Valentin Jimenez, 18 and fresh out of high school, has never lived away from home. He has rarely set foot outside East Los Angeles.

Now, with a few sweaters in his suitcase and $500 in his pocket, he has left his Mexican-born parents to attend Grinnell College in Iowa.

Jimenez is settling in the heartland with nine other Los Angeles-area high school graduates who are venturing as a group to the leafy, elite liberal arts college nearly 2,000 miles from home.

There is Lauro Franco, who graduated from San Fernando High School even though eight older brothers and sisters never finished high school.

And Nakeyia Poitier, an aspiring obstetrician whose south Los Angeles apartment lies within earshot of the Harbor Freeway (Interstate 110).

And Steven Johnson, a gifted choral singer from Westchester High who hums Bach the way others rattle off hip-hop tunes.

The five Hispanics, four blacks and one Korean American in the group have spent months forging friendships to ease the transition from urban Los Angeles to rural Grinnell, a central Iowa community of 9,105 people where the closest mall is 50 miles away through countryside lined by corn and soybean fields.

"It's like taking a little piece of L.A. to Iowa," Jimenez, a Garfield High graduate whose parents do not speak English, said of the group. "We can deal with problems together."

Jimenez and the others gained admission to Grinnell, and full $25,000 annual tuition merit scholarships, thanks to a little-known group called the Posse Foundation.

The national organization recruits mostly minority high school seniors who demonstrate leadership and other qualities but may lack the stellar grades and SAT scores usually required by top universities.

At Grinnell, the average SAT score of incoming freshman this fall is nearly 1400 out of a possible 1600. Just one of Jimenez's fellow group members came close to that.

Jimenez, who plans to join Grinnell's cross-country running team and wants to become a school counselor or psychologist, scored 940. But he had the intangibles that trainers were looking for -- drive, ambition, open-mindedness. He never questioned whether he would go to college -- only where.

At Garfield High School, he was a track star and holds the school record for the two-mile run. He played cello and was active in the Escalera Project, which provides tutoring and helps students stay on track for college. In his senior year, Jimenez had an internship with Los Angeles Board of Education President Jose Huizar.

Similar qualities and interests can be found in other "posse scholars," who come from Los Angeles, New York, Boston and Chicago.

Two other posses from the Los Angeles area will head this fall to Claremont McKenna College in California and the University of Wisconsin at Madison. In all, 223 students from the four cities are entering 22 colleges and universities, including Vanderbilt in Tennessee and Brandeis in Massachusetts.

The New York-based program, which began 15 years ago, has helped snag more than $85 million worth of college scholarships and sent nearly 1,000 high school seniors through the posse pipeline.

The posses cultivate potential young leaders who might not otherwise make it to college or tough it out once they arrive.

"I think a lot of young people have great ambitions and aspirations and then are faced with the culture shock of these isolated campuses," said Deborah Bial, 39, an education activist who started the program in 1989 after meeting a college dropout in New York who said he would have made it if he had gone with his buddies.

"The idea of having a group of students you can relate to helps bridge that gap between home and campus," said Bial, adding that the posses' predominantly minority makeup reflects the enrollment of the public schools where the foundation does most of its recruiting.

Posse graduates say their close bonds remain strong even after they leave college and join the ranks of lawyers, teachers, bankers and other professions. Eight former posse members have joined the foundation's national staff of 45, running offices around the country or working at the New York headquarters.

The posses have served as surrogate families for youngsters living far from home, some for the first time.

Jimenez will be leaving a family of five brothers and sisters. His father, a carpenter with an elementary school education, would prefer that his son stay closer to Los Angeles. But Jose Luis Jimenez also wants Valentin to live a more prosperous life than the one he and his wife, a seamstress, have known.

"I don't want any more laborers in the house," the father said in Spanish. "I want my children to be professionals."

For Jimenez and the other students, the journey to Grinnell has been unfolding for eight months, during weekly meetings with adult trainers to prepare socially and with tutors to improve their research and writing skills.

In these afternoon meetings, high school rivalries quickly dissolved as the Grinnell-bound students talked about all of the issues they will confront in the coming year -- managing time and money, coping with homesickness.

"I'm scared. I've always lived in the big city. I'm going to Grinnell in the middle of basically nowhere," Sandra Herrera, a Carson High School graduate, acknowledged during one of the meetings. "The only thing that gives me comfort is my posse."

So far, 90 percent of posse students have finished college within five years, and most finish in four, the Posse Foundation reported.

That contrasts with the 53 percent of all students nationwide who earn bachelor's degrees within six years, according to the most recent federal statistics. The figures are lowest for minorities: Forty percent of Hispanics finish within six years, while 37 percent of blacks make it.

Researchers said the low minority graduation rates are partly because of the isolation these students experience on campuses such as Grinnell that have overwhelmingly white enrollments. At Grinnell, 78 percent of the 1,400 students are white.

"It's not enough to take a kid and dump him on a campus," said Walter R. Allen, a professor at the University of California at Los Angeles who studies diversity in higher education. "You have to be in situations where you can succeed. That requires the presence of some like-minded souls. Those who come in without any kind of support or connections are more likely to fail."

Grinnell accepted its first posse of 12 Los Angeles-area students last year. All of them did well and are returning, joined by the 10 newcomers in Jimenez's group, university officials said. The college will have 80 posse students on campus within four years, including others from the District of Columbia, accounting for about 5 percent of its students.

Grinnell President Russell K. Osgood, who helped pick the first Los Angeles posse, said he was impressed by the students' serious attitudes and supportive approach.

He is not worried about the students' high school grades or SAT scores, pointing out that they will meet as a group weekly with a university mentor during the first two years on campus as a part of the posse program.

"A lot of colleges work hard to admit diverse students but don't do enough to retain them," Osgood said. "One of our interests is not only getting diverse and interesting students, but [having] a support structure so they will stay here and graduate."

Jimenez is ambivalent about leaving east L.A. He will miss his 11-year-old brother, Peter, with whom he shared a bedroom, and his girlfriend. He will miss his church and his little home, where pictures depicting Jesus share the walls with family portraits taken in Mexico.

But he is ready for the change.

"I've always wanted to live around other people . . . who live differently from the way I do," he said.

Valentin Jimenez runs on the track around a cemetery near his house in East Los Angeles. He hopes to join the cross-country team at Grinnell College.Sandra Herrera, 18, and Daniel Zamora, 20, part of a group that will attend Grinnell in the fall, participate in a team-building exercise.Nakeyia Poitier, who is headed for Grinnell College, shops for bedding in Los Angeles with her mother, Tonja Ross.