Stage 3 or higher

 

Stages don’t really end, but we refer to stage 3 as the last one since we are swapping most stock parts with either reinforced ones, or with parts from the same family of cars with the bigger engines. Stage 3 isn’t for the faint of heart, and most likely you came to this stage in order to make big big power. WIth big gains, come great responsibilities though. At this stage you are pushing the engine way harder than what it was originally designed to do. All various components that were happily working together before at lower power levels, now need replacing with much stronger parts.

 

Fuel Injectors

 

While some engines might not need them, the majority will need them at this stage. Having higher needs from the engine, means you need more fuel. Long gone are the days of stage one where you could enjoy some fuel savings, now you won’t anymore. With more power and more revving, you need to keep the fuel flowing efficiently in order to reduce temperatures inside the cylinder. Not being able to spray the right amount of fuel inside the cylinder and parts will start melting very easily. Often, we will use injectors from the same family with bigger engines in order to keep everything in check. For example, its very common for higher power Golf GTI’s to use injectors from the RS4 or similar models.

 

Fuel Pumps

 

As with the injectors, in order to cope with the higher needs of stage 3, you need to upgrade your pumps most of the times in order to keep the fuel flowing in correctly and without interruptions. For the most tuned engines, pumps can be upgraded simply by changing their internals, or even upgrading the whole units. These need remapping as well, as well as the injectors.

 

Turbocharger

 

On a turbocharged engine, the most limiting factor in how much power it can make, is the turbocharger itself. You can only spin a turbocharger so fast before either the turbocharger can’t take it, or the air it pushes becomes too hot to make any power. At that point you need a bigger turbo. Turbochargers can we swapped for bigger units, or you can change the internals of the turbocharger to some larger ones, creating the so called hybrid turbos. People call them hybrid because they are using the stock encasing of the old turbocharger, with new larger components that can push more air. There are a lot of turbochargers out there to try, so this is an option of the owner as well. As with every part on stage 3, a turbocharger swap, needs serious modifications when remapping in order to make it work.

 

Engine internals

 

Your engine at stock configuration is full of finely moving parts of metal. By increasing the power its making by a lot on stage 3, the stress you put on that metals increase a lot more than they would normally do. They are designed to withstand a certain amount of stress but most likely at this stage you are exceeding those limits so you need to swap that for stronger versions. For some engines out there, we know the limits of the stock working parts, but when we buy aftermarket parts, the manufacturer normally warns us of these limits. Some engines come out of the factory overbuilt for power levels far in excess of what the car runs from the factory and can cope well with the extra power, but some need big changes and upgrades to withstand less power increase.

 

Stage 3 example

 

On the same Golf 6 GTI we used for examples on our 2 previous stages we know it has 210 horsepower as it comes from the factory. The car normally uses a K03 turbo that won’t go above 300 hp easily. In that case, using a K04 from the Golf 6 R, we can safely get the engine to 380 horsepower from stage 2 that could take us close to 300 before. Of course in order to get there, we need bigger intercooler, uprated spark plugs, and everything we mentioned above.