Big Port Heads

i didn't think they were, i know ko3 and ko3s are the same
 
it is different mate, i just googled it!-) still though if the exhaust ports are bigger than the manifold whats going to happen there??? exhaust gases will hit a wall!?

unless they are all big port?
 
get them match i guess if they are different, someone who has done it will be along shortly I'm sure, i might need to know too, I'm picking up an S3 tomorrow and no doubt ill have a little play with it
 
justarn said:
it is different mate, i just googled it!-) still though if the exhaust ports are bigger than the manifold whats going to happen there??? exhaust gases will hit a wall!?

unless they are all big port?
Click to expand...

You are assuming that the mani ports are not big enough or matched to the respective heads in the first place..

Just measured a K04 mani and its 38mm vs LP exhaust which is 36mm and for reference the SP exhaust ports are 34mm... also measured a K03 mani and thats 38mm too

<tuffty/>
 
larger ports dont neccessarily = more power/torque

the flow/output would need to be matched to make the best "match" of components

bigger aint always better
 
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badger5 said:
larger ports dont neccessarily = more power/torque

the flow/output would need to be matched to make the best "match" of components

bigger aint always better
Click to expand...

if im not mistaken i was looking at westys 300bhp ko4 build a while back and i think he said the bp head gave him 20bhp at high stage 2 mods!? what you reckon?
 
justarn said:
if im not mistaken i was looking at westys 300bhp ko4 build a while back and i think he said the bp head gave him 20bhp at high stage 2 mods!? what you reckon?
Click to expand...

He may of gained 20bhp but I bet he lost about 20+lbs/ft of torque in midrange. Large port will give you more power depending on what's been done but it kill drivability
 
with small turbo people with experience says that big port head is not good choice
some people say large port head only up 350hp
 
justarn said:
if im not mistaken i was looking at westys 300bhp ko4 build a while back and i think he said the bp head gave him 20bhp at high stage 2 mods!? what you reckon?
Click to expand...

doubt it in reality

largeport can support more flow..
k04 does'nt huff enough to make use of it, but will loose low and mid torque vs its smallport counterpart on k04 framed unit.

depends which "headline" figure is being grasped

Lupos exemplorary K04 hybrid power is being made on std aum engine, smallport.. just rods in it. 372bhp/(370lbft)
 
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anyone know why VAG decided it was a good idea to use a large port head on a ko3 car if it suffers from a loss of torque?
 
i buy an AEB head, but will stay in garage for a long long time
 
badger5 said:
doubt it in reality

largeport can support more flow..
k04 does'nt huff enough to make use of it, but will loose low and mid torque vs its smallport counterpart on k04 framed unit.

depends which "headline" figure is being grasped

Lupos exemplorary K04 hybrid power is being made on std aum engine, smallport.. just rods in it. 372bhp/(370lbft)
Click to expand...

im not questioning this but im curious how westy got not only 300bhp but ran a 13.1 at santa pod?? we have pretty much the same mods besides the big port head and obviously a custom remap (i will be coming to see you in the coming months btw bill, now i have it running sweet!-) i ran a 14.6 at 94 with a 1.8sec 60ft with bolt ons and no map at 212bhp, the other week i ran a 14.0 at 98 with a poorly car so i didnt launch it too hard getting a 2.1 sec 60ft, so for arguments sake the car should now do a 13.7... i was assuming the big port head and my low torque figure were to blame?
after all the mess when i got my amd map on here im sure they mapped it very safely to avoid any come backs after that dispute (apologise about dragging you into that bill) hence 280bhp and only 263 lb/ft, after he said it was the healthiest 1.8t they had had in a very long time, others have made good torque on their maps!?

is westy still about? didnt he sell the s3?
 
the 300hp was at 5000rpm and dropped off fairly quickly..
0D1C61B5-B5BA-4108-A646-1C566785213F-6772-00000299C4FC88CF.jpg


As a comparison... mine (stroker, LP head, GT35 and 11psi)
tuffty-runnning-in-gt35-actuator.jpg


...and a TT Bill mapped today with a BBT baby hybrid turbo (smallport head I believe)
10494610_579967732121316_4229186319113450474_n.jpg


<tuffty/>
 
cheers tuffty... looking at westys graph that is bhp at the wheels then? and torque at the fly 338lb/ft!! i see it does drop off quickly tho, do you think he could have achieved 305bhp without the bp head?

considering the furthest i plan on going is hybrid turbo i guess im better of sticking with the sp head then...

you car looks pretty drivable from that graph, not that i expected much less tbh, the bt graphs at amd show virtually no power until 5k but yours looks pretty linear, whats it like to live with is it all or nothing when it comes to boost?? guessing the larger capacity helps combat the lag tho,,,
 
justarn said:
im not questioning this but im curious how westy got not only 300bhp but ran a 13.1 at santa pod?? we have pretty much the same mods besides the big port head and obviously a custom remap (i will be coming to see you in the coming months btw bill, now i have it running sweet!-) i ran a 14.6 at 94 with a 1.8sec 60ft with bolt ons and no map at 212bhp, the other week i ran a 14.0 at 98 with a poorly car so i didnt launch it too hard getting a 2.1 sec 60ft, so for arguments sake the car should now do a 13.7... i was assuming the big port head and my low torque figure were to blame?
after all the mess when i got my amd map on here im sure they mapped it very safely to avoid any come backs after that dispute (apologise about dragging you into that bill) hence 280bhp and only 263 lb/ft, after he said it was the healthiest 1.8t they had had in a very long time, others have made good torque on their maps!?

is westy still about? didnt he sell the s3?
Click to expand...


Fixating on peak power number..... is just that a peak number..
how long is the torque sustained is what makes for the faster car. not the bs dyno plots of "peak" look at me figures which folks get hung up on.. Repeatability also, not a one off cold run to squeak the max number to willy wave a dyno plot on.

Westys went well... Brand new k04 helped a lot. It had all the usual bolt ons, inc water meth... which is a game changer vs not running it.
dont expect old worn units to perform the same.. most are plain worn out these days. more business opportunity for BBT, lol

and I will remind folks, lupos 372bhp and 328lbft (badger torque) is managed on aum smallport motor.
the best suited head setup for k04 framed units imho. largeports will flow way more than a k04 hybrid can ever mustre

DynoIT%20-%20J50ANB-372bhp.jpg


Next to the excellent TT from yesterday on dans baby hybrid, you can see the potential on a healthy motor (both of them aum's and in excellent fettle)
DynoIT%20-%20J50ANB-372-vs-tt-k418.jpg
 
Last edited:
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justarn said:
...you car looks pretty drivable from that graph, not that i expected much less tbh, the bt graphs at amd show virtually no power until 5k but yours looks pretty linear, whats it like to live with is it all or nothing when it comes to boost?? guessing the larger capacity helps combat the lag tho,,,
Click to expand...

Its fantastically drivable... the GT35 is a big old blower but its not just the stroker thats helping, the mix of parts here is what makes it what it is... I have a 0.63 A/R hotside vs the more typical 0.82 A/R which makes a big difference to spool on any turbo (not just GT35)... the stroker is doing its bit on bringing torque in lower down the rev range and of course contributing to spool

Be interesting to see what happens when I get the final mapping sorted as the engine is still running on my old GT30 map with a few fuelling tweaks in unisettings to give the ECU a chance...

<tuffty/>
 
badger5 said:
Fixating on peak power number..... is just that a peak number..
how long is the torque sustained is what makes for the faster car. not the bs dyno plots of "peak" look at me figures which folks get hung up on.. Repeatability also, not a one off cold run to squeak the max number to willy wave a dyno plot on.

Westys went well... Brand new k04 helped a lot. It had all the usual bolt ons, inc water meth... which is a game changer vs not running it.
dont expect old worn units to perform the same.. most are plain worn out these days. more business opportunity for BBT, lol

and I will remind folks, lupos 372bhp and 328lbft (badger torque) is managed on aum smallport motor.
the best suited head setup for k04 framed units imho. largeports will flow way more than a k04 hybrid can ever mustre

DynoIT%20-%20J50ANB-372bhp.jpg


Next to the excellent TT from yesterday on dans baby hybrid, you can see the potential on a healthy motor (both of them aum's and in excellent fettle)
DynoIT%20-%20J50ANB-372-vs-tt-k418.jpg
Click to expand...

All makes perfect sense that a large port probably would not help with a 370bhp hybrid build, but would it be a disadvantage at this spec?

Or to put it another way, if you already have a large port engine with a large port inlet mani etc. is it going to be beneficial at hybrid level to go to the effort of swapping to small port?

Imagine there must be a level where the large port is not an advantage, but also not a disadvantage either.
 
Last edited:
you loose port velocity and torque on largeport..

BT's which have their higher flow potential also deliver it higher up the rev range, so the delivery is the higher end of where you would be loosing the low/torque............. swings/roundabouts
 
just amazing badger5, 360hp at 7800rpm on a hybrid
congratulations your new mani is fantastic
maybe now lupo needs a bigger compressor in his hybrid....
 
Miguel_S# said:
just amazing badger5, 360hp at 7800rpm on a hybrid
congratulations your new mani is fantastic
maybe now lupo needs a bigger compressor in his hybrid....
Click to expand...

Its "no single compnent" enabling this dude.. mani's just one component, the whole setup is what enables it, along with what is a very good yet std aum engine
 
yes every component is important
just talking about your last dyno and this new
 
badger5 said:
no change in peak power, just sustained longer on it
Click to expand...
peak power earlier and make power more 1000rpm, thats great
to my goals its superb, i only want 350hp for a long long time
 
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