Launch RPM

[Don W.]

Well the 2step is in and first race is this Wed. As I write this I haven't even road tested it yet.

Anyway, considering my build (below), stock trans, stock TC with lockup sw., and street tires, what would you suggest as good place to start for launch RPM. I'm thinkin' 2100 but ???.

TIA

 

[turbodig]

Re: Launch RPM

Well the 2step is in and first race is this Wed. As I write this I haven't even road tested it yet.

Anyway, considering my build (below), stock trans, stock TC with lockup sw., and street tires, what would you suggest as good place to start for launch RPM. I'm thinkin' 2100 but ???.

TIA

Look at your DM files. Take the ones that you got the best traction, find the RPM where the vehicle moving flag tripped, and subtract 500 RPM or so. That should be pretty close.

 

[Don W.]

Re: Launch RPM

Cool, thanks!

I think have the DM from when I broke 12.5 (or a couple others that are real close) so I think I'll start there eh? :roll:

 

[Don W.]

Re: Launch RPM

OK, did a little launch "testing" with the 2step. The 2step doesn't come off immediately when I let up on the brake. If you watch me launch in this vid you can actually see it. The truck is moving when the brake lights go out and you can be assured I have long since let up on the brake.

http://www.youtube.com/watch?v=IvTlBLE1bFU

My plan is to fiddle with the brake switch adjustment so the lights go out sooner as-it-were.

 

[sharkbait]

Re: Launch RPM

OK, did a little launch "testing" with the 2step. The 2step doesn't come off immediately when I let up on the brake. If you watch me launch in this vid you can actually see it. The truck is moving when the brake lights go out and you can be assured I have long since let up on the brake.

http://www.youtube.com/watch?v=IvTlBLE1bFU

My plan is to fiddle with the brake switch adjustment so the lights go out sooner as-it-were.

thats sounds like an advantage in a street race if you can negotiate getting the brake.

 

[ed hess]

Re: Launch RPM

don

i would find out the exact rpm and boost you can get to without creeeping as use a number just below that.

once you let your foot off the brake there is some lag in the pedal travel.... put a line lock switch on the shifter and leave off that... btw the switch comes with the dual line locks your going to buy and install.

ed

 

[Don W.]

Re: Launch RPM

... btw the switch comes with the dual line locks your going to buy and install.

ed

ooooK :rotf:

 

[sy445]

Re: Launch RPM

I just installed the dual line locks and 2 step as well. I havnt gotten a chance to run it yet. I used a transbrake switch as it is VERY sensitive.

 

[dgoodhue]

Re: Launch RPM

As mention the brake pedal has a delay. I wired up a wired push button switch that I can move around the cab to activation the 2 step (ie hold switch with both hand on the the steering wheel). The only problem is that I accidently randomly engage it. I am going to also wire it to the brake pedal as well, so the two 2 step can only be activate when I have the brake pedal on.

 

[ed hess]

Re: Launch RPM

As mention the brake pedal has a delay. I wired up a wired push button switch that I can move around the cab to activation the 2 step (ie hold switch with both hand on the the steering wheel). The only problem is that I accidently randomly engage it. I am going to also wire it to the brake pedal as well, so the two 2 step can only be activate when I have the brake pedal on.

do the brake pedal and you will be leaving the line while still on the 2 step

 

[dgoodhue]

Re: Launch RPM

do the brake pedal and you will be leaving the line while still on the 2 step

Assuming you have line locks. I don't have line locks nor do I ever plan to add them.

 

[ed hess]

Re: Launch RPM

Assuming you have line locks. I don't have line locks nor do I ever plan to add them.

doesnt matter if you dont have line locks. if you have a time delay due to brake pedal travel and your 2 step is connected to the brake pedal it will still be on the 2 step thru a part of the 60ft. a few feet anyway.

 

[dgoodhue]

Re: Launch RPM

doesnt matter if you dont have line locks. if you have a time delay due to brake pedal travel and your 2 step is connected to the brake pedal it will still be on the 2 step thru a part of the 60ft. a few feet anyway.

My 2 step is triggered by the switch. Brake pedal disengages the switch.

 

[Maverick87]

Re: Launch RPM

And when you mess with the switch you also mess when the brake lights come on and go off. If you set it so that it disengages at the bottom of the travel your brake lights wont come on during normal use. Put a button on the gear shift of use the horn button. Or do like I did and put a micro switch under the shifter that engages when you pull the truck into low. Nice and stealthy and no chance of it being accidental engaged

 

[Don W.]

Re: Launch RPM

Since when is there a "delay" in the sw? Never heard of such a thing. And no, I won't adjust the sw to where the brake lights don't work. I may have to not use the brake light sw though. We'll see.

As usual, thanks for all the ideas.

 

[sy2675]

Re: Launch RPM

Since when is there a "delay" in the sw? Never heard of such a thing. And no, I

Push the pedal in while in park and then let off the brake, the pedal doesnt spring right back, thus the delay on the switch telling the brake light you have let off the brake. The pedal has to come up to turn the switch off. just my $.02

 

[ChevelleDude71]

Re: Launch RPM

And when you mess with the switch you also mess when the brake lights come on and go off. If you set it so that it disengages at the bottom of the travel your brake lights wont come on during normal use. Put a button on the gear shift of use the horn button. Or do like I did and put a micro switch under the shifter that engages when you pull the truck into low. Nice and stealthy and no chance of it being accidental engaged

I would also suggest using a button that you can place on the shifter or steering wheel. I placed my line lock on the shifter of my chevelle, then the exact second I wanted to stop making white smoke I could just release the button, no delay. I know a Line lock is a little different, but I still think with a 2 step it would work out best for you that way. Just my :2cents:

P.S. I don't know if I'm going to make it out there tomorrow. I hope to, but if I don't get off work in time I may just use the rest of the day to install my fuel lins.

 

[THEMADTYPH00N]

Re: Launch RPM

If you don't have cruise, I have seen people use the set button for the cruise control to activate the 2step.

 

[Don W.]

Re: Launch RPM

If you don't have cruise, I have seen people use the set button for the cruise control to activate the 2step.

I had actually thought of that. Still mulling all this over. I'll keep ya posted.

 

[turbodig]

Re: Launch RPM

I've got my line-lock button on a springy-cord in the center console. When I want to use it, pop the lid open and grab "the button". Got a connector in there so I can take the whole thing out if I like, they run footbrake-only races every now and again that I like to get into.