Where Is the Tach pickup for the dyno?

[SS - 2000/7/5] There are two tachometer pick-off points.

1. The connector on the right side of the engine bay, as you describe below. This is intended for physical connection to the tach signal. I dont know who uses it, but its there.
2. The wire loop in the wiring harness immediately to the rear of the Ignition Control Module (ICM). The ICM is located on the throttle body underneath those 4 or 5 metal vacuum lines. See the vacuum lines? Now look just to the rear, between the lines and the strut brace. See the wire loop coming out of the rear ICM harness and then going back in? This is the inductive pick off point for the tach, which is used by everybody.

Manufacturer Claims

Stock NSX : - 235 hp

With Comptech Header/Airbox/Exhaust: - 245-250 hp
With Comptech Header/Airbox/Exhaust/Cams/Heads : - 265-270 hp
With Comptech Header/Airbox/Exhaust/Supercharger: - 300-305 hp
With Comptech Header/Airbox/Exhaust/Supercharger/Cams/Heads: - 315-320 hp

3.2L NSX - (Horsepower at the rear wheel)

Stock: - 250 hp
With Comptech Header/Airbox/Exhaust/Supercharger: - 350-355 hp
With Comptech Header/Airbox/Exhaust/Supercharger/Cams/Heads: - 360-365 hp

NSteXpo 2002 Dyno Day Results

[EDR - 2002/5/1] The information is presented in a "here-it-is" format. There is no twisting of the numbers, scaling of the graphs, or interpretations of the data. There are 17 vehicles with three pulls each, followed by a " Supercharger Shootout", where I compare three different 3.0L supercharged vehicles (BaschBoost, Comptech and GruppeM) against a normally aspirated vehicle of similar configuration as well as against each other.

The only disclaimer, warning, or consumer product alert that I felt was necessary to include was the fact that the BaschBoost supercharged vehicle was utilizing a pulley designed to provide about 4 lbs. of boost, yet the ECU software (fuel map, etc.) is expecting 9 lbs. of boost. I felt it was fair to note this... not because I have one on order and need to feel better about the results, but because I can imagine the sh*tstorm that is likely to pop up on certain web message boards about the performance being different than the graphs / reports on the Science of Speed or Dali Racing websites where the units are sold. Again... it's not an excuse... just the facts in a "here-it-is" format.

Owners' Dyno Results

Wilson Shiu 91 NSX 30k miles
STOCK
Max bhp 231.3
Max Torque 181.7
With air conditioning running: Max hp = 221.1, Max Torque = 172. The curve looks exactly the same except the line shift down to the right. The 10HP power loss is not bad at all.

Brent Cobb, 91 NSX, 112k miles
DC Headers, DC Exhaust, RM conical Air Filter, Dinan chip
Max bhp=255.9
Max Torque=196.7

Christopher Anders, 94 NSX 56k miles
RM Headers, RM exhaust, RM chip, K&N filter
Max bhp=259.8
Max Torque=194.8

Skaria Thomas, 1995 NSX-T
On the same DynoJet Model 248H Dynamometer, 4th gear runs:

K&N drop in filter and Comptech exhaust: Max POWER: 252.3 HP    Max Torque: 196.1 ft-lbs
K&N drop in filter and Comptech headers & exhaust: Max POWER: 242.0 HP     Max Torque: 185.9 ft-lbs

The SAE corrected numbers are shown above. When I graph the curves on the same sheet, there is a consistent loss across the entire operating band in HP and torque from 2000 RPM to 8000 RPM. I am anxiously waiting for Mark's Dyno Day results to see if there were any cars, both OBD I and II, that put out more power/torque with headers without changing the software. One additional note, the only other change to my car is the that it did not have the short gears and 4.55 R&P before... but that should not affect the numbers anyway.

I have called around and no one seems to know why this happened. Needless to say, I am quite disappointed. Should have left well enough alone.... or maybe not. ;-)

SoCal NSX Dyno Day Results

Facility: Mech Tech Motorsports, 1277 Simpson Way, Escondido, CA 92029, (760)432-0555
Temperature: 71.3 °F
Pressure: 29.30-0.50 in. Hg
Altitude: 680 ft

Note: the hp and torque are measured at the rear wheels. Typical drivetrain loses are 15-20%.

[RMC - 99/11/10] 1991 NSX w/ cat-back and intake 257.2 HP to wheels with 196.8 Torque