LS3 good to 7k?

[UsedTaHaveA68]

Not that I would consider tearing a perfectly good camshaft out of a still warrantied engine... But let's just say someone did. Is the stock bottom end good for another 500rpm? I'm not looking at anything huge, but most cams for the LS3 seem to really start picking up around 5500 and go to 7000. I'm not going to window my block am I? Should I start saving up to invest in a forged crank/rods?

[CamaroSpike23]

it'll be fine. the pcm will cut the fuel/timing off/back before you can spin it too high... that is unless you miss a gear downshifting. then you are SOL

[UsedTaHaveA68]

Well with a new camshaft I would obviously retune the PCM, but would want to take advantage of the new power up top, so would reset the limit a little higher. Is the stock bottom end able to handle 7000rpm?

[CamaroSpike23]

Originally Posted by UsedTaHaveA68

Well with a new camshaft I would obviously retune the PCM, but would want to take advantage of the new power up top, so would reset the limit a little higher. Is the stock bottom end able to handle 7000rpm?

yes. theres stock bottom end LS1s and LS2s out there turning 7000+




but why do you want to spin past 7000? maybe im too old for thinkin this, but I like having power across the board, not just for a 2500 rpm span. granted, for peak power numbers you can throw a cam in that will make your dyno look like mount everest, but id rather have useable power thruout the power band



its nice to rev, its nicer to move.

[spd98]

Should be but most cams will fall flat on thier face before you ge there. you need valvtrain upgrades. Remember the cam is spinning at 2x the speed of the crank.

[UsedTaHaveA68]

I agree about the "better to move." I'm not looking to make 550rwhp N/A with stock cubes. I'm shooting for about 450 with LT headers, high flow cats, catback, CAI, and a mild cam. On the dyno graphs I've seen of the LS3's, MOST mild cams make only slightly more hp/tq than the stock cams until about 5500rpm, where the stock engine starts to turn down, and the aftermarket cams continue the trend upward until around 7000. Maybe one day I'll build a 416 stroker and make 500tq at 2500rpm, but for now I'd like to keep the bottom end stock. So basically I'm just looking to keep similar power levels below 5000rpm and gain the 50-60hp above that for my trips to the strip. That's why I was wanting to know if the stock bottom end can handle the extra revs. It certainly won't spend the majority of its time there.

And I will upgrade the valvetrain with appropriate valvesprings/titanium retainers. I've read the valves on the LS3's are the hollow sodium filled, so those should be good. Thanks for the info guys!

[SS 376]

Originally Posted by UsedTaHaveA68

I agree about the "better to move." I'm not looking to make 550rwhp N/A with stock cubes. I'm shooting for about 450 with LT headers, high flow cats, catback, CAI, and a mild cam. On the dyno graphs I've seen of the LS3's, MOST mild cams make only slightly more hp/tq than the stock cams until about 5500rpm, where the stock engine starts to turn down, and the aftermarket cams continue the trend upward until around 7000. Maybe one day I'll build a 416 stroker and make 500tq at 2500rpm, but for now I'd like to keep the bottom end stock. So basically I'm just looking to keep similar power levels below 5000rpm and gain the 50-60hp above that for my trips to the strip. That's why I was wanting to know if the stock bottom end can handle the extra revs. It certainly won't spend the majority of its time there.

And I will upgrade the valvetrain with appropriate valvesprings/titanium retainers. I've read the valves on the LS3's are the hollow sodium filled, so those should be good. Thanks for the info guys!

Judging by the numbers the C6 guys are putting out on their LS3s, you should be able to hit your goal. Their experience should be a good benchmark for us. 450 whp is very realistic and, from what I remember, it's not a problem for the LS3 to rev just a little bit more to 7000 RPM.

[CamaroSpike23]

Originally Posted by UsedTaHaveA68

I agree about the "better to move." I'm not looking to make 550rwhp N/A with stock cubes. I'm shooting for about 450 with LT headers, high flow cats, catback, CAI, and a mild cam. On the dyno graphs I've seen of the LS3's, MOST mild cams make only slightly more hp/tq than the stock cams until about 5500rpm, where the stock engine starts to turn down, and the aftermarket cams continue the trend upward until around 7000. Maybe one day I'll build a 416 stroker and make 500tq at 2500rpm, but for now I'd like to keep the bottom end stock. So basically I'm just looking to keep similar power levels below 5000rpm and gain the 50-60hp above that for my trips to the strip. That's why I was wanting to know if the stock bottom end can handle the extra revs. It certainly won't spend the majority of its time there.

And I will upgrade the valvetrain with appropriate valvesprings/titanium retainers. I've read the valves on the LS3's are the hollow sodium filled, so those should be good. Thanks for the info guys!

swap in the hot cam and all the bolt-ons and you should be around 450 fwhp easy.

these heads that are on the car tho... they are bad-freaking-ass. you can get the exhaust ported a little bit over stock, but they flow incredibly well compared to previous heads.

[Mr Twisty]

Originally Posted by CamaroSpike23

yes. theres stock bottom end LS1s and LS2s out there turning 7000+




but why do you want to spin past 7000? maybe im too old for thinkin this, but I like having power across the board, not just for a 2500 rpm span. granted, for peak power numbers you can throw a cam in that will make your dyno look like mount everest, but id rather have useable power thruout the power band



its nice to rev, its nicer to move.

Agree...Look close at the stock torque curve compared to aftermarket sticks. Better top end but sacrifice low end grunt.

[UsedTaHaveA68]

Most mild cams I've seen (less than 230 duration at .050", .575 lift or less) make about the same, maybe slightly better than, power as the stock curve until around 5000 where they continue to pull. Just go to the GMPP catalog (http://www.gmperformanceparts.com/_r...09_Catalog.pdf) and look at the HOT cam.

Stock tq@2500 ~ 375
HOT cam tq@2500 ~ 400

The stock starts to level off around 5500 and is falling by 6000. Not by much, I understand that, but gains up top are what I'm looking for without giving up power down low. That's why I'm staying with a fairly mild cam, because I don't want to give up all the low end grunt. Mostly I'm looking for bragging rights at the strip/autocross while staying fairly incognito. And if the occasional Challenger or Mustang GT comes along, I'd like it to be less of a driver's race and more of my engine kicking the crap out if theirs.

[camaro5]

CAI, Longtube headers, Catback and Cam. Just Do It!

Check out Corvette Forum for more info, very common.

[gunslinger]

Uhh, just to correct the above post, the cam spins at HALF the crankshaft speed, which is still quite fast considering what is does!

[o2camaross]

Originally Posted by gunslinger

Uhh, just to correct the above post, the cam spins at HALF the crankshaft speed, which is still quite fast considering what is does!

i was just about to point that out


the car redlines at 6600 stock, when you put a bigger cam in it, i dont see why it would not make power up to 7k, so i dont see a problem reving it that high.

[CamaroSpike23]

Originally Posted by o2camaross

i was just about to point that out


the car redlines at 6600 stock, when you put a bigger cam in it, i dont see why it would not make power up to 7k, so i dont see a problem reving it that high.

well, its not just making power up to 7k, its also being able to spin the motor that high before the rotation of the motor exceeds its capabilities.

however, I dont see that being much of a problem with the LS3