Sports Car Forum - MotorWorld.net - View Single Post - Why it's good to put your car on a chassis dyno.

Wutputt · 11-21-2004, 06:05 PM

A single dyno test isn't really a very accurate indication of how much power you gained (or lost) when tuning the engine. Cause the specs on the sheet of the car are measured on a test engine according to a certain standard (SAE, DIN, ECE, BHP, CUNA, JIS, etc.). For example when testing according to the SAE standard, the losses for driving the auxiliary parts are not counted in.

If you want to know how much power you've gained by tuning, you'd have to do two dyno runs on the same dyno in approximately the same conditions: one when the engine was stock, and one when the engine is tuned. Only then you’d have an accurate indication of the power gain of tuning. So don't draw fast conclusions out of a single dyno run.

But in your case you can draw conclusions, since you know you have a misfire at 5000 rpm and the valves for the variable intake length system doesn't work properly.

11-21-2004, 06:05 PM	#3
Wutputt Regular User Join Date: Dec 2003 Location: Belgium Posts: 3,371	A single dyno test isn't really a very accurate indication of how much power you gained (or lost) when tuning the engine. Cause the specs on the sheet of the car are measured on a test engine according to a certain standard (SAE, DIN, ECE, BHP, CUNA, JIS, etc.). For example when testing according to the SAE standard, the losses for driving the auxiliary parts are not counted in. If you want to know how much power you've gained by tuning, you'd have to do two dyno runs on the same dyno in approximately the same conditions: one when the engine was stock, and one when the engine is tuned. Only then you’d have an accurate indication of the power gain of tuning. So don't draw fast conclusions out of a single dyno run. But in your case you can draw conclusions, since you know you have a misfire at 5000 rpm and the valves for the variable intake length system doesn't work properly.