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Old 06-14-2012, 12:38 PM   #1
BlueOval Ralph
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Default Re: Data Recorder Shows 300 rpm 'droop' After Car Launches??

A little richer at peak torque if EFI give it a little pump shot

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Originally Posted by Don Whitmore View Post
All...thanks for the input.

@KRatcliff....what is different that the Comp cars don't see to have the 'droop?'

@BlueOval Ralph...would you go leaner / richer in this area? I forgot to mention it is a fuel injected combo.

Thanks for the help!!
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Old 06-14-2012, 01:48 PM   #2
Ed Wright
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Default Re: Data Recorder Shows 300 rpm 'droop' After Car Launches??

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Originally Posted by BlueOval Ralph View Post
A little richer at peak torque if EFI give it a little pump shot
Mine used to do it when it was too rich "down there". It was simply pulling the engine down. Now only if it turns the tires. 1.3X 60's there's a hump, 1.2X 60's, no hump.
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Old 06-14-2012, 04:43 PM   #3
Vic Santos
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Default Re: Data Recorder Shows 300 rpm 'droop' After Car Launches??

Don, I use to have the "hump" in my SS car and got rid of it by working on the Q-Jet. The basic problem is the Q-jet bowl. Its too small and makes the secondaries rich during high G's (launch). It takes a lot of detailed testing to solve this problem. Work on secondary rod shapes and hangers. If you don't have a Q-Jet disregard what I've said except for the "too rich" part.
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Old 06-14-2012, 05:08 PM   #4
Michael Compton
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Default Re: Data Recorder Shows 300 rpm 'droop' After Car Launches??

Having ran a car in traditional Super Stock and now SS/BS (comp style), I have encountered the same exact thing that you are describing. According to everyone I talked to, it is almost like the motor takes a big drink of fuel right off the starting line. If you have AFR meters on the car, you can really see the "rich" issue. Some of it I believe was fuel pressure driven and some of it the jetting we were running.

A couple things that did help my current combo in SS/BS were moving the AFR sensors to the headers and not the collectors to get a better reading and increasing the timing on the starting line and pulling it back down track. Seems that the increased timing on the starting line helps burn the fuel a little better when on the tranny brake and within the first 60 feet.

And I think Kyle might be onto something. My issue has almost gone away since changing to the Quickfuel carb and my new A-1 convertor. Maybe it is a combination of the changes I made over the winter but I still think carb and converter helped tremendously.
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