MKV Big Turbo Build

[Jremey]

So I've decided to pull the trigger and start a BT build but I wanna make sure I have everything that I need (supporting mods and install hardware) to do it right. Yes I have already googled and researched but I haven't found anything definitive, and other builds I've found create more power than what im shooting for. I've decided to go with a gtx2860r from ATP. They offer optional add-ons like oil and coolant lines and fittings, which I assume I'll need, high flow compressor outlet pipe and stock diameter compressor inlet elbow (which I'm not sure I'll need either of them). The other add-ons are an adapter plate for OE flange which I'm not sure if that's to the DP or for the exhaust manifold. I'm currently running the Unitronics K04 stage 2, which relocates the DV, with the stage 2+ tune. Current supporting mods are 3" custom exhaust straight pipe with 4" resonator, Forge Twintake, Forge Twintercooler, Forge BOV with the 15-23 psi spring, R8 red top coils, IE oil catch can with PCV delete, and ECS dogbone mount. I'm also planning on getting HPA's V2 intake manifold. The other thing I'm unsure of is if the DV relocation kit is gonna be compatible with the new turbo. I've got a buddy that's gonna set me up at his friends dyno shop for a custom tune and I need to find out from him if he's able to tune VW. My HP goal is 380-400 as it's my daily and I don't really have the means to do an engine build for new rods. If there is anything I'm missing or if anyone has any clarification on hardware requirements I'd greatly appreciate it.

 

[GIACUser]

Good morning sir. As someone who has run just about every stage of power on his GTI over the last 12 years I would say just stay K04 and enjoy it. That is a great setup you have and probably the most problem free big power upgrade you can get for the money. If you don't have the money to rebuild the motor don't go BT until you can support it if you rely on this car for daily transportation. Lots of stuff can happen when you step off the edge of what is basically an OEM setup. I built my motor before going forward and it still blew up in the first 150 miles after going BT. Not that it always happens but you have to have the money in reserve as there are many new ways you can have a major failure as you switch out to more aftermarket parts of less than OEM quality and a lot more power. I ran my K04 setup for over 4 years at 340whp using just a tune, water meth and only 91 in the tank with zero issues on my daily driver.

Note - if you do go ahead with your plans stick with OEM intake manifold, at that power level (400whp) HPA manifold will not help and will add a touch of delay over stock manifold, will help if you are running direct water meth and are looking at 500whp. I did use it on my build.

 

[Jremey]

Good morning sir. As someone who has run just about every stage of power on his GTI over the last 12 years I would say just stay K04 and enjoy it. That is a great setup you have and probably the most problem free big power upgrade you can get for the money. If you don't have the money to rebuild the motor don't go BT until you can support it if you rely on this car for daily transportation. Lots of stuff can happen when you step off the edge of what is basically an OEM setup. I built my motor before going forward and it still blew up in the first 150 miles after going BT. Not that it always happens but you have to have the money in reserve as there are many new ways you can have a major failure as you switch out to more aftermarket parts of less than OEM quality and a lot more power. I ran my K04 setup for over 4 years at 340whp using just a tune, water meth and only 91 in the tank with zero issues on my daily driver.

Note - if you do go ahead with your plans stick with OEM intake manifold, at that power level (400whp) HPA manifold will not help and will add a touch of delay over stock manifold, will help if you are running direct water meth and are looking at 500whp. I did use it on my build.

How much power were you pushing on your BT build when the engine blew? From what I understand stock internals should support CHP up to 400 though I do remember reading one post saying they're good up to 500. I was really wanting to increase top end power but I'm not really sure there's much else I can do other than doing a BT setup. Also I was under the impression that the larger intake manifold decreases spool time since it can supply a higher volume. Unless I interpreted it wrong which is possible lol. Thoughts?

 

[GIACUser]

I was at 480whp and on just my third lap at the track. The motor was built with fully forged parts not at all stock. Actually it didn't entirely blow, it still runs but it needs to come apart to have some damage fixed. Simple issue, guy who setup the fueling and tuned the car did not put in the correct range of plugs and the electrode on 2 of the plugs melted. My point being that at the higher power levels and the equipment etc you are venturing into an area where there is far less support and few standard solutions.

Stock manifold, at your planned power level flows plenty, adding a more voluminous intake manifold will add lag to fill it up. It does flow more but in your plan it is not a choke point. Going above 500whp there is value. In my case I wanted a metal intake manifold I could tap with water meth jets for each of the runners.

Your ATP turbo choice is one that often gets mixed reviews. The turbo sizing you are looking at is just a bit bigger than your K04 which will flow much better than the K04 on top and it will do it without making so much heat. Moving from the OEM style turbo K04 to the separate manifold, turbo, DV, and separate turbo etc means more places to leak and same goes for the funky aftermarket hoses for oil and water that comes with those kits. If it were me I would consider going TTE 480 which is a very well engineered K04 hybrid that has same flow as the ATP turbo you chose but is a full K04 on the outside so everything just bolts up. Cost of the ATP kit with the extras you would need would be close to 3500, the TTE480 is about same price and it allows you to just bolt right up to your existing oil/water lines, vacuum lines, plug right into the wastegate, bolt right up to your current downpipe, no need to get a different or custom intake because turbo is in a new position etc.

 

[Jremey]

It's starting to look more like there's not really much else I can do for power increases then. At this point it doesn't even seem logical to do fueling upgrades since I'm not over 400 whp. I still feel like there's something I'm missing, or maybe it's just wishful thinking.

 

[GIACUser]

There is plenty you can do, its just super expensive and much more risky and less reliable. I have modded a lot of cars and when you push power past the capacity or to the edge it gets expensive and reliability goes down.

Going past K04 gets expensive as you begin to exceed the safe capacity and longevity of the stock motor/engine. You also end up realizing the need for better suspension and braking etc. Save your money and buy a car that comes from the factory with 400hp or more. It will already be built for the power from end to end.