# Plastic variable intake on an ABA - any point?



## mr.brown (Oct 26, 2003)

Some quick background - I'm taking a couple of ABA OBD1 heads back with me to the UK this summer as these weren't available in the EU. 

I'm planning to fit an alloy block 1.6 8v mk IV Golf/Seat Leon engine into a mk1 Scirocco. These 1.6 "SR" engines came with a head identical to an OBD2 ABA so the head swap will be simple. The new OBD1 head will have a TT 276 cam. 

I have the option of using the stock ABA OBD2 intake or the intake from the 1.6 - which is a variable intake made of plastic. I haven't yet determined how the variable intake works but from what I remember it is vacuum operated so may be ECU independent or at worst a simple on/off switch. 

Would there be any point keeping the variable intake from a performance point of view? 

It would be running MS1 v3 if that has any bearing. 

 

Pic of intake 










Better view of switch/lever


----------



## mr.brown (Oct 26, 2003)

And this from VW's Self Study Program - it calls the intake "twin path" which would imply that it only has the two positions


----------



## mr.brown (Oct 26, 2003)

OK, so it looks as if the changeover is ECU activated at 4krpm. 


















So, given that the two intake lengths are fixed the question is would varying the rpm point at which it switches give any advantage for a given camshaft?


----------



## tdogg74 (Mar 1, 2002)

My main question would be this: what is the runner diameter on this manifold? 

This is for a 1.6L engine, so I can see the need for a variable intake to create a more robust low end. My concern would be the over-all runner diameter for top end performance. Smaller runners would generate more low end torque, but if they are too small, then your top end is going to suffer. And being plastic, there is no room for modification. For top end performance, if they are smaller in diameter than a MKIV manifold, I feel it would be a waste of time on a worked ABA head with a big cam. 

As for controlling the flap switch, use one of these: 

http://www.summitracing.com/search/?keyword=rpm switch&dds=1


----------



## mr.brown (Oct 26, 2003)

Thanks for your input. I've no idea on the runner diameter yet - I probably won't get hold of one til I'm back in England. 

I know that the 2.0 Beetle Cabrio came with a very similar manifold so I'll compare the two when I get a chance. 

And thanks for the link.


----------



## tdogg74 (Mar 1, 2002)

Regardless, I would definitely try to get one installed. Get everything running and put it on a dyno. Do a few runs with the flap open and a few with the flap closed. Get the averages of both, and then you can choose what rpm to set the rpm switch to occur. At the very least, you would still have a good top end, but now you could probably run a bigger cam, like a 288*, and you would have a much better low end. 

I've had this idea in the back of my head to do something like this for a long time...except with a design I came up with years ago. I can honestly say, I would love to get my hands on one of these plastic mani's to look at and take measurements off of.


----------



## jettred3 (Aug 5, 2005)

Good stuff Mr. Brown. 

Look forward to seeing your progress.


----------



## mr.brown (Oct 26, 2003)

Progress won't be anytime soon :laugh: 

@911_fan - the 1.6 intakes are dirt cheap in the UK as probably more than 50% of mk4 Goofs sold were 1.6 - not to mention Audi A3, Seat Leon, Skoda Octavia etc... I'll send you one when I get back. 

Example - $27 

http://www.ebay.co.uk/itm/VW-GOLF-M...CarParts_SM&hash=item3cc18ab06a#ht_500wt_1375 

The 2.0 ones are a bit rarer and costlier as i'm 99% sure they only came on the Beetle Cabriolet 

http://www.ebay.co.uk/itm/vw-golf-m...CarParts_SM&hash=item19cc8eb69c#ht_500wt_1375


----------



## tdogg74 (Mar 1, 2002)

*FV-QR*

Oh, hell ya. We'll figure this thing out.


----------



## mr.brown (Oct 26, 2003)

Anyhoo, just had a quick look at ETKA 

Golf/New Beetle 2.0 engine code AZJ 

Upper manifold - 06A 133 203 EE 
Lower manifold - 06A 133 204 CP 

Golf etc 1.6 engine code AKL 

Upper manifold - 06A 133 203 DR 
Lower manifold - 06A 133 206 BB 

So it looks like the upper manifolds are in fact the same (or as near as dammit) - which is borne out by the ETKA diagrams below 

1.6 









2.0 









The lower manifold is a lot chunkier on the 2.0 - I wonder what the effect of putting that on a cammed 1.6 would be.


----------



## jettatech (Oct 26, 2001)

yeah theyre common on the first year beetle convertable 2.0l. in the states, 2.0l dog slow in a heavy car.....BDC is the 2003 convertable engine code which had these here. vw later put in the 1.8t and 2.5l which gave the car some more pep.


----------



## tdogg74 (Mar 1, 2002)

*FV-QR*

judging from those pictures, the 1.6 upper has the houses the dual plenum, while the 2.0 lower does the job. Only I dont see the part description for the vacuum assist. (part 18 on the 1.6 diagram) 

My guess would be for the differences would mainly be the different camshaft profiles. Runner length is determined when the intake valve cracks open. I can only assume these two different engines have different profile cams....hence the need for the different "shorter" runner variances. 

Keep in mind, either one of these should work fine because you will be using a different head and you will be modifying the input signal to the flapper to open when YOU want it to...with the aid of a dyno sheet. Stick with the 1.6 manifold.


----------



## anlxn (Oct 18, 2009)

another Idea I had was the use of an adjustable Cam gear.

I am also toying with this Idea of Useing a beetle intake on an ABA

and does anyone know the specs of a late model 2.0 cam from a variable intake motor?


----------

