I know this has been discussed before, but not this particular question. Let me know if my logic is flawed.

The MSD 2 step launch controller will not activate during shifts.

As I understand it, the LNC will activate during shifts if wired to do so through the clutch switch. To me this seems like it could be an advantage in that you could power shift, activating the rpm limiter in the launch controller and reduce strain on the drive train while improving shift time.

In other words, I shift with the throttle floored, the LNC kicks in reducing power, then turns off when I let the clutch out again. I shift quicker and stress on the drive train is reduced.

Does this make sense? Am I missing something here??

Thanks!

 

Interesting theory, I'm in for some answers

 

The LNC is only going to activate again if the RPM's drop below a 1/3rd of the rpm range based on what the LNC is set to though. I.e you have the LNC set to 6000 the rpms would have to fall below 4000 when you are shifting or it will not activate again.

 

MSD box is the same way.

Although I think there was an LNC (maybe 003) box that they setup to activate anytime the clutch switch was on/off regardless of RPM vs selected RPM.

Also, don't quote me on this because I only have the MSD, but the LNC (excluding the 003) cuts fuel and spark, where the MSD will just cut spark and dump fuel.

 

Hmm maybe the MSD was what I was thinking of in terms of how it operates then. I remember having the LNC-002 and reading about it and didn't like how it operated so I got the MSD instead for some reason.

 

Youre exactly right, I never lift the throttle when making a pass at the track & the launch controller prevents the motor from bouncing off the limiter. I have the LNC-003 & it works great.

 

LNC only cuts spark, it connects to the coils, thats why sometimes the car will backfire on shifts. Cuts spark but not fuel.

 

Yep that was it. That's why I got the MSD instead.

 

Both units only cut spark as I understand it.

 

That's what I needed to know, thanks. Which clutch switch do you have it wired to, the upper or lower? I want to wire it to the upper clutch switch so I can stage with the clutch in the upper 1/2 of it's travel.

 

That's the MSD, not the LNC

 

correct! The MSD hooks directly to the coils only.

 

I didnt know there was a 2nd clutch switch? Its wired into the clutch switch & relay installed as the LNC comes with several diagrams for wiring in the relay.

 

Yes, some customers use the LNC 2-steps to do just what you describe. Activating it each time they depress the clutch pedal. Some of the 4 cylinder guys do the same thing with other spark cut boxes.

Our LNC-TC1 does the same thing but has the length of the torque cut programmable and it accepts an input from a load cell shift ****. The LNC-TC1 is primarily designed for use with dog-engagement/pro-cut type transmissions when doing a no lift/no clutch shift though.

 

Just to clarify/reiterate, as someone else already correctly pointed out, the above is NOT the case for the Lingenfelter LNC products (LNC-002, LNC-003, LNC-2000, LNC-2001 or the LNC-TC1). This is why the LNC can also be used as an overall engine RPM limiter (primarily needed in applications with secondary injectors or nitrous applications) and why it can also be used as a no-lift shift type controller.

The control logic described above in the quoted text, sometimes referred to as latched operation, is how the MSD works but NOT the LPE products.

Because of this you do have to have a way to disable the LNC after you have left the line if you have it triggered off of the clutch pedal or the brake pedal if you don't want it to activate every time to press either pedal. This can be done with a simple manual switch or it can be done with our MPH switch or via some other method.

 

Just to clarify, as someone else already pointed out, the MSD and the Lingenfelter LNC 2-step products both cut spark (disable cylinders) to control engine RPM as do most aftermarket RPM limiting devices including virtually every RPM limiter that is built into the MSD, Accel, Mallory, etc. ignition boxes many of you have used on earlier vehicles and engines.

Most aftermarket/racing engine management systems allow you to limit RPM via spark or fuel but they can do so because they are controlling both.

Most newer emissions controlled OEM RPM limiters work on fuel and/or throttle for emissions related reasons.

 

On the 1998-2002 Camaro/Firebird, 1997-2007 Corvette, 2004-2007 CTSV and other similar GM vehicles that use two switches on the clutch travel, we do not recommend using the upper switch. That switch has very erratic signals and bounces around a lot, causing erratic activation/deactivation. The wiring diagrams in our instructions are for connecting to the second switch (the one near the end of the travel). The upper switch is the cruise control disable switch. The lower switch is the starter enable switch.

On newer GM vehicles (2010+ Camaro, 2008+ Corvette, 2009+ CTSV etc.) they now use a clutch position travel sensor (see attached image) that works a lot like a throttle position sensor so now the ECM knows the entire travel of the pedal (and they only have to use one device on the pedal). We are about to release a box that reads that signal and allows you to program exactly where in the travel you want to activate/deactivate your device. I am not sure how hard it would be to install one of these sensors onto an older pedal if you wanted that level of adjustment. The other thing you can do is install a separate microswitch on an adjustable bracket or something similar and then you could adjust the activation point that way. We offer a small pre-wired microswitch for this type of use or I am sure Radio Shack etc. has something you could use.

 

i have the lnc-002 and i love it. it works good only thing is if it is set low on the rpm it will pop in between shift when you push in the clutch in as in if its set at 2500 and you shift at 3000 it will pop but when im at the track i leave at 5800 and shift at 6200 and it will never pop