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Converting To Injection

Posted: Tue Mar 01, 2011 7:40 pm
by tmcmahon92
I have a mk2 scirocco GT2 running a single webber car on a 2.0l 8v engine (i believe its the 3a engine from the audi's) it is an injection head and ideally i would like to see the car returned back to injection to get the most out of this car, so here it is. I was just wondering if anyone knew the best (andmost cost effective) way of doing this. cheers in advance.

Re: Converting To Injection

Posted: Tue Mar 01, 2011 7:47 pm
by Risocco
tmcmahon92 wrote:I have a mk2 scirocco GT2 running a single webber car on a 2.0l 8v engine (i believe its the 3a engine from the audi's)
First of all, you lucky sod! Been looking for a 3a block on and off for years!

IMHO, its probably more hassle than its worth, maybe worth looking into twin carbs?

Your car mate at the end of the day, just my 2p

Alex

Re: Converting To Injection

Posted: Tue Mar 01, 2011 7:54 pm
by tmcmahon92
cheers for quick reply mate,this is my first scirocco (first car infact lol) so excuse me if my questions are daft. with fast road cam and full exhaust/manifolds/port and polished all the usuals its running at around 130bhp but carb really needs a tune (was takenstraight off a 1.8 8v, hoping to get to around the 135-40 mark soon as, what power gains would i see from twin carbs? and how difficult to impliment this.

tom

Re: Converting To Injection

Posted: Tue Mar 01, 2011 8:33 pm
by Risocco
OK mate, it sounds to me that your running a carb jetted for a 1.8 engine, when your running a 2l engine? Is that correct? If so getting the carb sorted will give you a much better car, and power gains to boot.

In terms of running twin carbs, its a little bit of a minefield to be fair. Wouldn't like to guess at power gains there.

You would need to buy:

The twin carbs
Manifold
Throttle Linkage
Electric Fuel Pump
Fuel Pressure Regulator
A few fixings, such as a T Piece, possibly some fuel lines

And maybe a few other bits I've forgotten.

Don't be put off going to injection by any means, its just I would personally stick with the single Weber, or start to budget for a twin carb set-up :good:

Alex

Re: Converting To Injection

Posted: Thu Mar 03, 2011 9:23 am
by fonzooorooo
I'd get it to someone who knows about Webers (not someone who pretends to!!!) ... Get the carb you've got jetted and set up properly for a start, and ask the guy about where to go next. As I understand it, injection vs carbs is all swings and roundabouts anyway... I'd expect that in pure performance terms, you'd be able to get the same out of carbs as you would from injection, perhaps at the expense of some economy.

Where abouts are you? I can recommend a guy in Nottingham.

Re: Converting To Injection

Posted: Thu Mar 03, 2011 9:41 am
by tmcmahon92
yeah not far from notts, im in worksop. about an hour away. any recommendations are much appreciated as i'm new on the scirocco road :)

Re: Converting To Injection

Posted: Thu Mar 03, 2011 9:48 am
by tmcmahon92
Im getting a definite screw injection and keep carb vibe :good:

Re: Converting To Injection

Posted: Thu Mar 03, 2011 7:21 pm
by fonzooorooo
That's a handy place to live:

D & B CARBURETTOR SPECIALISTS LTD
NOTTINGHAMSHIRE, NG2 3GY NOTTINGHAM, CATTLE MARKET, CATTLE MARKET ROAD
+44 (0) 115 986 4971

Give them a bell about all your Weber needs....

I've no connection with the firm, I've used them, Jay on here's used them a couple of times too. Proper old-school place. Very helpful. Parts in stock etc...

Re: Converting To Injection

Posted: Fri Mar 04, 2011 4:39 pm
by Funky Diver
tmcmahon92 wrote:Im getting a definite screw injection and keep carb vibe :good:
In fairness... you'd be better sticking to carbs as the car is set up for it.

Going injection is a lot more involved than you might think... unless you have the WHOLE car available to use as a donor, and that basically means you will be able to swap everything right the way from the petrol tank through to wiring loom as it ALL needs doing. In fact anything attached to the engine would basically need swapping except exhaust and gearbox.

The 3a bubble block is a particularly nice block to use, as it doesn't add height. Bear in mind that if you went new on twin carbs, it's going to cost around £750 just for the carbs (DCOE or the like) and then the £180-200 for the inlet manifold.

I'd be tempted to do as indicated and go with flow work (on both head AND inlet manifold), cam, free flow exhaust and possibly (if you're up for it) ditching the dizzy to use a mappable ignition system (I'm going to be using megajolt) Stronger spark delivery, smoother up and down the rev range and generally better all round. If you really wanted to up the intake... 38DGAS would give you more flow through the carb, no so much in terms of better speed, but better response.

Re: Converting To Injection

Posted: Tue Mar 08, 2011 5:52 pm
by MikeH
Depends what kind of mileage you do in the car. If it's a daily commuter, injection will always be more economical. No major power advantage over a well set up 32/34 carb though.

It's not a conversion for the faint hearted though - fuel system / induction system / engine loom all need to be changed. Lots of aggro, and you need to find a decent donor car being broken to get all the bits at a sensible cost. You might be better to buy a running but rusty/crash damaged injection car to start with. Easier to swap your engine into an injection car, really.

I'd avoid twin carbs on a roadgoing 8v. 20-25mpg if you're lucky, and lots of heat issues with carbs sat above the exhaust manifold. Also, there's a shortage of room to get a decent length manifold and filters on there.... and buy a fire extinguisher!

Re: Converting To Injection

Posted: Mon Apr 18, 2011 2:00 pm
by hyperdrinky
It's not a conversion for the faint hearted though - fuel system / induction system / engine loom all need to be changed. Lots of aggro, and you need to find a decent donor car being broken to get all the bits at a sensible cost. You might be better to buy a running but rusty/crash damaged injection car to start with. Easier to swap your engine into an injection car, really.
Alternatively go for megasquirt. You really need to be technically minded, and do a shed load of research but it looks promising. Same amount of agro but you get a warm, fuzzy feeling that you're doing it all yourself.

Re: Converting To Injection

Posted: Mon Apr 18, 2011 2:26 pm
by MikeH
hyperdrinky wrote:
It's not a conversion for the faint hearted though - fuel system / induction system / engine loom all need to be changed. Lots of aggro, and you need to find a decent donor car being broken to get all the bits at a sensible cost. You might be better to buy a running but rusty/crash damaged injection car to start with. Easier to swap your engine into an injection car, really.
Alternatively go for megasquirt. You really need to be technically minded, and do a shed load of research but it looks promising. Same amount of agro but you get a warm, fuzzy feeling that you're doing it all yourself.
.... and you still need to rebuild all the fuel system to injection spec, as Megasquirt needs to run around 3-4 bar, rather than 3-4 psi in a carb setup. Megasquirt is MORE work than converting to Kjet, as you have to find the right combination of bits, then fit them, then map the whole thing, as opposed to fitting a load of factory spec standard parts. I've done a megasquirt conversion, and the results are great, but it's a lot of work (even with the expert help I had, and on a car that was injection to start with).

Unless there's something really special about your shell, buy an injection car and put your engine in it, or get your 32/34 carb rejetted to suit the engine.