Background:
A previous post discussed round one with the Mabotech M520H turbocharger. Tuning was done with E30 fuel and an HPA high-pressure fuel pump; otherwise, the fueling setup was stock.
A few months ago, the GTI visited Noster Motorsport in Orlando to have the fueling system upgraded, as discussed in this August post.
Tuning resumed with the SimosTools platform leaning on Russell Road & Racing for tuning support, as detailed in this post.
With the catted downpipe, boost pressure was riding between 30 and 32 psi, and the switch to a catless downpipe lowered the wastegate duty cycle enough that raising boost further was on the table.
I chose to eschew the EQT bandaid approach to tuning of raising the knock thresholds and had Russel Road & Racing retain the OEM knock sensor settings. If increasing boost pressure results in the onset of knock, I would increase the percentage of ethanol.
Continuation:
After four revisions, boost pressure was sitting just below the level where the wastegate duty cycle would increase disproportionately to the increase in boost pressure and about the same operating point as with the catted downpipe. This suggested that the tune was at a good level for long-term operation.
With the catless downpipe, the boost pressure could be increased to a range between 32 and 34 psi.
Timing was reaching 13-14 degrees around 6500 rpm.
Ignition timing retard was looking good, with the help of a bump in the ethanol percentage from 30% to 50%.
Noise levels were also below the OEM thresholds.
Power output is increased by approximately 40 whp compared to the catted exhaust tune on E30.
Peak values are 496 whp / 472 wtq.
Next:
Getting the GTI over to the dyno to see what that device shows is planned before further hardware changes are made.
As mentioned in the previous post, installing the Mabotech intake manifold is on deck.
