Previously I’ve shown a dyno chart provided by The Turbo Engineers of their TTE 550 turbocharger for the B5 S4 and RS4.  The TTE 550 is on my candidate list as a potential replacement turbocharger for my B5 S4 and the dyno chart comparison of the TTE 550’s versus the same car (B5 RS4) with K04 turbochargers was encouraging.

While the dyno chart was showing encouraging performance from the TTE 550 I was skeptical of the K04 turbo results being representative of what a K04 equipped car would produce when tuned for performance, the comparison numbers on the chart are apparently for a stock RS4.

I came across a dyno chart from the same shop, MRC Tuning, that was of a K04 equipped S4 in a seemingly tuned state.  Below is an overlay of the K04’d S4 torque and horsepower curves and the TTE 550 dyno’s.  It’s evident that the base dyno chart does not illustrate well the performance differences between the TTE 550 and K04’s in a typical state of tune on a modified B5 S4 or RS4.  The differences in performance for tuned cars are not as large as they appear on the dyno chart alone.

On the other hand, what is impressive is how well the TTE 550 can match the K04 in low end performance with nearly identical torque and horsepower numbers below 3000 rpm.  Above 3000 rpm the TTE 550’s have a solid advantage over the K04’s all the way to redline.