Dunlop SP 8080 Tires (from TireRack - no longer available) OEM. First time around,
I chose Yokohama's AVS Sport as best value upgrade
option. (TireRack Survey)
But the next time I went for Bridgestone's Potenza S-03 Pole Position - a faultless tire - only $800 over the web.
When my car went off warranty, I went for these performance upgrades:
Jim Conforti's Shark Injector and Cold Air Intake purchased from Turner Motorsport
and StrongStrut's COMPETITION-LIGHTWEIGHT front tower strut brace.
I am very pleased with each of these modifications. The computer chip re-programming gives much sportier performance across all RPM's, and the CAIntake makes a very obvious boost (and incredible wooshing sound) at RPM>4000. Since performance was boosted across the whole range, my roadster should now be doing about 4.9 seconds in 0-60 mph, and 13.4 seconds in the quarter mile. After these power increases, it seemed like I needed more control and rigidity, so I got the StrongStrut lightweight tower brace (only 4.5 lbs). Again, I was surprised to notice better handling, road feel, stability and control, in all sporty driving situations, cornering and bumpy roads. Highly recommended. In the picture below, you can see the StrongStrut brace and the CAIntake.
Over the next year, I struggled with a persistent gas smell that steadily got worse. It was very obvious under sporty driving conditions. Despite taking the car to John Roberts BMW dealership 3 fucking times they refused to identify the problem. Finally after 3 months at another BMW repair shop (almost a comedy of errors) and $1200 later, they found 2 holes in a blowback tube connected to the neck of the gas tank. I was just relieved it was fixed.
Feeling good about my car again, I started another round of upgrades. Replacing the fluids with AMSOIL Series 2000 0W-30 oil (see review), Royal Purple Syncromax, and perhaps, Redline Differential Fluid is supposed to give 4-9 extra hp at the wheel (lower drive train loss in friction). Because this will make shifting looser, I felt I had to get UUC's improved transmission mounts. Finally, I did the new UUC Underdrive-Pulley change, which cuts power loss by the accessories. Another 4-8 hp gain.
Now in 2006 - almost 8 years old! - time to upgrade failing parts (after a disastrous encounter with a flat tire - use the M Mobility System only if you want to buy a new tire!). My brake upgrade consisted of Zimmermann cross-drilled Rotors, Mintex Sport Pads, racing brakefluid, and Bavarian Auto's teflon-coated stainless steel brake lines. Success! - the brakes seem safe again - noticeably stiffer and stronger. I had reinforced tie-rods installed and the driveshaft flex disc (guibo) replaced. (And finally installed the transmission mount enforcers with only a little added Syncromax to the transmission.)
|Perf Mod||Stock/New HP||Max HP Gain||Stock/New TQ||Max TQ Gain||New Max Rev||Cost|
|Shark Injector||240 / 264||34 @ 6000||237 / 276||40 @ 4500||7000||$350|
|CAI||/ +10||18||/ +16||22||$400|
|UUC Transmission Mount Enforcers||$70|
|Zimmermann cross-drilled Rotors (front)||$250|
|Bavarian Auto Ultimate Brake Lines||$125|
My previous car was the Z in the background - new Z's pretty nice.