Cascade Crew

[blue89]

Only post if you have a 60v6 and have experienced this. I don't care if the motor doesn't make power yaddy yaddy....


What is the freewheeling rev limit for your 60v6? For example, in park/nuetral mash the gas. Where does it stop due to computer or valvetrain?

Mine is stopping at 6200 RPM with a 91 SD computer and I can't figure out why. It almost sounds like a fuel cutoff because it dies down to 5700'ish and then rev's back up and falls again and again.

[Dewey316]

It could be a few things there, valve float is the most likely cause. I am not aware of a factory rev limiter on our cars.

Now, most of the fuel tables stop at 6400 in the computers, and your going to float your valves.

[blue89]

I had LS1 springs installed (i hope they were) so it shouldn't be float. And the fuel table didn't show a fuel cutoff, and the modified 350TPI chip we ran is known for not having a fuel cutoff, but it stops there just the same.

[Dewey316]

There is no fuel cutoff. YOu have to modify the GM code to ceate a RPM limiter.

whatever you limit is, its mechancal. it could be many things. Valve float, injectors going static, etc.

Really, without having more data from your car, we won't know.

[blue89]

[Dewey316]

Thats what I am saying , the limit is going to vary. There is not limiter in the computer, any limit is going to be mechanical.

I guess I have no idea what you are looking for?

[blue89]

Thats why I started this thread. If you have a 60v6, what does it rev to? I didn't want it cluttered with useless posts that aren't related to the question. I understand that it will be mechanical, and I have my own motives for asking this question.

[Quasi-Traction]

*calling danked* *calling danked*

I personally have been in the car once with tony when it got it up real high. Somewhere in the 5000rpm range. Fell on its face at about 4800rpm.

[Twilightoptics]

[QwkTrip]

I had a fuel cut-off rev limiter on my '89 V6. I can't remember exactly where it engaged but it was above 6000 rpm.

[Twilightoptics]

The Z24 I'm driving has a 6500 RPM red line. I know it's seen it too.

[rjmcgee]

[aaron_sK]

[QwkTrip]

[blue89]

I really wanted to figure out if my "machinist" put the wrong valve springs in. I was hoping to get some real figures so I could compare it to what I'm observing from my end. If all of the other 60v6's quit there as well, then I would assume I didn't get the springs I asked for.

[CheezX]

Well see if I can add more info.

We tried a stock SD V6 chip and also a SD V8 chip with some parameters changed. Mixture is good at 6k+, we got a bit more RPM by playing with the timing. The fuel cutoff was basically disabled, so that's not the problem.

The ECM will run above the limit of the tables, it will just use the values from the highest RPM. It is not an ECM problem. Travis did say he got a little more RPM with the Y-pipe disconnected. I don't know what he's done since then but it does sound mechanical. With full throttle just seems to stop at 6200 RPM, even in neutral. It doesn't backfire or run rough, just stops accelerating.

You know what Travis, it does sound like valve float. Have you checked if the cat is clogged (maybe you gutted it, can't remember). Could the hydraulic lifters be collapsing?

[Danked]

i hit 12k rpms or so once on my old engine, so i really couldnt tell ya. dont ask how i did it, because ill never do it again, and only look like a jackass because of doing it. if that makes any sense

[Dewey316]

[Xophertony]

[QwkTrip]