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Old 10-05-2010, 07:22 PM   #1
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Default Launch control settings? Spark cut + fuel?

Just curious how people have theirs setup, and what provided the best results. I am currently running a hydra and I have tried out a few different settings pulling spark at fuel. I tried out a 60%spark cut 40% fuel cut this morning and it seemed to work OK.

Tried a search but did not find what I was looking for. Also I posted it here because no one reads the hydra forum.
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Old 10-05-2010, 07:40 PM   #2
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Just curious how people have theirs setup, and what provided the best results. I am currently running a hydra and I have tried out a few different settings pulling spark at fuel. I tried out a 60%spark cut 40% fuel cut this morning and it seemed to work OK.

Tried a search but did not find what I was looking for. Also I posted it here because no one reads the hydra forum.
For best result you have to retard the timing A LOT.
Im not sure how Hydra does it, but if youre retarding off of your normal ignition map you will want to retard it so that its just barely retarded from TDC. So probably like 20 degrees.
You dont have to add very much fuel really, lots of unburned fuel is introduced from the misfiring. Just try adding a little bit of fuel and work your way up until it starts working well.

This is my buddies honda, it has not problem quickly building 10+ psi (where the wastegate would open) with launch control settings similar to what I described.
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Old 10-05-2010, 08:03 PM   #3
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The hydra gives you 3 settings to *** with. RPM, spark cycles cut%, and fuel cycles cut %.

However there is a anti-lag map that gives you the option to pull/add timing and fuel.

People keep saying more spark cut is bad due to stress on components. Depending on how I screw around with the spark and fuel cut it either revs up too high, falls on its ***, or sounds like it is going to blow the turbo clean off the car.
I'm probably going to take it to the track to get it dialed in, although it would be nice if someone has some settings that already work well.
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Old 10-05-2010, 08:07 PM   #4
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I dont really understand the settings.
I would be inclinded to ignore the spark cycle and fuel cycle cut settings. Set the launch limiter RPM to like 4k, and modify the anti-lag map to have 0 degrees of advance and just a touch of fuel enrichment.
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Old 10-05-2010, 08:17 PM   #5
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It does not really work like that, at least as far as I can tell. The anti-lag maps look much like the standard fuel and spark maps. There does not look to be a setting for it to hold the rpm at. Although I suppose the maps could be set to pull fuel and spark at the desired RPM.
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Old 10-05-2010, 08:33 PM   #6
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i cut both spark and fuel, and cut 9 out of 10 cycles and retard to 10*. can spool easily to 10psi in seconds.
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Old 10-05-2010, 09:23 PM   #7
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So roughly 90% in terms of the hydra. I'll give it a shot when I have a chance, but usually with settings that high it cant even keep the revs up.
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Old 10-05-2010, 09:24 PM   #8
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Youre not just holding the throttle wide open are you?
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Old 10-05-2010, 09:56 PM   #9
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Youre not just holding the throttle wide open are you?
Isn't that the idea?
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Old 10-05-2010, 10:07 PM   #10
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No. Youre supposed to be holding the throttle right on the limiter, thats how you get it to bounce off the limiter really fast. Other wise the inertia will go through the limiter and it has to fall back below it, and repeat. If you throttle it you can get it to bounce really fast.

This applies to a normal launch limiter with or without the addition of anti-lag (fuel + ignition retard). Maybe hyrda is different, idk.
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Old 10-05-2010, 10:37 PM   #11
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if you have a real ems you should be able to just mat it and use it as a launch control... otherwise as soon as you start rolling and the control goes away your going to bog since your not into the gas.

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Old 10-05-2010, 10:39 PM   #12
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I was always under the impression that you floor it with lc as well.

I've launched that way before too and with good results
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Old 10-06-2010, 09:35 AM   #13
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No. Youre supposed to be holding the throttle right on the limiter

The ECU cuts fuel/spark and timing and hold the RPMs where you set them in the software.

I don't understand, are you suggesting that you want to set your rev limiter for LC, then go part throttle and try to also hold that target yourself at the same time your ECU is as well?

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Old 10-06-2010, 11:53 AM   #14
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The ECU cuts fuel/spark and timing and hold the RPMs where you set them in the software.

I don't understand, are you suggesting that you want to set your rev limiter for LC, then go part throttle and try to also hold that target yourself at the same time your ECU is as well?

If you hold it WOT the inertia(If thats the correct term to use for this) of the engine will carry through the limiter a bit, then have to fall back below, and repeat. You get that slow bounce of the limiter.
If you let out of the throttle a bit its still bouncing off the limiter but it wont carry through the limiter as much and it will bounce faster. In this way you get a more consistent misfiring which introduces the unburnt fuel to the exhaust manifold.

You can stand on the throttle all day with a normal 2 step LC and only build 2 psi, but of you let off the throttle and get it bouncing fast it will build more.

Then once youve built some boost you can go WOT for your launch, or roll into it, or however you want to launch.
Throttling it is solely for building boost on the line.
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Old 10-06-2010, 12:20 PM   #15
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I wish I had my laptop we me today. I have a datalog of me building 10psi with the throttle at WOT and the RPMs sitting perfectly flat at 4K. if it's slowly bouncing you don't have it setup properly.
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Old 10-06-2010, 12:46 PM   #16
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Ugh.
I will build like that, Im just saying that it works better this way.
Ive personally seen a car only build a few psi WOT, and build more throttled a bit so its bouncing faster.
Im not saying "You can only build a few psi if your WOT"

Lets take this slow since youre not following me.
Do you agree that bouncing off the rev limiter rapidly would be better for creating the conditions in the exhaust manifold that will build boost?
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Old 10-06-2010, 12:52 PM   #17
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i just wanna blow flames and impresses n00bs.

but yes i do.
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Old 10-06-2010, 08:04 PM   #18
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you should be able to change how intense the lag is.

In my ems you can change how many RPM it cuts the spark for (from 30rpm differential to 300)

This is how you build full boost with your foot pegged.

If your management doesnt do this, then you need to upgrade to get something a more powerful management system.
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Old 10-07-2010, 12:25 AM   #19
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I have the Hydra set to cut at 3000, if I set the other two settings up right it will hold at 4000.

Tried fuxing with it again tonight, anything more then 60% on the fuel cut and it just boggs out.
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Old 10-07-2010, 01:29 AM   #20
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i cut both spark and fuel, and cut 9 out of 10 cycles and retard to 10*. can spool easily to 10psi in seconds.
^ This, but I'm cutting 8 from 10. It makes my car go rap pap pap pap pap pap and blow fireballs and ****.

Mad tyte, yo.
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