MercRacing Aftercooled Lysholm 1600 AX on K20Z1 Dyno Results on 16psi
374whp/265wtq
Preliminary runs resulted in a good bit more torque on the low end, but something was limiting it from carrying the same curve past around 5,000 RPM. Peak numbers stayed almost exactly the same, hovering at the 340whp area, but torque went up to 260wtq.
Initially, we figured there was just too much heat on the compressed charge that it was causing a huge efficiency drop as blower speed increased.
After a couple runs, we decided to pull the plugs.
To my dismay the plugs in the car were BKR7E’s! (Which is the OEM heat range, definitely not the colder plugs that should have been in it.)
Luckily, I had an old set of BRK8EIX’s from my personal car that were still good, so I threw those in.
Next pull resulted in 360whp and 260wtq. Goes to show, the aftercooler was doing just fine, and it was infact combustion heat dissipation that was causing the torque to take a constant downhill slump.
Once that was squared away, I was able to advance ignition a couple more degrees (21 degrees at 16.4psi now), and here was the final result.
374whp/265wtq
Here is a comparison of last session’s:
And finally, a comparision of the twin-screw project versus a K20A2 JRSC @ 11psi with methanol:
IAT’s at the end of a 10-second ramp reached 160 degrees according to the GM sensor, on back-to-back runs.
Indicated injector duty cycle when finished was hovering at the 79-82% level, and in fact, there was enough fuel present that the first couple pulls to rev limit (8,400 RPM) were as rich as 9.8:1 based on the old map (since I increased fuel value drastically get the 650’s to deliver something resembling a safe AFR.)
- Derek