2005 Acura RSX Type-S - Import Tuner Magazine

• Owner: Frankie Alliano
• Dynamometer Model: dyno dynamics 450 single axle chassis dynamometer
• Installation: mb racing (kevin maecha)
• K-pro Tuning: xenocron tuning

2005 Acura Rsx Type-S

Pros
The '05 RSX continued building on Honda's reputation for affordable performance and high modification potential. Powering the Type-S is Honda's K20Z1, producing 210 hp and 140 lb-ft of torque-making it (at the time) one of the highest specific outputs of any naturally aspirated production engine in the world. Combined with a diminutive curb weight of 2,775 lbs, power gains measured by the dyno easily translate to real-world performance.

Cons
Production of the Type-S with the K20Z1 only occurred in the '05 and '06 model years, making it a bit tricky to find upgrade options. While many aftermarket companies offer components specifically designed for this vehicle, many fail to recognize the subtle differences between the various trim levels, often neglecting to make the necessary alterations to insure proper fitment.

Notes
If the following dyno numbers appear lower than expected, please note all testing was performed utilizing a true heartbreaker: the Dyno Dynamics 450, reputed to be one of the most accurate and incorruptible chassis dynamometers in existence, albeit one that corrects for more drivetrain loss than most. Also, in order to insure the aftermarket parts tested here were not restricted by OEM components, our subject vehicle had been fitted with a K&N Typhoon intake and Skunk2 Megaflow cat-back exhaust prior to testing.

Pros
The legendary K-Pro EMS is unique amongst engine management systems (EMS) because although technically a stand-alone, it collaborates with the factory ECU, ensuring near-flawless operation with no loss in daily drivability. Interfacing with the K-Pro requires the use of Hondata's KManager software and a standard USB cable, both of which are provided with the unit. The KManager software seamlessly integrates both a complete engine management suite with an onboard data logger. This makes finding problem cells and altering maps nearly painless. Equally impressive is the speed at which you can upload these calibrations to the K-Pro, making fine-tuning your whip on the street, or a quick map switch at the track, almost effortless.

Cons
Having such a competent piece of hardware doesn't come cheap. In order to install the K-Pro into any '05-'06 RSX, one must provide or purchase a '02-'04 RSX ECU, since the newer unit is incompatible with the device. The primary wideband O2 senor must also be swapped with one for the '02-'04 model years-an important step, as the stock O2 is unable to properly interface with K-Pro, leading to inaccurate air/fuel readings.

Parts
Compatible ECU, K-Pro EMS, adapter harness, software CD, USB sable, stickers

Tools
Flathead screwdriver, 10mm sockets, ratchet, extension, Windows-enabled laptop

Installation Time
30 minutes

Notes
Installation and operation were surprisingly straightforward. The OEM ECU is located under the glove box and is easily accessible. However, if one wishes to fully conceal the K-Pro, the stock unit must be completely removed. If this is done, remember to plug in the USB cable prior to mounting and run the cable though the glove box to allow easy accessibility. Also note the K-Pro only comes with a 30-day warranty when purchased through an authorized Hondata dealer, so be prepared to complete the install the day you receive it to make sure it is properly functioning. We should also note that each product we installed on the RSX was tuned with the K-Pro to achieve maximum horsepower.

Hondata K-Pro Engine Management System

Horsepower Gain
• 2,000 to 3,500 rpm range: 8.0 to 10.0
• 3,500 to 5,500 rpm range: 3.0 to 6.0
• 5,500 to redline rpm range: 10.0 to 15.0

Torque Gain
• 2,000 to 3,500 rpm range: 10.0 to 15.0
• 3,500 to 5,500 rpm range: 5.0 to 10.0
• 5,500 to redline rpm range: 6.0 to 15.0

Strup Race Header
Horsepower Gain
• 2,000 to 3,500 rpm range: 2.0 to 3.0
• 3,500 to 5,500 rpm range: 3.0 to 12.0
• 5,500 to redline rpm range: 10 to 20

Torque Gain
• 2,500 to 3,500 rpm range: 1.0 to 4.0
• 3,500 to 5,500 rpm range: 4.0 to 15.0
• 5,500 to redline rpm range: 5.0 to 16.0

Pros
The Strup Acura RSX Type-S Race Header features a 4-2-1 design to increase flow and maximize power. Improvements to both power and torque were evident throughout the entire power band, with particularly great gains up top. The header is constructed of 304 mandrel-bent stainless steel tubing and is robotically TIG welded, resulting in a durable, high-quality product that should last for years.

Cons
Using the stock motor mounts, we experienced some knocking of the header against the frame. To eliminate this, Strup recommends replacing the OE mounts with stiffer Energy Suspension Motor Mount Inserts. The need to purchase new mounts does increase the overall cost of installation, but these should be added, regardless.

Parts
Two mufflers with piping, gaskets, hardware, decals

Tools
6-, 8- and 10mm socket, 10-, 12-, 14- and 17mm open-end wrench, ratchet, extension and swivel socket, hanger tool, WD-40

Installation Time
60 minutes

Notes
Worth acknowledging is that gains in the higher rpm range were made without sacrificing low-end power-an exceptional feat for this application. Using the K-Manager software and the factory wideband, we could quickly see the A/F ratio had become lean in the areas where the most power was being made. We increased fueling in these areas to prevent knock and high engine temps, which, if not corrected, could eventually cause damage to the combustion chambers.

Pros
The Brian Crower (BC) cams produced some desperately needed low-end torque and respectable horsepower gains up top, nicely complementing the previous mods. Even though we needed to engage VTEC a bit later than with the stockers, our RSX still pulled nicely from 4,000 onward. Overall, these cams performed great and didn't produce any drivability issues common when switching to a more aggressive cam.

Cons
The installation of camshafts can be difficult and time consuming, requiring an advanced understanding of the K-series engine. Although the cams themselves are competitively priced, they require the use of BC's Valve Spring and Retainer kit (part# BC0040) when upgrading from a stock motor.

Parts
Camshafts, titanium retainers, BC dual valve springs

Tools
10-, 12- and 14mm socket, 10- and 12mm open-end wrench, ratchet, extension, valve lash tool, valve adjustment tool, white marking paint for cams, zip ties, Hondabond

Install Time
5 hours

Notes
If you are going to attempt this cam install yourself, set aside a major block of time, as just the act of getting the timing chain positioned and threaded correctly can take upwards of 60 minutes. Kevin Maecha of MB Racing has this tip: "Before removing the stock cams, use zip ties or rubber bands to keep the rocker assembly together. This will make it easier to position them correctly once the new cam is in position." In addition to the wrenching, engine management is a crucial next step to ensure proper functioning and maximum power. The more aggressive profile of the BC cams required altering many parameters of our calibration-most critical are those controlling VTEC and cam angles.

Brian Crower
Stage 2 N/A Cams With Valve Springs & Retainer Kit
Horsepower Gain
• 2,000 to 3,500 rpm range: 3.0 to 5.0
• 3,500 to 5,500 rpm range: 5.0 to 9.0
• 5,500 to redline rpm range: -3.0 to 10.0

Torque Gain
• 2,500 to 3,500 rpm range: 3.0 to 6.0
• 3,500 to 5,500 rpm range: 6.0 to 0.0
• 5,500 to redline rpm range: -3.0 to 5.0

CONCLUSION HP Level +HP TQ Level +TQ BASELINE 167.1 119.1 HONDATA K-PRO 177.3 10.2 127.0 7.9 STRUP RACE HEADER 191.7 14.4 135.5 8.5 BRIAN CROWER ST2 CAMS 201.7 10.0 137.3 1.8 FINAL 201.7 34.6 137.3 18.2

Conclusion
As we've shown, the '05 RSX Type-S responded well to our modifications, achieving peak gains of approximately 35 whp and 18 lb-ft of torque. These numbers may not seem huge to some, but take a closer look at the dynos and what you'll find is that increases in power are consistent throughout the entire power band. However, most important is how the car feels on the streets, and once VTEC engages, it's astonishing how hard this little RSX pulls.

BANKROLL HONDATA K-PRO (W/ '02-'04 ECU) $1,595.00 STRUP RACE HEADER $600.00 BRIAN CROWER STAGE 2 N/A CAMS $595.00 BRIAN CROWER SPRINGS & RETAINER KIT $495.00 MSRP Total $3,285.00