2-step with an auto trans?

[SebringLX]

I'll be getting my car back from the trans shop on the 16th with a brand new beefy torque converter and 4000 rpm stall speed.

I have an MSD DIS-2+ on the car. It has a 2-step feature. All I need to do is hook the blue wire up to a button on a 12v switch to activate it.

I've never used a 2-step before, and all the cars I've seen with one have all been manual. Is it ok to use one with an auto trans, or does that even matter?

My thoughts...

Holding the brake and bringing the RPMs up toward stall speed is probably going to build around 15lbs of boost. If I do this with only part throttle, the PCM is going to try and maintain stoich. Probably not too good for the engine.

If I hook up the 2-step, I can set it to just below the stall speed at like 3800rpms, then just hold the button and the brake and floor it, then release the brake and button when the lights go. That should give me WOT fuel enrichment, so safe AFRs while it's building boost on the line, and a realy good launch right?

Am I on the right track here? If so, where is the best place to try and mount the button?

[Keito]

With a 2 step on an auto car, don't you need a trans brake?

[prepared]

I'll be getting my car back from the trans shop on the 16th with a brand new beefy torque converter and 4000 rpm stall speed.

I have an MSD DIS-2+ on the car. It has a 2-step feature. All I need to do is hook the blue wire up to a button on a 12v switch to activate it.

I've never used a 2-step before, and all the cars I've seen with one have all been manual. Is it ok to use one with an auto trans, or does that even matter?

My thoughts...

Holding the brake and bringing the RPMs up toward stall speed is probably going to build around 15lbs of boost. If I do this with only part throttle, the PCM is going to try and maintain stoich. Probably not too good for the engine.

If I hook up the 2-step, I can set it to just below the stall speed at like 3800rpms, then just hold the button and the brake and floor it, then release the brake and button when the lights go. That should give me WOT fuel enrichment, so safe AFRs while it's building boost on the line, and a realy good launch right?

Am I on the right track here? If so, where is the best place to try and mount the button?


With a 2 step on an auto car, don't you need a trans brake?

It will NOT be like sitting in neutral until 4000 rpms. Torque converters just don't work like that. The more torque you put in, the higher they will stall. So, as you build boost, the converter will slip a bit more and allow a bit higher RPM. However, if you just give it a bit of gas pedal, it will take off nearly normal.

You do NOT need a trans brake to run a two-step on an auto IF your brakes can hold the car back well enough.

I have a two-step in an auto (RWD V8) car. I have the 2-step wired to the switched wire from the brake light switch. At the line I simply hold the brake pedal down and the 2-step is active. When I release the brake pedal the 2-step drops out. No need to try to time the brake release with a button activation.

I also have a regular switch on the dash to deactivate the whole circuit for street driving.

[SebringLX]

I have the 2-step wired to the switched wire from the brake light switch. At the line I simply hold the brake pedal down and the 2-step is active. When I release the brake pedal the 2-step drops out. No need to try to time the brake release with a button activation.

That is what I was thinking of.



I also have a regular switch on the dash to deactivate the whole circuit for street driving.
Cool, that should work perfectly. Now I just need to figure out how to wire it all up. :thumb:

Is there a way I can wire my N2O kit into the brake light switch so it will deactivate when I'm on the brake, and activate when I let off the brake? I haven't put it on the car yet, but probably will this year. I don't want the N2O active while I'm 2-stepping. I also don't want to have to worry about trying to flip it on as I release the brake.

[prepared]

I would wire a relay off the brake light switch DPST so that it activates both the 2 step and N2O. Be sure to also include a manual off switch for devices and also a WOT switch so the N2O is only active at WOT

[SebringLX]

I would wire a relay off the brake light switch DPST so that it activates both the 2 step and N2O. Be sure to also include a manual off switch for devices and also a WOT switch so the N2O is only active at WOT

It has a WOT switch, the car would be at WOT while the 2-step is active (brake depressed). I would think that you do not want N2O active while bouncing off the 2-step rev limit? I don't have a window switch, otherwise I'd just set the window switch to start the N2O at an RPM just above the 2-step rev limit.

[prepared]

Hot ----->brake switch---->(relay coil)----->ground

Hot---->relay contact (Normally Open)--->manual switch---->2-step activation

Hot---->relay contact 2(Normally Closed)---->WOT switch---->manual switch---->N2O activaiton


I can see it in my mind, but can't draw and upload from work!

[turbovanman²]

FYI, 2 steps are very hard on rod bearings.

[BadAssPerformance]

It has a WOT switch, the car would be at WOT while the 2-step is active (brake depressed). I would think that you do not want N2O active while bouncing off the 2-step rev limit? I don't have a window switch, otherwise I'd just set the window switch to start the N2O at an RPM just above the 2-step rev limit.

Correct, no juice ont he limiter. Your DIS-2 should have a window to arm it tho?

And not sure what the advantage of the 2-step on an auto? Sounds like a trans killer?

[turbo2point2]

FYI, 2 steps are very hard on rod bearings.

I've never seen any signs of stress on the rod bearings from using a 2 step. Care to share your experiences?



And not sure what the advantage of the 2-step on an auto? Sounds like a trans killer?

Same advantage as a manual. Get some boost in her to leave hard:thumb: In my car, once the 2 step starts banging it is quite easy to footbrake. I feel it is only harder on the trans when launched, due to increased power from boost, not while staging.

[turbovanman²]

I've never seen any signs of stress on the rod bearings from using a 2 step. Care to share your experiences?



I was told this by a few racers, no first hand experience but if they are wrong, then this is good to know.

[BadAssPerformance]

Same advantage as a manual. Get some boost in her to leave hard:thumb: In my car, once the 2 step starts banging it is quite easy to footbrake. I feel it is only harder on the trans when launched, due to increased power from boost, not while staging.

An auto can make boost brake torquing unlike a stick... Or is this only with a trans brake?

My comment on being hard on the trans is thinking it would hit like a 'neutral drop'?

[turbo2point2]

I was told this by a few racers, no first hand experience but if they are wrong, then this is good to know.

Gotcha. I was curious to see what you may have found with your setup.


An auto can make boost brake torquing unlike a stick... Or is this only with a trans brake?

My comment on being hard on the trans is thinking it would hit like a 'neutral drop'?

Correct, an auto (on most setups)will make boost brake torquing it with a t-brake or not. I use the 2-step to build boost quicker and also use it as a way to soften or increase the hit.

With the trans in gear, a "neutral drop" will not occur, unless you break some parts;)

[BadAssPerformance]

LOL.....

So do you run a brake?

[turbo2point2]

LOL.....

So do you run a brake?

No. I have plans to get one in the car, need to get the suspension dialed in first. Then I can hit it with a brake:D

[BadAssPerformance]

Gotcha.... :thumb:

[turbovanman²]

Gotcha. I was curious to see what you may have found with your setup.

I just do the old school brake torque method, seems to work, lol.

The reasoning was the constant on/off of the spark loads and unloads the piston causing the bearing to hit the crank. Maybe on some engines, it can be an issue?




Correct, an auto (on most setups)will make boost brake torquing it with a t-brake or not. I use the 2-step to build boost quicker and also use it as a way to soften or increase the hit.

With the trans in gear, a "neutral drop" will not occur, unless you break some parts;)

I can build enough boost I don't need to run anything and yeah on the neutral drop, doh!

[prepared]

A 2-step is very helpful in bracket racing where consistency is more important than being as fast as possible.

[turbovanman²]

A 2-step is very helpful in bracket racing where consistency is more important than being as fast as possible.

Yeah, would sure take away some variables, :D

[SebringLX]

A 2-step is very helpful in bracket racing where consistency is more important than being as fast as possible.

Well the idea is to be as fast as possible and consistent at the same time. ;) I like to do index racing a little more than bracket racing, but I'm all for either.

Using the 2 step I'd still be brake torquing... Or maybe I wasn't brake torquing before? I have been holding the brake in and slowly increasing the throttle until the RPM gets to where I want it. My concern with doing it that way, or continuing to do it that way, is that the PCM will try to maintain stoich. Holding ~14.7:1 AFR with 15+lbs of boost seems like it'd be a lot worse on the engine than flooring it with a 2-step, which when properly tuned would hold ~11.5:1 AFR while keeping the RPMs below the stall point, which the brake should be able to hold the car still until released.

My ultimate goal is to get as close to an 11.5 without going faster. Then I can do 11.5 index races (heads up), and bracket races with an 11.5 dial in. I don't have the money to put a roll bar in, so that's the reason for not wanting to go faster than 11.5.

I want to try and break into the 11's, so an 11.9 something, with just the turbo I have now, then tune in the N2O to get to the 11.5 mark. I think the 2-step off the brake switch will help with this a lot.

[BadAssPerformance]

My concern with doing it that way, or continuing to do it that way, is that the PCM will try to maintain stoich. .

With the 2step you should be able to engage WOT.... if your brakes can hold the car?

[SebringLX]

With the 2step you should be able to engage WOT.... if your brakes can hold the car?

Yes, which is why I want to do it. I think the brakes can hold it with the 4000 rpm stall speed I'll have now. I know they wouldn't hold WOT without the 2-step. We'll find out on the 17th!

[Dusty_Duster]

You really should install an MSD RPM window switch (http://www.summitracing.com/parts/MSD-8969/) for your nitrous for added insurance. I wouldn't run nitrous without one.

[SebringLX]

Digging this thread back up... I'm not going to do anything with Nitrous at this time, just going to get the 2-step setup. I'm going to Radio Shack tomorrow to pick up supplies needed to do it.

The instructions for the DIS2 say to connect the blue wire to 12v to activate the 2-step rev limit. So I'm thinking of getting a toggle switch, and tapping into the brake switch. Toggle switch on = 2-step will activate when I step on the brakes, and deactivate when I let off the brake. Toggle switch off = 2-step disabled.

Is an SPST switch like this one http://www.radioshack.com/product/index.jsp?productId=3098835 the right way to go? Blue wire from DIS2 to 1 prong on switch, red wire to 12v side of brake switch on another prong, and black wire to ground on the last prong?

[SebringLX]

I got the switch I linked to in my last post, but I'm still not sure how to hook it up. The connections on it are "POWER, ACC, GROUND". The brake switch has about a half dozen wires coming out of it, so I'm not sure which one I need to tap on it. I'm guessing the blue wire from the DIS2 should go to the ACC prong on the toggle switch? Then when I figure out which is the 12v wire on the brake switch, I should run a wire to it from the POWER prong on the toggle switch to it. Ground should go to a convient location on the cassis?

[Ondonti]

I think the 2 step is a great idea. The rod bearing issue and many other issues are just fraudulent comments made by a few "experts" who don't understand engine dynamics. Sad that they have to pass these things on as facts to the rest of us. You are not going to create metal to metal contact on bearings without engine killing detonation or a lack of oil. I have had my main block girdle separate from the block and that did include some physical bearing damage. It was killer detonation. Simple lack of spark or fuel for a 2 step is no different on the motor then the exhaust stroke! Its like having 2 exhaust strokes in a row. Engines handle hundreds of millions maybe billions of those cycles with no problem. The only problem with a 2 step could be if your valve springs have a resonance rpm that is between idle and redline and you set your 2 step at that bad rpm spot. Most valve springs try to avoid that by design.

I like the 2 step because I have seen a lot of mild auto trans TD's be terribly inconsistent off the line.
The 2 step can be set to whatever the max your brakes will hold, or to whatever you feel gives you a quality launch, or any other requirement you have.

Seen them get really pissed at auto trans turbo vehicals on pinks because the dipwad wants to sit their for 30 seconds brake boosting with their improperly built setup.

[SebringLX]

*BUMP* I still need help with the wiring. I wanted to try and get this done today, but I still can't seem to figure out how to wire this into the brake switch. See posts 24 and 25...

[BadAssPerformance]

I used a momentary button switch istead of a toggle and a clutch switch (stick) so the button was only held during launch and the 2-step would not engage each clutching/gear You can use a toggle but have to remember to flip it off after you launch or it will activate when you brake in shutdown.

I'm guessing it is a lighted troggle? or is it a on-off-on? typically a 2 pole is all that is needed... I'm guessing it is a lighted switch then yes the ACC is your 12V "on"

Look in the FSM to figure out which wire is the +12V signal for the brake lights... tap and send that to the +12V side of the switch, then the ACC terminal to the blue wire ont he DIS2... ground the switch ... should work that way so BOTH the brake have to be pressed and toggle switched to "on" to send +12V to the box

[SebringLX]

I used a momentary button switch istead of a toggle and a clutch switch (stick) so the button was only held during launch and the 2-step would not engage each clutching/gear You can use a toggle but have to remember to flip it off after you launch or it will activate when you brake in shutdown.

I'm guessing it is a lighted troggle? or is it a on-off-on? typically a 2 pole is all that is needed... I'm guessing it is a lighted switch then yes the ACC is your 12V "on"

Look in the FSM to figure out which wire is the +12V signal for the brake lights... tap and send that to the +12V side of the switch, then the ACC terminal to the blue wire ont he DIS2... ground the switch ... should work that way so BOTH the brake have to be pressed and toggle switched to "on" to send +12V to the box

Yes it's the blue LED lighted toggle switch I linked to. DOH, can't believe I spaced on the FSM... I think I have one in PDF format somewhere, I just need to find it.

---------- Post added at 11:07 AM ---------- Previous post was at 10:59 AM ----------

Ok this is what I found in the FSM...

BRAKE LAMP SWITCH - GRAY 6 WAY
CAV CIRCUIT FUNCTION
1 K29 20WT/PK (2.0L/2.4L) BRAKE SWITCH SIGNAL
1 K29 20WT/PK (2.7L) BRAKE SWITCH SENSE
2 Z241 20BK (2.7L MTX) GROUND
2 Z241 20BK/LG (EXCEPT 2.7L MTX) GROUND
3 V32 20YL/RD (2.0L/2.4L) S/C SUPPLY
3 V32 20YL/RD (2.7L) SPEED CONTROL POWER SUPPLY
4 V30 20DB/RD SPEED CONTROL BRAKE SWITCH OUTPUT
5 L50 16WT/TN BRAKE LAMP SWITCH OUTPUT
6 A7 18RD/BK FUSED B(+)

#5, the output is what I want to connect to?

---------- Post added at 11:09 AM ---------- Previous post was at 11:07 AM ----------

I also found that #23 on the C3 plug of the PCM is the "Brake Switch Signal". It may be easier to tap than than to try and get to the actual brake switch, if that's the right wire to use.

[SebringLX]

I tested the #23 wire on the C3 plug of the PCM, it jumps up to 8v when I press the brake. I don't think that's going to work since it says it needs 12v... Any ideas?

[SebringLX]

Nevermind I think I found it... there was a wire on the brake switch that was already tapped into, I think it was for the aftermarket alarm system I had installed when I 1st got the back back in 2003. I tested it, and it delivers 12v when the brake is pressed. I have the switch on mounted on a dash panel next to my mirror adjustment switches. Going to get the soldering iron out and start wiring it up, then test it out.

[BadAssPerformance]

Cool, deal, sounds like you got it man :thumb:

[SebringLX]

Great success! The switch lights up blue when the brake is pressed. I set it at 3800rpms and tested it in nuetral. Can't wait to try it out at the track.

Next question, should I retard the timing at all while the 2-step is engaged? If so, how many degrees?

[BadAssPerformance]

Sweet. You can play with that at the track, the retard will make it build more boost.

[SebringLX]

Sweet. You can play with that at the track, the retard will make it build more boost.

Well I didn't connect that wire, but it would be easy to do at this point. Pink wire to 12v activates step retard. I suppose I could hook it up, leave it 0'd out, and adjust the dials as needed later on.

[BadAssPerformance]

true...

[22shelby]

josh you are going to LOVE the 2 step.... no more tring to hold it at XXXX RPM just set it where u want it and go... just make sure u engage it at a lessor RPM than your stall speed, not fun when it starts buckin... just on my normal ignition advance i can make 12 PSI @3400 RPM sitting still... i do however want to play with "anti lag" timing retard to get a few more PSI out of it, im just below my stall speed so it pretty much will sit there i just feel with the old 2.5 it could have grunted out of the hole a lil better, never once spun with the 22X8 mickeys...

when we go to the track, ill help ya dial it in...we'll get that tank sling shottin out of the hole!!

[SebringLX]

josh you are going to LOVE the 2 step.... no more tring to hold it at XXXX RPM just set it where u want it and go... just make sure u engage it at a lessor RPM than your stall speed, not fun when it starts buckin... just on my normal ignition advance i can make 12 PSI @3400 RPM sitting still... i do however want to play with "anti lag" timing retard to get a few more PSI out of it, im just below my stall speed so it pretty much will sit there i just feel with the old 2.5 it could have grunted out of the hole a lil better, never once spun with the 22X8 mickeys...

when we go to the track, ill help ya dial it in...we'll get that tank sling shottin out of the hole!!

I have it set at 3800RPM, my torque converter has a 4000RPM stall. :D I figure if it bucks I'll drop it another 200 rpm. I think after I get my exhaust leak fixed, I'll be able to launch at or near full boost. Hoping to hit the T&T at Byron on April 9th.

[ohiorob]

don't know if this was mention but the brake light is slow to turn off and may need some adjustment to make it work properly.

[SebringLX]

don't know if this was mention but the brake light is slow to turn off and may need some adjustment to make it work properly.

Seemed really quick to me... like millisecond quick. The toggle switch is illuminated when the brake is on, and it shuts off immediately when the brake is released. I won't know for sure how responsive it is in real world use until I get to the track.

[ohiorob]

Seemed really quick to me... like millisecond quick. The toggle switch is illuminated when the brake is on, and it shuts off immediately when the brake is released. I won't know for sure how responsive it is in real world use until I get to the track.
get it to the track and you'll see what I mean. your r/t will be off. if the brake light don't go out as soon as you just start to lift it will screw with your r/t.

[SebringLX]

get it to the track and you'll see what I mean. your r/t will be off. if the brake light don't go out as soon as you just start to lift it will screw with your r/t.

I don't know that I'll be able to tell. :( I haven't raced often enough to get a good consistent r/t down. I usually only make it to the track 2-4 times a year. My best r/t ever was a .005 last year, but I've been anywhere from a .2 to a .5 before that.