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Caimin

205 gti running twin webber 40's (general advice)

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Caimin

Hello, im a new member on here but ive been reading the posts for months without being a member. excuse if this is the wrong section or if it is all obviously pointed out somewhere else.

 

First off, i have finally bought a 1987 205 gti with a 1.6 engine running twin webber 40 dcoe's. It was a rallycar, has a rollcage etc.

Nothing is original to the car, apparently it has 1.9 shafts and hubs, but i dont know whether its true or not?

 

Im looking to use it first for trackdays and maby progress to something else after a while.

Ive been doing bits to it in my spare time for a few weeks. (Mostly just oil, plugs etc)

 

So my first question is how do i find out what model engine i have? I hear so much about different models but i cant find any numbers on my engine. 

 

And i will be looking for all the advice i can get on setting up the webber carbs,

the engine runs ok now but the carbs are filthy and out of balance so im planning to put 2 rebuild kits into them and clean them up. I also bought a syncrometer to help tune but its my first time so all advice appreciated.

Ive no idea what jets etc are in them at the moment but when i strip them ill take note.

 

Also my throttle linkage is a bit home made and has play in it, any reveiws on the ebay linkages are they good? Or do you reccomend another type?

 

Sorry for no pictures if someone can tell me how you all add them ill post a few just im not sure how.

 

Thanks in advance for all help

 

Edited by Caimin

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SootySport

I’m guessing the carb jetting would have been sorted before the car started its competition phase so that shouldn’t need changing.   Give them a good clean. Remove the jets and wash in petrol and blow an airline through.  Fit new gaskets and o ring service kit and rebalance on the car.  
Two big tips for you is, strip one carb down at a time, you’ll then have the other carb as a reference to where all the parts fit.   Have a clean table/bench with a white sheet to work on some of those o rings and parts are tiny and can get lost.

To get the most out of twin carbs you would need a carb expert to rolling road tune them, there’s still a few guys that do this around the country.

Linkage can be bought from Sytec engineering or Eurocarb.
You can buy a book  ‘How To Build & PowerTune Weber and Dellorto Carbs’ by Des Hamill on eBay which explains everything about carbs.

Genuine parts and service kits from Eurocarb. 

Edited by SootySport

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Caimin
34 minutes ago, SootySport said:

I’m guessing the carb jetting would have been sorted before the car started its competition phase so that shouldn’t need changing.   Give them a good clean. Remove the jets and wash in petrol and blow an airline through.  Fit new gaskets and o ring service kit and rebalance on the car.  
Two big tips for you is, strip one carb down at a time, you’ll then have the other carb as a reference to where all the parts fit.   Have a clean table/bench with a white sheet to work on some of those o rings and parts are tiny and can get lost.

To get the most out of twin carbs you would need a carb expert to rolling road tune them, there’s still a few guys that do this around the country.

Linkage can be bought from Sytec engineering or Eurocarb.
You can buy a book  ‘How To Build & PowerTune Weber and Dellorto Carbs’ by Des Hamill on eBay which explains everything about carbs.

Genuine parts and service kits from Eurocarb. 

Great reply thanks very much!

I hope that the carbs wer set up like that originally but it has been a few years since it was rallying and i dont know for sure whether or not the carbs wer on it at the time or if it was just someone who pulled them off another car and put them on this. So worth checking out.

All good advice, i will take it all on board, i just ordered that book now too so should be useful.

I would like to get it done on a rolling road but as i live in ireland i dont know if there is anyone who can do it the old way, any i can find online tend to be all ecu remap specialists which is useless. Would be great though if i can find one that is familiar/ experienced with webbers. (If anyone knows someone itd be great i have a trailer so can bring it to them)

Failing that ive read that fitting a wideband lambda and having the correct info to go by it could be done well, any comment/ reccomendations on a sensor kit?

I will get one of those linkages, any idea why they have 2 cables though? Seems unnecessary and a bit tricky to attach to the pedal..

 

 

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welshpug

competition cars have to have two return springs, two cables give a failsafe as well.

 

1.9 hubs can be identified by the larger M24 threaded hub nuts, oem were R clipped though aftermarket can be staked, 1.6 and base model use M20 and staked nuts.

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SootySport
14 hours ago, Caimin said:

Great reply thanks very much!

I hope that the carbs wer set up like that originally but it has been a few years since it was rallying and i dont know for sure whether or not the carbs wer on it at the time or if it was just someone who pulled them off another car and put them on this. So worth checking out.

All good advice, i will take it all on board, i just ordered that book now too so should be useful.

I would like to get it done on a rolling road but as i live in ireland i dont know if there is anyone who can do it the old way, any i can find online tend to be all ecu remap specialists which is useless. Would be great though if i can find one that is familiar/ experienced with webbers. (If anyone knows someone itd be great i have a trailer so can bring it to them)

Failing that ive read that fitting a wideband lambda and having the correct info to go by it could be done well, any comment/ reccomendations on a sensor kit?

I will get one of those linkages, any idea why they have 2 cables though? Seems unnecessary and a bit tricky to attach to the pedal..

 

 

Single cable will be ok for a road car and you can achieve the desirable pedal feel with an extra return spring, try different tension springs if the linkage is not adjustable.  

There will be a carb tuner near to you, just phone local motorsport companies and someone will know who can tune them.  

My carb man fitted a boss for the a wide band and just fits the sensor for tuning, then fits a blanking cap when he’s finished.
 

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barneys66

As above, hopefully your main jets are already optimised, so it's balance and idle you can play with.

 

I set my balance with a syncrometer (the type you stuff into the trumpet) and my idle with a Colourtune both of which worked really well.  If your linkage has play between the carbs then trying to balance them will be pointless.  When you fit the new linkage ensure it is correctly adjusted or has a stop so you're not pulling on the carbs themselves at WOT, and make sure you have the rubber washers to mount the carbs when you put it all back together.

 

I need to play around with the return springs on mine, as the two eBay specials combined are far too heavy..

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Caimin

Ok so you say the 2 cables are more of a backup incase one was to break, makes sense. Ill see how it looks when i get it whether ill fit the 2 or just the 1.

The linkage im looking at is this one: (i hope its ok to post links) https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F273062678070

Anyone use the same one? Seems to be sytec anyway.

I will ring around to try and find a tuner, i seen one nearby that says he tunes webbers, but his website doesnt say wether or not he uses a rolling road. Ill ring monday.

That colourtune idea looks interesting i was just doing some reading on it, i had never heard of one before. My question is are they all the same? Or would it be like different spark plug numbers where youd need the correct colourtuner for your engine? 

I will try to get some pictures up tomorrow if i can figure out how. (I know all the writing is a pain)

Thanks for all the replies, 

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barneys66

Links on here are fine - there are a couple of negative reviews for that product though.

 

Unsure on varieties of Colourtune, though mine is the branded Gunson one.  Was good for setting the idle (only) and reinforced visually how you could hear the engine was reacting as you adjusted - the latter is probably how the pros do it !!

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Caimin

Ny5WnUUQnbTkxmoo6Ny5WnUUQnbTkxmoo6Ny5WnUUQnbTkxmoo6photo test

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opticaltrigger
20 hours ago, SootySport said:

My carb man fitted a boss for the a wide band and just fits the sensor for tuning, then fits a blanking cap when he’s finished.

That's the best way, or leave the sensor in for full time monitoring...

If it's a thing that interests you,,,, both of these are great and the Spartan 3 version will stream the output to an app on your phone if you don't want a gauge.

 

https://diy-efi.co.uk/product-category/accessories-2/wideband-lambda-kits

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Caimin

finally some photos, hopefully you can all see them.

 

Gv2ljAuIO-wUR5JNAHViFfNfvc1Cs6H-QZR5NiEV

FRovVjJMAgz_zSd8yHAZDoHtvqibgmeUqcLWN4CP

 

21VzSHQKeBSP2AxTp9DhT49R0L2zlz6U5s5L0-EH

 

HMHfTfMLg_H1wP7a-Afjikujd8xYM7xNN_d9jQURmhd0zSx9NQXlBYUq1Chey0D8la2_Qf08RwhwoyGo

 

ZlkdZT6WkXh5uNkYaOikyFPQjManHlu04yGX6NQN

 

im actually thinking this linkage was made properly at one point, but has been butchered or "repaired" since, it doesn't seem to have play between the carbs, but every other part of it is very loose.

 

q36UkW3iHVtBHiNLDrsiK_vUwKGdpc4BetJpX9nJ

 

as you can see the whole thing needs a serious clean up, bit of work to do but i basically bought it very cheap off a man that just wanted it out of his garage so i dont mind doing a bit of work, if anyone on here thinks they recognize the car from anywhere in the past it'd be interesting to know.

also im still unsure which engine i actually have, can anyone see it from the pictures or do you want pictures of other  parts of the engine to narrow it down?

Edited by Caimin

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barneys66

That's strange - thought I saw these last night but can't now..?

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SootySport

I can’t see the photos either.

Colurtune is made by Gunsons. I had one and it’s not that accurate.  I set the mixture by trial and error, by looking at the spark plug colour after every tweak of the mixture screws.   
The Sytec linkage is the one I suggested earlier, hope there is enough space between its mounting point and the bonnet.

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welshpug

I'm a fan of the AEM wideband kits, Sandy Brown uses them too, they have a gauge that you can monitor if needs be, as well as an output for an ecu to use.

 

can be found under £150 and the sensor is easy to find if you knacker one.

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Caimin

Im not sure whats happening with the photos, i can see them fine.. im using google photos as the host and i followed a tutorial on how to share with a forum.. is there a better way im new to this so im not sure? 

Ya im tempted to go the wideband rout, not just for tuning but for monitoring the tuning when at the track.

The bonet clearance is a concern aswell, i think the current linkage only barely misses it.  Was thinking though that where the carbs are located doesnt allow much cold air to them, right above the radiator etc isnt ideal. Was thinking of cutting a hole above them and maby fitting a scoop or something to get air to them. Any thoughts on this? Am i right in thinking that they wont get enough cold air with the bonnet closed?

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Romb

I think you're right on the hot air.

 

That's also my main gripe with many aftermarket air filters, they mostly just hang loose in the engine compartment. When idling a while after driving and then going again I'm pretty sure the air won't be dense.

 

Given the little room compromises must be made and the default 1.9 GTI setup is not optimal either with the air filter on top of the exhaust manifold and a pretty long way for the air to travel with all kinds of bends, but it does look pretty decent. There is some RAM air effect there, having fresh, cold air from outside pushed in there.

 

At one point I went with it and bought a pretty expensive K&N cone filter, but switched back to default. Still have it if anyone wants to buy, hardly used, I think it's the 57i. Placement is pretty decent behind left headlight but what bugged me was the short piece of rubber between intake manifold and air flow meter making the latter all wobbly due to engine vibrations. Default setup is way more durable. It did have a flexible hose that was supposed to channel fresh air from underside of the car but that had the risk of putting loads of water in the car when driving through big puddles. All in all trade off wasn't worth it imo, although it sounded nice.

 

By the way, just stumbled on below post, I guess that's the worst you can do; open filter right on top of the exhaust :-P

 

 

 

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welshpug

I'd lower the rad or get a shorter one before cutting any holes, aerodynamically IIRC the area just behind the nose of the bonnet is actually under vacuum so hot air from the radiator will go straight up into the trumpets if you make a hole there, also makes it likely for water to fall in.

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Caimin

Thats the issue i think with a lot of these induction kits, they look cool but dont tend to go to the best part of the engine bay. Something i think that is overlooked a lot is that most engines tend to get tuned with the bonnet open, then when its closed the air supply would be much different.

 

Thats interesting to know about the bonnet, shows its good to get second opinions. Ill have a look at how the rad is mounted see if it can go any lower, i imagine it being a headache though to find pipes that fit in the new position. Maby better to find a different rad with a hose kit with it ill have to check out options.

 Either way i think something shoùld be done because the carbs seem to be in a bad position, hard to see how any air will get to them without going through something hot first

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Caimin

Sorry for lack of progress, not getting much time at the car recently, i think ive decided on a linkage though:

https://www.burtonpower.com/throttle-linkage-kit-twin-weber-dcoe-fsestlk100.html

Looks a bit better and maby lower then the previous one.

I have seen different intake gaskets for the carbs, some made totally of rubber https://www.burtonpower.com/sandwich-plates-40-dcoe-x-2-nylex-websp40.html  and some are metal with a rubber oring built in such as this one: https://www.burtonpower.com/sandwich-plates-misab-40-45dcoe-x-2-set-of-4-webmisab.html (i think this might be whats on the car at the moment) 

Also i see mounting kits with thick rubber washers like this: 

https://www.burtonpower.com/carb-mounting-kit-dcoe-carbs-x-2-webcmk.html

Any ideas what situations all these kits are needed for and which ideally should i get for when i put the carbs back on the car? At the moment the carbs just seem to be bolted straight to the manifold with a basic enough (metal?) gasket, ill take them off this week to see for sure whats on there.

Edited by Caimin

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barneys66

I might be wrong, and it may be universal, but don't you need a cable that exits / pulls to the left, or are the cables long enough to compensate..?  See mine below:

 

I use the similar plastic sandwich plates to the ones you've linked, with a rubber washer on each face, and do have the same washer kit - both to facilitate non-solid mounting of the carbs as recommended.

 

Can't comment on the metal ones, though they look very thin to me..

 

 

36216149094_eee46acc75_b.jpg

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SootySport

The rubber mountings help prevent frothing of the fuel due to vibration of the engine.  The carb mountings and Mishab washers are used in conjunction with each other.

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