Guess he's redlined it before, and is wondering if it's ok to do it again...? Actually, there's no real purpose to revving past 6800rpm anyways, because that's peak HP. The HP graph falls off from there.
Thanks fellas, I was asking cause i was cruising with some of my buddies and i started to pass this mini van and did not shift gears from 2-3 then it got in the red about 8k rpms and it made a funny sound and i was like Oh shit.... but thanks. n8
I have 178k+ miles on my G20 and , take it to redline pretty much every day (70 mph in 2nd gear is common). I have NEVER had any engine problems the entire time I've owned the car, and have NEVER had to add oil between changes. The only repairs I've made are stuts, brakes, PS hose, clutch and altenator...basic stuff that any car with 178k would need. My old roomate has a g20 that is 5 years and 100k newer, and I have no problems keeping up with him in a race, so the engine seems no worse for wear.
Your water pump doens't particularly like high RPM's and it will cavitate (starts frothing the liquid) and overheat, so don't sustain if you don't have underdrive pulleys to compensate. Previous poster is correct about not getting anything worth while beyond 6800 rpm, but that next gear does hit a lot harder with more RPMs behind it.
I'm pretty sure that Nissan limited the engine at 7,500 rpm due to fuel delivery and/or timing issues. I know that many of the reprogrammed ECU's with increased fuel mappings and timing advance will up the rev limit to 8,000 rpm. Not sure what the effect is on HP above 6800 rpm, since most people have changed out their headers/cams/exhaust before upgrading the ECU.
On the '92 G20 that I used to have, my RPM's cut out at 8000 exactly. I would assume that this was a fuel cut off mechanism, but it may just be valve float. I didn't go that high intentionally and I don't intend to find out what the limit is on my '96, so that's all the info I'm gonna have.