Inlet manifold opinions?

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darren t

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So I finally got round too fitting a large port agu head that i have had for a while I took it too my engine specialists who stated it needed new valve stem seals and the exshaust guides were worn tuffty already told me I'd need these as a minimum!
so I fitted the head over the weekend and new cambelt ect..
im at the stage were I don't know what too do with my inletmanifold as I have a small port manifold and a large port...
My question is can I extend map sensor wiring any throttle body so I can run agu inlet manifold or would I be ok too fit my small port inlet manifold for now as I'm itching too start her up??
or should I open up the small port manifold best I can?id like too stick with the small port as I have had it powder coated?
 

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I opened my small port up to large port size, did a good job if i do say so myself, check it in my thread.
Small ports no matter what you do with them have narrower runners than large ports.
Putting the large port runners on your small port plenum would be the best/cheapest/easiest option for maximum effect.
But depending on the level of mods you have you might not notice it. So just stick the small port on and enjoy the car, if it really bugs you you can put the LP runners on the SP plenum
 
superkarl said:
I opened my small port up to large port size, did a good job if i do say so myself, check it in my thread.
Small ports no matter what you do with them have narrower runners than large ports.
Putting the large port runners on your small port plenum would be the best/cheapest/easiest option for maximum effect.
But depending on the level of mods you have you might not notice it. So just stick the small port on and enjoy the car, if it really bugs you you can put the LP runners on the SP plenum
Click to expand...
doing it as wee speak just what I wanted too hear lol money money money never ends..
with the smaller runners I gather quicker spool up?
 
Do you have a link for the thread plz Karl saves looking through page after page lol
 
superkarl said:
I opened my small port up to large port size, did a good job if i do say so myself, check it in my thread.
Small ports no matter what you do with them have narrower runners than large ports.
Putting the large port runners on your small port plenum would be the best/cheapest/easiest option for maximum effect.
But depending on the level of mods you have you might not notice it. So just stick the small port on and enjoy the car, if it really bugs you you can put the LP runners on the SP plenum
Click to expand...

and you have data showing difference 'super'karl?

;)
 
You will lose low end torque with large port runners but gains to be had top end typically... still not massively convinced large port is the way to go on smaller framed turbos (K04's etc) as they don't have the puff to support large port flow gains...

Spool won't be affected by inlet runner choice directly... larger plenum's and charge pipe/FMIC will affect the perceived boost build due to more volume to fill before pressure can build...

Swings and roundabouts... still a fair amount of effort to graft largeport runners to an S3 plenum... need to make sure there are no massive gaps to fill with weld... also take note that AGU and AEB runners are differnt... AEB runners are parallel to each other but AGU as cyl 1 runner at a different angle to the other three

<tuffty/>
 
Depends what turbo.
Thats pretty untested and speculative tho.
On small turbos like ko4s the gains of largeport are pretty small, and no ones really played with inlet manifolds on small turbos.

On the bigger stuff, some people even argue small port is better for spool.
But in general narrower longer runners are better for spool and midrange gains.

All depends on the blower and the rest of the setup, but its not like people have tested everything out there on different sized turbos.

I always wanted westy to sort out an inlet manifold just to see what the results are, as his car is the benchmark for stock ko4s.
Wouldve also been good if prawn had done the same on his old hybrid.
 
badger5 said:
and you have data showing difference 'super'karl?

;)
Click to expand...
data for which?
Putting large runners on a large port head?

Are you suggesting that without data to back it up, large port runners WONT make the most of a largeport head???

Sometimes common sense and a bit of theory is enough even without data.

And as i said later on in here, data would be great to actually quantify things.
We know tuffty benefit from it, on a smaller turbo, smaller air mass, but still might see similar % gains as tuffty
 
Well my max air flow on my old bam head was 226gs my aim is big turbo but I'm in 2 minds weather too keep or sell I'm going too fit the small port and doo some logs and compare them too my old bam cylinder head logs...
will I run cooler with the larger cylinder head at all?
 
superkarl said:
data for which?
Putting large runners on a large port head?

Are you suggesting that without data to back it up, large port runners WONT make the most of a largeport head???

Sometimes common sense and a bit of theory is enough even without data.

And as i said later on in here, data would be great to actually quantify things.
We know tuffty benefit from it, on a smaller turbo, smaller air mass, but still might see similar % gains as tuffty
Click to expand...


I have the benefit of having run various combinations and know what actually happens
 
badger5 said:
I have the benefit of having run various combinations and know what actually happens
Click to expand...
whats your opinion then bill?
will I be ok for now till I can afford/sort out another manifold without causing any damage ect..
 
audi upgrades
The problem with a ported small port manifold is at the end of the day it's still a small port after port work.

You ports have just opened up the end when the rest of the port is still small.
 
Andrew@A.L.D said:
The problem with a ported small port manifold is at the end of the day it's still a small port after port work.

You ports have just opened up the end when the rest of the port is still small.
Click to expand...
yep. Like i said further up, the runners are still only so big.
i just thought itd be better to make that transition smooth.
i had alsways intended on a homebrew, or 034 mani, so its unlikely to stay like that.
 
I'm building an engine with, rods, AEB head and the turbo will be the k04-064 k16 hybrid version...
I've reading and camshafts for this type of turbo does'nt give good gains... So the idea of buying the new IE street intake camshaft seems waste of money.

But what should I do with the intake manifold?

Use the small port, do something like superkarls or go for the Badger5 large port with 70mm throtle bodie???
 
Inlet off a 1.8T sharan 1998 or 1999 car is large port with the throttle body on the correct side.

I found one in a scrap yard to go on my AEB head.

Image
 
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