How many seconds on two step?

Old 05-07-2008, 12:20 AM
  #1  
triniemi
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Default How many seconds on two step?

How many seconds can I stay on twostep? I'm racing full tree bracket racing with electrionics (delay box) banned. Throttle responce isn't so great with 1050 dominator, big heads and 38 degrees of advance locked at all rpms (cranktrigger, msd billet distributor, MSD 7AL2 ignition box).

8" transbrake converter, glide, stallspeed about 5000+ and I'm planning 2600-3200rpm on two step which is of course hooked to transbrake.

I have a trans temp gauge, how much it should read at maximum at the end of the run?

How about the engine, can there be damage done?

Could I stay on 2step on full throttle like 3 seconds or 5 seconds?
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Old 05-07-2008, 03:20 PM
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billhendren
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You could stay on the rev limiter for far more than 5 seconds without hurting the engine. you would need to ask your transmission supplier how high he wants the temp.Bill
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Old 05-07-2008, 11:35 PM
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triniemi
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Thanks for your opinion. Anybody else got one?

I read somewhere that trans temp will go up 10-15 Fahrenheit on every second on the transbrake. I also believe that stallspeed and rpm on limiter has a big influence to that. If I would use 4800rpm chip with my 5000+ converter, the heat buildup would be dramatically higher compared to about 3000rpm that I use now.

Also I found this: "We have seen piston and pin failure in a few Hemis.In some of the cases it was caused by staying on the two step to long.We seen guys jump on the two step as soon as they stage and hang there way to long.The Hemi with it's mass piston will pull the pin boss out of shape till it lets loose.Usually it seperates at the big end or on shut down.This hammering effect will make the pins tight in the piston.We tell our guys to wait for the first yellow bulb before floorboarding it.We can always tell if a guys been living to long on the two step with a Hemi,you have to beat the pins out."

I have H-beam steel connecting rods and Arias nitrous style pistons (I do not use nitrous) so they weight also some. 509" BB Chevy, 4.5" bore, 4" stroke. But isn't a Hemi piston hundrets of grams heavier? Also, more rpm on twostep equals more piston speed and more stress to the pins.
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Old 05-08-2008, 07:18 AM
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billhendren
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That doesn't make sense,there is essentially no pressure above the piston on every single ex stroke the rod must stop the piston.when the rev limiter kills the spark if anything you have slightly less load on the pin and rod because of the compressed mixture.we use the rev limiter on circle track cars with low power that need a steep gear to come off the corner,those cars are on the chip for several seconds twice a lap with absolutely no damage. we have never seen a pin problem on our blown Hemi engines from the limiter,pin problems are usually caused from detonation or using a pin with to thin of a wall for the intended application.Bill
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Old 05-09-2008, 08:13 PM
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us7race
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I was told by my converter guy to never be on the converter for more than 4-5 seonds he said at like 8 secinds it will boil the fluid and break things. Not good. My normal is to stage and them hit the button idling I don't hit the gas until my light starts coming down. That was I am only revved up for 2-3 seconds...
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Old 05-09-2008, 08:38 PM
  #6  
I972Nova
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I have a "starting line enhancer" which is basically a throttle stop. It works through the delay box.

What it does is you stage and hit the transbrake button and mat the gas, but the car stays at a predtermined rpm. mine is 1200.

Then the delay box tells it half a second before the brake is going to release to open the throttle. It opens the throttle the same everytime and it doesnt matter if I am spotting someone 5 seconds it is very consistant that way and no more bogging down when you go to stick the gas.

I hope I explained it right..lol...
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Old 05-09-2008, 09:23 PM
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zipper06
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Originally Posted by DragsterJosh
I have a "starting line enhancer" which is basically a throttle stop. It works through the delay box.

What it does is you stage and hit the transbrake button and mat the gas, but the car stays at a predtermined rpm. mine is 1200.

Then the delay box tells it half a second before the brake is going to release to open the throttle. It opens the throttle the same everytime and it doesnt matter if I am spotting someone 5 seconds it is very consistant that way and no more bogging down when you go to stick the gas.

I hope I explained it right..lol...
Hey Josh,

Who make the starting line enhancer? and does it require a 3 step or can it be used with a 2 step?

Zip.
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Old 05-10-2008, 04:19 AM
  #8  
sc3314
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Default starting line control

ZIP Biondo makes a couple diffrent types of these.
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