Launch Control: Fuel Cut or Ignition cut?

s300 and SManager software questions & answers
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Killa-X
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Launch Control: Fuel Cut or Ignition cut?

Post by Killa-X »

I'm use to the MSD setup, where when its on the stutterbox the turbo is still building boost for off the line power.

I was told that Honda ECU's cut the fuel when they are rev-limiting, and i'm wondering if this is the same with the S300 and Launch Control. I want to be making boost off the line, and I was told only ignition cut can give you this, because you need fuel to make power.

Please enlighten me on the S300 and how this works compared to the MSD way.
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Spunkster
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Post by Spunkster »

You can use either a fuel only cut, or a fuel and ignition cut. You can also go into the launch control settings and set it up to retard timing so that you can help build more boost. This is very hard on turbos, but it is an option for you. I would suggest downloading the software and take a look at the options.
Killa-X
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Post by Killa-X »

Thanks Spunkster, I was wondering though, you can cut fuel, or fuel and ignition, but there isn't an ignition only.

So what good does it do to retard the timing, or cut timing if you are also cutting the fuel. Because if there isn't any fuel, then there is no exhaust to spool the turbo right?

When does the timing retard occur in relation to the fuel being cut when Launch Control is activated. I've looked at the software, but it doesn't give a very helpful explanation of how the launch control works.
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Hondata
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Post by Hondata »

An igntion only cut very quickly washes down the cylinder walls with fuel and will damaged the engine.
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Spunkster
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Post by Spunkster »

Go to Help, Contents, and search for launch. Then look at the Launch control parameters...it has very detailed information on how to set things up.
Killa-X
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Post by Killa-X »

Hondata wrote:An igntion only cut very quickly washes down the cylinder walls with fuel and will damaged the engine.
And so that is why there is ignition AND fuel cut?

I gotcha. I'll check into those parameters again and see if it answers my next questions.
Killa-X
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Post by Killa-X »

Okay, I see in the help file that retarding the ignition and/or adding fuel during the launch limiter can increase EGT, manifold, turbo, and head temps, and it never dawned on me, but washing the cylinders would be horrible as well.

It says the activation RPM for this should be below the launch limiter RPM, but by how much? 200rpm where the motor will dip back into this band before it revs up and bounces off the launch limiter again? If the retarding ignition and/or adding fuel is happeneing before the launch limiter, does that mean that at the launch limiter, the S300 is cutting fuel, or cutting fuel and ignition (if you set it) to maintain that launch rpm?

Any other places where I can read more about builing boost of the line safely? How do you guys get this accomplished without washing the cylinders and heating everything else up?
tboostdsi
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Post by tboostdsi »

not a turbo owner but i have the jrsc 11 lbs and i was curious how to set up my lauch control and after setting it up i dont need a clutch sensor or anything like i did w the s200. and all i have to do is hold the pettal to the floor and it should stay at the rpm desired right? thanks, sorry for the noob question
Killa-X
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Post by Killa-X »

Can anybody answer his and my question. Last 2 posts. comon please
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Spunkster
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Post by Spunkster »

Information on how to set up launch control can be found in the help file in S-Manager.

I cannot tell you waht settings to use, as is is somethign you will have to experiment with and see what works best for you. WHat may work for one person may not work so well for another.
Killa-X
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Post by Killa-X »

Okay, I see in the help file that retarding the ignition and/or adding fuel during the launch limiter can increase EGT, manifold, turbo, and head temps, and it never dawned on me, but washing the cylinders would be horrible as well.

It says the activation RPM for this should be below the launch limiter RPM. If the retarding ignition and/or adding fuel is happeneing before the launch limiter, does that mean that at the launch limiter, the S300 is cutting fuel, or cutting fuel and ignition (if you set it) to maintain that launch rpm?

Anybody on here use the launch control and retard timing or add fuel for turbo spool up? Anybody care to share what their experience has been, EVEN IF EVER CAR, EVER SETUP IS DIFFERENT?
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