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Stratified E30 Tuning – rev 5

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Stratified Automotive Controls

Stratified’s fifth revision to a custom E30 tune is installed and produced the results shown in the following charts. The revision five results are compared to revision four. The dashed lines are Rev 5, the solid lines are Rev 4.

Boost onset is slightly sooner, but this is most likely a result of logging on a cooler day. IAT is about ten degrees lower during Rev 5 logging than with Rev 4.

Strat v1.5 vs 1.4 Boost & IAT
Strat v1.5 vs 1.4 Boost & IAT

Interestingly, despite being a cooler day and running the same boost the WGDC is slightly higher from about 5800 RPM on with revision 5.

Strat v1.5 vs 1.4 Boost & WGDC
Strat v1.5 vs 1.4 Boost & WGDC

Air-to-fuel ratio is remaining similar.

Strat v1.5 vs 1.4 Boost & AFR
Strat v1.5 vs 1.4 Boost & AFR

Timing is still showing that traction is an issue. Notably I did try lowering the tire pressure to around 28 psi from the normal 38 psi range, a follow-on from the Tire Contact Patch test. That did not resolve the traction issue.

Strat v1.5 vs 1.4 Boost & Timing
Strat v1.5 vs 1.4 Boost & Timing

Here’s what is happening to the measured speed, in areas along the line where the value jumps around there is a loss of traction:

Stratified v1.5 Boost and Speed
Stratified v1.5 Boost and Speed

The wheel spin is apparently causing the timing inconsistencies.

Stratified v1.5 Boost, Speed, and Timing
Stratified v1.5 Boost, Speed, and Timing

Here are a few Rev 5 acceleration times shown with the green bars. With traction problems seeming to cause timing drop it is no surprise that the overall acceleration time is getting worse as the tune is further refined.

Stratified v1.5 Acceleration Times
Stratified v1.5 Acceleration Times (Green Bars)

The pull data was combined and then used with the Virtual Dyno program to generate the next chart.

Stratified v1.5 Virtual Dyno
Stratified v1.5 Virtual Dyno

Looking into the slightly higher WGDC, one hardware change made between the Rev 4 and Rev 5 was to swap intercoolers between an IE v1 paired with Majesty FMIC (Bicooler), to an APR IC.

IE v1 plus Majesty FMIC
IE v1 + Majesty FMIC

Comparing the compressor outlet pressure and manifold pressure for these two configurations in the next charts:

IE+Majesty Charge Air Pressures
IE+Majesty Charge Air Pressures

APR IC:

APR Charge Air Pressures
APR Charge Air Pressures

The APR IC is producing about 3 psi of pressure drop at the point that I let up, where the combination of the IE+Majesty is producing about 1.25 psi of pressure drop at let up. This difference in pressure drop seems to be the likely source for the difference in WGDC.


Reference:

2 thoughts on “Stratified E30 Tuning – rev 5”

  1. Fantastic data! Did you happen log temps for the corresponding red and blue lines? It would be interesting to calc the air density delta between the two Ics.

    1. I did. The IAT would probably need to be adjusted to try and account for different ambient temperature. The higher pressure doesn’t generate significantly higher temperature from the turbo, and once the air passes through the IC the difference is fairly minimal.

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