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Neutral/clutch (0-VSS) factory rev limiter and N2MB Wotbox, can they coexist?

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I'm having a lot of trouble raising my clutch rev limiter while launching my 1st gen Chevy Sonic 1.4. Is it even necessary if I want to launch it 100-250 RPM lower around 3750 with the wot box? It slows down as it approaches the limit by about a 500 rpm hysteresis, but I can't find how to raise it on the HP tuners forum. Thanks in advance. Great course, cheers from Vegas.

Bump, anyone? Update, I do need to raise this limiter, launching under 4k isnt even worth it and is only going to be worse with the lighter (going from 33lb. To 18lb.) flywheel. Please chime in if anyone knows how to raise the neutral at stop rev limit on an e78 gm ecu please. 🙏 thanks

Sorry for the delay, I was supporting a race car at Pikes Peak Hill Climb all week.

If using a WOTBOX you'll need to set the stock ECU limiter higher than the RPM you want to set the WOTBOX, otherwise you'll get the factory cut behavior.

Setting CFCO 1000 RPM over your WOTBOX launch RPM should get you going.

If you want to use WOTBOX for NLTS, make sure you set the factory NLTS enable to something like 125% throttle, so it won't engage. I usually also set the enable VSS to a speed a little higher than you'll ever achieve, just in case ECU logic on a ROM operates differently.

Hey there, no problem. The race lifestyle right? Haha. So I did figure out that the rev limit needs to be taken up and out of the wot box's way for launching. I just can't figure out how to do it on the HP Tuners platform. I have the E78 on a 2013 chevy sonic, I'm told it's similar to the E38. I was able to get the rolling rev limiter up, but I cant get the 0-vss/clutch in to rev past 4k. There are no clear tables or settings. I was hoping for a little advice on where to look. I can get a screenshot up of the idle tab where I think it is if that would help. I really appreciate the reply. Cheers

Looking at a Cruze I worked on which is probably the closest thing...check the Fuel -> Cutoff, DFCO tab.

CFCO and Cutoff, In Gear are a good place to start.

Oh gotcha. I just re read your original post and you said cfco there too. Ok cool I'll give it a look over and report back. Thanks

Yeah so I HAVE DFCO disabled below 15 vss, the DFCO is very simple on my ecu. Could it be in these tables shown on my hotlines attachment below? I tried moving the "0" over to the 800 rpm + error column but that didnt work either.

Attached Files

heres my tune and also a log of it happening.

Attached Files
  • 2013-chevy-sonic-rs-1.4-mt-4K-REV-LIMITER-AT-LAUNCH.hpl
  • Attachments may only be downloaded by paid Gold members. Read more about becoming a Gold member here.

  • 2013-chevy-sonic-rs-1.4-mt.hpt
  • Attachments may only be downloaded by paid Gold members. Read more about becoming a Gold member here.

DFCO would be related to decel, coast down.

CFCO is related to the clutch being pressed.

FCO = Fuel Cut Off, D = Decel, C = Clutch in this context.

DFCO wouldn't be related to launching, but CFCO is since you have the clutch in while on launch control.

Sorry, i know the difference. Was just a typo. The cfco is simple as you can see in the picture. It's definitely not the setting that is limiting.

Bump....

I see you raised the main limiters.

I would start by raising CFCO from the 1300 RPM you currently have it set to, to a value above the highest RPM you'd want to use WOTBOX.

I would datalog more torque related monitors to verify torque limiting isn't at play.

To narrow things down you could also increase the switchover delay which delays throttle reduction during a rev limit, and in that way differentiate between a rev limit and a torque limit.

We usually reply within 12hrs (often sooner)

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