I was wondering how a motor's redline was determined...integrity of valvetrain, cam profile? What? Then once thses variouse issues have been addressed how is the motors new redline determined? I have a 99 LS, what do I have to do in order to be able to run highere RPM's? Then how do I figure out how high is safe? Thanx.

 

build up your internals, and run a different ECU, i know LS's that are built and boosted, red lining at like 9000....

 

A VTEC head would change that as well.

 

vtec motors have to oiling holes in the bottom of the pistons to keep the wrist pin lubricated unlike the ls.. thats why most ls vtec motor can still only redline around 7k? with a stock ls bottom end

 

a vtec head would allow the valvetrain to rev higher, but the LS bottom end wasn't made to rev that high. It's rod bolts and rods aren't that great, and after being subjected to beyond stock RPM for long enough can fail.
Why do you want to raise your redline? Would you even be making power up there? Or are you just trying to go for bragging rights?
The LS rod/stroke ratio is a little low for high-revving. If you want to build a screamer, get yourself a b16, they have a near perfect rod/stroke ratio. After getting that, just build up all the internals and get some super high lift cams to go with your ridiculously high compression, and you'll be screaming.

Or you could buy a sportbike. My .6 liter bike revs to 14000rpms, runs a 10 second quarter mile, has a near perfect rod/stroke ratio, gets better gas mileage than most cars, AND was cheaper than my integra.

 

yea a common set up for a high revving ls vtec is type r pistons with stock ls rods with arp rod bolts

 

I'm not interested in VTEC at all. I failed to mention in my original post that I am turboing and want to maintain the lower compression from my LS plus I've heard you run into valve overlap problems with VTEC and high boost. As far as the bottom end of the LS I already plan on upgrading the rods and pistons to handle the stress. I would just like to know how a new redline figure is established once the internals are upgraded? I'm redlining at 6800rpm on my LS now, how do I know that its safe to push to 8000 or even 10000rpm?

 

Your LS will never, ever see 10,000 rpm. Really you should concentrate on things other than a higher redline. If you really set on increasing your redline, you need to look into altering your rod/stroke ratio and building up your head.

 

10,000 RPMs is just crazy! I also have an LS and once I get standalone, the new head I got with Crower valvetrain will be going on. A few more RPMs will help me cause I am supercharged. But, I will also be talkng care of the lower end. If you wanna rev like a madman then look to spend some $$$ to build it right or BOOM!

 

Who cares if you can rev to 10K. You need to get the car built, tuned and have some good dyno pulls to show you where the power is droping off. If you are not producing any power over 7500, then there is no point in going to 10k

 

some crower 404 with the upgraded valtrain, some eagle rods, ARP and the pistion of your choice and you'll rev high, keep the 89 mm stroke on the LS it gives you good bottom end power.