Project Fiesta ST-Improving the Brakes with mountune USA
by Mike Kojima
So far we have improved the handling and shifting on our Project Ford Fiesta ST with some stuff from ST Suspension and mountune USA. We are very impressed with the base car. If you are into tuning FWD Sport Compacts you can really appreciate just how good this car is from the factory. If you have built Turbo Hondas or perhaps a Sentra SE-R we equate the Stock ST to one of those cars with a T28.
The car is a lot of turbo fun but with solid OEM reliability, great handling and OEM refinement. On the track the car has proven to be exceptionally reliable putting down lap after lap with not a single problem. No overheating, no fade, no unbalanced handling and most of all, the brakes are up to snuff for track abuse even stock!
We did want to improve them a bit though. Our OEM fluid was getting heat cycled and thrashed and the brake pedal was getting spongy. Now was a good time to get some better brake feel with some mountune braided steel brake lines and improve fluid fade resistance with some Motul RBF 660 brake fluid.
We first began work on Project Fiesta ST's brakes by putting the car on the rack and replacing the stock brake pads with new stock brake pads as well as removing the stock rubber brake lines. When running on the track with street compound UHP tires, surprisingly the stock pads will hold up to lap after lap of pounding with little fade. This will probably change with R-Compound tires but for now stock is great!
Here is the mountune brake line laid out next to the stock Ford part. The mountune line is made of teflon lined braided steel. Its principal advantage is that it will not expand under normal brake operating pressures like the stock rubber part. The expansion of the stock part is significant and has a big impact on the brake pedal feel contributing to pedal free play and mush.
The mountune brake lines fit perfectly using all of the stock hardware. This is actually a pretty impressive fit. This is important for the front wheels since they must pivot for tuning and excessive line can snag or whip.
The fit into the stock chassis hangers is quite good as well.