Using delay box timer, relay and retard box to slow down

Old 09-26-2010, 05:41 PM
  #1  
markdunlap
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Default Using delay box timer, relay and retard box to slow down

Has anyone used a retard box to slow a car down instead of a throttle stop??

I am thinking of using a timer on my Mega 450 delay box to activate a relay to turn on a MSD retard box with enough retard and time to slow a 3000# BBC door car from 6.30 to above 6.40 ET in 1/8 mile (No license for faster than 6.40 ET) . I want to do this while in high gear and then turn it back off in time to have full power before the lights.

The delay box puts out 12 VDC and the retard box wants to see ground broken to turn on the relay, so that's why the relay would be needed.

I am thinking about taking out 10 degrees for 1.5 seconds initially, but wonder if the 1050 carb will flood the engine or any other negative side effects.
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Old 10-07-2010, 04:45 PM
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jaxsmith
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It will work you will just have to play with it to get it slowed down where you need it. As you know the sooner you kill the timing the more it will slow. My car when running 6.50 would slow to 7.00 by killing timing, shift point and a plate under carb like NASCAR uses. I used the shift point to speed up or slow down.
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Old 10-07-2010, 05:32 PM
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hammertime
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just shift it earlier easy to kill that much.
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Old 10-07-2010, 07:51 PM
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markdunlap
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Default using delay timer

Thanks for the comments guys. I have dropped shift point from 7400 to 6800. When I tried 6400 it hit so really hard at the shift I just didn't like it.
I reduced the timing from 38 to 34. I reduced the start RPM from 4600 to 4000. Finally I just cranked the bolt stop under the pedal up until it killed .10 second in 60 ft, but the mph stayed the same. Then the throttle linkage started slipping by the stop bolt. Now I have it back to full throttle.
This week I will try out the timing retard system I have installed.
Initial setting is retard 6 degrees at 3.5 seconds until 5.5 seconds for a 1/8 mile track.
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Old 10-13-2010, 02:57 PM
  #5  
markdunlap
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Default using delay box

Just thought I would let you know that the delay box/timed retard works OK. Need to shift by time though to be sure it retards after shift.

It killed about .10 second and thats what I needed.
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