Pros
Mystery enveloped the R35's engine management system until the release of Cobb Tuning's GT-R AccessPORT reflash in August of 2008. The GT-R AccessPORT reflashes the ECU through the vehicle's factory OBD data port, and comes pre-calibrated to maximize performance for stock or modified vehicles. The AccessPORT can be updated with current maps through the internet with a simple click of the mouse; currently, Cobb offers up to eight maps listed on their website with new updates periodically. The plug-and-play unit also serves as a multi-functional system, enabling the end user to read and reset any DTC (trouble) codes, lock the vehicle's ECU into anti-theft mode, or set the R35 to valet mode.
Cons
The AccessPORT is one of the more successful tuning devices offered for the R35 on the market today, but this user-friendly reprogramming device does have its limitations for the hardcore enthusiast. If you're looking to fine tune your vehicle's parameters, you should note that the AccessPORT only has specific maps that can be downloaded and cannot be custom tailored or altered. Cobb's AccessPORT Pro Manager software, which would grant authorized AccessPORT tuners full access to vehicle systems, is currently in the works.
Parts
Stage 1 kit: AccessPORT, quick start user guide, USB cable, OBDII connector, software CD.
Tools
None
Installation Time
10 minutes
Notes
The HKS Legamax exhaust was removed from the vehicle prior to testing the AccessPORT. In order to test the full potential of the Cobb stage 1 (91 octane) map, the stock exhaust was reinstalled. Cobb advises that any high-flow exhaust or downpipe requires the tuner to reflash the Cobb unit to a Stage 2 calibration. With the new software uploaded into the ECU, the AccessPORT Stage 1 bumped boost up from 11.6 psi to a 14.5 psi, delivering an improvement of 25 hp and 14 lb-ft torque over baseline, with an impressive 47 hp and 61 lb-ft torque gain at 4,545 rpm.
Horsepower Gain
* 2,500 to 3,500 HP range: 3 to 2
* 3,500 to 5,500 HP range: 2 to 14
* 5,500 to redline HP range: 20 to 32
Torque Gain
* 4,000 to 5,500 HP range: 24 to 6
* 4,000 to 5,500 TQ range: 13 to 24
* 5,500 to redline TQ range: 32 to 23
Pros
California not only claims rights to owning the most stringent emissions laws, but also gasoline production. Throughout the years, gasoline has gone though a series of reformulations, starting in 1996, with Phase II, then in 1999, with CaRFG3 or Phase III gas, which eliminates MTBE, reduces various chemicals and increases the use of ethanol mixture. Sunoco's 100-octane fuel was engineered for high-performance street cars. Phase III gasoline is environmentally friendly and street legal throughout the U.S., and local gas stations throughout greater L.A. offer 100-octane unleaded fuel for those in search of higher octane for their street machines.
Cons
The cost of gasoline has dropped ever so slightly during these tough economic times. Unfortunately, 100-octane fuel does not come cheap, as we priced this mixture at 10 dollars per gallon.
Parts
Five gallon fuel canister
Tools
Fuel funnel, misc. tools to drain 91 octane fuel
Installation Time
60 minutes
Notes
The R35 posted impressive power numbers using the AccessPORT on 91 octane fuel, and with a switch to a new Stage 1 (97 RON) map, tuning had delivered an additional 10 hp and lb-ft of torque over the 91 octane setup. Using a canister of Sunoco 100 octane, we drained the vehicle of its 91 fuel and pumped the fuel tank full of 100 octane. The R35 spun the dyno at 17.4 psi, and delivered a healthy mid-range torque gain of 24-32 lb-ft from 3,700 rpm to redline. The 3.8-liter engine gained 20 peak hp, with the largest pick-up of 32 hp at 6,722 rpm.
Horsepower Gain* 2,500 to 3,500 HP range: 0 to -3
* 3,500 to 5,500 HP range: 4 to -16
* 5,500 to redline HP range: -9 to -4
Torque Gain
* 4,000 to 5,500 HP range: 0 to -7
* 4,000 to 5,500 TQ range: -22 to -18
* 5,500 to redline TQ range: -1 to -4