5 bike carbs?
 

anyone know details about fitting 5 bike carbs to a kv? :D

like this guy has done?

Cause i want!, i want! i want! i want!.. :D i wonder if power will be much improved at all once set up properly? any one know? :confused:



on the move
http://www.youtube.com/watch?v=oW1HHDrH48I

under bonnet
http://www.youtube.com/watch?v=DBOttDwCru0

http://www.youtube.com/watch?v=Dz7lkHEqddk

http://www.youtube.com/watch?v=7_6R84Xqv8g

http://www.youtube.com/watch?v=jlfmw7zHAAo

http://www.youtube.com/watch?v=tBfGC9EYOd4

oops! :eek:
http://www.youtube.com/watch?v=lNn21xj1Fks

nice!

Nightmare
 

If its anything like the DCOE carbs on my Mk1 escort many years ago it must be a nightmare keeping them all balanced and where is the air filter?!
A properly set up K-jet with ported head will be far more reliable, produce just as much torque which is what you need and be more economic with the fuel. Looks impressive if that's what your main aim is?!

This seems to come up a lot on the usual forums.
Do people understand the differance between a Carb and a Throttle body or just mis-use the terminology?( genuine Q)
TB's on a I5 will give an improvement but are a pain in the arse to source (ask Lee folley about his set on his ex works rally cross running a 2 stage K-pump). Where as carbs are a retro step and you lose the gains from injection.

ok.. TB's gain i understand.

but surly these carbs would have some advantages? Allowing less restriction doing with out the air sensor plate in a K-jet, & if set properly with right fuelling give more power? Maybe not as good as modern TB's but maybe better than using a single inlet manifold perhaps?

i know people who have seen gains using twin carbs on a 2.0L ford ZETEC compared to the original inlet EFi set up. :confused:

But either way,.. the noise will be nice? and as said will look cool when u pop the bonnet. :)


Also, the cost of TB's would be a LOT more expensive? right? :confused:

Big hassle, big money. Maybe more power.., but at the expense of your sanity. You'll be forever tuning it and fiddling under the bonnet. I'm sure it would get right on your tits.
Bit of head work, as mentioned above would be far more economical.

You realy need to spend some time in a book and read up on this subject.
How often do single venturi side mount carbs come up for sale??? and then you need 5
What manifold are you going to use?
If you find 5 carbs that will do the job where are you going to get jets and needles?
I would be amazed at any gains by just swaping efi for carbs, those situations that are reported are always with the cavat that some engine work was also done at the same time .

ANY THINGING IN 5'S WILL BE EXPENSIVE OR REQUIRE WORK SHOP TIME.
Tb's are a lot simpler to make as you make how ever many you need, and you can set out the manifold direct. But you need a stand alone ECU.

Get a 100 turbo and strip it for the engine.

This is for another project along side the 2.5 ??? as that is tuned for K jet.

Maybe easier to actually install (if possible as per Gib's doubts) but thatd be about it.

Take a look into the mouth of any carb and youll see a venturi- a restriction now times that by 5.
The air sensor plate on a kjet wont be anywhere near as restrictive as 5 carbs and itll meter the fuel more efficiently because thats what Bosch engineers designed it to do.
If carbs were any major advantage at all, everyone would be using them, but theyre not.
Carbs need extreme amounts of know how to set up and even then, theyre a compromise setup compared to a bespoke injection system that can be altered at will to supply fuel in just the right quantity and atomisation levels to promote good idle, part and full throttle.
Then theres the absolutely compromised fuelling for economy and power- DCOE's are a good carb, but compared to a fully mappable injection system ( even compared to Kjet) theyre a very poor second choice.


Not at all. That inlet manifold serves a good purpose; its a tuned length to enhance torque.
If you replace it with a shorter setup say 5 carbs, you lose the resonance effects that the manifold provides and end up with a big hole in the torque curve, for a possible gain in power at the top end- but very likely itd be out of the engines normal rpm range.

But are you comparing like for like?
Did engine A have some fault before the swap?
Injection really IS far and away superior in most every way over carbs and its not even that hard to understand- try working out whats happening within a carb at any particular time......

Might look "cool" but itd be a backward step as regards power and torque- which is where youd like to go? :)


Bike TB's can be had off ebay for little cost in triple and double forms, the expense comes when you go to get it all mapped if you can do the rest yourself, but in any case why bother?
Optimise the original head, induction and exhaust system and then force induct the engine to take advantage.

For me, its a no brainer- would i like a "cool" looking setup or a powerful one?
;)
Whichever you decide id not knock the plan as its each to his own, just dont expect much in the way of exceptional outputs if you go the one direction. :D

already have all that side of it sorted. apart from getting a different cam... hopefully a fast road cam will be in there after i've fixed my car. :)


i was thinking about it for the 2.5L . it was only an idea...

i had 'thought' a standalone ECU and TB setup would costly?? :confused:

Bike Carbs are very reliable, much more so then DCOE Weber 40's or 45's that go out of balance every 3000 miles!!!! Especially if you get some of the more modern set up like from an R1 or GSXR750/1000 etc as these use electronic fuel pumps aswell! The only prob I can see is getting 5 of the things as they usually come in banks of 4!!!

Good power gains can be had from them aswell, once properly set-up etc! I know a guy who as a set of R1 carbs on his 16V 'rocco. Only other mod is a polished and ported head and that pushing the 170bhp mark!!! Pretty good i'd say, plus it sounds awesome on full chat!

Like This:http://uk.youtube.com/watch?v=-vvUc3...eature=related

You can pick a set of R1 carbs complete with pump etc for £100 or so on fleabay! Company you really need to talk to are Bogg Brothers! They are the daddies, they will build you a custom manifold and can even redrill and set up your carbs for your particular car! Looking at your you tube links in the 1st post Bogg Brothers actually sorted the manifold etc on that audi so would deffo be worth talking to them!

Here: http://www.boggbros.co.uk/index.html

You will need to keep the ignition side of fuel injection system etc but I reckon you could be up and running on bike carbs for £500 to £1000 including the carbs, manifolds and RR set up!

Plus who else has done this in the UK??? Bet they're ain't many, modding is about doing stuff that ain't been done before.......I think it would be cool!

The Noise will be worth it :)

Haha, carbs :D :D We live in 21st century, guys :D
Carbs - it's a simple and complicete solution in the same time. Simple - because there isn't so many bolts :D In the same time - what else u can do with car like this, apart from sound and a little power increase, because it doesn't consumes fuel anymore, it guzzles. Example with corrado & carbs = 170 bhp isn't cool - i know ppl with mk2 golf, 2.0 DOHC engine, vems and some minor modifications, and 175 bhp. I'm afraid, that car with vems can be used dayly, unlike car with some primitive carbs. Well, i also know one another example - B2 A90q, ppl installed in this car 7A engine, installing on it pure k-jetronic from KV, only nozzles were different. Fuel consumption was 10l/100 km on road, 20l in city :D :D Price for torque :) As owner said - he was able to drive in 4th gear on 1k rpm without downshifting :eek:

going from a 136bhp 16V motor to 170bhp with the addition of carbs and a head job (Head prob gives 10-15bhp increase) I think is pretty decent add some cams in the mix and you'll be knocking on the door of 180bhp!!!

Anything that increases engine performance is going to knock fuel economy, Bike carbs are a lot more fuel efficent then a set of twin 40's webbers etc!

And what u will do, if u want 200, and not 180? :confused: In that case u will trow out your "very cool" carbs to install EFI & turbo :D

If I wanted 200 bhp I'd throw away the old motor and fit a 1.8T :)

TB's
 

As stated already the inlet manifold length is there for a reason. Take the 20V 7A, the inlet was 'tuned' to help midrange torque. Fitting bike carbs or TB's right next to the head might be great for top end power but on a road car thats not going to be as useful as a good spread of torque that can be achieved with tuned inlet and EFi. Unless it is going to be used as a track car don't bother, there are better tried and tested solutions . See July's Audi Driver on fitting a larger MAF to the 7A for instance. 190bhp and 180lb/ft torque from aspirated 2.3 engine.

Think most of you are missing the point, it's all well and good saying well I'd just put a bigger better engine in than carbs or i would have gone for 2k worth of throttle bodies and a mapped ECU if you're gonna argue that why not just buy a faster car.

Is this what modifing old cars is about?

Surely the point is to make an improvement over the stock equipment?
Carbs are not going to achieve it in my opinion, as the stock injection system say on a KV engine isnt restrictive at the power levels the head is capable of supporting in stock trim.

Im all for modding engines, cars etc but id not sacrifice power economy and reliability for uniqueness, however appealing the idea.

Having said that though, each to his own, and if Gaz or indeed anyone did do a conversion to carbs id not knock such an effort id always applaud it. :)

Well... Why 2k? 1k would be much real :D

Originally I was wanting to fit a 5 cylinder 20valve turbo engine to my car.. but when i saw the 2.5 Nasp lump for sale i went for that instead.

I do scratch my head and wonder 'WHY?' sometimes, esp when looking at 20vcqdriver's turbo install, i think i'll have fun trying to reach 200bhp from my 2.5L. :D

How exactly i'm going to achieve that i don't know, but i'm hoping with a fast road cam i should see about 190bhp, Any ideas tho how i might take it from there to 200brake?? :confused:

Talk to Bogg Brothers! They know their Shit :cool:

Well you already have the main item covered- thats the modified head.

In getting extra power youre basically playing a game of "chase the restriction".
Because youve got a 10 valve head (thats two ports per cylinder) youve got a restriction in the actual design, although youve obviously had the benefits of the modifier at work on those ports to make them more efficient.
Even so, its not ever going to approach the flow potential of the 4 valve heads- so if you want to stay N/A thats where id be going, unless you really want to keep it 10 valves of course. :)

Camshafts going to be a trade off- aint it always so, whereby youll lose torque low down for a possible gain in power further up the rpm range.
In any case id suspect the camshaft you have already is an optimal grind for that engine so probably little to gain for a lot of outlay.

You could go for something like a vortex supercharger install to give you some positve boost pressure which would allow you to get to 200bhp and most probably some way beyond it, without the plumbing issues of the turbo install, thatd be a fairly unique install also, or maybe a nitrous install for a temporary kick in the pants. :D

Beyond the obvious stuff like a less restrictive air filter, exhaust and optimised injection and ignition timing i think youre going to struggle to hit 200bhp- short of a hike in rpm to get more work done in the same time, but again thats dependent on cylinder head airflow, and the 2 port head wont go there without some boosted help i think.

Votex Audi GT5-s from the 80's made iirc 160bhp from a modified 1921cc wn code engine(bored to 1933) but that was heavily breathed on and again its a two valve head design.
If the 20 valve design had been available they could well have been knocking on the 200bhp door. :)

changes
 

The 2.5 GTi engine was an excellent conversion at the time and was more about torque than outright power. At the end of the day it is torque that gives you great in gear acceleration which is what you are after not a load of bhp and no torque. The 2.5 GTi engine used the standard KV cam and fitting a Shrick will give more power and torque but higher up the rev range. If you can live with that then it should be capable of getting to 190bhp. After that you need to look at fitting a bespoke injection system and getting it accurately mapped on a rolling road etc. It should with a decent exhaust and work to match the inlet easily reach over 200bhp with around 190lb/ft.
The turbo conversion was a nightmare and needed some ingenious solutions and is still in development as intercooler too small. It is the torque of this engine that really impresses. Presently producing around 250bhp and 280lb/ft. In gear acceleration which is the important on road figure is spectacular. 50-70 in 5th in 4.8seconds and in 4th it comes down to 3.6secs. I'd go for good torque every time in a road car.....

nitrous?