Converting to Annular Boostres on Holley 80513 Carb

[rgalajda]

Cheaper to buy the main body if don't have the tooling for installing the boosters.

https://allcarbs.com/product/holley-hp- ... -boosters/

[CDN]

I know of someone who can install do you have opinion on sizing .156-166 is what BLP sells but I have no idea on how to calc size

[Right hand drive]

In the past I have bought this kit from Allstate. Choose the same downleg as per factory in your carb now so you can change back if necessary.

https://allcarbs.com/product/down-leg-b ... ation-kit/

The thread Allstate uses is 5/16-32 UNEF. If you then source a 5/16-32 UNEF die you are then able to broaden the available boosters to try in the main body and are not locked into what Allstate supply. I purchase the BLP banjos and .600” id inserts and have also tried their machined downleg booster and Braswell style. The die can be run down any of these boosters mounting section to make the thread without needing to size first. Doing this greatly improves the tuning flexibility of your carburetor.

These are BLP 16 hole annulars that have been threaded with the mentioned die


On the left is a BLP machined downleg. On the right Braswell style I’m yet to trial.

[rgalajda]

Right hand drive , what size leg are your BLP annular boosters .156 or .166 , and what size are the 16 holes ?

I also threaded my own boosters.

[CDN]

Appreciate all this input everyone I have learned alot ......... keep it coming,

at this point Im going to try my carb with annular boosters , now just to understand sizing etc

I found an old post from 2015 on Yellow Bullet
" Annular Boosters ...Please educate me " jmarkaudio had some very good posts that were very encouraging to try annular boosters on street car with a large venturi carb
My current carb has no performance issues its just I now drive my car alot at low rpm on street with manual trans and my afr is very irregular between banks with dual plane intake esp after I went down in the IFR and up in bleeds to get nice clean idle and lean cruise

[Right hand drive]

[rgalajda]

My annular boosters are a 1.56 ID in the leg. The booster centre has 8 discharge holes aprox .072".

Your carb has a larger venturi size . That being the case I don't know what to recommend, as I don't work on large venturi carbs booster setups.
Right hand drive has given good info on what he has used. That sounds like it is working well for him. I would call BLP and ask them what they recommend, given your setup and of course street driving.
Booster leg ID and discharge hole is an important part of the equation, especially if you can't easily remove the booster for reconfiguration.
Mike Laws or Jmarkaudio could help here if they are still reading this forum.

[jmarkaudio]

Use a BLP .600 annular, they used to have one with 16 holes that worked well.