Is this bad for my transmission?
 

I have a 1998 Camaro 3.8L V6 and it is an automatic transmission.

A friend of mine has the same Camaro and when he wants to race or go fast, he puts the car in first gear, then once he hits about 2500-3000 RPMs he shifts to second, then once he hits 2500-3000 again he shifts to drive or overdrive.

Again, it is an automatic and he is shifting somewhat like a manual.

If I do this, is it bad for my engine or my transmission?

It'll only hurt the trans if he accidentally slips it into reverse or park. Otherwise, nope, not gonna hurt a thing.
He's not gaining anything either, at the low rpm's he's shifting at. He'd get better performance if he just left it in drive and floored it.
Also moved this thread to the 4th gen section.

The only thing he's hurting is his gas mileage. I drive like that sometimes too but I wait till I get higher up into the rpm range but I also have shift kit in my tranny that doesn't automatically change gears when the throttle is floored. In other words, it'll stay in first till I shift till second. Yours being stock as a safety feature that'll automatically upshift to second, third or OD to prevent damage. Any ways, like Camaro 69 said, you won't do damage unless you some how shift into reverse or park.....though that shouldn't happen since you don't need to hold the button in when up shifting.

im not sure about the camaro but my sisters grand prix with the 3800 will rev higher in OD than if i put it in first. ex. if i put it in first from a dead stop the car will automatically shift to second at 5400rpm, if i leave it in OD shell go all the way up to 6100. same with my 300.

on my old 96 3.8 i could put it in first and it would still auto shift