Category Archives: Turbo Selection

Temperature Rise Comparison

In the last post about the Turbo Concepts turbochargers I mentioned that the temperature rise across the compressor was looking a bit better than what I recorded with some other turbochargers.  To try to simplify the process of making a comparison I’ve chosen to assess the products in the following way.

I chose 5500 rpm as the engine speed at which to compare the temperature rise.  As the chart below illustrates, the rise in temperature is reasonably linear past 4000 rpm, yes there is some slight curvature to the data, but for my purposes this assumption of linearity with engine speed isn’t something that I feel will change the outcome of the comparison.  If I took the reading at 6000 or 6500 rpm the relative differences between products would still be like that made at 5500 rpm.

It is clear that the temperature delta at the start will exist throughout, though the magnitude does decrease some in the example below.  I have chosen some datasets, from many, that have starting deltas in the same ballpark, around 20-30 degF, and by using at least four samples and then averaging them I hope to show a ‘typical’ case comparison.

Below is how the BW K04’s, FT F21’s, TTE 550’s and TC Stg1 turbochargers compare.  Again, this is the rise in the temperature through the turbochargers compressor when the turbo’s boost profile is approximately the same and with approximately similar starting delta’s.  The conditions are not exactly the same in each case, which is why there are 4 to 5 samples taken and then averaged for each turbocharger, to give a general idea of how the products compare in this regard.

K04’s and Hybrids Compared

It’s clear that three of the products perform about the same as one another, and one, the Turbo Concepts, performs differently.  The Turbo Concepts turbocharger produces a lower temperature output from the compressor versus the other turbochargers.

This lower temperature produced by the TC turbo’s is a good thing, but as I discussed in the earlier post, the intercooler and water-methanol injection come into play before the charge air reaches the engine, resulting in an intake air temperature that is not much different between these products.

Turbo Concepts Stg1 Backpressure

With the tune for the Turbo Concepts Stage 1 turbochargers now tapering in a manner similar to what I had with the BW K04’s it’s a good time to measure the pre-turbine exhaust back pressure.

The results for three pulls are shown below:

Turbo Concepts Stg1 Manifold and Pre-Turbine Pressure
Turbo Concepts Stg1 Manifold and Pre-Turbine Pressure

Compared to the BorgWarner K04’s readings:

TC vs BW Manifold and Pre-Turbine Pressure

These results put the Turbo Concepts product in the same range as the other K04-hybrids I have measured, the FrankenTurbo F21 and Turbo Engineers TTE550.

The ratio of exhaust back pressure to manifold pressure for the different turbo’s around 6500-6600 rpm is shown below:

  • BW K04 – 1.56:1
  • TTE550 – 1.70:1
  • TC S1 – 1.85:1
  • F21 – 1.80:1

 

A different look at boost onset

A question was posed to me about how the turbocharger boost onset data might look if the range being compared was expanded from 2 to 11 psi to go from 1 psi up to 20 psi.  The 20 psi top end results in the BW K03 data being lost on account of the boost profile that I used with the K03’s stopping short of 20 psi of boost.

For the remainder of the turbochargers the data that I have collected produces the following results with a 1-20 psi range.

1 to 20 psi Boost onset times
1 to 20 psi Boost onset times

The general trend is similar to before, although the FrankenTurbo F21 and TTE550 are now harder to distinguish differences between.  The differences between these two products now appear smaller than with the 2-11 chart, below.

Turbo Concepts 2-11 times
Turbo Concepts 2-11 times

Subjectively I feel that the 2-11 chart captures the differences in feel from the driver’s seat better, but in terms of practical differences the data on the 1-20 chart suggests that at least in one comparison the differences may be less than those I have perceived.