ls motor bogs and sputters only at full throttle and at around 8k rpms. any ideas

fuel pump?
plugs were good

oh, and when i'm driving at around 70mph and i down shift to 3rd and punch it. the car doesn't react like it should. it doesn't take off like it use to. any ideas

 

is this an ls/vtec or something? what is the rest of the setup?

although I don't remember exactly what the rev limit is, a stock ls would be bouncing off it by then

 

yep, ls/vtec- chipped p28, programmed for 52k vtec and 92k redline

 

Is it bogging or is it detonating? If it's detonating at the high end you'll feel it as a loss of power. You might not hear it.

This is the voice of experience, BTW . 19 degrees timing (4 degrees advanced) on 94 octane, and it was a-pingin'

 

i don't think it's detonating, but then again i wouldn't recognize detonation if it slapped me in the face.
what causes detonation, how does it sound.
the car just bogs and sputters at 8k rpm or so. sometimes it does it and sometimes it doesn't

 

i would start with re grounding your motor to the chasie(sp)

it sounds like a ignition problem.....mabye

 

what kind of program is it? i personally do not like "chipped" computers... people buy these chips with programs on them that advance ur timing... bump vtec engagement a little higher and change the fuel maps around and they make everyone think there motors are running better than ever when in reality u might be leaning the crap out of it and might not even know it...

 

it's a skunk2 program. you could be definetly correct about the program

 

detontaion happens when your fuel is burned, not by spark plugs, but heat on cylinder walls, piston, ect..

 

You mean when fuel is ignited prior to the spark being fired... and that's not entirely true... you can have detonation by advancing the spark too much, so the fuel's not preigniting but the flame front from the ignition of the mixture reaches the piston before it's gotten to TDC.

Pinging isn't always preignition, but it can be caused by preignition.