than outstanding, and we had a hard time keeping the rear of the car in line as a result.
However, the times were not that bad considering the conditions. While they were a few tenths slower than the second set of runs, they were an improvement over baseline. It’s impossible to stress enough the importance of keeping all test conditions the same. However, sometimes Mother Nature makes this task impossible.
Further Development
The second-generation Honda CRX could be capable of keeping up with its lighter predecessor on an autocross course, but only after extensive work at adding lightness. Andrew’s car is a great example of a dual-purpose machine that is loved by its owner for its user friendliness.
He can take it to the autocross course on Sunday, and then wake up Monday morning for the commute to work without hearing a single complaint from the Honda. Andrew, Tom and Heath all agree that at some point you have to draw the line between street car and race car and be done with the compromise of trying to make one car do two different things at once.
The difference in weight becomes apparent when you weigh both the early and late cars. Heath McMillian’s full-race, first-generation CRX weighs in at around 1620 pounds, while Andrew’s CRX checks in at 2180 pounds. Despite the fact that the newer CRX has a 1.6-liter engine while the earlier car must make do with a 1.5, it would be hard pressed in stock form to make up the nearly 600-pound difference.
Heath’s Street Prepared CRX, with a recently-rebuilt engine, registers a decent 92 horsepower at the wheels, while a second-generation car will produce a similar number. According to Tom Fowler, a properly set-up 1.6-liter CRX, especially those with the 1989 and later camshaft, will have horsepower figures in the low 120s at the wheel. This is a good 30-horsepower advantage over the early car–but one that is quickly negated by the extra bulk on an autocross course.
Speaking of bulk, Andrew’s car still has the stock seats, air-conditioning system and a heavy, subwoofer-equipped stereo. This amounts to about 100 or so pounds that could be removed in an afternoon if desired. However, doing so makes the car less comfortable for daily use, bringing into question the added expense of a second car or a tow vehicle.
If one were to build a truly ultimate, trailer queen, second-generation CRX for CSP competition, then a better starting point would be an HF model car, as the SCCA Solo II rules allow mixing and matching between all second-generation CRX models. Unlike the Si, the lightweight, fuel-efficient HF model didn’t come standard with a power sunroof and some other weight-adding creature comforts like rear window wiper, dual-remote side mirrors and adjustable steering column. The HF also sports lighter bumpers. (The HF only has 2.5 mph impact-absorbing bumpers, while the Si bumpers were rated for a 5 mph collision.)
Such a car, according to Heath, would weigh just under 1900 pounds, still a good 200-plus pounds more than the first-generation car. However, the nearly 30-horsepower advantage could allow the second-generation car to overcome the extra pounds.
Other than weight, there are a few other changes that Andrew could consider. Currently, he runs 225/50-13 Hoosiers, while a 225/45-13 sized tire is available, which yields a better gear ratio in addition to a shorter, stiffer sidewall. When the larger tires wear out, they will be replaced by the smaller 1ire, according to Andrew.
Since the Axxis street/autocross brake pads didn’t really mash the drivers into the Shroth harness belts like they should have, they could be replaced by a real /ace-bred brake compound such as the Carbotech Bobcat. While the Axxis pads are quiet and long lasting, they just don’t have the coefficient of friction necessary to haul the CRX down quickly enough.
Finally, Andrew’s CRX, while being equipped with a header, still uses the stock muffler. A few more ponies could be gained by switching to one of many aftermarket units on the market. Again, the trade-off is a loss of comfort during the week for performance gain on the weekends.
In the end, the little red Honda was considerably quicker and more balanced through the pylons with just a few simple tweaks. Further development could and will be made, but Andrew will have to decide the line between street comfort and race speed.
