5.7 vortec rev limit

[BTLD_LS1]

Sorry if this was covered somewhere and I missed it....

I am having issues trying to get this truck to rev over 5800 RPM. I have tried raising the limiter to 6200, but it still hits 5800 and dies. I tried using the search function and came up with http://www.hptuners.com/forum/showthread.php?p=86598 which is a very old thread that states it should have been in the next release / beta.

Is there a specific version of Beta I need for this to work? Or is it still something in the works?

Thanks!

[Bill@HPTuners]

States what should be in the next beta? That thread was started 4 years ago, you don't need a beta version to tune them.

[BTLD_LS1]

States what should be in the next beta? That thread was started 4 years ago, you don't need a beta version to tune them.

Your right Bill, I was searching for 5800 limit and found that post and read it in the wrong order. Is there any support for revving these over the 5800 mark?

and I realize that you can tune, sorry I was not clear. I have tried raising the only limit I can find (Fuel Control > Fuel Cutoff) to 6200 in the tune and it still dies at 5800.

[flame]

I tuned one for a buddy that he mudbogs and I'm sure it revs out past 5800. You're not running out of fuel are you? If the pressure drops on those CPI units they will not get fuel.

[Bill@HPTuners]

You might look into spark dwell on those applications.

[BTLD_LS1]

I tuned one for a buddy that he mudbogs and I'm sure it revs out past 5800. You're not running out of fuel are you? If the pressure drops on those CPI units they will not get fuel.

Its got a high volume pump in it and just replaced the fuel filter. Its got a brand new Accel coil, Accel wires, and MSD Cap and Rotor, so the iginition and fuel system should have no problem keeping up unless there is an issue with the CPI unit itself. Its running to about 88% duty cycle on the injectors at 5800 when it hits the wall. Ill take a log tonight and post it with the tune.

I know searching around the net I have read several posts, while all old, describing the 5600-5800 limit

[BTLD_LS1]

You might look into spark dwell on those applications.

Can you elaborate? I believe the table goes to 6000 RPM and has values all the way thru. I would assume unless set to 0, the could should have current going through it allowing the coil to fire.

[axekick]

I bet if you post your tune someone will be able to see why its not working.

[BTLD_LS1]

I bet if you post your tune someone will be able to see why its not working.

Yup just got my hands on it

[PitchblackC3]

Are you trying to rev it in P or N or do you mean it is shifting before it hits 5800?

[sandrock]

I read SOMEWHERE (I want to say it was LS1tech) that the "black box" PCMs will not go above 5800 rpm, EVEN if it's been reprogrammed to do so. Do a google search on "0411 pcm swap" and the answer will come to you.

[BTLD_LS1]

Are you trying to rev it in P or N or do you mean it is shifting before it hits 5800?

I've tried in P/N I've also tried manually commanding 1st with VCM scanner and it hits the wall regardless

I read SOMEWHERE (I want to say it was LS1tech) that the "black box" PCMs will not go above 5800 rpm, EVEN if it's been reprogrammed to do so. Do a google search on "0411 pcm swap" and the answer will come to you.

That was what I was afraid of, just trying to clarify if it works or not.

[Chris@HPTuners]

the problem is a minimum dwell limit table which it seems i overlooked for some OS's.

The dwell cannot go low enough to charge the coil, when you see the table you will notice the crossover point of the minimum limit. Be careful not to change it too low or you will fry the coils.

Should be fixed in the beta in the next day or so.

Chris...

[BTLD_LS1]

the problem is a minimum dwell limit table which it seems i overlooked for some OS's.

The dwell cannot go low enough to charge the coil, when you see the table you will notice the crossover point of the minimum limit. Be careful not to change it too low or you will fry the coils.

Should be fixed in the beta in the next day or so.

Chris...

Thanks for looking in to this Chris.

I'd appreciate it if you could PM me a link to the Beta or email it to me once you have added this in, [email protected].

Josh

[Chris@HPTuners]

please email support and Bill will let you know when it's available.

Chris...

[BTLD_LS1]

For those of you that were interested in this I attached a log where I had my buddy command 1st in VCM scanner and I ran it up in first and u'll see at ~5666 it hits a wall and will not rev any higher.

Also, I know the tune needs some work, any constructive criticism is more than welcomed.

I will be installing Roller rockers, a 75mm throttle body and a new CAI in the next week or so and will really start trying to dial in at that point. Im gonna throw my DynoJet wideband in the rear O2 as the truck has no cats at the moment.

[BTLD_LS1]

please email support and Bill will let you know when it's available.

Chris...

Hey Chris are these PCM's capable of using P codes P0301-P0308? or are these only available on vehicles with 1 coil per cylinder?

On some of the earlier GM V6 PCM's these are off from teh facotry and I have been able to turn them on thru VCM Editor.

Thanks in advance for the response.

[Bill@HPTuners]

New beta is up for anyone that needs it email support.

[justin99]

I just got the beta a couple of weeks ago. Is this new version much different?

[BTLD_LS1]

I'm happy to say this works great and the truck pulls to 5900 without issue.

Thanks for the prompt response as always guys!