RPM Limit

[Smokey]

I did some searching, but probably did not use the correct boolean or something. Anyway, what is the safe RPM limit for an +03 V8 3.9L during shifting? Right now, mine shifts 1-2, 2-3 and 3-4 at around 6500rpm. The stock was about 5900rpm.

 

[2002_LS_V8]

mine 02 stock shifts at redline every gear, i dotn know why urs shifted at 5900...

 

[LS_Monk]

hey smokey unrelated to your thread title. I was looking at your pictures. you have a really nice a car. Does that say LIMITED down the side. Thats isn't from the factory is it. If not where did you get it.

 

[402777LS]

The LS (all models) have an electronic rev limiter that kicks in at 6800. Unless you've removed it with the sct xcalibrator you don't need to worry about over reving.

 

[J3FF]

So if you took it to 8,000 RPM you would blow it? I know that many times I have forgotten it was on sst and it kicked back. I just know most engines can take 8,000 and I know my buddies 300ZX can handle like 10,000 RPM. I've never blown an engine before, so I'm not sure.

 

[SoonerLS]

Unless you've found someone foolish enough to disable the PCM's rev limiter, it's not possible to rev an LS's engine to 8K RPM--the PCM simply will not allow it.

The main problem is that high-revving engines require light weight valvetrain components and stiffer valve return springs, or you'll suffer "valve float." That's when the springs that close the valves can't rebound fast enough, and the valves don't fully close. If the float is bad enough, and the engine isn't freewheeling/non-interference, the pistons will catch the valves in the open position and beat them into the heads (like what happens to some engines when the timing belt breaks).

As for a 300ZX revving to 10K RPM, I wouldn't believe it without proof. To go to 10K RPM in a car engine, you're getting into exotic (read $$$$) materials or, as we used to call them, motorcycle parts (which are lightweight and designed for high-RPM applications).

And we'll not even get into what high revs do to the belt-driven accessories...

 

[J3FF]

Well, I figured it did alot of damage to a belt. He had some things under the hood of it when he had it. He's the one with the 3000 GT which I posted about a few weeks ago. We were talking about revs and I said that I can only goto 7K and he was like "WHAT!!! I've hit almost 10 K on my Z!"

 

[2002_LS_V8]

Integra TypeR hits almost 10K rpm's stock man, and its no exotic :shifty: and even stock GSR hits 9200 i belive..

Unless you've found someone foolish enough to disable the PCM's rev limiter, it's not possible to rev an LS's engine to 8K RPM--the PCM simply will not allow it.

The main problem is that high-revving engines require light weight valvetrain components and stiffer valve return springs, or you'll suffer "valve float." That's when the springs that close the valves can't rebound fast enough, and the valves don't fully close. If the float is bad enough, and the engine isn't freewheeling/non-interference, the pistons will catch the valves in the open position and beat them into the heads (like what happens to some engines when the timing belt breaks).

As for a 300ZX revving to 10K RPM, I wouldn't believe it without proof. To go to 10K RPM in a car engine, you're getting into exotic (read $$$$) materials or, as we used to call them, motorcycle parts (which are lightweight and designed for high-RPM applications).

And we'll not even get into what high revs do to the belt-driven accessories...

 

[SoonerLS]

Integra TypeR hits almost 10K rpm's stock man, and its no exotic :shifty: and even stock GSR hits 9200 i belive..

Exotic materials in the valvetrain does not neccessarily equal exotic car. If you cut into the engines of either of those cars, and if they can actually hit those RPM targets, I'm fairly certain that you'l find lightweight valves and stiffer-than-normal valve springs, and both will probably be made of different alloys than what you'll find in a non-Type R Integra.

 

[Quik LS]

We have had other LLSOC members bend valves missing shifts while racing.

 

[Smokey]

hey smokey unrelated to your thread title. I was looking at your pictures. you have a really nice a car. Does that say LIMITED down the side. Thats isn't from the factory is it. If not where did you get it.

Nope, they are not factory. I added them as well as the "LINCOLN" right below them. I like to personalize my rides in subtle ways. My criteria is it should look as if it could have come from the factory. The reason for the LINCOLN emblems was I got tired of people asking what kind of car it was.

I may remove the limited emblems, but it is funny when I get stares at them from "uneducated" LS owners. They are trying to figure out what a "LIMITED" LS is. Heck, I have even had salesmen at Ford and L/M dealerships say they have never seen one before. It is amazing the sales people that do now know the product they are selling.

The LINCOLN emblems are supposed to go on the tailight of a 1998-2002 Continental. I just ordered them from one of our LVC sponsors, Team Ford. In fact, I have ordered several small items from them and they are great to deal with.

 

[SoonerLS]

We have had other LLSOC members bend valves missing shifts while racing.

I take it that they were driving V6es, 'cause I don't see how you could do this with anything other than a manual transmission. My experience has been that the PCM won't allow an SST downshift that would put the engine over redline...