The Democratic mayoral primary seems poised to wind up here a week from today not with a bang, but a whimper.

On the same oddly subdued note, it also seems likely to shut down with it the comeback bid of former mayor Frank L. Rizzo.

For four months, Rizzo has been unable to cut into the 20-point lead in the polls of W. Wilson Goode, a former city managing director who is seeking to become Philadelphia's first black mayor. Rizzo seems content to ride out the campaign's final days in peace and quiet.

His campaign schedule has been light, his crowds modest and his rhetoric for the most part free of the bombastic flourishes that made him a national symbol of law and order in the 1960s and 1970s.

"We'd actually like to draw him [Rizzo] out some more," said Neil Oxman, media consultant to Goode. "Some shouting from him would probably help."

Some here attribute Rizzo's low-key tenor to a tactical conclusion that shouting is counterproductive, while others wonder whether his campaign has not embraced a "secondary agenda"--to cleanse his record of his former image as a racial polarizer. Friends say he is stung by that tag and is determined to comport himself in a way that buries it.

Whatever is causing the eerie hush, politicians from Rizzo's native South Philadelphia see it as just one more sign pointing to a Goode victory.

"There is a great malaise hanging over South Philadelphia," said state Sen. Vincent Fumo, who represents Rizzo's heavily Italian home district. "The Goode people had everybody convinced from the start that they were going to win, and nothing has happened during the campaign to change that."

One sign of this last week was Goode's financial report showing that he had raised $1.5 million to Rizzo's $1.9 million. Early predictions were that Rizzo would spend two or three times as much as Goode.

"Unless I do something really stupid in the last week, there doesn't seem to be any way I can lose," Goode said.

His press secretary, William Epstein, is even more blunt: "The television crews started covering this thing daily about a week ago, and they're wondering where all the excitement is. I've told them, 'This thing's been over for a month.' "

Epstein had in mind April 19, the night of the candidates' only televised debate. Local political observers thought neither performed particularly well and that Rizzo missed his best opportunity to make up lost ground.

An even more ominous development for the Rizzo campaign came later that same night at the city's Bellevue Stratford Hotel, where the Goode campaign threw a post-debate party that attracted a wildly enthusiastic crowd of 3,000. Hundreds more were turned away.

For much of the campaign, Goode's staff has been determined to limit overt enthusiasm by Goode's predominantly black supporters, perhaps on the theory that it might frighten whites. But the rally was the biggest and noisiest local political event here in years, and left an unmistakable message about the enthusiasm coursing through the black community.

"The blacks are going to come out like you've never seen them come out before," said former representative Charles Dougherty, a Republican locked in a tight, three-way campaign for his party's mayoral nomination.

Goode, 44, a sharecropper's son with a degree in public administration from the Wharton Business School, served as No. 2 man in the administration of Mayor William J. Green before resigning last fall to launch his first bid for elective office.

He was a highly visible managing director, turning up at fires, confronting citizens at community meetings and generally receiving good notices all over the city despite his rather stiff and formal bearing.

The Rizzo camp has been trying to portray Goode as an incumbent and has attacked him for increases in crime and taxes during the Green administration.

In a new round of hard-hitting advertisements that began last week, five Philadelphia residents talked more in sadness than in anger about their disappointment with Goode as a managing director. One of them, a black describing himself as an administrator, said he would like to vote for Goode but cannot because of his record, adding, "and that's a shame."

Goode strategists say they believe that the ad is not an appeal for black votes, which Rizzo presumably has long since written off, but Jewish votes. "It's a way of saying you can be against Wilson Goode and not be a racist," a Goode staffer said.

Jews make up about 15 percent of the Democratic vote, and have been targeted heavily by both campaigns. The latest Philadelphia Daily News poll last week showed Goode leading by 52 to 26 percent overall and 8 to 5 among Jewish voters. Among blacks, who make up about 44 percent of the Democratic electorate, Goode led, 84 to 2.

The GOP race is providing a cliffhanger and an intriguing test of that rarest of political dinosaurs, a big-city Republican "machine."

Philadelphia has 66 GOP ward leaders and 2,500 GOP committeemen. About one of every 75 registered Republicans, in a nearly 5-to-1 Democratic city, is a party official.

It also has an old-fashioned political boss, William A. Meehan, making what pundits here are probably mislabeling his last stand, trooping to four ward meetings a night and pumping up his ragged, victory-starved troops by telling them that "people say you've gone soft."

His push is on behalf of John Egan, 39, a rags-to-riches stockbroker who, until the day before he was endorsed by the GOP in January, was a lifelong Democrat and active party fund-raiser.

Meehan's slating decision enraged Tom Gola, the former La Salle College and professional basketball star who was the last Republican elected to citywide office here, as controller, in 1969. More recently, he served as regional director of the Department of Housing and Urban Development.

A longtime Meehan protege, Gola felt slighted and launched a campaign as the "real Republican."

Rounding out the threesome is Dougherty, Philadelphia's only GOP congressman in a generation and a casualty of last year's Democratic sweep to 26 additional congressional seats. Dougherty and Meehan have been bitter enemies for years.

Perhaps 80,000 people will vote in the GOP primary, and 35,000 votes should be enough to win.

Egan, who has the best financing, will have the most bodies on the street on election day and, in the Republican mayoral debate, showed himself quick on his feet.

Dougherty has a strong base in northeast Philadelphia, his old congressional and state Senate district, where about half of the city's Republicans live.

Gola, 50, at 6-foot-7 and just 2 pounds over his playing weight, is by far the most physically impressive figure of the three, but he was stiff in their debate last month and has not caught fire on the stump.