In case anyone's interested, I did a dyno comparo of before and after engine swap. Same drivetrain, same dyno:
- M20B25 99 kw (133 hp), 177 Nm.
- M52B28 126 kW (168 hp), 236 Nm.
The dyno sheets say Autronic, but I'm not sure if this is the type of dyno or just the software (so, yes, I have the dyno sheets if you doesn't trust me!)
Both engines were running well and unmodified, except the M52 swap included a custom exhaust and maybe some mixture tuning.
Unfortunately, they didn't use an exhaust probe for the M20. But I made sure they did for the M52:
- up to 3500 rpm, it cycles around 14.7 (the dyno guy said the fluctuation is due to closed-loop, but I thought these engines were meant to be open-loop at WOT?)
- above 3500 it quickly dives down to 11.5 - 12, where it remains until redline.
The DME is supposedly a stock tune, but the EWS had been removed, so there is a possibility that a different tune got in there somehow. Maybe this is the cause of the strange mixture readings? Or perhaps the car has a faulty O2 sensor?
- M20B25 99 kw (133 hp), 177 Nm.
- M52B28 126 kW (168 hp), 236 Nm.
The dyno sheets say Autronic, but I'm not sure if this is the type of dyno or just the software (so, yes, I have the dyno sheets if you doesn't trust me!)
Both engines were running well and unmodified, except the M52 swap included a custom exhaust and maybe some mixture tuning.
Unfortunately, they didn't use an exhaust probe for the M20. But I made sure they did for the M52:
- up to 3500 rpm, it cycles around 14.7 (the dyno guy said the fluctuation is due to closed-loop, but I thought these engines were meant to be open-loop at WOT?)
- above 3500 it quickly dives down to 11.5 - 12, where it remains until redline.
The DME is supposedly a stock tune, but the EWS had been removed, so there is a possibility that a different tune got in there somehow. Maybe this is the cause of the strange mixture readings? Or perhaps the car has a faulty O2 sensor?
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