Two-steps Bad/Good

Discussion in 'PSI Superchargers Tech Questions' started by Comax Racing, Nov 27, 2009.

  1. JP

    JP Member

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    We where .02 quicker in the 60 foot with the two step, yes it did take a little bit less cluth But we weren't bypassing fuel to get our cylinders to light right up. That is our next test.

    I was a tafc driver for 10 years no two step and No problems on swapping feet , However our only reason to put a two step is that nitrous guys like to take their sweet time staging when they hear our 6200rpm , with the two step I can smile and let her rip.......
     
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  2. bruce mullins

    bruce mullins Top Dragster

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    here is my opinion........ throw the electronic crap in the trash and put drivers behind the wheel!. .i have seen guys that can't swap feet at all in pro mods, then go to the 2-step and now they can leave. what's wrong..... these aren't super gas cars... grow a set boys and learn to drive.... convertor cars can go to that dual action pedal like nhra makes you run. oh, and you guys that have to run automatic shifters.... give me a break!!!!!. . alright go ahead.... flame away!
     
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  3. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    which chip or 'curve'

    Lonnie,

    I'm not saying it can't be done, just saying in my opinion, it just compounds the problems you face with a converter. I took 10-15 degrees out at the hit leaving at part throttle, d blower @ 92 od with the FC I drove.

    All I'm saying is based on my experience, all you're doing with a converter car is adding timing to take out at the hit. Now with the latest Davis traction control gadgets, it may be a simpler process to just go wide open and let the box do it's thing.

    Bruce, I'm with you, let the drivers do their thing. But when in Rome, do as the Romans do.....
     
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  4. Lonnie Houde

    Lonnie Houde Member

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    I understand what you are saying, and i def respect your opinion. The door car drivers had to do it, because some of the nitrous cars were hanging the blower cars out when swapping feet. I think the tuners found the cars to be more consistent when using the two step. Fred Hahn was, and still is regarded to be one of, if not the best drivers in an alcohol door car. But, Jim Oddy got sick of getting hung out to dry, and had Fred use the two step.
    If the rules allow it, why not use everything to your advantage?
     
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  5. roar

    roar New Member

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    Can someone please give some more info on the two stage pedal as to how they work ,can you adjust them for say a staging RPM of 4500? Do you still use a morse type cable with them ? and Who makes the two stage pedals that you have mentioned and do you have a contact for them. With Thanks.

    Lyle.
     
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  6. danrace

    danrace New Member

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    Love it bruce my thoughts exactly on two steps and auto shifts WOW give me a break that's not even drag racing may as well go race remote control cars. Cars will always go just as fast (i think faster) without two steps.
    read your logger two steps are not nessary
     
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    Last edited: Nov 30, 2009
  7. Mike Canter

    Mike Canter Top Dragster
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    There is no way you can have the boost up at staging if you are swapping feet. On the 2 step that boost is way up because the blades a wide open so you 60fts and 330 fts are better. Also you can not have the consistancy on the launch with swapping feet like you can with a 2 step. Yes you can luck out once in a while swapping feet. The 2 Step is here to stay until the rules change. Remember when racers tuned cars without data loggers and laptop computers or we had the drop of the flag to launch. Times change.
     
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  8. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    two stage pedal

    We had one on the Lencodrive FC I drove that was built/designed by Harry Clack, my car owner. Harker has one in his clutch dragster and it works great with that set up as well as a converter.

    Clack's design used two push cables. The pedal consisted of a 'piston' that you pushed in with your heel and a regular pedal. One cable was connected to the piston and one was connected to the 'toe' side of the pedal.

    We threaded the end of the linkage with a die on the heel side, then put a 'slider' mount on the linkage with nuts on each side of the slider. One nut set how far it moved the linkage for stage rpm, while the other prevented the cable from ever sliding out of the mount. The other cable, connected to the toe side, worked like a normal push cable. Due to the geometry, the heel and toe had to be fully engaged for wide open.

    I would push the heel down to bring it up to stage, then floor it like a normal pedal. Worked great, and was pretty consistent on stage rpm.
     
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  9. Moparious Crewcheif

    Moparious Crewcheif New Member

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    I agree with the throw the electronics in the trash. We run a nostalgia car and plan on staying that way. I can see the need for the electrics in the raceing going today as Will said when in Rome.

    We ahve had such bad luck with the stuff and costly BS we stay clear away from it. Way back we bought a super electromagic ignition set up ran it several rounds no trouble ----- last round [ for the money ] the car just quit out at about 100 foot or so. My first thought was driver didnt turn on the fuel. Nope the magic stoped working, looked in box and found loose parts no vibration protection at all. The manufacturer must have figured it was going on grandmas car.

    After we went injection Bought a magic gizmo that was supposed to playback fuel pressure after a pass. 1 pass done no magic.

    After a wild up in smoke pass with the blower we saw a 9200 on our tach so we went with a electromagic rev limiter. Tested in shop at 5000 checked in the pits again. Set it at 9000 double checked the setting made a pass. Car started missing a banging around at 6900 made a terible 1/8 and Larry shut it off. Unhooked the magic and made the best pass of the year.

    I may be off base here but Im thinking old style racing and or old cars don,t mix with electromagic. Or maybe its Old Fart crew. My 3 cents
     
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  10. jody stroud

    jody stroud ZOMBIE Top Dragster

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    On my blown BBC dragster I run a two step and an air throttle. Like others have said, when I get on the T-brake button and mat the throttle the blades only open appox. 1/4in. RPM's are appox. 4200 rpms then with a 4000 rpm chip in the two step it holds almost dead on 4000 rpms no matter how long I stay on the chip, when the t-brake releases it clacks the blades wide open and off we go. Mike my heap make appox. 26 lbs of boost on the chip (PSI 14/71 Retro HH) and goes to appox 38psi at 8000rpms (31.5% OD). Seems to work fine, other than when backing up since the t-brake must be enguaged (pro brake) I have no real throttle pedal, would have to mat it to make it respond just like on the line. However since I have the idle set at 1800 rpms it always backs up fine. The best thing about my dual action dedenbar (air in air out) is that worst case, if I lose air it will just not rev at all since air is what keeps everything tight, seems no way for it to affect the throttle other than make it inoperable.....unless I'm dumb enough to have my foot to the floor while backing up, in which case when I take my finger off the button and the box counts down it's gong to go wide open .... and then:eek: I'm coming back in a damn hurry. But have never had this happen. The other part of not having the blades jacked open is the fact that it don't milk the oil so bad and I don't have to bleed any fuel off.
     
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    Last edited: Nov 30, 2009
  11. bwpracer

    bwpracer Member

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    2 stepping

    I have a Brad 5 with a Lencodrive and Neal Chance that stalls at 7700. Std. rotor PSI roots 14-71 in a 32' Bantam altered. I two step to 4000 and she has 30 lbs of boost at the hit. Blades wide open. Sixty foots as low as .974 with 8 degrees of timing taken out for 3 tenths, then ramped back in with a 6 shooter and Leahy's cool box. I have no bearing issues at all. I have left this way for two years every run. Look on www.youtube.com and type in bernie plourd. You will see some launches with the pipes "out".
     
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  12. Blownalky

    Blownalky Top Sportsman

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    Jody,

    I have just about the same deal as you except I use a toggle switch for the burnout and backup. It engages a relay that shuts off the air release solenoid when I use the transbrake button to back up. Without power to the air release solenoid, the throttle acts normally when using the transbrake. When I stop backing up and start to move forward, I just flip the toggle switch back which sets the system up for a launch.

    Maybe I'm missing something here or it's my setup but I can't see how using this air throttle can be dangerous. I use a bell-crank off of my pedal to make my throttle a pull and I use a cable. I use the transbrake switch to release the air in the air throttle release solenoid so at that point, if I push the throttle, it just pulls the air cylinder apart and does not open the throttle. I have to really push hard to bring it up to the launch RPM set into the air cylinder adjustment. When the transbrake switch is off, C02 keeps the air throttle cylinder collapsed so my foot controls the throttle. With the transbrake switch on, the air in the cylinder is release and my foot will “flop” to the floor and then I have to push to bring it up to the stage RPM. If I forget to turn the air bottle on or run out of air, the throttle can only get to the stage RPM and that can only happen by me pushing the pedal.

    The only dangerous scenario I can think of is if I don’t use the burnout toggle switch and hit the transbrake to back up and have the pedal floored and then release the transbrake. It would go back pretty fast then but I can always let off the pedal as it acts like a normal throttle at that point.
    If a throttle control was designed to push open the blades by clutch release or transbrake button release, I could see this as a dangerous way to use it. I’d never use it that way either, too many chances for a surprise.

    I only use the throttle control without the 2 step. Why, because everyone has me spooked into not using the rev-control. I’ve been told by numerous people that it is hard on rods and bearings. I’ve been told by MSD that it causes no problem. I see many ProMod’s do it but I don’t know what their rods and bearings life expectancy is compared to not being on the rev-control. I’ve also been told that you have the potential to hydraulic a cylinder while on the rev-control (not sure how you could do that on a spinning engine). I know electronics and would love to use the rev-control but just can’t afford to spit rods out. I can monitor the bearings and change them out if they experience issues but the rods are a different story. Anyone have any solid data on what the rev-control at launch does in respect to rod and bearing life? I’d surly appreciate it.

    Tom
     
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  13. Comax Racing

    Comax Racing Member

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    Two Step

    Wow, thanks for all the info. Took me a while to read and attempt to understand everything. I run a Clutch and Lenco so if I'm reading correctly, the majority say that two stepping is fine and when used with a mechanical limit as well makes for a pretty nice setup .Also the best thing is to only open the injector enough to come up on the limiter, not full throttle so, shouldn't have to bleed any fuel.

    Guess the only thing to do now is set the car up and try it.:)

    Thanks
    Again
    Corey
     
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  14. Bottlefed

    Bottlefed New to Blowers

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    Jody,

    I helped a friend wire his car to use an air throttle, his car had a delay box so it already had a separate button to back up the car and another to set the delay box, the point being that we already had two buttons on the wheel of the dragster one to launch and one to backup so it was just a matter of figguring out how to make the car back up safely off one button and lauch off the other. This is no doubt how BlwnAway has his car setup except we use two pushbuttons instead of a pushbutton to launch and a toggle to back up.

    If you want I can send you an email of how to wire up the car with two push buttons or a pushbutton and a toggle as I already have a PDF file with a drawing and text showing the system.

    Shoot me a PM with your email address and I will be happy to send it your way.

    If I could just post it I would but I don't think you can post a PDF its probably just as well the drawing is kind of embarrasing ;)

    Richard G
     
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  15. jody stroud

    jody stroud ZOMBIE Top Dragster

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    Thanks Richard, thats just what I need... another button or switch in the cockpit.....:D. I've never had a problem with the setup, my cars have always idled fast enough to back up without the need to get on the throttle pedal. Hell, i's all I can do to hold it down slow with the brakes while backing up:eek:
    My e-mail is jodystroud@shtc.net, would like to see the drawing anyway though. Thanks
     
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