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Model specific boards => Golf mk3 => Topic started by: mrmafyew on 29 July 2010, 19:54

Title: Running Carbs On An ABF
Post by: mrmafyew on 29 July 2010, 19:54
I cant decide whether or not to run carbs on my abf  :undecided:

is running carbs on these engines quite common or not?

what parts would i need to do it?

I also have a polo and was going to convert it to carbs so pretty clued up on how to do that but is it as simple as what id do to the polo to tun carbs just do to the golf?
Title: Re: Running Carbs On An ABF
Post by: Wayne on 29 July 2010, 19:58
Backward step and not worth the hassle or expense.
Title: Re: Running Carbs On An ABF
Post by: mrmafyew on 29 July 2010, 20:01
in what sense do you mean backward step?

would it produce less power running carbs than the ecu?
Title: Re: Running Carbs On An ABF
Post by: Wayne on 29 July 2010, 20:20
in what sense do you mean backward step?

would it produce less power running carbs than the ecu?

Hard to say, but loads of hassle getting it run plus could be mot issues as you will struggle to run a cat with them.
Title: Re: Running Carbs On An ABF
Post by: mrmafyew on 29 July 2010, 20:24
hmm, will have to have a think about this abit longer then i think, cheers for help though  :smiley:
Title: Re: Running Carbs On An ABF
Post by: jonnypolish on 29 July 2010, 20:27
Injection all day.. A fuel rail IS a step backwards!
If you want a similar set-up, Go for ITB's mate, much better gains! Albeit more work!
Although you will get a meatier sound from carbs :) (as opposed to standard injection)
Title: Re: Running Carbs On An ABF
Post by: Leon27 on 29 July 2010, 20:31
Head towards throttle bodies with proper management and then you will make power, probably some serious power at that. For example the BMW M power range makes 100 bhp per litre, this is done using throttle bodies and a proper management set up.

With regards to is it common, doubt it very much. The reason for the Digifant 3.2 system the ABF uses is not only for reliability/performance purposes but also for emmisions. The system can control the emmisions whilst also running a CAT, something a car with carbs can't do. You would fail the MOT as the MK3 was built around the time that CATs were mandatory (1992 onwards)

Edit! ^^^ beat me to it!
Title: Re: Running Carbs On An ABF
Post by: LazyLunatic on 29 July 2010, 20:52
my friend runs a 9A on R1 bike carbs. sounds sick and is fairly quick. dont think you get much, if any extra bhp, but seems to produce more torque!

he made up a custom inlet and runs megajolt
Title: Re: Running Carbs On An ABF
Post by: LazyLunatic on 29 July 2010, 21:02
ITB's ftw, but ftl really cause they are a battle to fit and get right and cost a fortune to setup properly! I was thinking of a ITB project next, but after really looking into it, its a NO for me.
Title: Re: Running Carbs On An ABF
Post by: Len on 30 July 2010, 09:07
Carbs can be better than injection if set up properly, but the other alterations you need to do make it unviable. (ECU, CAT, etc. etc)

So throttle bodies is the only realistic option.
Believe me I would love to run a twin set of double choke Webers..........
Title: Re: Running Carbs On An ABF
Post by: VeeDubGTI16v on 30 July 2010, 09:21
the problem is most of the carb guru's have retired nowadays  :grin:

Title: Re: Running Carbs On An ABF
Post by: Diamond Hell on 30 July 2010, 09:28
Or is it that emissions laws have been tightened and electronic control has advanced a very long way?
Title: Re: Running Carbs On An ABF
Post by: Ess_Three on 30 July 2010, 09:34
Carbs can be better than injection if set up properly, but the other alterations you need to do make it unviable. (ECU, CAT, etc. etc)

So throttle bodies is the only realistic option.
Believe me I would love to run a twin set of double choke Webers..........

Carbs CAN be better than injection, if the injection system is restrictive or limited in it's adaptability.
Digi  3.2 is not.
The whole injection system is good for 190+ BHP if mapped correctly and when used with more aggressive cams.

On standard cams, changing to carbs would give little peak power gains over a re-mapped Digi 3.2 set-up, and you'd still need some means of controlling the spark - ideally fully mappable, so you'd need Magajolt or similar.
Failure to map the ignition would leave you with similar peak power to Digi 3.2 but with flat as a fart midrange and an effective power/torque drop through the rev band.

As has already been said, you would also kill the cat, so you'd need to remove it...and you'd fail the MOT.
It's just not worth it.
Especially downgrading a fully engine managed 16v to run stone-age approximately fuelled carbs.

Carbs can give good gains...once you get into wilder cams...but those wilder cams also bring the problems of jetting into play. Big peak power numbers, but awful drivability and midrange...whereas ITBs allow the same (if not higher) peak power numbers to be made but with perfect road manners and a much improved midrange.

Have many people ever run DCOEs?
They sound great...but are a pain. Always going out of adjustment, coughing and spluttering through the midrange, they won't idle when the engine is cold etc.

As for sounds, ITBs and carbs sound alike...
Title: Re: Running Carbs On An ABF
Post by: Ess_Three on 30 July 2010, 09:36
the problem is most of the carb guru's have retired nowadays  :grin:



..and along with them, the stocks of jets, emulsion tubes, chokes etc have dissapeared.

The art of balancing DCOEs with a length of hosepipe has long gone.
Many 'tuners' look baffled when they can't upload a new map with a laptop.
Shame really...
Title: Re: Running Carbs On An ABF
Post by: VeeDubGTI16v on 30 July 2010, 09:38
As for sounds, ITBs and carbs sound alike...

carbs go bwwwarp

bodies go thhhwarp
 
 :laugh:

both sound amazing
Title: Re: Running Carbs On An ABF
Post by: AlexMozza on 30 July 2010, 09:40
I have dual Carbs on my Mini and they sound awsome, but i would have thought that after balancing them and tuning them for MoT it would not be worth it?
However if you willing to put the time and set them up - Haynes do a really good carb book - It will be worth it :D
Title: Re: Running Carbs On An ABF
Post by: Len on 30 July 2010, 10:59
With carbs you get a constant fuel flow, its always there.

The only way it could be done properly is to remove ALL the sensors etc, scrap the ECU and use a TDC sensor and an electronic dizzy.
So no CAT or lambda etc. etc. therefore MOT problems!


Oh and I do know people that can tune DCOE carbs!  :wink:
Title: Re: Running Carbs On An ABF
Post by: Diamond Hell on 30 July 2010, 13:35
So no CAT or lambda etc. etc. therefore MOT problems!

Sounds like you shoulda got a Golf2, Len.  :grin:
Title: Re: Running Carbs On An ABF
Post by: A7 UFO on 30 July 2010, 14:53
I ran 4x45s on my old mk1....earth shaking noise but pain in the arse to get set up.
Title: Re: Running Carbs On An ABF
Post by: Misky on 30 July 2010, 15:15
Carbs are a pain in the ass!!!! I hated them on the 5GTT I even thought about a custom manifold to run injectors i hated them that much! If they are not set right a lot of things can & do go wrong, your always fiddelling with them  :laugh:
Title: Re: Running Carbs On An ABF
Post by: Len on 30 July 2010, 15:19
So no CAT or lambda etc. etc. therefore MOT problems!

Sounds like you shoulda got a Golf2, Len.  :grin:


Have always said I would have a Mk2 IF they came with ABS and air-con!  :wink:
Title: Re: Running Carbs On An ABF
Post by: Len on 30 July 2010, 15:19
Oh and NOT left hand drive!
Title: Re: Running Carbs On An ABF
Post by: Stirring Moose on 02 August 2010, 23:36
I like carbs, they're fun to tinker with and satisfy my inner Fred Dibnah. But I would never put them on an engine that is already fitted with full management. Total backwards step in my opinion. I'm all for grasping the technological nettle and laying to rest the lament of the pub "experts" that "you can't fiddle with these modern cars like you could the old ones, too many compooters..." Grrr :angry:

S.M.