Mk3 to mk4 vrt

[masterqaz]

Alright so those of you that might have seen my car know its a piece of shhit, a quick one but a piece none the less.

I'm thinking it's about time to reshell her. It's becoming pretty hard to find a clean mk3 shell with out someone trying to make a small fortune on it. Luckily for me mk4s are now becoming outdated yet they still retain that nice shell better than the mk3s

To make this short and simple I have a few questions regarding the swap to a mk4 body.

Will the down pipe still work? Will I be able to run my green top injectors? I'm assuming I'll have to swap the engine harness and coolant sensors, are the rest the same? I know I'll have to repin the coil pack as that's a different connector or just steal the newer style icm as I run msd.

Anything else?

Gonna have to buy a new computer which kinda sucks.

[Mk4VRSex]

Why would you swap the harness? Are you trying to swap the whole motor or just the turbo kit?

[masterqaz]

Whole motor, its cheaper it get a shell with a blown motor plus my motor is good and fresh.

[Mk4VRSex]

The aaa block and afp block mount differently the mk4 has 2 motor mounts on the unibody and a dog bone mount to the subframe. So unless the mk3 subframe bolts right in that's an issue. Plus I'm not sure the mk4 uses a ce2 fuse block so I don't know if your harness would plug right in.

[masterqaz]

The aaa block will mount just fine I have a newer block with the tapped holes for the side mount. I'll be using the 02j tranny so the dog isn't an issue although I'm sure it mounts to the 02a as well.

Mk3s use ce2 but aren't mk4 engines some new style?

Mainly interested in knowing the differences on the motor sensor wise.

[V-dubbulyuh]

With the later AAA block you are fine - ie Mk4 compatible.
The tranny is no issue.
The bosch greentops are Mk4 harness compatible.

You have not stated what manifold, dp or turbine configuration you are using (which are the main factors that potentially make the Mk4 VRT setup different from that of the Mk3). If you are on a Kinetic manifold and you choose to have the turbine outlet on the pass side then you are going to need a new dp. If you use ATP/ATP clone or a Kinetic but keep the dp on the driver's side you will be ok as there is no need for harsh bends to get out from the bay into the exhaust tunnel. That is why the Mk4 Kinetic setup has a harsh bend being on the pass side. If you run the dp on the driver's side one thing to consider is relocating the coolant bottle and/or power steering reservoir due to the intake plumbing and air filter (you can get creative with your piping to avoid this but it is a PITA).

What intake manifold? Keep in mind the Mk4 throttle body will need to be used.

[masterqaz]

Alright now that's what I'm talking about. I'm running a t4 on center on ATP Manu with a short runner intake. I forgot to ask about the tb as I know these are fly by wire, is the bolt patter the same as the mk3 obd2 tb?

After looking around I've seen a few setups with the coolant bottle relocated, I'm assuming this is a pretty simple thing to do, ie mk3 rad hoses correct?

Power steering res pretty simple as well right just grab a long hose.