weber on my 205 Gti?
  • Register
  • Help
Results 1 to 17 of 17
  1. #1
    Tadpole
    Join Date
    May 2001
    Location
    danmark
    Posts
    7

    weber on my 205 Gti?

    I'm the happy owner off an 205 gti 1,6. But i want to spice it a little.. so I am buyng 2x40 DCOE weber for it.. I have done the conversion on a 1,6cl golf, no big deale. But with the injection system, I don't konw how to do to get the bedst out off it(performance)I know that some uses parts off the injection system to feed the carburators or the manifold with.But how it is build, i don't know and thats what i would like help with... pleeeeace..
    Mechanic girl : )

    Advertisement

  2. #2
    Guru davemcbean's Avatar
    Join Date
    Apr 2001
    Location
    Camden NSW & Selwyn NZ
    Posts
    2,334
    Hi,

    I think it might be simplest, safest, and cheapest to use a mechanical fuel pump from one of the carburettored Peugeot/Citroen 1.9 models, like the 305GTX, BX19GT, or 405. Alternatively you could buy a pressure regulator to lower the pressure of the fuel injection lift pump (although I wouldn't recommend it). You could also buy a simple electric fuel pump designed for carburettors. Webers require between 1.5 and 2.5 PSI of pressure. If the pressure is too high, the carburettors won't work correctly.

    Regards,
    Dave
    NZ Fleet
    1976 504 Ti
    1984 205 GT twin carb
    1991 205 SI 1.6GTI motor
    1994 106 Xsi
    1996 Mondeo V6
    Aus Fleet
    1955 203C
    1997 Civic Cxi (great allrounder- revy, flexible, nimble, comfortable , economical, simple and durable )

  3. #3
    Tadpole
    Join Date
    May 2001
    Location
    danmark
    Posts
    7

  4. #4
    Tadpole
    Join Date
    May 2001
    Location
    danmark
    Posts
    7

    Yes!
    At least someone who knows something about it If it's ok, I will be mailing you(or maybe icq?) if i com out for any problems during the conversion. Thanks a lot dave!

  5. #5
    Fellow Frogger!
    Join Date
    Aug 2000
    Location
    St Mary's Pennsylvania
    Posts
    233
    Use a fuel pressure regulator. Set at around 3psi to feed both carbs individually. This is fed as mentioned above via a cam driven pump from the xu9j2 engine. Just screw a bolt into the fuel return line as the pressure regulator handles this now. If you check out the specs on the engine in my 405 in this forum under the topic 'forum open' you will get a better idea the challenges you will have with this conversion.
    Good Luck.

  6. #6
    Guru davemcbean's Avatar
    Join Date
    Apr 2001
    Location
    Camden NSW & Selwyn NZ
    Posts
    2,334
    James,

    I didn't realise that the mechanical pump from the XU9J2 could produce more than 3 PSI. Obviously, if they do, the fuel pressure regulator is a very good idea. I know the mechanical pumps used on the 203 through to the 505 had a maximum pressure of around 2.7 PSI.

    How much do fuel pressure regulators generally cost? Are they easy to adjust?

    Thanks for correcting my mistake.

    Regards,
    Dave
    NZ Fleet
    1976 504 Ti
    1984 205 GT twin carb
    1991 205 SI 1.6GTI motor
    1994 106 Xsi
    1996 Mondeo V6
    Aus Fleet
    1955 203C
    1997 Civic Cxi (great allrounder- revy, flexible, nimble, comfortable , economical, simple and durable )

  7. #7
    Fellow Frogger!
    Join Date
    Aug 2000
    Location
    St Mary's Pennsylvania
    Posts
    233
    I actualy have no idea what fuel pressure the standard pump delivers ! But it feeds the twin 45DCOEs sufficiently. If you could imagine the shape of a 'T' fuel comes in the bottom via a filter from the cam pump. It is mechanically regulated to 3psi from a screw atop the 'T'. The lines run from either side to each carb.
    The pressure regulator is called a 'Holley Blue', which works best for the pressure settings on the webers. Cost ~ $60 NZD from XL Performance in Otahuhu, South Auckland.
    You should be able to pick one up from a V8 performance shop.

  8. #8
    Tadpole
    Join Date
    Jun 2001
    Location
    bedford ,bedfordshire, united kingdom
    Posts
    3
    ????? aye? unless i am much mistaken, the 'i' in gti means fuel injection, so why do ya need a new carburretor for???? To make it faster you chip it. Or there is a 16 valve conversion i have heard of that you could get.

  9. #9
    Guru davemcbean's Avatar
    Join Date
    Apr 2001
    Location
    Camden NSW & Selwyn NZ
    Posts
    2,334
    A modern fuel injection system is better than dual side draught webers, but dual side draught webers are better than crappy 1980s injection, while crappy 1980s injection is better than crappy base model carburettors.

    Not all injection systems are better than all carburettors.

    Dave
    NZ Fleet
    1976 504 Ti
    1984 205 GT twin carb
    1991 205 SI 1.6GTI motor
    1994 106 Xsi
    1996 Mondeo V6
    Aus Fleet
    1955 203C
    1997 Civic Cxi (great allrounder- revy, flexible, nimble, comfortable , economical, simple and durable )

  10. #10
    Fellow Frogger!
    Join Date
    Apr 2001
    Location
    Melbourne Victoria
    Posts
    302
    Dave,

    How can you compare any carbi with fuel injection
    My 80's fuel injection has not had any maintenance for six years
    To put a weber on will be going backwards
    My car idles the same runs the same always starts first time everytime
    You cant compare any carbi to a bosch fuel injection system even if it is a Le Jetronic
    Come on what would i gain by pulling out my bosch fuel injection and replacing it with a weber
    Waste of time i reckon
    You could spend the time in improveing the performance of your 205

    Murat

  11. #11
    1000+ Posts PeterT's Avatar
    Join Date
    Jul 2000
    Location
    Castle Hill, Sydney
    Posts
    7,446
    I agree with lordnelson. There is nothing crappy about the Motronic injection on the 205. It fires twice per engine cycle @ 3bar like most multipoint units, uses std. Bosch sensors and has the advantage of separate ignition. This makes it very easy to upgrade to an aftermarket ECU such as Motec or Haltech. The only advantge of adding throttle bodies is crisper throttle response. Bottem end torque will decrease due to shorter inlet tract and top end power will decrease unless some type of cold air box is fitted. Go back and read the posts about the guy who fitted an after market filter to his 306. The cost of adding two new carburettors would exceed the cost of adding a fuel only ECU to correct any incorrect mixtures (if there are any on 1.6GTi!)If you must have throttle bodies, buy injection only types, add your injectors and go the extra yards and purchase an aftermarket ECU. Sorry just can't see the value in adding carbs, then tuning them, to achieve mixtures similar to the std. system.

    '92 205 Mi16
    '90 Mi16x4

  12. #12
    Guru davemcbean's Avatar
    Join Date
    Apr 2001
    Location
    Camden NSW & Selwyn NZ
    Posts
    2,334
    Sorry. You misunderstood what I ment. What I ment was that 4 throttle bodies (i.e. 2 DCOE's) are capable of a greater power output than a single 50mm (or there abouts). Of course it is cheaper, if you've already got the sensors in place, to upgrade the injection system and put a larger throttle body on. Yes fuel injection is better than most carbs, and alot of fuel injection is better than all carbs. I was merely trying to correct the misconception that all injection is better than all carb setups. Twin DCOE's, if properly set up, can give excellent performance and economy, but they are bloody expensive, so yes upgrading the stock injection would make alot more sense in alot of cases. Sometimes however people get hold of a set of DCOE's really cheap, so you can't blame them for using them.

    I wasn't aware that the early 1.6 GTi had Motronic. I thought it would have been one of the older constant spraying systems.

    Dave

    NZ Fleet
    1976 504 Ti
    1984 205 GT twin carb
    1991 205 SI 1.6GTI motor
    1994 106 Xsi
    1996 Mondeo V6
    Aus Fleet
    1955 203C
    1997 Civic Cxi (great allrounder- revy, flexible, nimble, comfortable , economical, simple and durable )

  13. #13
    Guru davemcbean's Avatar
    Join Date
    Apr 2001
    Location
    Camden NSW & Selwyn NZ
    Posts
    2,334
    Just because you have 4 throttle bodies doesn't mean you have to have a short inlet tract, but unfortunately this is the case with most aftermarket manifolds.
    Of course it is much better to have a cold air intake than an aircleaner drawing from inside the engine bay, but in Denmark (which is what this thread is talking about)in Autumn and Winter, the disadvantages of drawing from inside the engine bay are probably nowhere near as bad as they are in Australia.

    Please don't assume I'm in favour of spending $2000 to buy and tune a set of Webers drawing hot air, rather than spending $700 or so to upgrade the stock injection and manifolding.

    This thread is to do with someone who lives in Denmark, has a 1.6 GTi and may have got hold of some Webers cheaply. Also in Europe they seem to be more experienced in tuning Webers than Fuel injection. In Australia it's the other way around. Australia leads the world in the amount of people per capita who know what they're doing with EFI, so we have to be careful about assuming posters from other countries are in the same situation as us.

    Dave
    NZ Fleet
    1976 504 Ti
    1984 205 GT twin carb
    1991 205 SI 1.6GTI motor
    1994 106 Xsi
    1996 Mondeo V6
    Aus Fleet
    1955 203C
    1997 Civic Cxi (great allrounder- revy, flexible, nimble, comfortable , economical, simple and durable )

  14. #14
    Guru davemcbean's Avatar
    Join Date
    Apr 2001
    Location
    Camden NSW & Selwyn NZ
    Posts
    2,334
    Having worked on Mechatronic projects at TAFE and university and being involved with the winning UNSW Yamaha 600cc Motec injected Formula SAE-Australasia racing car, I am a big fan of Electronic fuel injection and it's benefits. I'm also a big fan of robotics, which I hope to get into, so I'm no luddite.

    Please forgive me for calling the 1980's injection systems "crappy" but from where I stand the programming looks quite primitive. In the 80s they were restricted in the computing power which they could fit into a car at the right cost, so they had to be rather economical with their programming. It is a testiment to their efforts that they were able to get such basic systems to work so effectively. It is also a demonstration of the law of diminishing returns that many of the benefits of fuel injection were obtained with the relatively simple early production systems. With a PC, C++ and a microcontroller, it is relatively easy and cheap these days to replicate those early ECUs, on your own, but the microcontroller wouldn't have all the hours of reliability and durability testing that a proper ECU has, so I don't think I'll ever make one for my road car, although I'm tempted to do it on a track car, if I ever get the time. The new versions of C almost write themselves.

    The guys who programmed the Lunar lander were some of the smartest progammers. They had to do so much with so little (I think they had about 34K of RAM).

    Dave
    NZ Fleet
    1976 504 Ti
    1984 205 GT twin carb
    1991 205 SI 1.6GTI motor
    1994 106 Xsi
    1996 Mondeo V6
    Aus Fleet
    1955 203C
    1997 Civic Cxi (great allrounder- revy, flexible, nimble, comfortable , economical, simple and durable )

  15. #15
    Real cars have hydraulics DoubleChevron's Avatar
    Join Date
    May 2000
    Location
    Ballarat,Vic,Aust.
    Posts
    16,366
    Hi Guys,

    I wouldn't be that quick to dismiss the early injection system. I've have an injected DS21 that is fitted with bosch 'D' jectronic injection way back in 1970. It's computer is really a 'electronic calculator'. It has no IC's and the components are entirly discrete. It breaks and you can fix it with parts from Dick Smiths.

    Though the most basic form on injection you can have, the power over the standard weber equiped (double barrel) jumped from 120hp to 140hp. Torque increased as much also, except the torque curved was dramaticly flatter. All this from a handfull of diodes/resisters/caps and about 20 transisters....

    Can't get more basic than that.

    seeya,

    Shane L.
    'Cit' homepage:
    Citroen Workshop
    Proper cars--
    '85 Series II CX2500 GTi Turbo I
    '63 ID19 http://www.aussiefrogs.com/forum/citro%EBn-forum/90325-best-project-car-you-have-ever-seen.html
    '72 DS21 ie 5spd pallas (last looked at ... about 15years ago)
    '78 GS1220 pallas
    '92 Range Rover Classic ... 5spd manual.

    Yay ... No Slugomatics


    Modern Junk:
    '07 Poogoe 407 HDi 6spd manual

  16. #16
    Guru davemcbean's Avatar
    Join Date
    Apr 2001
    Location
    Camden NSW & Selwyn NZ
    Posts
    2,334
    Shane,

    I agree those primitive systems work quite well. Don't forget though, that the carburettor they were replacing was only a single 2 barrel down draught, which is nothing special. The factory prototype DS's with twin side draughts were another matter entirely.

    Almost all forms of injection are better than a single carburettor (no matter how many throats it has). There is a big difference between having a plenum chamber carburettor system and a throat per cylinder carburettor system.

    The bosch K-jetronic injection system is a very primitive constant spraying system, but it has no trouble blowing away a single dual throat carburettor system.

    I wasn't denying the advantages of simple fuel injection, just trying to provide a balanced argument.

    Regards,
    Dave
    NZ Fleet
    1976 504 Ti
    1984 205 GT twin carb
    1991 205 SI 1.6GTI motor
    1994 106 Xsi
    1996 Mondeo V6
    Aus Fleet
    1955 203C
    1997 Civic Cxi (great allrounder- revy, flexible, nimble, comfortable , economical, simple and durable )

  17. #17
    1000+ Posts PeterT's Avatar
    Join Date
    Jul 2000
    Location
    Castle Hill, Sydney
    Posts
    7,446
    I guess I get annoyed and disappointed when I see people trying to improve on factory setups which are already at the end of their technological limit. The fuel injection system has not increased significantly over the last 15 years, with the exception of sequential injection, variable length inlet paths and multiple 02 sensors (all of which have only fine tuned a major breakthrough in technology).Manufacturers have done a great job of making good hp and torque out of ordinary fuel and smaller motors. There's little left to improve upon without spending big dollars. People are still trying to apply the same low cost improvements today which applied 25+ years ago. And unfortunately, businesses are still take their money off them.

    '92 205 Mi16
    '90 Mi16x4

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •