#1  
Old 01-12-2023, 07:46 AM
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461-69bird 461-69bird is offline
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Question ACC PUMP CHANGE?

Currently have 30cc front and rear. would I gain anything 60ft wise if I switched to 50cc on the front? 850xp carb and footbraking to 2000rpm launch.

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  #2  
Old 01-12-2023, 09:10 AM
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25stevem 25stevem is offline
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Try it, you have nothing to loose but 60 foot time and having black smoke coming out from under the car when the green comes on.

If your not sensing a hesitation now then I kinda think you don’t need such.

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Old 01-12-2023, 01:02 PM
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Tom Vaught Tom Vaught is offline
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Try the swap, front pump to rear, etc (and the related hardware) and let the car tell you if it is a benefit. DATA vs opinions.

Tom V.

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Old 01-12-2023, 05:27 PM
Dragncar Dragncar is offline
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I can not imagine it will hurt. Strong running 455s do not have bog in them from my experience. Ran a 850 for years with duel 50ccs and it just sucked it up wanting more.
IMO 30cc front and rear with a engine like that is not giving the engine what it wants.
You might not gain anything but the engine will not bog, you can take that to the bank.

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Old 01-13-2023, 06:43 AM
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Thanks. It doesn't bog or hesitate just wondered if it would help any. I have bought the kit so will try it.

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69 Firebird
472, KRE 85cc, Victor, 850xp, TH400, TSP 9.5" 4800, 3.90 10 bolt, Viking DA rears, QA1 single fronts, 3558lbs. best to date 10.90 @123
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Old 01-13-2023, 10:42 AM
mgarblik mgarblik is offline
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I would do a back to back test at the track, same day, same conditions. The beauty of a Holley carburetor is 8 screws and you have your answer!.

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Old 01-13-2023, 01:41 PM
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You have to remove a couple of "C-clips" too Mike and also the swap/readjust the Pump Cams. You do not want the pump diaphragms to ever run out of travel and rip.

Tom V.

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