idlingmike1

Would like to hear if anyone has actually had stock LS6 engine failures of any sort with a 7000rpm rev limiter. Also interested in hearing success stories (2years, 7k once a day, mileage, etc).

Please no speculation, please no "I was told X". Just facts.

-M

hotwheels57

That will severely limit the replies...
The stock rev limiter is 6,200 rpm, so you're thinking about a tune to raise the limits?

Robls6

Why would you raise the rev limiter on a "stock" LS6 to 7000rpm? It won't make anymore power up that high and will play hell with the stock valvesprings.

B-ras

6700 on the LS6, IIRC.

I agree though, that the stock dyno sheets I've seen show that the power curve drop past redline. Hopefully someone else can chime in to answer the OP's question.

idlingmike1

Stock rev limiter is 6500 or 6600. It's not for power production, it's for usability on the road course.

-M

idlingmike1

Thanks for finding a loophole regardless

-M

hotwheels57

:o I misspoke about the Z06 rev limiter. I found this past discussion and accepted the first reply I read as gospel...
http://forums.corvetteforum.com/show...06+rev+limiter

idlingmike1

ttt

vettenuts

The tack also doesn't keep up with the actual RPM of the motor, it lags. Two issues are the already mentioned valve springs and then the rod bolts are not up to task either.

Oldvetter

I would not know why anyone would raise the stock rpm limiter from 6700 rpm on a STOCK LS6, unless you WANT to damage the engine so you can rebuild. As stated before, you don't make any more power and you are beyond your rod bolts and valves safety margin.

Those ARE THE FACTS, you CAN choose to ignore them, but your engine WILL suffer.

AU N EGL

the LS6 engine was tested for 100 hours at 6900 rpms with no problems.

Many of the T1 race engines are tuned to 7100 so they can run 7000 rpms with out problems or bumping off the rev limiter

I have my car set to 6750 as I found no benefit above that rpm level

DALE C

I ran my stock 97 Ls1 with a 7200 Rev limiter for 2 years about 20k miles, mostly on the track after the first year I did replace the valve springs with 918's (there wasnt much available at the time) The car did have all the bolt ons but the longblock was stock. The engine still ran fine and looked new inside when we pulled it out, I still have it sitting around. I would not worry about 7000 at all other than the valve springs, the stock LS6's will work although not ideal and you should replace them often.

DALE C

I think Your FACTS are more OPINION. I have worked on one or two LS based engines and the only failures I have ever seen on stock engines were due to oil starvation, oil temp or huge mechanical over revs.


On some tracks with stock gearing it is a huge advantage not to make an upshift and then immediately downshift it will gain more time to stay in the same gear even though you are beyond peak power and torque.
It is a huge benefit to the auto-x guys

AU N EGL

with Dale

RAFTRACER

It is an advantage in either auto-x or on a road course. I am with Dale too, as I have a '03 Z06 with a stock long block that I have had since new and routinely buzz it to 7300 rpm.......I do replace valve springs on occasion as I have to use stock LS6 springs in that particular car. Another area of weakness that people here are not mentioning is that the stock early timing chain will ot stand up to this rpm for long periods of time ( ask the T1 guys about this ). I have updated my chain to the 04-later (LS2) chain with dampner. No timing chain likes repeated hammering on the rev-limiter, regardless of which chain you are using no matter who it is from. Chain failures @ +7k rpm are NASTY....

Running the engine that high of an rpm is an advantage to not have to make the high-speed corner entry downshift ....the upshift is never the problem. Additionally I have known a few drag racers be suprised by shifting higher than their peak HP rpm.... It helps up-shift recovery into the next gear by being higher in the next gears torque peak (rpm).

BTW....My '03 car only looses 11 rwhp from its peak @ 6400 to the 7300 rpm rev-limit.

I never "hold" my car on the rev-limiter though.

silver01z06

As a general rule you will not need a 7k rpm limiter. If you decide to do it make sure you change the things mentioned. Valve springs, timing chain and rod bolts.

Pumba

The GM Powertrain Engineers stated in their early presentations on the LS6 engine that in order to reliably exceed the 6,600 rpm rev limit they would need to improve the connecting rod bolt.

Katech sells such a bolt: http://www.katechengines.com/street_...etail.php?id=5





Katech also sells the best timing chain and gear set. See their web site.

And finally, consider a set of improved valve springs, such as Crane's 144833-16, along with the proper retainers - 144661-16, Hardened spring seats - 144640-16

Good luck with your decision.

rustyguns

excellent reply....matched my every expectation...how often do you change the stock springs? every 20 hours or 200 hrs or ? do you use the old retainers?

7000 rpm would help tremendously in the PIR banked curve. i always want to hit 5th (143 mph) right before i have to slow down, i always say ..just few more rpm baby get those damn ferraris off my ***! if i could carry 4th to 7000 i could shave .25 second i bet!

now if i could only carry more speed in those turns!!!!! hehehe