Previously, we talked about building a budget track car that could do double duty as a track car and as a performance oriented daily driver. In our first installment, we procured an Audi A4 quattro and began repairs, planning our upgrades and ordering parts.
With the new engine, transmission and sway bar mounts in place, we began to work our way forward starting with a new radiator. As the stock radiator support was trashed, and includes piping to the factory side mount inter-cooler that we will not need, we decided to fabricate a new support from thin wall box tubing. This will be a foundation for the radiator, AC condenser and new front mount intercooler.
With the new support in place, we installed the radiator and connected the radiator hoses and transmission cooling lines. Next, we installed the AC condenser which mounts to the radiator.
As we test fit the stock bumper as a guide to determine location of the intercooler, we used the mounting hardware provided by CX Racing. As we were using a non-factory radiator support, we made our own lower mounts from steel bar stock. The intercooler kit was pretty good out of the box, but we did need to re-tap several of the threaded bosses. The silicon hoses and clamps worked well.
First we installed the cold side connections to the throttle body, and made some minor modifications to our support in order to attach the new AC hose which connects the condenser to our new AC compressor.
As we moved over to the pressure side, this was a great time to upgrade the turbocharger and exhaust manifold to make greater use of the increased capacity of the new intercooler. We removed the stock K03 turbo and cast iron exhaust manifold, along with the stock cat, downpipe and exhaust system. The system on our car was not stock – it included Borla resonators and mufflers, but the pipes and mufflers were only 2″ diameter.
We will be fabricating our own exhaust with some larger pipe. There are many good kits available on the market as well.
For this stage, we are moving up to a K04 turbo which includes a larger compressor wheel, and a stainless steel equal length header that has been wrapped to keep the heat in the pipe which will not only benefit the turbo, but will reduce under hood temperatures.
We used Allen head bolts to attach the turbo to the header as the normal hex bolts would have been more difficult to manage, and then installed as a complete assembly. A new oil pressure line will be needed for several reasons. First, there is mechanical interference with the header. Secondly, we want to keep the oil as cool as possible, so routing it away from the pipes is a benefit. Lastly, a new pressure line is recommended with installation of a replacement turbo. If we weren’t replacing the line for the first two reasons, removing it and flushing it with solvent and compressed air would be a minimum precaution.
With the new turbo and header in place, we continued the installation of the coolant feed and return lines, oil drain back line and turbo brace.
We removed the factory air cleaner box and are installing a new reinforced silicon intake hose that will connect the mass airflow sensor and less restrictive air filter. This will require some further work with tube and clamps to plumb in the check valve for crankcase vent, re-circulation valve and electronic boost control.
We’ve ordered all new front end control arms and steering components, along with a set of H & R coil overs and Hotchkis front and rear sway bars. These have all arrived, so in our next installments we will tackle the suspension and fabricate a new down pipe and exhaust system.