Category Archives: Turbo Selection

FrankenTurbo, Turbo Selection

Big power FT21’s

During some of the recent activity showing the TTE 550’s and FT21’s on E85 tunes I forgot about this car’s results.  While the survey results thus far would indicate more are interested in quick spooling of the turbocharger, under the condition I outlined, it is still fun to look at what can be accomplished with these K04 hybrid turbochargers.

The S4 dyno’d below has the FrankenTurbo FT21 turbochargers, aftermarket rods, 2.8 cams, and using E85, no WMI.

Frankenturbo F21 E85 Dynojet

The car was also recorded on a FATS pull, a nice cross check to see how ‘legitimate’ the dyno numbers are.  It managed a 2.63 time in that acceleration exercise, which corroborates well with the dyno results.  Based upon the two results it would seem that around 500 whp is a decent estimate for the car’s power.

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My personal experience with comparing FATS to dyno numbers has been positive, I found when comparing my TiAL 605 setup on 100 octane race gas during a FATS pull with the results produced on EPL’s Mustang dyno that the two matched up quite well.

In the chart below the light blue line is what was recorded on the dyno (shown further down the page), and the other colored lines were FATS pulls of 2.69-2.71 seconds.

605 100 Octane Race Gas; FATS vs Dyno Results Compared
605 100 Octane Race Gas; FATS vs Dyno Results Compared

From the dyno chart below I have extracted the numbers for the solid red line to plot versus the FATS line above.

TiAL 605 results. 93 and 100 octane tunes. Stock S4 motor, no WMI.
TiAL 605 results. 93 and 100 octane tunes. Stock S4 motor, no WMI.

 

Turbo Selection

Wacky Turbo Comparisons

Within the last few days a couple of dyno charts have been put forth showing some impressive performance from the TTE 550 and FT 21 turbochargers.  Since both of these turbochargers are strong candidates for going onto my B5 S4 I decided to try and match up the results.

This is an exercise that must be approached with a great deal of consideration for the significant differences underlying the dyno charts.  These differences include:

  1. The dyno’s the cars were recorded on
  2. The conditions when they were produced
  3. The way measurements are reported
  4. The cars
  5. The fuel

There are enough points of difference here that a comparison should only be considered a ballpark estimate for how the turbochargers may compare under more controlled conditions.  Those more controlled conditions will hopefully be realized on another day, so for now I’ll charge onward with a crude comparison.

What I do know about the respective charts and vehicles.  The TTE 550 turbo’s were installed on a well modified B5 RS4 operating on 99 RON fuel with WMI spraying washer fluid.  The dyno chart displayed results at the engine, using an approximate 20% drivetrain loss.

The nature of the dyno readings meant that I needed to convert from NM to ft-lbs, and also apply the drivetrain  loss, more calculations than I’d like to do when trying to match performance, but necessary given the way data was presented for each vehicle.

The FT 21 turbochargers were installed on a stock motor B5 S4 operating with E85 fuel.  Dyno recording was made on a Mustang dynamometer and reported at the wheels.

And the comparison results…

tte 500 versus ft 21 dyno results
TTE 550 comparison with FT 21

Based on these *rough* curves it looks as though these two turbochargers match up well, but this comparison is far from being definitive.

The Turbo Engineers, Turbo Selection

TTE 550 Getting More Interesting

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.

TTE 550 vs RS4 K04 Dyno chart overlay
TTE 550 vs RS4 K04