If you could only do one mod...

Tires. Sticky sticky tires. If that doesn't count, then a wheel size down to 16x7 and sticky tires on those. Makes such a large difference.

+1 for Tires. You put someone on a track with any one mod, and I (or anyone) will beat them with just tires.

Access port and nothing else to me was the best and only mod I would do its the only thing that I noticed a difference other than sound which you don't really need I wont be modding my new car (vw golf r) maybe just a tune and nothing else already feels powerful to me.

Of course, but one is somewhat limited in great tire choices by our factory standard tire size and wheels.

Why 16x7 and what tires?

Come spring I'm thinking advanti storm S1 17x8s and 215/40/17 star spec II. Should be a pretty massive improvement over OEM wheels and tires. Although I'll have on Blizzaks over the winter.

Fixed that for you

215/225 size tires are going to be significantly faster on an 8 inch wheel vs. a smaller than stock 7 inch wheel. The issue is, none of the vendors are stepping up to the plate and providing that size.

Yeah I hear ya there, but we can still get a couple 200TW tires in 205/45/17, 215/40/17, and 205/45/17.

Absolutely!

But, due to the truth of the last sentence of your post above, I sadly may have NO CHOICE but to put an 'anti-stretch' 215/45. or 225/45 on a 16x7 for street use IF I decide to save the weight, and go 16, instead of 17x8s with a 215/40 on them.

Driving school.

Something I need desperately haha. I'm getting some decent experience at the track here but I could really use some serious input on my driving. Too bad my wife isn't more into it.

I just did the STOA and the instructors there gave us great feedback on our driving and how to improve. I'm 100% serious that driver education is the best thing you can spend money on. I have way more confidence in the car and know what I need to improve on at the track.

I'm glad my wife is into driving. She's got a Fiesta as well and she did awesome at STOA this weekend.

I wish I lived in the states just so I could go to STOA haha. I'm currently living in Germany but when I get back to the US I plan on going. Even though by then I'll have to pay for it. Maybe when I go back to the US on vacation I can find a way to squeeze it in. If I were a rich man I'd also go for a full week to team O'neil rally school.

7" is the stock width. an 8" wheel won't fit without issues of rubbing the fender on most available tires. Ask the fifteen52 owners. 16x7 is what I run for autocross competition and it does pretty well. The 215 width star specs in 215/40/17 seems to line up just fine on the oem wheel and are a very fast tire to boot. One of our best drivers in the Chicago region runs them quite successfully on his Fiesta, though it isn't his competition car.

AP and Tune +

Accessport all the way. It made the biggest difference in the car and gave me the ability to monitor temps and pressures. No other modification has made as big of an impact as the Accessport did.

AP and tune. Basically what I have now but an intake and plugs. If I waited a little bit before jumping the gun my opinion may be different. I felt my car lacked a massive amount of power so I ordered a tune asap. Well the car started to break in and wake up, I couldn't even spin the tires in 1st lol then it came alive day after day and by the time my tune arrived I was actually ok with the stock power. Now I have a tune though it's hard to look back, then again isn't that the way with every mod when done right

This car has really pleased me in stock form over my FoST. More feel, more sound, even something like pedal spacer isn't a must compared to the FoST. Some may see it as a downgrade but I definitely see it in an upgrade as a drivers car

^^^Nah, it's only a 'downgrade' when compared to the FoRS as far as I'm concerned, and yes, I know that most on here feel it is either even with, or above that monster as well.

The star spec II 215/40/17 fits on oem wheels? Hmmm. I wanted to go 17x8 just to fit that tire on there correctly. Maybe I can just go 16x7 on those 1.2s that I love so much.

^^^I would go with the 225/45-16 Star Specs on a 16x7 1.2 IF I knew it would not be ridiculous as far as turn-in destroying 'pinch' goes.

Hmmm let me ask my track tire councilor...Riiiiiick! Lol
Seeing as how you use your car in a similar fashion as me. Do you see any drawbacks with the 215/40/16 on a 16x7?
[MENTION=636]RAAMaudio[/MENTION]

I always recommend at least a bit of stretch for optimal contact patch and sidewall control which is generally going to be faster and more rewarding with greater feedback than a wider tire on a narrower wheel. Real specs on the tire are critical, side wall specs are far to generic to go by and some tires are designed with stiffer sidewalls so it gets a bit complicated to sort it all out but well worth it.

I would be looking at a tire with known great performance on track, a bit of stretch which means narrower tread than most 215's will have, lowest weight if you have more than one choice, best price and best wear rate if you need to keep them within a budget, etc.

If you post a list of the tires you are interested in we can go over them to help pick the best one.