Full Throttle/No Lift Shift - timing retard or ignition cut

[NXTLEVL]

Hi guys

I'm about to begin my journey down the drag racing path and have some perhaps simple but very important questions. I've got a 2010 Camaro SS M6 with a twin turbo setup pushing around 1,200HP to the wheels. I'm looking for better starts and am planning on adding a 2-step.

I've done extensive research and landed on the Lingenfelter LNC-2000-2SR. If you're not familiar with this box it offers one RPM limiter and two timing retard settings. It's mainly targeted to nitrous guys but I think it will work for my needs a well. Here's what I plan to do:

Given that I'm turbo'd I plan to set the rpm limiter for my launch, like a standard 2-step, and add in one of the timing retards as well to allow boost to be built. Then I plan on using the second timing retard, activated by the clutch pedal, to pull timing for no-lift-shifting.

I'm fairly confident on the launch setup but my questions is in a typical no-lift-shift setup are you pulling timing or cutting ignition? I'm under the impression it's cutting ignition but the box in question can't do that hence my though about pulling timing. Will it work the way I'm thinking?

Should I just get a standard 2-step box with two rpm limits and say screw pulling timing at the launch? Is it better to build boost off the line or full throttle shift? So many questions....

[NXTLEVL]

BUMP - Still really need some insight here. It's winter but I need to get going on installs.

[acammer]

I use an N2MB box for 2-step and for no lift shift - that's a cut only, no timing changes. I think you can slow the acceleration of the engine with a big timing retard on a no lift shift, but I'm not sure you'll stop it quite as well as an actual cut would.

[Aries240SS]

We have no lift shift set up through HP tuners. Clutch in cuts ignition back to 6000rpm.
You do NOT want to do NLS with timing retard. While the fireballs look neat, you can cause serious damage that way.

For launching we use the LNC2000 at 3400rpm. This also lets us pull 4 degrees of timing on demand if we need the nitrous in addition to the blower to guarantee a win.

[acammer]

Originally Posted by Aries240SS

We have no lift shift set up through HP tuners. Clutch in cuts ignition back to 6000rpm.

How do you accomplish this - on the Fuel Cutoff RPM (In Gear) table? Set the Park/Neutral values to 6000rpm, and then Control Method only enabled for Spark along with a healthy amount of switchover delay value for all gears to keep the throttle pegged? Very interested in what that looks like - the no lift on the N2MB causes some funky stuff to happen when it cuts back in, so I've not been using it. If I can make the tune do a nice NLS without the weird stuff then that would be sweet.

[Aries240SS]

Originally Posted by acammer

How do you accomplish this - on the Fuel Cutoff RPM (In Gear) table? Set the Park/Neutral values to 6000rpm, and then Control Method only enabled for Spark along with a healthy amount of switchover delay value for all gears to keep the throttle pegged? Very interested in what that looks like - the no lift on the N2MB causes some funky stuff to happen when it cuts back in, so I've not been using it. If I can make the tune do a nice NLS without the weird stuff then that would be sweet.

All you need to do is set the park/neutral rev limiter to just above the RPM you would drop to during a shift. We used a data log of a pass to give us the proper RPM and moved the shift point accordingly. Be aware that this will cut spark immediately when he clutch begins to be pressed and not return to your standard RPM limit until the clutch is fully released.

[NXTLEVL]

I guess I don't fully understand the implications of a big timing retard. I tried to walk the Lingenfelter rep through my plan and he seemed to think using the 2000-2SR's additional timing retard function would be ok but without a strong experience base I'm at a loss to agree/disagree with either thought. What is actually needed to achieve a no-lift-shift properly? Simply a decrease in power (torque) at the time you're executing the shift or something more? How does a severe timing retard and an all out cut of ignition, for a split second, differ in terms of results and potential damage?

[Aries240SS]

Originally Posted by NXTLEVL

I guess I don't fully understand the implications of a big timing retard. I tried to walk the Lingenfelter rep through my plan and he seemed to think using the 2000-2SR's additional timing retard function would be ok but without a strong experience base I'm at a loss to agree/disagree with either thought. What is actually needed to achieve a no-lift-shift properly? Simply a decrease in power (torque) at the time you're executing the shift or something more? How does a severe timing retard and an all out cut of ignition, for a split second, differ in terms of results and potential damage?

Large enough timing retards cause post-ignition or burning the fuel while the exhaust and/or possibly the intake valve are open. This can cause the motor to stumble or damage other components.
To properly create a no lift shift scenario you want ignition to pause during the time that the clutch is engaged and resume as soon as it has been released. Some systems and configurations may also stop fueling during this time, but most allow the fuel to continue. While this does frequently cause post ignition of the fuel in the exhaust, there is not a chance of ignition happening while the valves are open and far less risk of damaging critical components.

[NXTLEVL]

So the 2000-2SR's additional timing retard function (really meant for nitrous) is definitely NOT the way to go for NLS. From my research there's no single box that gives 2-step launch RPM limiting with timing retard and an additional timing cut at another selectable RPM.

I'd have to do a combination of say an LNC-2000 to get me launch control with timing retard and an LNC-TC1 to get my spark cut for NLS. But is that even possible given both wire directly to the coils?

[Aries240SS]

Originally Posted by NXTLEVL

So the 2000-2SR's additional timing retard function (really meant for nitrous) is definitely NOT the way to go for NLS. From my research there's no single box that gives 2-step launch RPM limiting with timing retard and an additional timing cut at another selectable RPM.

I'd have to do a combination of say an LNC-2000 to get me launch control with timing retard and an LNC-TC1 to get my spark cut for NLS. But is that even possible given both wire directly to the coils?

To use the pair mentioned, or the LNC2000 and say an MSD 2 step, you would need to wire them in line with each other. Not having done so, I can't say what the possible problems there might be.

This is why we went the direction we did on my car. The neutral limiter in HP Tuners along with the LNC2000 lets me have the 2step for launch and still maintain no lift shifting.

[acammer]

Originally Posted by Aries240SS

All you need to do is set the park/neutral rev limiter to just above the RPM you would drop to during a shift. We used a data log of a pass to give us the proper RPM and moved the shift point accordingly. Be aware that this will cut spark immediately when he clutch begins to be pressed and not return to your standard RPM limit until the clutch is fully released.

Makes sense to me. I guess I'm going to have to try it out and see how it works. I have some concerns that I may not be able to set the park/neutral rev limit low enough, as my launch RPM is sometimes higher than my shift recovery RPM. I may be able to have the park/neutral set up at like 6,000 to give me enough of a break on the NLS to get me into the next gear, without interfering with my launch.

[NXTLEVL]

I'm going to reach out to Lingenfelter and get their input on the dual wiring option. I haven't done any research into HP Tuners or any other tuning software but given my setup I think I probably should. Any place I should start to better understand what would best meet my needs? Is there a good place for gaining knowledge of the basics of the software?

[acammer]

Originally Posted by NXTLEVL

I'm going to reach out to Lingenfelter and get their input on the dual wiring option. I haven't done any research into HP Tuners or any other tuning software but given my setup I think I probably should. Any place I should start to better understand what would best meet my needs? Is there a good place for gaining knowledge of the basics of the software?

Best way to learn HPT is just do a LOT of reading over on the HPTuners forum. There are a few facebook groups you can join too. The tune based NLS should work good for you. I think the timing retard on launch is definitely important - leaving on some boost will reduce the need to have dramatically high RPM at the launch, you should be able to leave with more torque, less rpm, and just stick the tire, rather than trying to waste the clutch slipping like a maniac trying to get the wheel speed up and keep the engine singing up where it makes power.