Need feedback on track day engine upgrades for NA 2.0L MTX?
I have read several threads on 2.0L 5-speed engine builds, but I still need help in finalizing my to-do list - any and all feedback is appreciated, as I am not a mechanic (learning as I go here).
Background: I have an NA 2007 Mazda 3 2.0L i-touring 5-speed sedan. It is my daily driver, and I track the car several times a year at HPDE/track days. 145,000 miles on the car, and she still runs like a champ, with the exception of replacing stripped 2nd to 3rd synchro. I live in a 4-season area, extreme heat and cold throughout the year.
Goal: I want to improve my torque and horsepower on an NA basis, but keep modifications within reason for daily driving and long-distance travel considerations. I’m not looking to go crazy here in an attempt to get to 200 HP, I just want to safely (and intelligently) squeeze what I can out of the high-revving 2.0L without the risk of damaging my engine. Keeping in mind that 95% of track day time is spent in 3rd – 4th gear (with occasional 5th gear), improving the 4000-7000 RPM power band is highly desirable. I have modified the car for the sole purpose of improving track day performance as follows:
Performance modifications include:
* Injen Cold Air Intake
* Magnaflow Exhaust
Handling / Suspension / Braking mods include:
* Koni Sport Shocks (yellows)
* H&R Sport Springs
* SPC Adjustable Rear Camber Arms
* Tri-Point Engineering Racing Rear Sway Bar with Endlinks (set to middle)
* Goodridge G-Stop SS Brake Lines
* Centric Rotors
* Hawk HP+ pads
* Enkei RPF1 Wheels with Nitto NT01 tires for track days (inaugural run this weekend)
* On the suspension to-do list are GT Spec mid chassis brace & frront strut bar
I'm not planning on going Turbo in the near future. My “final” engine/performance to-do list is as follows:
* Advanced Timing Mod
* Buddy Club Racing Condenser
* Grounded Throttle Body
* Motor Mounts – 60A durometer for DD
* Vibrant Header and downpipe
* VCTS Removal
* SR Motorsports lightweight pulleys
* Once all of the above is completed, I will be getting a Dynotronics Tuning ECU Flash for performance tuning and to eliminate the rev and top speed limiters.
My questions include:
Other than the above, what am I missing?
What WOULDN’T you do on the above list?
Are forged internals necessary with all of the above? If so, what exactly would you do given the above?
Given the 145,000 miles on the car, should I replace anything in the engine when getting the above work done?
Should I optimize the throttle body?
I’m not convinced an upgraded intake manifold is going to help. Looking for 1) pros and cons of doing this with the above mods, 2) what brand (or Mazda IM) is best performance-wise for 2.0L engines, and 3) what’s required to get the promised performance upgrade?
Thank you one and all for your help!
2007 Mazda3 2.0L 5-Speed Black Sedan; Injen CAI; Vibrant Header; Magnaflow Exhaust; SRS Pulleys; Mazda5 Tranny; Exedy Stage2 Clutch/Flywheel; Koni Sport Shocks; HR Sport Springs; SPC Adj Rear Camber Arms; TriPoint Racing RSB; Corksport Mid-Chassis and 4-Point Braces; Centric Rotors; Hawk Pads; Technafit SS Brake Lines; AWR PMM; TRZ RMM, TM; Visual Garage Shark Fin; Sparco/Sabelt Seats; Sparco Harness Bar; Schroth/Racequip Harnesses; Enkei RPF1 w/NittoNT01