I was wondering if i could get some help on what size carb. i should buy. Heres some info on what i have so far. Engine 455 bored 38 over block has been decked to give it 10.1 compression cam is T/A 413 Heads are T/A Stage 1 with roller rockers I have a B4B as of now but have been thinking about the SP1 Car also has T/A headers and 3 in. exhaust I'll be useing a turbo 400 trans with a 3500 stall and i will be useing a Jim Mitschke built 3.73 8.5 rear The reason i ask is because is because when i ask local speed shops and some vendors they claim that the 830-850 range is plenty big enough. This car will be driven more on the street than track but i still want it to perform well when i do race it. So any opinions are welcome.
A lot of us are using the HP1000 with good results. Mine is very streetable. I start the car cold and it idles fine in less than 30 seconds. I never worry about stalling at lights anymore. :TU: Plus I picked up a half second from the Q-jet.
Get the annular discharge version of the 1000 HP and go with the SP-1. Dual plane manifolds like vacuum secondary carbs. Do not work as well with mechanical secondary. Look up AED carbs here and give them a call. They know a lot more about Buicks than your local speed shop. Here is a great thread on big carbs and our Buicks. http://www.v8buick.com/showthread.php?t=119193&highlight=AED
Everytime i mention a carb of that size they say no way you can run a carb. that size on a street/strip Buick. But then these are Chevy guys. One of the guys telling me this works at a local speedshop and also teaches at Penn tech. I'll be the first to say i no nothing about holley carbs. So i need something that hopefully will work good right out of the box.
The don't know crap about Buicks. I have the same combination you do. Might have a different ratio on the rockers and I run less stall, but they are almost identical. I ran an HP 950 QuickFuel for a while this year until the my buddy needed it back. Ran that with the SP-1 and ran 12.65 and still needed more tuning. Was a very drivable carb on the street. I am now playing around with a 830 HP modified by Baker and it flows in the 900's. Currently on a B4B. Makes too much torque now and cannot hook up the drag radials. Made 335 HP at the rear wheels from 3000 rpm to 6000 rpm. Need to change back to the SP-1 and get the AF's a little leaner but still drives great and would not go smaller on the carb. At the dyno last week the owner of the shop said the carb was working really good but needed to go to the single plane manifold. This guy works with Scott Brown of Straightline Cams and Finishline Racing in Lansing. Here is AED http://www.aedperformance.com/HO.htm To bad you are not here in MI. VT Competition in Lansing will put your car on the dyno and match you up right there.
My fat pig loves the SP1 and the 1000 cfm Barry Grant Silver Claw. Even better kick in the pants than my modded Holley 850. Devon
CID displacement X Max RPM / 3456 X efficiency X manifold factor = recommended CFM So, for example: 455 cid X 6000 RPM = 2730000 2730000 / 3456 = 790 where 3456 is a constant that takes into account the number of cubic inches in a cubic foot; and the fact that the engine is a 4-stroke not a 2-stroke. 790 X .85 = 671 where .85 is a guess at your volumetric (mass) efficiency 671 X 1.4 = 940 CFM where 1.4 is a guess at your intake manifold's efficiency. Single plane intakes would range from 1.1 to 1.3; dual-plane manifolds range from 1.3 to 1.5. More efficient manifolds use a LOWER number as a correction factor.
Looks like something from the TV show numbers. lol Guess i should have done better in math when i was in school.
