Just wondering, has anyone put bike carb set up on a 1.4 16v 6n? I'm interested in get some info about bike carbs etc.. so any help appreciated.

I'm looking for more power to my already quick polo.

So i think carbs are the next step along for more power, without spending thosands on turbo or s/charger.

heres whats already done to engine...

BMC CDA Induction kit, Janspeed full s/s exhaust system, Decat, Supersprint 4-2-1 exhaust manifold, Stage 3 head, Sorg Group N Cams, Ported throttle body, Modified inlet manifold,Dastek Piggyback ECU, Dastek custom mapping, Splitfire platinum spark plugs, Magnecor 8mm Ignition Leads.

cheers.

They'd be nice,and a definate improvement imo,but you've already got good induction so you wont see such a performance benefit as you would over standard fuelling. You'll hear it,though..

But more of a problem will be legalities. Too keen on the throttle,and you'll kill the catalyst. Reports of what gets through the MOT at that age,and what doesnt,vary considerably.

Theres that lad with a mk1 golf, with a mk4 16V engine on bike carbs....and all I'm saying is, DO IT! Lol

We met up with him to convoy down to the blackpool cruise not long back, and on the motorway, he put his foot down, and christ it went like stink! And the nosie was to die for! Seriously! I do think hes on here, got a turquoise mk1 with pin striping on the boot iirc?

My youtube is being a bit tempromental atm, but if you type "mk1 golf 1.4 bike carbs" I'm pretty sure its one of the first ones!

They'd be nice,and a definate improvement imo,but you've already got good induction so you wont see such a performance benefit as you would over standard fuelling. You'll hear it,though..

But more of a problem will be legalities. Too keen on the throttle,and you'll kill the catalyst. Reports of what gets through the MOT at that age,and what doesnt,vary considerably.

I reckon i could get more bhp maybe 25-40 increase? so its a lot more than the good induction just now. And my car does not have a cat in it, decat. I can still get it passed at MOT time.

and also the bike carbs look great under the bonnet and also sound very meaty!

My cars bhp is around 135-140bhp at the moment. So looking to add some more ponnies.

Id like to know how the bike carbs work and how they are set up etc..??? especially on a 16v engine.

and also the bike carbs look great under the bonnet and also sound very meaty!

I know :grin: But my 37's are probably a bit small for a highly tuned valver - you'll probably want some with chokes of 40-45mm if you use revs - efficient for circa 140-190bhp.

Jetting it,i dont know. Generally to .thou of engine size - but id start with 1.45mm,and then calibrate your slides. Once they open right,if its lean top end and they're fully open,you can drill the jets a touch wider - 1.5,1.55,1.60,1.65.. You'll be rich by then.

I've had to cut and stretch the slide diaphram springs so they slide perfectly in sync to the rev range(with needles from a 900 for the torque curve that suits my 8v),but still they're fully open at 5.5k rpm.

Which wont suit your revvy 16v. So you'll have to adjust necessary to your needs,and I'm estimating on only my factory 8v experience.

hum... would any of you know of any threads i could see you builds in other forums? I'm interested in doing something similar to my 1.3 6n

If you want info contact Boggbrothers they will help you out.

Google it mate and theres tonnes of info. Its all pretty generic except the set up of the actual carbs.

I think youll want 750+ cc bike carbs so 38mm up?

I think the mk1 golf was running 750's.

Theres a guide somewhere from a vauxhall mag/websie with a step by step, just contact boggbrothers about what carbs/jet you will need.

all you need to know http://users.telenet.be/halcyon/forums/Bik...%20how%20to.pdf

now this last replay was what you can call "early, still half sleaping english" :) sorry about that, my brain was still off hahaha

quote

"f you want info contact Boggbrothers they will help you out.

Google it mate and theres tonnes of info. Its all pretty generic except the set up of the actual carbs.

I think youll want 750+ cc bike carbs so 38mm up?

I think the mk1 golf was running 750's.

Theres a guide somewhere from a vauxhall mag/websie with a step by step, just contact boggbrothers about what carbs/jet you will need.

all you need to know http://users.telenet.be/halcyon/forums/Bik...%20how%20to.pdf"

cheers mate.. and by the way... nice sett of wheels your car looks gr8

:)

Edited 9 February, 200917 yr by drakpolo

heg123 has bike carbs on his 16v polo

probably worth pm'ing him about his setup

and drakpolo, I'm doing this to my 1.4 8v for my uni project and will be a build thread once its finished :)

Edited 9 February, 200917 yr by goose

Easy enough to do on a 8v what about 16v's tho? Heard there more hassle than there worth?

Ho far away is bogg bros from croydon as id bee very tempted to run bike carbs on my 1.6 also how much would it be for the conversion?

Ill def be doing this to my 16v, going to sort it over the next few months. then after the carbs ill be looking into getting LSD fitted! :-)

Ho far away is bogg bros from croydon as id bee very tempted to run bike carbs on my 1.6 also how much would it be for the conversion?

Dude just google it, all the info is on their site.

you can just get them to make a manifold and set them up for you if you don't wanna travel and do the rest yourself.

I was planning to do it to my valver but it was written off,

so just have to drop the AFH in a mk1 and do it instead

Hmm... bike carb an 8v or do a 16v swap.....

/\/\/\/\/\/\ both? carb it whilst its out the bay, then drop it straight in and go!

I presume you must have a friendly MOT man, as the emissions test would most likely prevent you from running carbs on a car of that age.

Given that you've effectively got your current setup custom mapped with the Dastek, I'm not sure you'd see that any gains from the carbs - definitely not the 25-40bhp you're hoping for.

To give you an idea, a chap on here (red Mk2 breadvan) did a 1.6 8v on bike carbs, which he had setup on a dyno - think they made 106bhp or so. That's a decent gain from the 75bhp as stock running emissions/economy orientated Polo 6N injection. However, the few 1.6 8v Polos running tweaked Polo GT multipoint Digifant injection tend to make 100-110bhp, so there's nothing in it.

Put simply, your fuelling has already been optimised for your motor, removing restrictions on the inlet side by going to individual throttles may gain you a little more power, but the loss of accurate fuelling control by switching to carbs would negate any gains in my opinion. The way to go is to retain fuel injection, but go for throttle bodies - the best of both worlds. You've already got a tweakable fuel injection setup, so the cost difference between individual throttle bodies or bike carbs is next to nothing - and with ITBs you could get the car through a genuine MOT with the cat back on.

I presume you must have a friendly MOT man, as the emissions test would most likely prevent you from running carbs on a car of that age.

Given that you've effectively got your current setup custom mapped with the Dastek, I'm not sure you'd see that any gains from the carbs - definitely not the 25-40bhp you're hoping for.

To give you an idea, a chap on here (red Mk2 breadvan) did a 1.6 8v on bike carbs, which he had setup on a dyno - think they made 106bhp or so. That's a decent gain from the 75bhp as stock running emissions/economy orientated Polo 6N injection. However, the few 1.6 8v Polos running tweaked Polo GT multipoint Digifant injection tend to make 100-110bhp, so there's nothing in it.

Put simply, your fuelling has already been optimised for your motor, removing restrictions on the inlet side by going to individual throttles may gain you a little more power, but the loss of accurate fuelling control by switching to carbs would negate any gains in my opinion. The way to go is to retain fuel injection, but go for throttle bodies - the best of both worlds. You've already got a tweakable fuel injection setup, so the cost difference between individual throttle bodies or bike carbs is next to nothing - and with ITBs you could get the car through a genuine MOT with the cat back on.

I worked in a garage and still have many friends in the motor trade, its not hard to get your car passed in an MOT.

I dont know much about Bike carbs and Throtle bodies, whats the differance?

i might save up £ and just take the full car to Bogg Bros.

I presume you must have a friendly MOT man, as the emissions test would most likely prevent you from running carbs on a car of that age.

Given that you've effectively got your current setup custom mapped with the Dastek, I'm not sure you'd see that any gains from the carbs - definitely not the 25-40bhp you're hoping for.

To give you an idea, a chap on here (red Mk2 breadvan) did a 1.6 8v on bike carbs, which he had setup on a dyno - think they made 106bhp or so. That's a decent gain from the 75bhp as stock running emissions/economy orientated Polo 6N injection. However, the few 1.6 8v Polos running tweaked Polo GT multipoint Digifant injection tend to make 100-110bhp, so there's nothing in it.

Put simply, your fuelling has already been optimised for your motor, removing restrictions on the inlet side by going to individual throttles may gain you a little more power, but the loss of accurate fuelling control by switching to carbs would negate any gains in my opinion. The way to go is to retain fuel injection, but go for throttle bodies - the best of both worlds. You've already got a tweakable fuel injection setup, so the cost difference between individual throttle bodies or bike carbs is next to nothing - and with ITBs you could get the car through a genuine MOT with the cat back on.

I worked in a garage and still have many friends in the motor trade, its not hard to get your car passed in an MOT.

I dont know much about Bike carbs and Throtle bodies, whats the differance?

i might save up £ and just take the full car to Bogg Bros.

Might be best to keep it a bit quiet if you're getting Stevie Wonder MOTs.

Throttle bodies give you an individual throttle (hence Individual Throttle Bodies) for each cylinder, but still retain fuel injectors. Bike carbs will give you an individual carburetor per cylinder - so you get the same flow advantages as ITBs more or less, but without the accurate electronic control of the fuelling.

That's why I was saying that whilst bike carbs would perhaps gain you some flow advantages over your current setup, you lose on the fuelling control side. Whereas with ITBs you don't lose out on the fuelling, and you gain on the flow still.

I presume you must have a friendly MOT man, as the emissions test would most likely prevent you from running carbs on a car of that age.

Given that you've effectively got your current setup custom mapped with the Dastek, I'm not sure you'd see that any gains from the carbs - definitely not the 25-40bhp you're hoping for.

To give you an idea, a chap on here (red Mk2 breadvan) did a 1.6 8v on bike carbs, which he had setup on a dyno - think they made 106bhp or so. That's a decent gain from the 75bhp as stock running emissions/economy orientated Polo 6N injection. However, the few 1.6 8v Polos running tweaked Polo GT multipoint Digifant injection tend to make 100-110bhp, so there's nothing in it.

Put simply, your fuelling has already been optimised for your motor, removing restrictions on the inlet side by going to individual throttles may gain you a little more power, but the loss of accurate fuelling control by switching to carbs would negate any gains in my opinion. The way to go is to retain fuel injection, but go for throttle bodies - the best of both worlds. You've already got a tweakable fuel injection setup, so the cost difference between individual throttle bodies or bike carbs is next to nothing - and with ITBs you could get the car through a genuine MOT with the cat back on.

I worked in a garage and still have many friends in the motor trade, its not hard to get your car passed in an MOT.

I dont know much about Bike carbs and Throtle bodies, whats the differance?

i might save up £ and just take the full car to Bogg Bros.

Might be best to keep it a bit quiet if you're getting Stevie Wonder MOTs.

Throttle bodies give you an individual throttle (hence Individual Throttle Bodies) for each cylinder, but still retain fuel injectors. Bike carbs will give you an individual carburetor per cylinder - so you get the same flow advantages as ITBs more or less, but without the accurate electronic control of the fuelling.

That's why I was saying that whilst bike carbs would perhaps gain you some flow advantages over your current setup, you lose on the fuelling control side. Whereas with ITBs you don't lose out on the fuelling, and you gain on the flow still.

so u reckon take the full car to bogg bros and let them deal with it?

i wouldn't, i doubt they will want to work out your ignition system to use when on bike carbs and source/fit it...

Bogg bro's specialise in fitting bike carbs to cars,but car-friendly bike tuners could do the job.

I didnt use a manifold,just bolted a top hat flange to each port and connected the carbs to them with some vacuum pipe. It just has to be long enough to clear the plugs,and then i bolted the carbs to the cylinder head - i can stand on them.

ITB's are a throttle body (round door in the inlet pipe,to control flow of air),with a fuel injector spraying fuel into it. Basically an ideal upgrade of your current setup - so you then have a choke on each cylinder instead of the one for all four to fight over,and tune your management for the better flow.

Bike carbs are also an individual throttle body on each cylinder just the same,but the fuel is sucked through a jet which is plugged by a tapered needle,which passes through the tract - the further the needle withdraws,the more fuel seeps up/around it. When the needle is coated in fuel,the air rushing into the engine blows it off the needle,and its subsequently taken into the cylinder in spray form.

The carb is ultra accurate when set up properly,but once you drill the jet,the needle isnt perfectly matched. Still,as with a cam,it keeps its nature - but that profile will not perfectly match your rev range.

Until someone is able to custom manufacture needles,bike carbs will always be fractionally flawed.

But it is fractionally,as long as the jets are right and the diaphrams open at the correct rate.

Its not fair to compare Joels red breadvan to a mapped GT conversion,as he didn't tune it. All he did was drill the jets to 1.5,his printout was on a starting point. In addition,he used the low-rev camshaft. This limits the bhp figure considerably,against the revvy GT cam used in the GT injection conversions. So bike carbs tend to start where standard GT injection ends.

But yeah,ITB's are then superior to bike carbs - but i dont personally believe any other n/a system to be - though I've not yet looked into FSi..

And if ITB's are too expensive,remember you only need the hardware - which you could get off a fuel injected sports bike.

None of the GT injected 1.6 conversions had been mapped. Perfectly setup bike carbs vs perfectly mapped single throttle MPI, the bike carbs will have the edge on power but not on economy or emissions. In the real world, nobody's willing to put in the time and money to get such a perfect setup - so my original analagy is more relevant.

BTW - FSI conversions on non-FSI motors aren't really feasible, as you'd need to change the piston design completely to work with the stratified charge.

On a slightly related topic...

I'm getting a manifold made up to work with my 16v and then running it on my Coupe S ignition. Is it worth getting a pipe welding in to the side of the manifold to deal with the Vacuum Advance on the Dizzy?

Edited 10 February, 200917 yr by max_crox

I'd say so. We added a vacuum take-off on Yoof's ITB manifold on his GT, though that was for the brake servo. I suspect you might find that it's more consistent if you common up a take-off from all 4 inlet runners.

With mappable ignition an AFH on bike carbs would be impressive - though I think Aldon Automotive would be happy to tweak a Coupe S dizzy to give you a more suitable advance curve.