Provided the OEM intake manifold meets the engines CFM requirements then changing it for an aftermarket manifold which is capable of even greater CFM flow rates will not on its own increase engine power, and can in some instances have an adverse effect on the engines torque curve/output.

The results of the tests comparing the flow rates of each runner of the ABD manifold might look impressive to some people......but it has to be rememberd the results measured water flow rates through the manifold and runners, and not boosted intake air.

Bill.

That’s the whole point; the OEM manifold does not give evenflow across all the runners. Extra power is nearly all about increased airthrough the engine. Amongst other influences, the faster and more volume of airflowing through the head the better.

I cannot comment on the above Elitedubs test conditions, Ican only base my comments on my before and after air flow bench test results ona modified ABD manifold. I did the same air tests on a modified AUQ head (whichI fitted to my old black vRS them later on the Red Devil) with fantasticresults. Differing air intake volumes into each cylinder will definitely havean adverse effect on turbo exhaust pulse pressure, so even pressure through each runner can only be good.

Mind you I have been known to be wrong and blown **** up.

Trial and error...... Expensive but fun!!!!!

There's nothing like a bit of inspiration. Just quick question. Where do you guys mainly source your parts from. Also is vw vortex more for the enthusiasts than the dingbat that can't change a wheel and goes onto a forum to ask how to do it?

Extra power is nearly all about increased airthrough the engine. Amongst other influences, the faster and more volume of airflowing through the head the better.

If we were having this discussion 25-30 years ago when the chances are our cars would have been naturally aspirated (N/A) then I would have totally agreed with you

However, its an engineering fact that "Extra power" is all about increasing an engines volumetric efficiency (VE) in relation to its displacement.

N/A engines with a wide open throttle struggle to acheive VE's of around 80% due to factors like you mention, restrictions through the air intake, manifold, TB, valves, head etc......

And by increasing the air flow (CFM) through a naturally aspirated engine it is possible to acheive VE's in excess of 100%, but such engines are no good for road use due to them having a very narrow power band and virtually no torque.

Our turbo boosted 1.8t engines have no such air flow problems or restrictions due to the fact the air entering the cylinders is boosted to higher than atmospheric pressure, which results in VE's well in excess of 100%.

What that means is..... that provided a manifold can flow the required amount of boosted air (CFM) for the engine to acheive its target power output be it 200hp or 500hp then it will do just fine, and fitting a manifold capable of exceeding the engines max CFM requirements will give no improvement in VE.

HTH

Bill.

Edited 5 January, 201115 yr by vrs180

If we were having this discussion 25-30 years ago when the chances are our cars would have been naturally aspirated (N/A) then I would have totally agreed with you

However, its an engineering fact that "Extra power" is all about increasing an engines volumetric efficiency (VE) in relation to its displacement.

N/A engines with a wide open throttle struggle to acheive VE's of around 80% due to factors like you mention, restrictions through the air intake, manifold, TB, valves, head etc......

And by increasing the air flow (CFM) through a naturally aspirated engine it is possible to acheive VE's in excess of 100%, but such engines are no good for road use due to them having a very narrow power band and virtually no torque.

Our turbo boosted 1.8t engines have no such air flow problems or restrictions due to the fact the air entering the cylinders is boosted to higher than atmospheric pressure, which results in VE's well in excess of 100%.

What that means is..... that provided a manifold can flow the required amount of boosted air (CFM) for the engine to acheive its target power output be it 200hp or 500hp then it will do just fine, and fitting a manifold capable of exceeding the engines max CFM requirements will give no improvement in VE.

HTH

Bill.

Umm, your statement below is in agreement with my firstparagraph?? It's all about the amount of air forced into the head and out theother side.

its an engineering fact that "Extra power" is allabout increasing an engines volumetric efficiency (VE) in relation to itsdisplacement.

The big difference is I am taking about making a 1.8T engineexceed it's intended BHP figure by large amounts. For example if you fitted aGT30 to a standard 1.8T engine set up it would take for ever to spool up. Theonly way to overcome this problem is to move a higher volume of air from theturbo into the head. Removing restrictions like low diameter pipework withsharp bends, enlarging cylinder head ports, increasing displacement (i.e.re-bores, stroker kits, dished pistons etc) and shock horror bigger intakemanifolds that distribute air into each cylinder better than stock. There areobviously many things that effect spool up time but these are just a few. Thereis a problem with the stock mani as it's distribution of air into each runneris not even whereby cylinder 1 gets more air than the others. This isemphasised when remapped as cylinder 1 burns leaner than the others.

I do agree with everything you say but we are taking abouttwo differing states of tune. My posts are in reply to the questions in thisthread about turbo'ed cars and ABD manifolds. It's all about balancing all ofthese to exceed the manufacturers intended power figures for me.

Sorry for all the ramblings.

Thereis a problem with the stock mani as it's distribution of air into each runneris not even whereby cylinder 1 gets more air than the others. This isemphasised when remapped as cylinder 1 burns leaner than the others.

Sorry for all the ramblings.

I dont think your rambling mate....your giving your opinion based on your own personal experience of building a high powered 1.8t, and I acknowledge that

It is rather odd that you found cylinder No 1 gets more air than the others and therefore runs leaner, when then flow test results for the std OEM manifold show that cyl No 1 gets the least air flow @ 130 CFM, No 2 cyl flows 145 CFM, No 3 & 4 cyl's flow 153 CFM.

It just goes to prove how unreliable "bench" tests like these can be, and that you cant beat proper on car, on the roller's testing.

Bill.

Edited 7 January, 201115 yr by vrs180

I dont think your rambling mate....your giving your opinion based on your own personal experience of building a high powered 1.8t, and I acknowledge that

It is rather odd that you found cylinder No 1 gets more air than the others and therefore runs leaner, when then flow test results for the std OEM manifold show that cyl No 1 gets the least air flow @ 130 CFM, No 2 cyl flows 145 CFM, No 3 & 4 cyl's flow 153 CFM.

It just goes to prove how unreliable "bench" tests like these can be, and that you cant beat proper on car, on the roller's testing.

Bill.

Just before I got made redundent back in 2009 I had a lot of enforced time off, luckily for me Mike at IP did not have much work himself. It's suprising what you can break on a set of rollers when you are bored sensless. The up side is you can discover quite a bit as well, silly things like a dual N75 set up to controll high boost settings.

There's nothing like a bit of inspiration. Just quick question. Where do you guys mainly source your parts from. Also is vw vortex more for the enthusiasts than the dingbat that can't change a wheel and goes onto a forum to ask how to do it?

What ever you do don't ask the later on Vortex as they are a nasty bunch when they get going.

Most of the parts I have made myself or at the very least make a standard part fit the job. It's amazing what you can do with a grinder.

What ever you do don't ask the later on Vortex as they are a nasty bunch when they get going.

Most of the parts I have made myself or at the very least make a standard part fit the job. It's amazing what you can do with a grinder.

Cheers

Preparing the intake manifold for fitting

I'm too tight to pay $30 for an impact socket to use once for 5 minutes but an M12 bolt did the job perfectly.

silly things like a dual N75 set up to controll high boost settings.

that is awesome!!

Very nice Rob

Looks like you've used loctite or something to hold the injector inserts in?

It looks like that manifold also has one less vac port than the standard manifold? That central one underneath normally has a partner (one for breather system, one for suction pump system)! I've got one of mine blocked off, so this would be an extra perk to the ABD manifold for me!

Are you still running the suction spray pump system?

Very nice Rob

Looks like you've used loctite or something to hold the injector inserts in?

It looks like that manifold also has one less vac port than the standard manifold? That central one underneath normally has a partner (one for breather system, one for suction pump system)! I've got one of mine blocked off, so this would be an extra perk to the ABD manifold for me!

Are you still running the suction spray pump system?

Yeah I used Loctite blue - best option I could find locally! Should do the trick.

Suction spray system is long gone. The manifold comes with an extra bit of pipe and a Y piece just in case

It also comes with new gaskets for both sides which I didn't expect.

very nice

another thing you can do rob to tidy the bay up a bit is loose the brass vac point on the end of the mannifold and fit a bung in there like i did and then run you brake servo pipe from underneath and around the left hand side of the engine hidden make it look so much cleaner

top work

very nice

another thing you can do rob to tidy the bay up a bit is loose the brass vac point on the end of the mannifold and fit a bung in there like i did and then run you brake servo pipe from underneath and around the left hand side of the engine hidden make it look so much cleaner

top work

I was thinking about doing that. Will have to get some pipe

do it rob really does tidy it up as that fitting is huge lol

also replacing the brake servo line to a shorter run can only be a good thing

Don't suppose you know off the top of your head what thread it needs to be for the bung??

havent a clue andyrew got me it from a plumbers merchant lol

Cant the standard inlet be "improved" to be more even?

I know back in the land of cosworth's, they used to run a little leaner on number 3.

havent a clue andyrew got me it from a plumbers merchant lol

Apparently it's a 3/8 NPT thread according to some random bloke on Vortex. Plumbers merchants next week I think..

Things are not going entirely according to plan. Got it all fitted - no throttle body on yet but all bolted down. Then realised I got the wrong injector seats - doh!!

The holes are too small. Will have to buy that socket after all to get them out again!

So my car's all in bits at the moment :(

Things are not going entirely according to plan. Got it all fitted - no throttle body on yet but all bolted down. Then realised I got the wrong injector seats - doh!!

The holes are too small. Will have to buy that socket after all to get them out again!

So my car's all in bits at the moment :(

Oooops..... modding cars rarely goes to plan

Will that mean the manifold has to come back off to ensure no particals of Loctite sealant gets into the inlet tract when the seats are removed ???

Looking forward to you getting this up and running and to here your thoughts on how it compares to the OEM manifold.

Bill.

Good point I'd better take it off again. Bummer!

It's a bit disheartening after you get most of the way through a job and you have to take it apart again!

That should look really nice Rob once finished!!!

I like it, a lot!!!!!

Steve

Oooops..... modding cars rarely goes to plan

Will that mean the manifold has to come back off to ensure no particals of Loctite sealant gets into the inlet tract when the seats are removed ???

Looking forward to you getting this up and running and to here your thoughts on how it compares to the OEM manifold.

Bill.

no difference with the small turbo on but its then future proofed as this will be a good mod once bigger turbo's are fitted