These sorts of threads crack me up.
Hijink is one of the most level headed posters on this, the Focus ST forum or Vortex.
Telling others what they should use their car for is from some might high horse some people are on, when I'm pretty sure I can beat them doing anything they think I should be doing with my car, IE track days and auto-x make drivers; okay put money on it and I'll make sure I whoop your as*.
A 400hp Focus ST doing mid 13's at 113 mph is doing sh*t ass backwards. I do drag race my car and take it seriously, I bought slicks as my first mod. In California we have crappy gas, down 10-15 hp to the cars with 93 available, sorry that's not acceptable; I got a E30 tune.
I see 3rd owner SRT-4's at the track with street tires, this is comical. Rarely would original owners of these cars go to the strip without at least drag radials but most found that was almost as pointless as regular street tires and very expensive.
I can certainly say that HDPE's are expensive for no reason really and auto-x is too limiting if you like making power. That leaves drag racing where there aren't any rules, just the one's made up in your head unless you're really trying to run a class. But you won't be competitive to a bunch of cut up Hondas in most cases, stick to brackets and test-n-tunes.
My Focus ST has run 13.4 on the stock turbo, tune and slicks. Nothing removed...
I have my second of three first round modifications coming soon; I got everything here.
That said I'm going to try to run a 13 flat before I install that. I've been to the dyno once and that basically confirmed my water-meth nozzle was too small; it's just as fast on WMI as it is on E30.
These cars don't need much and while I agree both Cobb and Mountune take advantage of the ignorance of this new generation of car enthusiast, they continue to offer parts when other companies don't, other than a couple of one-man operations out there.
The best bang for the buck is a tune and down pipe. Then tires for your application, you will wheel hop on street tires and that breaks things if you drag race, Pat who I met at Fontana two weeks go broke a motor mount.
I run slicks and stock mounts, no additional NVH to deal with and my best 60 ft times are 1.761 and 1.779. Besides 15" slicks are cheap about $120 each or so, compared to the 17" slicks I had to buy for the Focus ST ($233 each), you'll save your street tires from the additional wear, it won't wheel hop and you can't get 1.xx out of street tires. I think Fiesta ST with larger turbos need to make more torque or go to a track with better prep cause 1.8x isn't that great on slicks.