when to speed shift?
 

new to this site. i own a mazda 3 (not mazdaspeed) everything stock. i wanna take my car for my first race against a stock rsx. i just wanted to know how far cani push my car with out killing it. i tried it out once with an rsx before i took my rpms up to 5, do i need to go more or what?

shift right at 6k. shouldnt hurt her, power dies right at 6k for some reason, so shift right then

thanks bro

I have pushed my 2009 Mazda 3 (not Mazdaspeed ;) ) right up to about 100mph before and it the power just seems to die right about there. It still accelerates but by that time I am already in 5th topping out at 4500 rpm so you may have an issue with that.
I say put it balls to the wall one you hit 4th and hope for the best. I always shift right around 5000rpm when racing but I guess that is just personal preference.

For best performance you should actually shift sooner than the redline, for best results on when to shift, use a PC program (i've got Auterra) as a dyno tool to look at the acceleration in each gear to see what the best combination is.
I think something in the 4500-5000 is where to shift, basically you want to make sure the next gear will have good power, above ~3000.

Remember it takes time to shift, so that plays into the scenario a little bit, depends what max speed you want to get. So don't shift at 55 when your looking for 0-60 time.