Twin carb advise

[spud]

I'm needing some info about twin carb setups i did a search but it didn't come back with much.

I'm considering putting twin Weber 45's on my VW Caddy which has a 1.8 16v Golf engine fitted. I just want to free up space in the engine bay and Ive always wanted a twin carb setup on a car.

People Ive spoke to keep saying there shocking on fuel and i would be forever getting them setup is this true?
The reason i ask is out of all the people i only know one has had them on his car, which was the forth car they were on and he never had them jetted or setup to suit the engine.

The only other person that has experience was a garage near me who said on motorways they might be a bit better on fuel than the mechanical fuel injection, also they wouldn't be that bad city driving. He said the reason people say there heavy on fuel is because there not setup or there driven flat out just for the cool noise which i could understand.
Am i just being told this for him to get the business?

Last thing is there anyone one here fitted twin carbs to the 1.8 16v VW engine? What do you do with the plugs that go to the metering unit, throttle body, 5th injector and the ISV? Do you just tuck the wiring neatly out the way or do you put a link or something across the plug?

Need to make my mind up soon its either carbs or a new mountain bike lol.

Cheers Graeme

[SeventyNine]

its all been covered, i can ask my pal to give you a run through when he is next online.........

i ran carbs on my daily, and they were stupid on fuel, a fiver would return me 20 miles tops, but i did (and do) drive like a complete idiot everywhere so thats on my head. (that was on a 1.3 crossflow btw)

[big end floater aka lb]

my 1,3/4 sus imade up a manifold for my pinto


and finished with speed well filters and they sounded absolutley beautiful suckysucky long time

[sprintmini]

Twin Webers on a VW engine has been done a few times mate.I believe they give a small gain in power over the injection set up.
I will try dig out the website where some of the members have done the conversion.

[sprintmini]

Try on here: www.clubgti.com/forum/search.php?searchid=1008333 someone on there may be able to help you.

[harris66]

two 45s on a 1.8 road goer are maybe a bit over kill, on a high revving racer it would be usefull but normal driving they could be a pig

[gearoil]

Bike carbs...?

[RoadRacer>>>>>>>>>>]

Glug Glug Glug,

[spud]

Thanks for the help guy's found a good topic on club gti ( cheers sprintmini ).

I like the SU's first time ive seen that done.

So everyone agrees there heavy on fuel, perhaps not the best idea for driving up and down the country to go cycling.

New bike it is then

Cheers Graeme

[avtovaz]

its bolocks when people just say that they use more fuel, they are there to do a job, and if that job done right means it takes more fuel then so be it. BUT correctly set up, twin carbs suited to an engines needs will be very hard to beet.

When people have no power low down, then usualy its down to one of two things, too wold a cam, or the carb venture's are too big.

A carb works--> air flowing into the engine flows over a smaller pipe than the main venturey, this big pipe small pipe effect sucks the fuel up. thats the easyest way to expalin it...

Now if the venturey is too big then the air flow is slow, the fuel dosnt get picked up properly and the engine runs weak....

you maybe better using 40's not sure...


BUT, bike carbs are the best aparently unless you have a good injection system. Ill see if i can find some stuff to quote on here for you.....

If you goto the Bog Brothers, they;ll charge you about £500 make you a manifold, suply the carbs and set it all up for you.

Bargin!

[avtovaz]

the info has gone but phone Steve Bogg at Bogg Brothers 01944 738234

[avtovaz]

i must just say also, sorry i didnt mean to be so rude at teh start

[Broke4speed]

Tune a carb for economy, you get economy. Tune a carb for power, you get power.

The sound though....the souuuuuuuuuuuuuuuuund..... ;D

[bazzateer]

Tune your engine (all aspects) for maximum efficiency and you will get a good compromise between power and economy. I think Dave Vizard taught me that via his Tuning the A Series book.

[popuptoaster]

I had twin 40's on my mk1 escort x flow, they were not bad on fuel, slightly worse than the standard twinchoke in normal driving and MUCH worse when flat out, and they were a pain when the car was cold, but then I didnt bother with a choke so thats my fault, I used my car every day for work, it took us shopping and took the missus and kids on holiday in it etc etc, they do gradually go out of tune, but once set up on the rolling road you can actually balance them by ear with a bit of practise, besides, if you only have an 1800 in road tune it cant use that much juice.

nyom nyom nyom, this car sounded wicked on the rolling road with its crackly single box ashley and these carbs, the guy said in 20 years he'd never heard one as "crisp" as mine.




ps, cant see twin carbs freeing up space in an engine bay, they are bloody massive usually.

[spud]

Cheers for the help i was in working on it today and i think I'm going for carbs, i just cant get the thing to idle below 2000rpm with the mechanical fuel injection.

Also some good news my dads boss has 40mm Weber's hes going to give me for free, not sure what there from as hes had lots of jags, mgs etc you name it hes had it.

What should i look for on them? Is there any models i should avoid?

ps, cant see twin carbs freeing up space in an engine bay, they are bloody massive usually.

I know what you mean but it does in a caddy because you lose the metering unit, pipe to the throttle body and plenum chamber over the head makes it look alot neater.

[davemk1gti]

twin webbers on a 16v head mean very very short trum inthere for them, start pets (none really) there is naf all room in there, start thinking audi 80 throttle bodies and other VAG parts, a decent exhaust manifold on these engines sounds awsome and actually free up some revs from the engine - much cheaper and still get a 'nice' roary sound. try 'raceland' there is a belguim company on ebay who list them, Ive used them and the manifold nearly fitted first time.

[JohnnySomersett]

Ive been toying wih going for twins on my A12 engine when i drop it in. Its on a single hitachi carb atm. can get a dedicated manifold on eGay for it but wouldnt have a clue which carbs to go for! 40's would be WAY too big methinks. Maybe 30's? anyone ever twin carbed a 1.2 petrol engine?

*ps. thread hijack sorry LOL

[popuptoaster]

johnnysomersett said:

Ive been toying wih going for twins on my A12 engine when I drop it in. Its on a single hitachi carb atm. can get a dedicated manifold on eGay for it but wouldnt have a clue which carbs to go for! 40's would be WAY too big methinks. Maybe 30's? anyone ever twin carbed a 1.2 petrol engine?

*ps. thread hijack sorry LOL

use bike carbs, mucho cheaper and will work better, i'd use bike carbs on anything these days, only reason the x flow had the 40's on was cos they were genuine mexico option ones complete with manifold and were a good price.

[JohnnySomersett]

popuptoaster said:

johnnysomersett said:

Ive been toying wih going for twins on my A12 engine when I drop it in. Its on a single hitachi carb atm. can get a dedicated manifold on eGay for it but wouldnt have a clue which carbs to go for! 40's would be WAY too big methinks. Maybe 30's? anyone ever twin carbed a 1.2 petrol engine?

*ps. thread hijack sorry LOL

use bike carbs, mucho cheaper and will work better, i'd use bike carbs on anything these days, only reason the x flow had the 40's on was cos they were genuine mexico option ones complete with manifold and were a good price.

I see, good plan. Carbs from any particular bike you can reccomend?