N2MB Rev Limiter Function

IllCobra

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I haven't seen this discussed at all when I searched, so I am hoping I can get some answers.

What do you guys have your Rev Limiter function set on your N2MB WOT box to? Based on my understanding, when our cars hit the rev limiter, the ECU cuts fuel which could cause engine damage. If you enable the N2MB's rev limiter function, rather than cut fuel, it will cut power to the coil packs. So let's say your car's rev limiter is 6750 rpm, you can set the N2MB's rev limiter to 6500 rpm so your car will never be able to reach the dangers of that 6750 rpm fuel cut.

Is all this correct? If so, why does it seem that many WOT box owners don't enable this great function? If I am completely wrong, please let me know. I just installed this on my car so I am trying to fully understand all these features.
 

Nadra

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I don't quite understand your statement about the factory rev limiter function and how cutting fuel could damage the engine. But that aside, no idea how others are doing it but my tune has the factory rev limiter disabled. Then simply set the global rev limiter on the WOT box to wherever you want.
 

keith89

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i'm guessing you're thinking cutting fuel = lean = detonation. However, the factory limiter completely cuts fuel so there is no fuel to detonate. The only thing I'd be worried about the factory limiter damaging is the supercharger snout and crank drive but that would happen with any limiter or 2 step. The on/off creates a lot of stress on the belt driven components.
 

IllCobra

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i'm guessing you're thinking cutting fuel = lean = detonation. However, the factory limiter completely cuts fuel so there is no fuel to detonate. The only thing I'd be worried about the factory limiter damaging is the supercharger snout and crank drive but that would happen with any limiter or 2 step. The on/off creates a lot of stress on the belt driven components.
Yes, that is exactly what I was thinking would happen with the factory rev limiter. So, there's no risk at all with detonation if you bounce off the limiter? In either case, wouldn't you rather have the limiter cut off power to the coil packs than fuel?
 

IllCobra

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I don't quite understand your statement about the factory rev limiter function and how cutting fuel could damage the engine. But that aside, no idea how others are doing it but my tune has the factory rev limiter disabled. Then simply set the global rev limiter on the WOT box to wherever you want.
Out of curiosity, what rpm do you shift at? I'll have to talk to my tuner about disabling my factory limiter and just setting up the limiter on my WOT box.
 

keith89

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Yes, that is exactly what I was thinking would happen with the factory rev limiter. So, there's no risk at all with detonation if you bounce off the limiter? In either case, wouldn't you rather have the limiter cut off power to the coil packs than fuel?
I would prefer cutting fuel...this way you're not dumping fuel when bouncing off the 2 step. I still have cats so that would be bad for them...If you don't have cats its probably not as much of an issue but its probably still not good to load up the exhaust with fuel.
 

Nadra

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You're looking way too much into this. When you bounce it off the rev limiter/2 step, whatever... it's for a fraction of a second. The entire point of a rev limiter is to keep the engine from wind milling and potentially hurting it. Not the other way around. Cutting fuel or cutting ignition... Either way isn't going to hurt a thing. Set your rev limiter at a reasonable rpm and forget about it. For reference, the factory cams are out of their use able power band around 6200-6400. Much more than that, while the valve train can easily withstand it, is not necessary. Set your shift light at 6400, rev limiter just after that and put it on the wood...

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