I am a little new to engines and don't understand everything completely. From my understanding the redline is the maximum point your engine can rev to without doing any serious damage. Is that a correct defination? What goes into determining the redline? In our L03 the redline is at 5000rpm's, what mods could you do to allow for higher revs. Thanks for any guidance.

 

well, the lo3 isn't going to even make power to 5k, so it is really not a concern.

 

Well mod it first, it wont pull past 4k stock so I wouldnt really worry about it. We have a rev limiter at 5k so itll cut off at 5grand cuz of hte computer. Can be by passed by splicing some wire or something, Jet makes chips that raise the limiter to like 5.5 grand at totally get rid of the 115mph speed limiter. Hope that helps.

 

im about 110% sure the L03 doesnt have a rev limiter




and just because a honda starts making power at 143,000 rpm doesnt mean you need to rev that high

 

So do we have a rev limiter or not?

 

no, i know from experience.

 

There is no rev. limiter stock, but it can be programed in ( I think it's a patch kinda using the speed limiter and making it read rpms (just a guess))

Anyways, the stock valvetrain will basically dictate the max safe rpm on our engines. The stock cam will make revving past 5000rpm pointless. My car has seen ~5500 rpm all stock plenty of times. After upgrading the cam and valvetrain (crane springs, LT4 retainers, etc.) the engine has seen 6000 a few times with no problems.

The redline is basically just a reference point on our engines and most that you don't go past the redline for max engine life.

 

Coulda sworn my **** had a rev limiter...oh wellz, I have one now lol.

 

I have a 92 L03 with 70,000 and it doesn't have a rev limiter, also its an automatic and pulls all the way to 4300-4400 and its only mod is a K&N filter in the bone stock single snorkle housing.

 

With my mods my power drops off at about 4900. I'm hoping that with headers and an intake with some Ultimate TBI maybe it can pull to 5500 on the stock valvetrain. But I'm betting that I'll need some PROM tuning.

 

With a new intake manifold perhaps, id think that the stock 305 TBI cam doesnt have enough duration tho.

 

i have a 92 305 tbi with 108k with a 5 speed with minor bolt ons and mine pulls to 5.5k and has seen 6 on numerous occasions

 

With a decent exhaust and manifold, an ultimate TBI should still peak out somewhere in the low 5k range. The greatest limiting factor at that point are the heads (jeevus those heads!).

Back to redlining- your right; the redline is the point at which the valve-train and rolling-stock is not tested/designed for. First thing to go would be the valve springs. Then valve float and the rest of the valve-train problems. The stock rotating assembly should be good for pretty far into the RPM range, but I'd say 6000 would be the ultimate max I'd push a 305, there's no real point going higher because the bore/stroke combo won't make anymore power.

 

Um i donno maybe "Pulling" has a different definition in ur book, yes mine runs until 5.5k aswell no problem, BUT it started (when mine was stock) to lose power after 4k if u were racing and shifted at 5.5k with a stock TBI ud lose 4 sure. 4k and next gear here I come.

 

For you guys saying your stock lo3 would pull upto or past 5k, i have a question. Were you going by the factory tach in the dash? If so don't take those numbers seriously. Mine is so inacurate that it says that the trans is shifting at 7K+ rpm at WOT. Now i know that is wrong and at a guess i am going to say its around 5k little more or less. Now mine is an extreme example, but i have seen few of these tachs that, left alone and not recalibrated, read accuratly. Besides the float limit on the valve train is around 5700-6000 so you aren't going to go that high.

 

no mine still has power to 5.5k otherwise i wouldnt take it that high, why go out of your power band defeats the purpose of useful power

 

hey guys

i dunno about valve float in a SBC i have turned the eyes out of my old z 4bbl and never had it float the valves the only thing it did float was a rod !. it would pin 7k on a sunpro tach like it was nothing. i thought too the tach was off. it was off around 150 rpm's

 

from what I have read and experianced the L03 engines power range caps out at around 4k rpms stock. There is no pull at that point. The automatic transmission in my GFs seems to shift a little late at around 4.2k rpms and I can feel a drop off in how much pull I am getting just before it shifts. I do know that it is common place for a stock tach to read off by 1k rpms or so I have seen several stock camaros do this. Unless you expect me to believe they idle at 2.5k rpms.