info and guidance hunt - Carbs.

[DeanO.72]

hiya chaps and chapettes  , bacisally want to find out a few things about putting carbs onto an abf lump for a performance upgrade  . my plan is to do the conversion in the summer and then maybe put the carbs on over the winter period next year, and be all ready for when the temperature increases  . now i always here people talking about ''weber 45's'' so i'm guessing these are pretty sh1te hot? Are they the ''prefered'' choice or is there a better or cheaper but equivalent setup on the market?

 Now off the top of my head im thinking that i'll be needing the carbs themselves, a new inlet manifold, an uprated fuel pump and larger diameter lines, a linkage to allow for the new intake system and maybe some head work? Does this sound about right and have you guys had any experience with components to use and not to?  . Will i have to use a stand alone ECU or can the original one be mapped to save cost?

i hope i've asked some decent enough questions for you to think about  ... but im sure i'll think of some more after pressing the post button haha!

[mk2bal]

You can't 'map' carbs. The carbs control air/fuel mix, but you need a form of ignition. I know of people using kr ignition with carbs, but unsure on abf equipment. Webers were sh!te hot 20 years ago, but nowadays, there's far better ways of doing things. Not knocking carbs, a mate had a 2.0 8v mk1 on 40's and it was rapid + mental. If you plan to use carbs your list above prob isn't far off. Once mounted,linked, jetted, tuned and plumbed etc they only need a throttle cable to control them. Do a search, there's 20+ years of weber info about.

[DeanO.72]

cheers for that muka  , i know a lot of poeple are going down the forced induction route but i just fancy having that sounds of pure N/A grunt under the bonnet haha  !! I see that VWheritage are doing a kit for a weber 45 set including the manifolds and linkages but its around the £1300 mark  . Plus i have no idea how much the set up would cost and perhaps to have it set up on the rolling road?.. or even anywhere that does that?

thanks for your reply dude  .

[Simeon]

Most mappable way of doing it is to use a megajolt ecu (about 100quid). Bogg Bros can set up a carb/megajolt combo on their rolling road.

[Sam]

Most people now run sets of bike carbs i.e yam r1 carbs with bigger nozzles. They seem to be easier to tune and parts are readily available e.g. finding a new 'x' for a carb made in 2009 is going to be simpler than finding 'x' for the webber made in 1979

[DeanO.72]

ah yeah I get you! I'm guessing that they would be far cheaper and readily available on say.. ebay and forums too  . what are your thoughts on running performance cams and having some head work done? i guess it would all be worth it for the overall result but it just depends on how big your savings account is haha!

[Diamond Hell]

what are your thoughts on running performance cams and having some head work done?

That only a fool would do the above running carbs on an ABF.

[DeanO.72]

okay thanks  , how come?

[Diamond Hell]

Carbs have none of the sensors and closed feedback loops of injection, thus will not get the same output, reliability or driveability of an injection set up.

They are for the very old or dim-witted, especially where a motor is equipped with all of these sensors out of the box.

Stick a 4-branch on it, running on OEM management and see where you're at, at that point.

[Sam]

what are your thoughts on running performance cams and having some head work done?

That only a fool would do the above running carbs on an ABF.

I would second this even with my limited knowledge. The ABF lump can be a little thirsty when running with carbs according to a few threads I have read around the interwebs and putting in lairy cams will not help this at all plus will probally not give you any real advantage. I would look at mega jizz or some other custom fuel injection system if your chasing donkeys. Carbs are far too primative in comparison.
Just because they work on a cold december morning with mega dense air doesnt mean they will work a week later when its mild and raining, they cannot compensate for this.