Project Celica: Part 1

By now it's no secret that Toyota's new Celica has won a special place in the hearts of SCC's staff. The first time we got our hands on one, we loved it, and in our review of the factory GT-S for Eight Great Rides this year, we called it "one of the few performance cars truly worthy of that label." It offers a purity of design concept almost unique in today's selection of committee-driven product offerings. And for the most part, the hardware lives up to the promises made by the sheet metal.

The Celica's interior ergonomics are superb, the six-speed transmission's shifter is as good as one could ever require. The steering requires just the right level of effort, while providing as much feel as 14-year-olds at the back of a movie theater. Its 2ZZ-GE engine makes 100 hp per liter at its power peak and offers a stratospheric redline. Its brakes are large and powerful. The Celica GT-S is a car we desire. Lucky for us, Toyota decided to let us have one for a long-term test/project. Now we get to drive it as often and as hard as we want, and to see if we can make it even better. From our previous experience, we were pretty sure that we would be able to live with the Celica day to day, but who knew what problems or little irritations might arise? We had some ideas about how to improve the car, as well as a pretty clear picture of what people would try as soon as they could. We wanted to see whether the changes would be improvements, and try to find the right way, so that you, the reader, wouldn't have to go through as much trial and error with your own cars.

The Celica GT-S sent by Toyota has carbon blue paint, which invariably looks black in photographs, but is black and blue in person, depending on the light. Options on our car are a sunroof, spoiler, 16-inch wheels, ABS, side airbags and leather seats. Normally we shy away from leather in performance cars, but the Celica's seats manage to maintain good grip during hard cornering, despite their slippery surface. Since it arrived, we've already put over 8,000 miles on our GT-S and have gotten cozy with it, getting to know it better. The first thing I have to say is that it is still a fantastic car. Every time I get out of it, I think, "what a great car." Not many cars elicit that response, and our constant delight comes in spite of a major shortcoming that keeps the Celica GT-S from being truly great, which we will explain in-depth later. Whether running at the track, driving enthusiastically through a favorite canyon or just cruising to the office on the freeway, this car pleases.

From the smallest guy to the tallest guy, the seats fit comfortably and all of the controls and instruments are in just the right place. Toyota is one of several OE manufacturers to have finally figured out the art of the three spoke steering wheel, and the Celica's tiller is top notch, just the right size, shape and thickness. The shifter is on par with any other. Positioned high and close to the wheel, throws are short and the gates so close they are almost indistinguishable, except you always get the one you're thinking about. As the resident tall guy, I find that the sunroof impinges on headroom, causing odd hairstyles and requiring my head to be tilted sideways when wearing a helmet. The Celica's plastics are much nicer than a Civic or Integra's, but can still be improved. Driving into the sun, the grey dash was reflected in the windshield, making it difficult to see into shaded turns, and the driver-side door panel shows many scratches from the seat belt. Rear visibility is poor enough that one sometimes wishes for a CRX-like tailgate window.

The Celica's brakes are big, with ABS. I have been able to fade them only when running fast down a canyon. They could clearly be improved though. When using just the edge of the pedal, the rubber dots do little to make the smooth aluminum pedals less slippery, so heel-and-toeing deep into a turn from 90 mph (at the race track, of course) is done with less certainty than I desire. The stock pads bite well when cool, but response gets soft when they heat up, aggravating a spongy pedal feel. I suspect the car would benefit significantly from braided lines and more aggressive pad compounds--two upgrades we are currently searching for.

At the streets of Willow Springs, after one warm-up lap in the Celica, I was able to go all-out. The Toyota is utterly communicative and controllable, possibly one of the best handling stock front-wheel-drive cars ever, if not the fastest. I'm looking forward to a shootout with the Integra GS-R, or even Type R. There is plenty of roll, but the car turns in quickly without feeling wallowy--it simply rolls and goes around the corner. The Celica's dual-arm rear suspension provides a mechanical form of stability control.

In addition to providing excellent camber control, the geometry toes the tires out under compression and toes them in under droop. The benefits are many, starting with stability under braking, whether in a straight-line or deep into a turn. In the latter case, the tail lifts and steps out, but the outside tire toes in and holds it, to the point that directed effort is almost required for the car to swap ends. In a turn, body roll points both rear wheels toward the outside, providing a nice, balanced cornering attitude right up to the point where front-wheel-drive understeer takes over. Exiting a chicane onto a straight with the power on, the tail squats and the outside rear again toes out, nicely simulating a perfect rear-wheel-drive drift. The Celica's rear suspension tames lift throttle oversteer, while making the car incredibly tossable, controllable and fun to drive. On the street, ride quality is superb. At 2,560 lbs, it is more difficult to isolate the Celica from pavement roughness than some other cars, but that said, the Celica GT-S' damper tuning is among the best available in any new car.

The Celica's engine holds the car's tragic flaw, the only thing keeping the car from being truly great. A light flywheel makes it exuberantly responsive, allowing one to rev-match downshifts instantly. The engine is quiet while cruising under light load at freeway speeds. To really use the engine, though, it must be revved past 6000 rpm, the point where it switches cams and the party starts. Then, as you rocket forward, you may notice that the engine is quite a bit louder. Owners of other front-wheel-drive cars will be surprised to find that torque steer, even at this point, is surprisingly absent. Redline is a stratospheric 7800 rpm and the rev limiter doesn't actually kick in until 8400 rpm. Unfortunately, while the top three gears in the six-speed transmission are spaced perfectly, 6000 rpm in any of them is deep into go-to-jail territory. The first three cogs, on the other hand, are spaced too far apart and it is impossible to stay above 6000 rpm, even by pushing into the redline and shifting at the fuel cut. Redline shifts put you at 5050 rpm in second and 5635 rpm in third, so the engine feels like a pipey two-stroke or old-fashioned turbo with lag till tomorrow. At the track, I frequently had much less torque than I wanted, while seconds later, I had to feather the throttle to keep from understeering into the dirt. In canyons, constant second gear work sounds like this: vvvvvvvvwhhaaai... (braking)... vvvvvvvvwhhaaaii. In out-Honda'ing Honda, Toyota has gone too far. Spreading out the whhaaaa, even if it were reduced in intensity, would make a much better car.

So what's the solution? The engine could rev even higher than the stock fuel cut allows, but it would take 9300 rpm in first gear to get to 6000 rpm in second. That's a bit excessive, unless we're going for a national championship, and is not the way to make even this engine go the 150,000 miles or more that even abused Toyotas are known for.

Based on the size of the power jump when the big cam is engaged, it appears that it could be engaged sooner-perhaps at 5000 rpm-and still offer a power boost. We spoke with Eric Lapka, of E.L. Prototypes, and learned he is working on a VVTL-i controller that would allow just that. So far, he has found that Toyota's VVTL-i is not as simple as Honda's VTEC in this regard. The intake cam timing (the VVT-i part of the system) needs to be adjusted as well as changing the rpm at which the high-rpm cam lobes are engaged. He is working on it, but hasn't yet gotten there. Toyota Racing Development has told us they have full access to the software, but they aren't allowed to sell modified versions to the public, even in conjunction with something like a turbo or supercharger kit, which they have hinted they may work on.

Upgrades
What's this? A project intro with no modifications? The Celica GT-S is a serious enough performance car that we have been spending more time than usual driving it stock. The need to tinker has been getting steadily stronger, however, and we just couldn't leave well enough alone. When we first tested the GT-S back in the October '99 issue, we noted some unusual features in the stock air filter box. First, the mass air flow meter is integrated into the air filter box, making aftermarket intakes significantly more complex to design. Rod Millen Motorsports has managed however, and we are currently testing its intake. So far, it appears to make about 7 hp and lower intake temperatures by about 5 degrees. We want to put some more miles on it before making a full report, however.

Before installing the Rod Millen intake, we made some slight modifications to the stock air filter box. Back in October, we noted a strange flap door before the air filter that muffles intake noise below 3000 rpm. We had been frustrated about the Celica's seemingly stubborn resistance to smooth shifting and there appeared to be some correlation between the flap door opening and closing and the fact the the car tended to buck during the 1-2 shift. After recording a 15.6-second quarter mile time, we removed the flap door (the whole assembly simply lifts out) and plugged the vacuum line that controls the door's operation and tried again. A few runs later we had a 15.3-second quarter mile. Brilliant! Free horsepower! Or not... We next took the car to R&D Dyno in Gardena and found the flap door to have no effect on power whatsoever. Still, drivability was greatly improved, wasn't it?

Despite the fact we had felt a huge improvement in responsiveness and predictability, re-installing the flapper could not duplicate the bucking we had complained about earlier. After conducting blind tests on several staffers, we finally decided that perhaps it was our imagination. Still, removing the flap doesn't hurt anything, and it just might help...

We expect handling improvements to be easier to talk about than to accomplish. Wheels and tires are on their way to our offices, but beyond that, we see a lot work yet to be done. We wonder whether stiffening up the suspension to reduce roll and dive/squat reactions won't adversely decrease the rear suspension's geometry effects at the same time it allows the MacPherson strut front to work better. TRD has a package available, consisting of springs, dampers and anti-roll bars. We tested it for Eight Great Rides, in the April '99 issue and found that, though skidpad grip was increased, our slalom speed fell slightly and the fabulously tossable handling characteristics had deteriorated. Both Koni and Ground Control tell us they have assembled very expensive double-adjustable coil-over setups, which are really only suitable for racing use. We know of one Celica with cut springs, but as good as that car looks, we have yet to see it turn a wheel on a track or autocross course.

There is no need to cut springs now, though, as performance springs are available from Eibach, H&R, Intrax and Progress, as well as possibly others we have not yet heard about. The problem is that for stiffer springs to work, they require stronger dampers 99 percent of the time, and the choices in that area are limited. Koni says street dampers for the Celica are on the to-do list, but not at the top, so it will be several months at least before they are available. Tokico told us they are in no hurry, because the Celica's stock handling is so good. If anything, they could sell adjustable Illuminas, but making a rear shock that can be adjusted while on the car is problematic. So far, the only aftermarket dampers that we are aware of are the TRD units, made by KYB. A front strut tower brace is available from Rod Millen Motorsports, and a triangulated rear brace is available from TRD, but we have not been able to install either on our car yet. The Celica offers as close to vault-like chassis rigidity as can be found in a 2,560 lb, 2+2 hatch, so we expect the difference these parts make to be subtle.

It is clear that a limited-slip differential would be an improvement, but we have yet to hear of one becoming available for the Celica. Quaife America has asked us about this car in the past, so we'll definitely be speaking to them.

We have done little about the brakes as of yet, except flog them and decide that we need to make them better. Stopping distances are superb (113 feet from 60 mph in our Eight Great Rides testing), but pedal feel and fade resistance could be improved. Braided stainless lines and pad experimentation are the first orders of business for the binders and you can be sure we'll let you know as soon as we have a story to tell.

With that, we'll wrap up the introduction to our long-term Celica GT-S project. We hope you're as excited about this project as we are. There's lots of fun to be had, and even more to learn. If you see us out at the track sometime, be sure and stop to say hello. We'll try not to talk your ear off about the Celica--unless you start asking questions.