MSD Two step for the 5.0

[JDM74]

MSD is ignition cut. SCT is fuel cut which is not as safe.

After doing some research, I think which one is safer is debatable. What kind of limiter is used on the GT500? Fuel cut or ignition cut? All the stuff I have read about "going lean" with fuel cut has said it doesn't happen that way, fuel cut is fuel cut meaning no fuel is put in the cylinder at all. So therefore, no combustion occurs.

 

[Full_Tilt]

MSD is ignition cut. SCT is fuel cut which is not as safe.

Usually OEM rev limiters are fuel cut, so I cant imagine fuel cut is dangerous (except when nitrous is involved).

Ignition cut can be bad because you could possibly wash the cylinder walls with gas, or even get gas in the oil... of course that would only be from 2 stepping for too long (i.e. showing off foolishly)

 

[SlowA$$5.0]

After doing some research, I think which one is safer is debatable. What kind of limiter is used on the GT500? Fuel cut or ignition cut? All the stuff I have read about "going lean" with fuel cut has said it doesn't happen that way, fuel cut is fuel cut meaning no fuel is put in the cylinder at all. So therefore, no combustion occurs.

You can run whatever you want bud. I'm not going to argue which is safer. I can assure you that you will build more power off the ignition cut 2 step set at 4500 rpm than you can using the factory 2 step set at 7000 rpm.

 

[Trav4011]

Fuel cut is only dangerous when the engine is under a load.. Free revving does not induce a load.

 

[acrbill]

The SCT neutral rev limiter does not hold the RPM nearly as well as the MSD does. It bounces around a lot. People have been using MSD 2-steps for years, just don't sit on the limiter for too long. On a sportsman tree bring it up as the lights begin to drop. The n2mb is nice but is a serious PITA to install.

 

[Trav4011]

On a car with cats.. why not wire it up to cut the injector out for the cylinder that's being cut out at the same time? If the cylinder is dead from no spark, then, there's no reason for the injector to spray fuel anyway. There should be no difference in the way it performs, but, you won't torch your cats.

If it's a turbo car, then, leaving the injector on would be beneficial, as unburned fuel ignites in the turbine housing and causes it to spool the turbine.

Does the MSD box simply cut the voltage to the coil pack(s)?

Travis

 

[Full_Tilt]

Fuel cut is only dangerous when the engine is under a load.. Free revving does not induce a load.

Why is it dangerous exactly?

 

[SlowA$$5.0]

The SCT neutral rev limiter does not hold the RPM nearly as well as the MSD does. It bounces around a lot. People have been using MSD 2-steps for years, just don't sit on the limiter for too long. On a sportsman tree bring it up as the lights begin to drop. The n2mb is nice but is a serious PITA to install.

Its 4 wires and I emailed them the exact wire color and pins to wire it to. Definitely not hard to install now. It was hard when I did it because it had never been done before. Simple now. Progressive nitrous control, no lift shift, and spark rev limiter are enough for me to buy it.

 

[Trav4011]

Why is it dangerous exactly?

Why is it dangerous to run a motor lean under a load? Detonation would occur.. broken/melted ring lands, rings, etc.

Running lean with no load doesn't hurt anything (free revving)..

 

[PBstallis]

On a car with cats.. why not wire it up to cut the injector out for the cylinder that's being cut out at the same time? If the cylinder is dead from no spark, then, there's no reason for the injector to spray fuel anyway. There should be no difference in the way it performs, but, you won't torch your cats.

If it's a turbo car, then, leaving the injector on would be beneficial, as unburned fuel ignites in the turbine housing and causes it to spool the turbine.

Does the MSD box simply cut the voltage to the coil pack(s)?

Travis

I think doing both at the same time would shut the car off but I could be wrong

 

[SlowA$$5.0]

I think doing both at the same time would shut the car off but I could be wrong

This.

No spark, no fuel, no combustion, no revving.

 

[rford426]

WOTbox a PITA????? Maybe for a retard

 

[05yellowgt]

Why is it dangerous to run a motor lean under a load? Detonation would occur.. broken/melted ring lands, rings, etc.

Running lean with no load doesn't hurt anything (free revving)..

There is a difference between running too little fuel and running no fuel (fuel cut). 100% air in the cylinder, 0% fuel, and spark= no combustion and no lean event.

 

[rsb5772]

The SCT 2 step and the MSD 2 step don't do the same thing. MSD is nice, but the N2MB WOT box has more features.

What features does the N2MB have that the MSD doesn't? Can the setting for shifting be adjusted on the MSD?

 

[SlowA$$5.0]

What features does the N2MB have that the MSD doesn't? Can the setting for shifting be adjusted on the MSD?

I already mentioned most of them above. Progressive nitrous control, no lift shift, spark rev limiter, shift light, meth control. Not sure what you mean about adjusting shifting, but the answer is no because all the msd unit does is activate a limiter.

 

[SlowA$$5.0]

There is a difference between running too little fuel and running no fuel (fuel cut). 100% air in the cylinder, 0% fuel, and spark= no combustion and no lean event.

Are you sure that it is a 100% fuel cut? If I hit my fuel limiter when doing a burnout it has a nasty backfire. Can't imagine that being safe under boost.

 

[Full_Tilt]

Why is it dangerous to run a motor lean under a load? Detonation would occur.. broken/melted ring lands, rings, etc.

Running lean with no load doesn't hurt anything (free revving)..

Well, its 2 step, so its not under load.
Also, its not like its cutting the injectors 10% or something, its cutting them dramatically, it wont take damage from running lean because its going so lean that there is little combustion, this means very low cylinder pressure, which means no detonation.
If you tried to put load on the engine while its 2 stepping with fuel cut it would just stall out, hence the reason for tying it into the clutch switch.

 

[Trav4011]

Well, its 2 step, so its not under load.
Also, its not like its cutting the injectors 10% or something, its cutting them dramatically, it wont take damage from running lean because its going so lean that there is little combustion, this means very low cylinder pressure, which means no detonation.
If you tried to put load on the engine while its 2 stepping with fuel cut it would just stall out, hence the reason for tying it into the clutch switch.

I know that.. lol.. I was simply explaining to the guy why running lean under a load was bad, versus running lean without a load.

 

[Trav4011]

There is a difference between running too little fuel and running no fuel (fuel cut). 100% air in the cylinder, 0% fuel, and spark= no combustion and no lean event.

I know.. as I said, I was explaining the difference to the guy who asked me why it was dangerous to run lean under load, versus without a load.

 

[Trav4011]

I think doing both at the same time would shut the car off but I could be wrong

You would be cutting the fuel the same time the 2 step is cutting the spark. What I need to know is if the ignition is completely cut off to the specific cylinders during the two steps operation, or, if it just retards the hell out of it. If it completely cuts the spark, then, you could cut the fuel to that specific cylinder in the sequence and it would just be a dead cylinder.

Travis