MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: Gti_petrolhead on April 19, 2021, 10:36:48 pm

Title: Turbo upgrade
Post by: Gti_petrolhead on April 19, 2021, 10:36:48 pm
Hi guys i am thinking to buy a ko3 hybrid turbo something like bbtk360 turbo i cant find any could you guys plz tell me where i could find that turbo?
Title: Re: Turbo upgrade
Post by: colesey on April 20, 2021, 07:24:11 am
I don’t think they make that anymore however Turbo Technics offer a k03 hybrid.
Title: Re: Turbo upgrade
Post by: Gti_petrolhead on April 21, 2021, 08:25:40 pm
So guys which turbo should i get ko3 hybrid or ko4?


Also if i want more then 360bhp what do i need to do? Forge my engine?
Title: Re: Turbo upgrade
Post by: brian_badonde on April 22, 2021, 06:16:17 am
Integrated Engineering have a good guide on what internals you'll need to change at each level of power: https://performancebyie.com/blogs/ie-auto-blog/definitive-guide-building-2-0t-fsi-bottom-end

But you'll need to budget for more than just pistons...if you've got a manual, you'll need a hefty clutch. Then you'll need some more powerful brakes. You'll probably want to upgrade your suspension too, and maybe consider a limited slip diff to get the power down when conditions aren't ideal. There's also questions over how long gearboxes will last when you start really pushing the peak torque figure.

The point I'm making is that getting high power figures requires a whole bunch of other things to spend money on to make the car both reliable and enjoyable to drive. It starts getting really expensive really quickly.

If you're just interested in accelerating fast, buy a motorbike - much cheaper!

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Title: Re: Turbo upgrade
Post by: pudding on April 23, 2021, 09:48:05 pm
So guys which turbo should i get ko3 hybrid or ko4?


Also if i want more then 360bhp what do i need to do? Forge my engine?

Do you like worms?  If so, get your can opener and dig in!

For me, K04 or K04 hybrid all day long.  Make the power from flow rather than psi.  It makes for a far less stressed engine.  The most power from the least PSI is the goal for engine lifespan.

It's why when VAG designed the S3/6R, rather than simply just whacking the boost up on a K03, they fitted a bigger turbo, bigger intercooler, bigger bore boost pipes, more HPFP cam lift, stronger head, stronger rods, better pistons etc etc.  It's why you need to ask yourself, if VAG went to those lengths to add a seemingly insignificant 65hp over a 200hp K03 engine, what stress does over boosting a GTI engine cause in the long term?

Something else to bear in mind with the K03 engine is it has a higher compression and weaker rods/pistons compared to a K04 engine, so it has it's mechanical limits regardless of what turbo you fit.

Over boosted stock blocks break ring lands very easily if stressed beyond the limits, so absolutely you should forge it if you want to run 360+ all day long.  And that's a genuine 360hp, not the fantasy figures most dynos churn out.

Making power gets real expensive, real fast, so give it some thought as it may not be worth it in the long run.  Sometimes it's better to cut your losses and buy a car with that much power as standard for an easier life.


Title: Re: Turbo upgrade
Post by: alexcon3 on April 29, 2021, 01:04:49 am
My best friend has a Mk5 GTi BWA with a hybrid beach buggy turbo that r-tech have remapped to 360bhp without forging. His car only has 42k miles so it's a very healthy turbo. You will need turbo, S3 injectors, hpfp upgrade, intercooler, downpipe, R8 coils, irridum plugs. Catch can optional. Vis freewheel for oil pump optional too. I can't remember if he did the tank fuel pump don't think he did.

His car is still strong after nearly 2 years and now he is forging it and doing a massive build 500+

Personally If you do decide to do the work get a safe map to 340 - 350bhp I wouldn't go more.

My car has a hybrid turbo: machined out compressor cover to fit a 56mm billet wheel new bearing housing and 360 bearing Ect