header size for spray

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header size for spray

#1 Post by invegarating » Sun Feb 06, 2011 5:11 pm

hey guys,
i havent posted in awhile but i have finally gotten serious about the nitrous motor,i blew up the old 406 so the new combination is a nitrous only combination
sbc 406
motor on alcohol
nitrous on gas
sportsman fogger
bigshot plate
afr 227 eliminators-standard exhaust port
comp custom grind.697/.696 270/278 114 lsa 4-7 swap

now the question i have is will my 1 3/4" to 1 7/8" 3 1/2" collector headers be enough for this or should i be buying j-bends and header flanges for a bigger set

any help is appreciated

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Joined: Fri Jan 07, 2011 10:44 am

Re: header size for spray

#2 Post by SG4029 » Mon Apr 04, 2011 10:23 pm

Doesn't look like you're getting any rapid help here. I don't have a lot of knowledge with nitrous but I'm trying to run it and having a hard time. My suggestion to you is run the headers you have, establish a performance level, then if you think it's not up to par, increase the header size and see what it does. Personally, I think the bigger headers will increase the performance. 1 3/4" and 1 7/8" will barely support a 406 NA. 2 1/4 runners and 4 1/2" collectors are more your speed, if they'll fit. You may be stuck with 2" max.

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Craig W.
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Location: Columbia, KY

Re: header size for spray

#3 Post by Craig W. » Mon Apr 04, 2011 10:30 pm

2-1/4 and 4.5" collectors will kill that motor down low. For that setup, I'd look at no more than 2" primaries and 3.5" collectors.

I have 2-1/8" with 4" collectors and could really tell I lost torque on my 434 last year when moving up from 1-7/8" and 3.5" collectors. I gained some back with 3.5" mufflers on it.
Craig Watson
2QuickNovas Racing

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