Race on Sunday, sell on Monday.

It has been a standby saying in the industry for decades and the reasonthe factories lend their expertise-and their vehicles, engines andtransmissions-to the sport.

Race on Sunday, sell on Monday is what Chevrolet hopes to do this yearas the supplier of the pace car for the 74th running of the 500-mileIndianapolis 500.

A Chevy Beretta convertible was picked to do the honors with generalmanager Jim Perkins at the wheel.

Chevy hopes motorists equate the brilliant yellow Beretta convertible`sappearance at Indy with speed and performance and run out and buy one of thereplicas-or any other vehicle bearing a Chevy bow tie.

Chevy also hopes that having Perkins, a former racecar driver, at thewheel, will be beneficial. A run by a performance-oriented racer wouldindicate that the division is performance oriented. It can`t hurt.

Detroit manufacturers supply the pace car on a rotating basis. After therace, a limited number of cars that look like the one that circled the trackat 120 miles per hour go on sale for the commoners. The manufacturer slaps afew decals on the doors and a hefty sticker on the window and for a few monthslures consumers to the showroom to take a look.

This year it`s a bit different.

Though Beretta convertible got the nod as the pace car, the limited-edition replicas are hardtop coupes. Chevy is having a quality-control problemin building a convertible Beretta (Autos, Monday, May 7), which was supposedto go on sale this spring but might not appear in 1990.

Only 4,500 pace car coupes will be built, 1,500 of them finished inbrilliant yellow and 3,000 in turquoise.

We test drove the turquoise model. The sales brochures make the exteriorlook blue. But with the sun beating down on it, the color comes out green-anunusual green. Did you ever change the diaper of a two-month-old babynourished on soybean-enriched formula? That`s the green we`re talking about.It`s a love it or hate it green. The younger the person, the more appealingthe color. The older the person, the more dislike, based on the responses-fromprofanity to rude gestures-we got from fellow motorists.

In addition to the limited color choices, the pace car stands out fromall other Berettas in that all sheet metal, plastic rocker skirts air dam and spoiler are color coordinated plus there`s decal work on the doors and quarterpanels and the word ``Indy`` in what looks like pink or mauve on the door.

The pace car Beretta has a 3.4-liter, 225-horsepower, V-6, an enginethat`s not on the market yet. The pace car replica coupe is powered by a 3.1- liter, 135-h.p., V-6 available in a variety of Chevy cars. Our car came withthe optional ($540) automatic rather than standard 5-speed.

The 3.1 is lively but to ensure the impression of top performance,there`s a rumble-tuned exhaust to provide ample sound effects of a few morehorses under the h ood.

Other than the turquoise exterior, the only annoyance with the pace carwe drove was the driver`s seat, one of the more uncomfortable units we`ve comeacross in the last several years.

The bottom is hard, the back is hard and the side bolsters extend too far to make you feel as if someone is picking your coat pocket while you drive. A handle along the right side of the driver`s seat adjusts height by rockingforward or backward. No comfort at all. In catering to magazines that likemulti-adjustable seats with the pliability of granite, Chevy has done aninjustice to consumers. To be sentenced to drive 500 miles in that seat would be cruel and unusual punishment.

Race on Sunday, sell on Monday.

Having the pace car gives Chevy some added exposure and probably willbring in a sale or two it might not have made this spring.

But the real purpose of the pace car was to focus on the future-in termsof color and engine.

Turquoise seems out of p lace in Chicago, but pastels have become hot onthe West Coast and Chevy and the industry are expected to come up with someunusual exterior colors soon. The pace car is a warning of what`s to come.

More importantly is the 3.4-liter, 225-h.p. V-6. That`s 225-h.p. withoutcostly multivalve configuration or a turbocharger or supercharger for a boost. That`s also a 3.4-liter V-6 like the one that will be offered in the newperformance Chevy Lumina Z-34 for 1991, though not at 225 h.p.

So everytime someone says, ``The pace car is quick, but you`ll never find that engine on the street,`` Chevy will be able to say, `Oh, yeah, justwait.``

When the Lumina Z-34 appears in 1991, Chevy will be able to say,``Remember the pace car at last year`s Indy? This has the same engine.``

The pace car replica starts at $14,758. Our car added a removable sunroof at $350, electric rear window defogger at $160, automatic transmission at$540, electronically tuned AM/FM stereo with cassette and clock at $150 andthe Beretta GT preferred equipment package at $1,037. That included suchgoodies as power windows and door locks, cruise control, tilt steering,intermittent wipers, power trunk opener, color-keyed front and rear mats andan upgraded radio system. With a $445 freight charge, the sticker read$17,440.