I got in a hairy drag race yesterday and spun my 4.8 up to 5700 RPM's until it bounced off the rev limiter. Are these things tough enough to do this often or is it hard on these things over time? Will this kind of behavior lead to anything like CSK over time or just speeding tickets? How strong are these 4.8L rotating assemblies? Geometrically can these things be consistenly revved up this higher than the old 5.7L or 5.3L for that matter?

BTW: I won

 

My 5.3 has the rev limiter set at 6100 and I do several WOT each day. Got 140K now and she still runs like a top so I don't think it's doing any damage.

 

You should safely spin it 6000 on stock trim.

 

Great to hear, I will continue to hand out the beatings By the way if you're the one I raced yesterday and you're reading this, nice try but no cigar It was on Rockford Road in New hope, MN. A kid in a ext cab 4x4 thought he'd do a ricer and flyby, I quickly made up the distance in 3rd gear and ran 'er up to redline Woot! Needless to say he wasn't too happy.


Joe

 

Nice.. ya im spinning my 01 4.8 to 6500 but I usually shift on the column with the shift kit at like 6200 or so.

 

I'm shifting at 6400, on the dyno I went to 6700 a couple of times.

 

ya.. idk if we would need to upgrade the bolts to arp's or not.. ah well.. i'll drive it till it breaks

 

Not to hijack but.... Are these high rpm's safe on a 5.3 as well? I'm still shifting at stock rpm's. The tach doesn't show a redline so I didn't know what was safe. Should I get it re-tuned to 6K? See sig for details.

 

after your radix install.. i would have it shift at about 6300-6500 or so.. the hypertech programmer will let you go as high as 6200 which is still safe bc anything you do with a hypertech is backed by a garuntee basically stating tht it wont **** anything up... but i just have it set at 6500 to give me room on the shifts and than i shift anywhere between 6000-6300 or so... i can choose where im shifting at by going through the gears on the column bc of the shift kit.. you should really consider doing that as well. Texas speed's web page.. sponser on the right >>>>>... has them for 110 with the corvette servo... dont even have to drop the tranny

they do a good tune too... either them or nelson are good mail order tuners.

 

Are these motors really that tough? I was thinking with the goofy oil pumping system we have with that long *** pickup tube and the concentric oil pump on the crank that these are weaker than the old style chevy smallblocks (i'm used to that old technology) Or am I wrong? Not trying to dog on these motors, I own one myself I'm just wondering how tough these things are compared to the smallblocks of yesteryear that I am so familiar with.....

Thanks already for the great input.

Joe