Backtobasics
Well-Known Member
I got what I believe to be a BBD 2 bbl carb with the intakeand exhaust manifold. I am using the cracked exhaust manifold for a turbo setup. Can the BBD be modified for blow through purposes? Anyone with any input?
Blow through on BBD carb?
- Thread starter Backtobasics
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I believe in the turbo article on slantsix.org the guy is using a bbd. Been a while but should work with the 2280 holley too and all he did was increase the jets 14 sizes. I've heard that any carb can be modded for blow through infact I think I've read on this site that someone as a turbo single barrel. So ultimately it can be done, but there's alot more information on here and around the web when using the big holley 2 barrels since they are easier to mod and flow better. This question has actually been asked more than a few times on here and the org. You never mentioned what engine this is for but I assume its either a slant or maybe a 273 or 318?
Backtobasics
Well-Known Member
This is on a /6.
Yeah, the Holley stuff is easier, but I have the BBD, this is a budget build, and I am pretty sure the Holley won't fit stock 2bbl intake. To my understanding most are using 2 bbl on 4 bbl intake since the 350 and 500 cfm are a better fit then bigger 4 bbls.
Yeah, the Holley stuff is easier, but I have the BBD, this is a budget build, and I am pretty sure the Holley won't fit stock 2bbl intake. To my understanding most are using 2 bbl on 4 bbl intake since the 350 and 500 cfm are a better fit then bigger 4 bbls.
Actually most of us are using the super six manifold with a large 2 barrel to small 2 barrel adapter you can find about anywhere. Jegs, summit, even your local parts store or speed shop may have it sitting on the shelf. Its about 13 bucks so its real cheap. The usual holley everyone goes for is the 4412-S 2300 model. They aren't cheap when you find them. They are on ebay alot but they go for around 100 bucks and that's for a rebuildable core. Everyone is after them for various reasons since they are great for many different applications. I personally am using a 2100 holley because its what I had and buying a 100 dollar carb that still needs a rebuild would blow my budget. To use the big holleys on a 4 barrel intake would also require an adapter so its not a slap it on and go type of deal. Again its not impossible to use your bbd for blow through but not many people do it for various reasons. As I said before you could/should read the turbo article on slantsix.org its right up your alley as the author used a bbd/2280 stock supersix carb. He just upped his jets 14 sizes and then ran it like that. He does mention the mileage suffered from it and eventually switched to a 4 barrel running only the primaries and got stock mileage back doing so. Which ever way you decide to go will be met with the same issues you will have to address. You will spend most of your time tinkering and tuning. Getting the most power or mileage will be more involved since you'll be changing jet sizes, drilling pvcrs, changing power valves etc the carb and alot of time on the dyno/highway.
player1up
Well-Known Member
I tried both the BBD and a 2280....the BBD seems to handle boost better initially but has a brass float that will crush under boost pressure.
The 2280 seems to be better as far as tuning is concerned, HOWEVER, you need to understand the hanger 18 mods and how to accomplish the same things with the 2280. I butchered mine beyond repair before I was able to make sense of what was going on. I had too many variables that I was working on and didn't understand exactly how they corresponded to each other...
I have no idea how to setup the BBD for boost...
What I did learn about the 2280 is that there are 2 enrichment circuits ( mech and vac ) and it is possible to richen it up by "turning" the enrichment pins ( like shaving them down, not screw "turning" ) to have them come in sooner and making the passages underneath them larger to deliver more fuel.
A little goes a loooong way.... I hosed mine up and was so rich it would almost stall...no good.
If you don't care about ruining the 2280 or spending months tinkering, then try it, otherwise pick up a 2300.
Plenty of advice and articles about tuning it.
On my slant, I'm using the 2300 with the stock jets, pink accelerator pump cam, vent tube extensions and it runs well at 6psi...except for the heat soak because I don't have the intercooler installed yet ( and I'm starting to lean it back to regain some of the fuel mileage...
The 2280 seems to be better as far as tuning is concerned, HOWEVER, you need to understand the hanger 18 mods and how to accomplish the same things with the 2280. I butchered mine beyond repair before I was able to make sense of what was going on. I had too many variables that I was working on and didn't understand exactly how they corresponded to each other...
I have no idea how to setup the BBD for boost...
What I did learn about the 2280 is that there are 2 enrichment circuits ( mech and vac ) and it is possible to richen it up by "turning" the enrichment pins ( like shaving them down, not screw "turning" ) to have them come in sooner and making the passages underneath them larger to deliver more fuel.
A little goes a loooong way.... I hosed mine up and was so rich it would almost stall...no good.
If you don't care about ruining the 2280 or spending months tinkering, then try it, otherwise pick up a 2300.
Plenty of advice and articles about tuning it.
On my slant, I'm using the 2300 with the stock jets, pink accelerator pump cam, vent tube extensions and it runs well at 6psi...except for the heat soak because I don't have the intercooler installed yet ( and I'm starting to lean it back to regain some of the fuel mileage...
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