Is stroker worth it?

vroomtshh

Registered User
I'm currently in the process of gathering parts for a hybrid build.
Im looking for a nice strong reliable motor, hopefully around the 350bhp mark.
At this level, is the expense of a stroker worthwhile, or would I be better spending the money on some head work?
 

Westy

Registered User
I wouldn't bother if your jut aiming for 350bhp. The boys going Stroker are all knocking on the door of 500bhp.
 

Prawn

My other car is a MINI!!!!
A hybrid will spool very early anyway, and I think you'll still be limited on how much boost you can run early on due to the size of the exhaust housing, so you'd not be ble to use the additional low down boost, it the turbo would run out of puff sooner at the top end.

Id stick with 1781cc for a hybrid
 

superkarl

MAN OF STEEL
Agree with prawn.

Strokers have their place with bigger turbos to spool them earlier whilst still making power, makes them more usable.

On a small turbo, bot much point really. Better low-mid range torque, thats it
 

vroomtshh

Registered User
Agree with prawn.

Strokers have their place with bigger turbos to spool them earlier whilst still making power, makes them more usable.

On a small turbo, bot much point really. Better low-mid range torque, thats it

thats why I was thinking of it. More mid-low range is always good. It's a fair expense though which could be better used eelsewhere.

I wasn't sure as well if 350 was a bit of a push, and the extra capacity would help with that
 

superkarl

MAN OF STEEL
If youve got the money then do it.
Were just saying its not as beneficial on smaller turbos.
 

superkarl

MAN OF STEEL
Nope, 350 is doable.
 

slappy_dunbar

Let's Do This
Having tested our hybrid turbo on an increased-displacement motor for over a year, I think I can speak pretty knowledgeably on this question. And my recommendation would be to skip the expense unless you really value boost onset at 2700rpms versus at 3000rpms. Because that's the only benefit. Up top, the capacity limits are with the turbo hot side rather than the engine displacement. So you would net zero additional horsepower. The only change will be how the motor feels between 2000-3000rpms.

Trust me, this finding is a disappointment. I'd had grand plans of introducing our own, branded stroker kit. But the modified motor simply doesn't wow me on this size of a turbo. I'd say your money is better spent on a WMI system.
 

superkarl

MAN OF STEEL
You could say it would be better spent on headwork. But a hybrid wouldnt produce anything considerable that high up so that would be even less worth the expense. If anything the stroker is a better idea than valvetrain. But still, not that worth it.

Looking at the bigger picture, if you were considering a stroker on a hybrid ko4 with 350hp in mind, id say that money you were considering spending on a stroker kit (£2k?), would be better spent on a turbo capable of 350 more comfortably, that would be the wisest thing to do
 

Prawn

My other car is a MINI!!!!
to be honest though, very very few will see 350 from a ko4 hybrid. 330 seems to be the typical figure most will produce.

To my knowledge (in the UK - not sure about Dougs stuff in the states) mine is the only one that's produced anything above 350, with hardly any others reaching 340, so a safe assumed max for the ko4 hybrid still really remains around 330-335 as it was 3 years ago
 

<tuffty/>

Badger 5 Edition...Its all about the flow...
Staff member
Moderator
jeez, wish i hadnt gone through all the hassle of 'big turbo' now for a few extra horses as its been a complete pain in the ***

Big turbo power delivery is different to small hybrid turbos... don't get fixated on peak power... area under the curve etc....

to be honest though, very very few will see 350 from a ko4 hybrid. 330 seems to be the typical figure most will produce.

To my knowledge (in the UK - not sure about Dougs stuff in the states) mine is the only one that's produced anything above 350, with hardly any others reaching 340, so a safe assumed max for the ko4 hybrid still really remains around 330-335 as it was 3 years ago

This is very true... while a decent hybrid setup can knock on the door of 350hp it doesn't do it comfortably...

<tuffty/>
 

vroomtshh

Registered User
Big turbo power delivery is different to small hybrid turbos... don't get fixated on peak power... area under the curve etc....



This is very true... while a decent hybrid setup can knock on the door of 350hp it doesn't do it comfortably...

<tuffty/>

thats what I thought. I'm not exactly bothered if it doesn't make 350. That's just the number I'm aiming for. I'd prefer not to go BT, because of the reasons you mention above. I don't want peak power figures to brag about. I want a quick, tractable, reliable (ish) car.
Maybe I'm better waiting to see how the testing of the new tfsi conversion goes
 

badger5

www.badger5.co.uk
Site Sponsor
to be honest though, very very few will see 350 from a ko4 hybrid. 330 seems to be the typical figure most will produce.

To my knowledge (in the UK - not sure about Dougs stuff in the states) mine is the only one that's produced anything above 350, with hardly any others reaching 340, so a safe assumed max for the ko4 hybrid still really remains around 330-335 as it was 3 years ago

Exactly - Nail on head.
Unfortunately, yours is the ONE which gets banded about as having done 350+bhp... (including you in your siggy, lol)

Doing it Once, then turning it back to a "safer level" proves what exactly?

I could say our lupos 332bhp k03 hybrid.. but no.. its not in reality although it has done it.. Its 300bhp solid, and 332bhp if turned into the stupid hot level.

People latch onto the fact the power has been achieved once, on a cold run, non repeatable but then sent out on a lower level....... for reliability.

the vast majority of k04 hybrids make a little over 300bhp, and some venture into the 320-330bhp range.... Realistic Dyno figures. Not fictional airflow based ones from logging alone.


For the ~OP, invest in wmi with your hybrid... Essential ingredient for 1.8t's imho, especially small hotside hybrids. It will help you realise it potential safely
comparison of a couple of very similar hybrid spec's one lcr one agu (prawnys as the gauge reference)
You can see the boost and torque difference between them, and ones road car and the others track car, which will spend its time getting ragged on track, so appropriate level of tune to keep it together, that and no egt protection possible in agu ecu, unlike LCR. It is possible to get these figures as you can see, even on a tight **** dyno like mine, but the dice needs to be stacked and all boxes ticked for decent mods, added properly.
1098202_410567745727983_647775591_n.jpg



USA/Dougs figures all fall into US happy dyno category, where they all seem to make atw figures where we get @fly figures from same hardware, same boost etc etc.... Accepting that for what it is.
eg below:
183610_410565499061541_715866717_n.jpg



The tell tale for where inefficiencies creep in are where the mass air flow divide 0.8 correlation diverges, and this is where large, usually heat effect inifficiencies creep in.. Pushing a lot of air thru a small turbo hotside.


Its all about the flow, AND thermal management
tick these two boxes and it will be as good as it can with suitable mapping encouring it to do its thing. :)
 
Last edited:

Neru

Registered User
to be honest though, very very few will see 350 from a ko4 hybrid. 330 seems to be the typical figure most will produce.

To my knowledge (in the UK - not sure about Dougs stuff in the states) mine is the only one that's produced anything above 350, with hardly any others reaching 340, so a safe assumed max for the ko4 hybrid still really remains around 330-335 as it was 3 years ago

Whats the reason for yours producing such high power, my aim with the k04 hybrid is 300bhp which is a bit harder in Australia as our quality of petrol is lower than yours
 

badger5

www.badger5.co.uk
Site Sponsor
Whats the reason for yours producing such high power, my aim with the k04 hybrid is 300bhp which is a bit harder in Australia as our quality of petrol is lower than yours

a well built engine, well thought thru install, which flows well, ported clearanced hotside ... and sensible boost level.... Relatively low on torque but built for tractive power not headline torque as its a track car..... and some Prawny "magic" :)

Some setups just "work" really well.... and prawnys is one of those rare beasties..
Wellys on hybrid was mutant, and gops's lately was superb, and a couple of others I have tuned and dyno'd stand out from the majority which just dont often work so well... for reasons unkonwn.

Prawnys has always been superb.. and is a credit to his attention to detail and building it right.
 

v5 tt

Registered User
I'm currently in the process of gathering parts for a hybrid build.
Im looking for a nice strong reliable motor, hopefully around the 350bhp mark.
At this level, is the expense of a stroker worthwhile, or would I be better spending the money on some head work?


Hi mate im doing exactly that 2ltr stroker running a k04 hybrid ...
reason being one i wanted a rebuild anyway and was going for
a 1.9ltr but you can pick up fsi crankshafts pretty cheap
so it just made sense to go for a stroker setup plus the fact
any future turbo changes i,ll have the whole setup for BT...

i will be running CP 83mm pistons 9,5 compression
hopefully the build may start this month...
 

v5 tt

Registered User
how cheap did you pick up a tfsi crank for then dude?

Got it quite a while back was about £100 from ebay then £20 30 for the correct gear from I.E
so for the sake of just over £100 why not i,ll get it polished hopefully should be good to go
 

Prawn

My other car is a MINI!!!!
Are you still doing your build V5tt? I seem to remember it was a great looking spec, anywhere near completion yet>?
 

v5 tt

Registered User
Are you still doing your build V5tt? I seem to remember it was a great looking spec, anywhere near completion yet>?

Yeah iv picked up pretty much the last parts for the engine build so its just a case of
getting it assembled so may make a start this month ....

Having an ECU conversion as well i have the old narrowband so got a
BAM ECU and loom

Finally need to get my clutch so iv still got a bit on my plate to do
but its getting there...

Cheers
 

ReDBull

Registered User
a well built engine, well thought thru install, which flows well, ported clearanced hotside ... and sensible boost level.... Relatively low on torque but built for tractive power not headline torque as its a track car..... and some Prawny "magic" :)

Some setups just "work" really well.... and prawnys is one of those rare beasties..
Wellys on hybrid was mutant, and gops's lately was superb, and a couple of others I have tuned and dyno'd stand out from the majority which just dont often work so well... for reasons unkonwn.

Prawnys has always been superb.. and is a credit to his attention to detail and building it right.

How important are the AGU pistions to the mix?
 

superkarl

MAN OF STEEL
If my car hadnt have blown, heres what i wouldve done.

Total engine rebuild, arp the crap out of it, stroker, 83mm cp pistons, rods, bearings the lot. Rebuild that and whack it in the car even with the stock turbo.
Then, when id have the money for the next chapter, id do the turbo, mani intake exhaust etc.
That would be an epic way of doing things, for me anyway.

But no, il settle for a 1.8, and enjoy saying 'its just a 1.8 mate...'
 

vroomtshh

Registered User
If my car hadnt have blown, heres what i wouldve done.

Total engine rebuild, arp the crap out of it, stroker, 83mm cp pistons, rods, bearings the lot. Rebuild that and whack it in the car even with the stock turbo.
Then, when id have the money for the next chapter, id do the turbo, mani intake exhaust etc.
That would be an epic way of doing things, for me anyway.

But no, il settle for a 1.8, and enjoy saying 'its just a 1.8 mate...'

Thats what I'm thinking of doing. I have a spare largeport engine. And I'm considering building it up like this and running it on hybrid.
Then 'when' I get bored, I already have the foundations there. Or If I decide to sell, the foundations are there for the next person
 

badger5

www.badger5.co.uk
Site Sponsor
Got it quite a while back was about £100 from ebay then £20 30 for the correct gear from I.E
so for the sake of just over £100 why not i,ll get it polished hopefully should be good to go

awesome find!
:)

want one myself now..
 

badger5

www.badger5.co.uk
Site Sponsor
How important are the AGU pistions to the mix?

not worth changing them unless you have to... but if you have them and have the motor apart a little more CR peps up the overall response.. in my experience.
 

Scullies

Registered User
That crank is from a fsi engine and not the Tfsi. The difference being the 2.0 fsi n/a engine has a cast crank, same as the 2.0 8v mk4 golf etc.
The Tfsi is a forged crank and looks a little different.

It can still be used for a stroker build though :)


heres a nice link with a lot of pictures showing the differences between 1.8t crank and 2.0t crank

VWVortex.com - 2.0 TFSI vs. 1.8T crankshaft
 
Last edited:

superkarl

MAN OF STEEL
tfSi crank is 1kg heavier that guy says.
So fluid damper pulley pretty damn sensible thing to fit then
 

v5 tt

Registered User
ALT the 2.0 20v ally block one? I dont remember
To be honest i cant say for sure ??? ...here is a nice
reference from issam from vwvortex

Handy for when your hunting down a stroker crank.....

CAST 92.8mm Crankshafts
w/out modification to oil pump gear (i.e. changing to work with 06A | 06B oil pump)
  • AZJ
  • AVH
  • BHP
  • BEV
  • AZG
  • BEJ
  • CBPA
Basically any 2.0 8V Motor found in the MKIV or MKVI.

FORGED 92.8mm Crankshafts:
all require modification to go from 06F to 06A | 06B oil pump gear.
  • BPY
  • BMP
  • ALT
  • AXW
  • BMB
  • AWA
  • CDLC
  • CDLF
  • CDLG
  • CZRA
:beerchug:
 

v5 tt

Registered User
That crank is from a fsi engine and not the Tfsi. The difference being the 2.0 fsi n/a engine has a cast crank, same as the 2.0 8v mk4 golf etc.
The Tfsi is a forged crank and looks a little different.

It can still be used for a stroker build though :)






heres a nice link with a lot of pictures showing the differences between 1.8t crank and 2.0t crank

VWVortex.com - 2.0 TFSI vs. 1.8T crankshaft

i think you will find its the forged crank its normally the diesels running the
cast cranks

all the same you still would be hard pushed to brake a cast crank
but i opted for the forged crank as will probably most people
 

<tuffty/>

Badger 5 Edition...Its all about the flow...
Staff member
Moderator
tfSi crank is 1kg heavier that guy says.
So fluid damper pulley pretty damn sensible thing to fit then

Shan't be on mine but it will all be getting balanced... std damper should be fine as long as the revs aren't too high...

<tuffty/>
 

Scullies

Registered User
i think you will find its the forged crank its normally the diesels running the
cast cranks

all the same you still would be hard pushed to brake a cast crank
but i opted for the forged crank as will probably most people

That ebay crank is definitely not forged. As well as 2001-2005 passat's weren't fsi. I bet its the same 2.0 cast crack from a mk4 golf.
Seems Bill is right about the alt passat engine code being a 20v
 
Top