discussion - why is rev limit stock 6000?

[navyblue2000]

I've done some thinking about it. I don't know if this discussion has been brought up before, but heck, last time if it was, was never concluded.
why is the motor's stock rev limiter ~6000? dominic's 2002 had it set at 5800 for some reason.
At first, I thought maybe it was bottom end, but ruled that out because the L67 has all forged internals, and still has a limiter of 6000.
That in mind, we move up a notch to the pushrods, valves, keepers, springs, and retainers. Basically the head assembly and a little below.
we share that with the L67.
After a brief discussion with someone, the thought of valve float came to mind. valve float can kill a motor...since the valves are staying open and what not.
I heard somewhere else too, that the transmission is the reason, but I can't see any hard evidence. the 4l60e is used in the vette, and ZO6, and redline is 6500 in those.

open for discussion...i'd like to know. when i install the cam that was once magnus', i'm looking to go with some aftermarket LS1 springs, which are good for .600 valve lift at over 6000 rpm.

[Tiago]

upgrade the valvetrain and rock to 7k if u can get rid of thelimiter and the cam is big enough ;)

[Dominic]

I personally don't feel that it is safe to go past 6500RPM on the stock crank/rods, and I mean 6500RPM as the maximum.

With stronger internals, better valving, better flowing heads, and a tougher timing chain - not to mention an improved oiling system, underdrive pulleys for water and alt, and anything else you can think of that might sheer or break past 6000, then you might consider 6500-7000RPM okay.

Our stock motors lose power after 5200RPM anyways, so shifting around 5800 is about what you want. It isn't until you start changing the cam and such and bumping the powerband higher do you need the higher revlimit to take advantage of this stuff.

I bumped mine to 6000 though since that is indeed the redline for our cars...

[navyblue2000]

<blockquote>quote:</font><hr>Originally posted by navyblue2000:
when i install the cam that was once magnus'<hr></blockquote>


why don't you read the whole post?

[3.4 slow to go]

are the rods forged too or is everything?
yeah, rev limiter sux ;) , but at least I'm still driving the GT.

[wolf]

<blockquote>quote:</font><hr>Originally posted by Tiago NOS'd Bird:
upgrade the valvetrain and rock to 7k if u can get rid of thelimiter and the cam is big enough ;) <hr></blockquote>

yep, mine spins to 7k scary fast :eek:

[HAZ-Matt]

<blockquote>quote:</font><hr>Originally posted by navyblue2000:
T4l60e is used in the vette, and ZO6, and redline is 6500 in those.<hr></blockquote>

The 4L60E is in the coupe and convertible only, not the Z06. The Z06 has a 6500 rpm redline, not the LS1... it is also 6000rpm.

[Magnus]

Many GTP guys spin well past 6500.. :eek:

[99BlueSuperSix]

<blockquote>quote:</font><hr>Originally posted by navyblue2000:
open for discussion...i'd like to know. when i install the cam that was once magnus', i'm looking to go with some aftermarket LS1 springs, which are good for .600 valve lift at over 6000 rpm.<hr></blockquote>

I've never heard of this, but should work out ok...

[navyblue2000]

hmm...
now, let's have a conversation, just like we would have had MAGNUS started it :rolleyes:

[Dominic]

navy, dont get mad, maybe I didn't understand what you said. Please restate your concern? :(

[navyblue2000]

eh, no need to :(

i'm concerned with how well the valve train will hold up... the valve/keeper/retainer assembly, and the rocker.
i'd bet the rocker would hold up, but .54" lift is too much for the spring.
hows that sound?

[Arctc Wolf]

it could be the cooling system isn't built to handle higher rpms(more combustions, more heat it has to dissipate). I'm gonna try to get a HPP3 by late october and bump the rev limit to maybe 6100-6200 max, or I may play it safe and stay at 6000. Also, even though our cam's r small, if u have the right combo such as a low-backpressure exhaust(headers, larger outlet cat, mandrel bent 2.5" or bigger cat-back), u'll be able to get much better hp in top end because hp is directly related to rpm. Torque peak will be higher, but still limited to the cam and heads ability to pull air in easily, but who knows. Dyno ur car and see if it's worth bumping up the rev limiter w/ the stock cam. Personally, I'm gonna set up the valvetrain to handle higher rpms before i go crazy w/ anything. cooling will also be addressed.

[Magnus]

<blockquote>quote:</font><hr>Originally posted by Arctc Wolf:
it could be the cooling system isn't built to handle higher rpms(more combustions, more heat it has to dissipate). I'm gonna try to get a HPP3 by late october and bump the rev limit to maybe 6100-6200 max, or I may play it safe and stay at 6000. Also, even though our cam's r small, if u have the right combo such as a low-backpressure exhaust(headers, larger outlet cat, mandrel bent 2.5" or bigger cat-back), u'll be able to get much better hp in top end because hp is directly related to rpm. Torque peak will be higher, but still limited to the cam and heads ability to pull air in easily, but who knows. Dyno ur car and see if it's worth bumping up the rev limiter w/ the stock cam. Personally, I'm gonna set up the valvetrain to handle higher rpms before i go crazy w/ anything. cooling will also be addressed.<hr></blockquote>

as with any cam, the power is taken up in the powerband slightly...how do you plan on 'addressng the cooling?'


*exp*

[MustangEater8251]

t on the other side, is there any limits to the ignition and fuels systems?

I mena sure they can be upgraded, but just a thought.

Cooling and oil woudl be other issues too mind, assuming the mechanical parts all hold up. If hte GTPs are doing it I woudl go check out clubgp

wow 3.4Ls truning up past 6k fast? Damn.... i don'tlike to take it much pastr 5k [img]smile.gif[/img]