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How many MM are the butterflys on a 38/38


nbristow01
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so 38mm each so 76m total? If that is the case and say dual 40's would then be 160mm total? So then why would my max size of a Tbody be 67mm? I believe what you said I am trying to understand what i really need for tbody size. I am trying to get max performance when I set up my EFI and want my power band to be say 2500rpm to 4500 rpm

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Guest Anonymous

Its a lot more complicated than that. 2 38 mm holes are nowhere near as large as 1 76 mm hole. as for the dcoe situation, each cylinder only pulls through one 40 mm barrel. a common throttle body or carb is available to each cylinder (only one sucks at a time)

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Fuel injection is WAY less sensitive to throttle body size than a carb setup. a carb needs good vacuum (small size) to pull fuel into the airstream properly over a wide rpm range . fuel injection doesnt care much as fuel is being injected no matter what vacuum. Ideally, you want the smallest TB that does not restrict high rpm horsepower.

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I can't thank you enough. That totally cleared it up for me. I just like to actually understand what i am doing vs just doing it because thats how others do it. The 325tbody adapter from Tom is what I will order and track down a good 325Tbody. next is injector sizing. Tom told me 21's are good for what i need.

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