t18drifts Posted December 19, 2010 Report Share Posted December 19, 2010 hay guys my gf dad races a xf falcon (production sedans speedway stuff) he has a few spare 2bbl webers from the falcon he races we were talking and we thinking of puting one maybe 2 on it is it easily possible would there be more power output then the original 3tc carbie Quote Link to comment Share on other sites More sharing options...
ROLLA FOR L1FE Posted December 19, 2010 Report Share Posted December 19, 2010 hay guys my gf dad races a xf falcon (production sedans speedway stuff) he has a few spare 2bbl webers from the falcon he races we were talking and we thinking of puting one maybe 2 on it is it easily possible would there be more power output then the original 3tc carbie whats his name? Quote Link to comment Share on other sites More sharing options...
t18drifts Posted December 19, 2010 Author Report Share Posted December 19, 2010 john kenney ?????? :blinks: ....any help with the carbie thing any one lol Quote Link to comment Share on other sites More sharing options...
t18drifts Posted December 20, 2010 Author Report Share Posted December 20, 2010 come on any one got any tips for me Quote Link to comment Share on other sites More sharing options...
19914afc Posted December 20, 2010 Report Share Posted December 20, 2010 just get an adapter off ebay one for a 4ac will fit so just search for that or a 3t one. Quote Link to comment Share on other sites More sharing options...
t18drifts Posted December 20, 2010 Author Report Share Posted December 20, 2010 awwk so if i did like twin webers i would get a bit more power yeh Quote Link to comment Share on other sites More sharing options...
19914afc Posted December 20, 2010 Report Share Posted December 20, 2010 ye twin sidedrafts will make a big difference otherwise just use a single weber on the std intake manifold will make a bit of difference. Quote Link to comment Share on other sites More sharing options...
t18drifts Posted December 20, 2010 Author Report Share Posted December 20, 2010 can u do twin down drafts or quad thats what we kinda wana try we have a welder and a spare 3tc intake so this should happen Quote Link to comment Share on other sites More sharing options...
nme308 Posted December 22, 2010 Report Share Posted December 22, 2010 Hi there, A 2tb twin carb manifold would be what you need here - read that as damn rare here is Australia though! This manifold mounted 2 of the standard 2barrel carbs I believe so with adapters should be suitable for dual downdraft webers. Please forgive the extremely crappy pic as it was the only one I could dig up quickly... Of course it will bolt directly up to a 3t engine as only the twincams had different manifold bolt spacing. Cheers, Jason Quote Link to comment Share on other sites More sharing options...
t18drifts Posted December 23, 2010 Author Report Share Posted December 23, 2010 aww yeah well I'm thinking of cutting up to stock 3t intake manifolds and doing it all from scratch :laff: Quote Link to comment Share on other sites More sharing options...
TheNOBBLER[RL] Posted December 27, 2010 Report Share Posted December 27, 2010 Can anyone say overcarb'd??? One will be waaaaay more than any stock 4 pot will be able to use. On off throttle transition will be terrible, almost like turbo lag. Just won't have the air speed with twins to run properly! It will run, but I don't like your chances of ever getting it nice enough to daily drive etc. I would be going for a pair of smaller webers or side suckers if I were dead set on twins. Otherwise you might get one falcon weber to be happy. Mind you, with boost a single xf weber would be great. JP Quote Link to comment Share on other sites More sharing options...
nme308 Posted December 27, 2010 Report Share Posted December 27, 2010 Can anyone say overcarb'd??? One will be waaaaay more than any stock 4 pot will be able to use. On off throttle transition will be terrible, almost like turbo lag. Just won't have the air speed with twins to run properly! It will run, but I don't like your chances of ever getting it nice enough to daily drive etc. I would be going for a pair of smaller webers or side suckers if I were dead set on twins. Otherwise you might get one falcon weber to be happy. Mind you, with boost a single xf weber would be great. JP And I guess you'd also say a 650 double pumper 4 barrel holley on a very mild 3tc was overcarbed too? :hmm: Cheers, Jason Quote Link to comment Share on other sites More sharing options...
Bamboo Posted December 27, 2010 Report Share Posted December 27, 2010 (edited) And I guess you'd also say a 650 double pumper 4 barrel holley on a very mild 3tc was overcarbed too? :hmm: Cheers, Jason I'd say yes. http://en.wikipedia.org/wiki/Venturi_effect The link may be over complicated, but think of it this way. If the engine doesn't have a lot of "suck" (4 cyl), it's unable to get the air past the venturi to make it effective. Then your just pumping fuel with the pump without effect. (rich). Like your garden hose with the spray end. Less water come out but the pressure is enough to make the dog run away. Without the spray end, it's just a leak from the end of the hose. Slightly under carbed is the fuel forcing in as hard as it can. Over carbed is an 80 year old with a prostate problem, getting up in the middle of the night. Just dribbling! Bamboo Edited December 27, 2010 by Bamboo Quote Link to comment Share on other sites More sharing options...
nme308 Posted December 27, 2010 Report Share Posted December 27, 2010 I'd say yes. http://en.wikipedia.org/wiki/Venturi_effect The link may be over complicated, but think of it this way. If the engine doesn't have a lot of "suck" (4 cyl), it's unable to get the air past the venturi to make it effective. Then your just pumping fuel with the pump without effect. (rich). Like your garden hose with the spray end. Less water come out but the pressure is enough to make the dog run away. Without the spray end, it's just a leak from the end of the hose. Slightly under carbed is the fuel forcing in as hard as it can. Over carbed is an 80 year old with a prostate problem, getting up in the middle of the night. Just dribbling! Bamboo So how much 'suck' does any carb have once the throttle blade/s is/are open? Did Wikipedea tell you that one? :bash: For the rest - Once a throttle blade is opened there is no vacuum rather 14.7 pounds per square inch atmospheric pressure pushing air into the vacant space created when the piston is drawn down the bore in the intake stroke. A booster is NOT a fuel injector and no fuel comes out unless there is airspeed past it. That is why a holley carb has an idle and an intermediate circuit to fuel the engine at idle and small throttle openings. A 650DP holley has 2 primary barrels which are smaller than the classic 350 holley's 2 barrels and so will be just fine on the primary's. Now if the carb is oversized for the application at what then it will run lean on standard jetting due to lack of airspeed. The cure is of course to up the jet sizes till proper AFR's are achieved. The converse of an undersized carb is of course bulk airspeed causing the engine to run rich with stock jetting and needs to be jetted down till proper AFR's are achieved. You have to go absolutely stupidly off one end of the scale or the other size wise to make a carb unworkable. Its amazing what a little tuning smarts can achieve! Cheers, Jason Quote Link to comment Share on other sites More sharing options...
Bamboo Posted December 27, 2010 Report Share Posted December 27, 2010 Jason, thank you for your reply, I'm not starting a war. Atmospheric pressure does not push when it is equalised. Air speed is always required. The faster the better. Remember fuel, spark and air. Google how a plane flies. You can't get away from that principle. No suck/draw = no power! Believe me wikipedia tells me nothing. Laying under cars for countless years has taught me! A 450 on a V8 can make more power when tuned properly. On a 4, you can't ejaculate hard enough to make that type of pressure. Bamboo Quote Link to comment Share on other sites More sharing options...
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