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We ran it ultra rich just to play things safe. The wideband showed 11.3:1 for most of the run.
Wheel horsepower was over 400 from 5,100 RPM all the way to 7,200 RPM.
Peak wheel horsepower was 535.6 at 6,200 RPM.
Peak crank horsepower works out to 669.5 at 6,200 RPM. Pretty respectable for a little T64E!
The story is a long one for many reasons. Instead of boring everyone with all the details, we'll just list a few of the issues we had:
- - Our first two pulls wouldn't log at all in second gear. The dyno operators theorized that the engine was revving too fast to permit data capture. It took us a couple tries to realize that third gear pulls were going to be mandatory for this car.
- - Once we got horsepower data, we still couldn't get engine speed or torque for some reason. Eventually, we were able to pick up an optical signal by putting tape marks on the harmonic balancer. Unfortunately, we didn't have RPM or torque on the early runs.
- - We kept running lean and as we turned the boost up the horsepower went DOWN and the air/fuel ratio dropped as well. On one pull we actually hit 17.0:1 on the wideband oxygen sensor. Don't ask us how this engine stayed together, but we're pretty impressed!
- - Finally we noticed (we're a little slow sometimes) that we were off the end of the MAF table, exceeding 11,500 Hz. around 5,400 RPM with 19.8 pounds of boost.
- - And then there was the tranny failure. At this point, we suspect we busted a pump shaft. If we're right, our chrome moly pump shaft is already spec'd and sourced, and we'll get the first production run in process later this week. This was disheartening, but these kinds of failures at 650+ horsepower are what gives us the knowledge to build trannies to handle 450 and 500 horsepower without breaking a sweat.
- - Once we got horsepower data, we still couldn't get engine speed or torque for some reason. Eventually, we were able to pick up an optical signal by putting tape marks on the harmonic balancer. Unfortunately, we didn't have RPM or torque on the early runs.
Peak horsepower was 530.4 (at the wheels) somewhere near 5,400 RPM. The graph was still going up at a nice pace, so we're thinking we can squeeze a little more power out of this combination once we resolve the fuel issue.
