noob question - wats the d15b4 (dual carb) venturi size?

looking to upgrade carbs. wat venturi size is needed for a d15b4?

you shouldnt really need to mess with venturi of any factory carbs, wont really get you an improvement, might actually create some flatspots.

i saw u replied on the other thread about running rich or lean.
i just found out about the potential of carbs..about time!

so i was thinking of upgrading to performance motorbike carbs -one of the keihin ones http://www.keihin-us.com/am/products/fcr.php- but would they enhance any performance? let alone would motorbiike carbs even fit on my engine?? i was going to do the two cone filters as mentioned in the other thread but thought maybe an aftermarket racing carb would do better?..not sure..

right now my engine feels pretty strong -compared to my previous single carb d13b2- but i always have this feeling that it's got potential to do more..like it can handle more power or something..(so my research began on carburetors)

future plans include zc camshafts and balancing but after some more research..

so would it b better off going for the cone filters?

motorbike carbs fit.
go to http://onecamonly.com/showthread.php?t=1528
once you scroll past the pics of SOHCinWA's pink ed6 sedan, you can see that he is running a pair of dcoe45 weber carburetors, and if you evaluate the design of the weber dcoe, youll find it its a quad carburetor setup he's running. cryz2 on onecamonly has a quad motorbike carby setup as well.

im just getting the last annoying linkage before i get my dcoe40 skracing carbs in my d15b4.

head to www.onecamonly.com for massive carb build ideas, www.fjdistributors.com for cheap high quality parts, or head to www.bisimoto.com and contact him for carb advice. you might think he might not know much, but he did his college paper on mathematical proof that the atomisation of carburetors is far greater than efi (long story short, efi would need injectors positioned 4ft away from the intake valves to match a weber's atomisation). he also currently holds the world record for single cam NA quarter mile i believe, 10.7 with a d series, 9.5 with an f22a (from your mothers accord), both using carbs. and if you wanna know how he does things, look up the castrol syntec top shop challenge, he is currently the competitor for superstreet magazine, so you can see vids and blogs from him.

but first step in getting carbs, dont look online, instead, head to a wrecker or a upullit, and head straight to the alfa romeo/european section. you might be able to gank a dcoe40 weber from them for dirt cheap.

next step, if you cant get something good from a wrecker, check american ebay, a while ago they had several quad carburetor setups from yamaha r1000 with all linkages, etc, so all you'd need is a custom manifold.

keihin carbs are good, but messy due to them mainly being an electric carb and using a lot of vacuum hosing.

had a look around..decided to go with r1 quad carbs. are there manifolds ready made for d15b4 ? if not where should i be looking at?

^^^ I am also interested in this!

for manifolds, you'll generally have to go custom. or you can contact the other members of that forum who are using motorbike carbs and see if they are willing to sell you their prototypes. alternatively, you can google rowland manifolds, buy their dcoe weber manifold (was $180 including shipping, dirt cheap for a high quality manifold), and then just have a custom adapter plate made, which would be much cheaper.

on the other hand, im pretty sure bisimoto has a few motorbike carby manifolds.