Dynamometer Baseline
Paradise Garage




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© 1999 Brian F. Schreurs
Even we have a disclaimer.

4:40 is my favorite time of day.
The Charger is strapped onto a DynoJet inertial dynamometer.
With the total teardown of the Paradise Garage 1970 Dodge Charger creeping ever closer, we decided it was time to do some baseline testing. It's always nice to have a benchmark to compare against.

The tests really needed to be done in order of importance, because with the current state of the tranny (and the engine to some extent) it was anybody's guess whether the Charger would be driven home or towed. The dyno test seemed to be the most important, as it could be easily replicated in a few years since conditions are a constant. Track testing, while important, relies on so many variables that the numbers are less meaningful.

We took the Charger to our friends at Woodbridge Dynotech for some baseline pulls. Since the Charger currently has an automatic, kickdown could interfere with the results. To prevent this, we loosened the kickdown lever sufficiently that it no longer worked. That way it would hold whatever gear we asked of it.

With a little trepidation, we pulled the Charger onto the dyno. John Sealock, the owner of the dyno shop, carefully strapped our old girl down. We knew power wouldn't be that high from a 318 slug, but nevertheless we would have a real number, no guesses or calculations, for the first time. But that didn't stop us from guessing and calculating. We figured 150 would be the magic number; Josh, our Mustang-driving friend, bet on 135.

John fired the Charger up and pulled it out to third gear. Then, whomp the pedal hit the floor -- in a moment we'd know whether the engine could still handle a pull to redline. Engine rpm soared; engine sound wailed like never before. Black smoke poured out the exhaust, obscuring the parking lot behind the car.

All wired up.
It survived!

In fact it did quite well: 145 hp (at 4000 rpm) and 243 lb-ft of torque (at a ridiculously low 2300 rpm). Not far at all from the predicted 150 hp. Sorry Josh.

Both numbers peaked early -- in fact, the torque curve would be better described as a slope. Downhill. This odd-looking graph, plus the billowing black smoke, were both caused by overcarburetion. Since we're running an Edelbrock Performer 600-cfm 4-bbl, we don't have a lot of room to step down. We may look into a jet kit with really small jets. John, however, recommended putting a 2-bbl back on. Perhaps. Or perhaps the best solution is to step up the performance of the engine until it matches the carb. Yes. We like that.

A couple minutes later John got back into the Charger and started the second pull. It didn't take long for the thick black smoke to appear, but this time we also saw and smelled some nasty grey smoke from under the car. John managed to finish the pull but wasted no time in exiting the vehicle afterward.

Turns out, the headers we installed last winter still hadn't finished curing. No harm done.

"I guess this car doesn't see these rpms very often," John dryly observed.

Pull two saw 144 hp and 239 lb-ft, down slightly from the first pull. Since Mopars like to run cold, this came as no surprise. Still the torque showed up as a slope rather than a curve. This was odd. We gave the Charger some time to cool before we started the final pull.

With all the smoke coming from all the various orifices, we were having second thoughts about a third pull. But we just sent a quick prayer to the Mopar Gods that the beastie would hold together one last time. John got to work and we kept our fingers crossed.

Not to worry. The Charger held fine. In fact it was her best run: 148 hp and a huge jump in torque to 287 lb-ft! Where on Earth did this extra 40 lbs of torque come from??

Turns out John started recording earlier. Whereas previously he hit the switch at around 2300 rpm, this time the clock started ticking at 1400. The torque peak is actually at an amazingly low 1800 rpm -- it was well on its way downhill by the time we started recording on the previous two runs. This explains perfectly why the car will shoot across an intersection but runs out of breath early. We'd been wondering.

It's hardly fair to compare the results of this 318 with the results of the future monster motor, but on the other hand, this is what the Charger has had for a decade. From that point of view it's the only fair way to make a comparison at all. It's the Charger's evolution; no other yardstick matters.

See you at the dyno in a couple years.