GIVEN the advantages hub dynos have over roller dynos in terms of tyre loss and operator safety, Mainline set about designing a hub dyno that was better equipped to meet the demands of high-powered street and race cars than what was on offer at the time.
The range kicks off with the PH2000 (rated at 2000hp), moving through to the PH3000, PH4000, and the 5000hp-rated PH5000 model. The 2000 and 3000 models are the same physical size, but the big-hitting 4000 and 5000 have twin retarders on either side of car. Four retarders effectively provides them with double the capacity of a traditional twin-retarder roller dyno.
“On our system, the dyno is fixed to the ground,” Craig says. “The modules slide outwards, then you reverse the car in and put a floor jack under it, take the wheels off, slide in the modules, attach the adapter with the vehicle’s wheel nuts, and mate it up with the flange on the dyno. Three dowels and three heavy-duty bolts secure the module to the vehicle. The modules can be pushed in and out by one person. The dyno is a fixture in the workshop; you have to have a dedicated position for it.”
For racers, the real benefit of the Prohub dyno is it allows a tuner to confidently creep up on ignition timing. It’s something that’s very difficult to do with real accuracy at the track because the load on the engine changes all the time as the car moves in and out of traction and the suspension loads and unloads.
“With a hub dyno the operator can dial up the desired load and acceleration rate, and creep up on the timing in a controlled way,” Craig explains. “You can really shoot for optimum ignition timing without risking the engine like you would at the track. We’re seeing drag cars making 10 per cent power increases purely by tuning, and that’s where the gains are made. It’s like getting 200hp for free.”
Cost-wise, the smallest PH2000 retails for AU$70,000, compared to a twinretarder roller dyno, which will set you back $60,000. So they are more expensive, but they’re also decidedly more capable. And there’s no better way to prove it than to bolt a 35000hp Pro Mod to it and pull the string. We tagged along as Mainline put their PH2000 under the pump, running up the JSS Racing Doorslammer at their facility in Western Sydney.
“The car is a 3000hp+ car, and we were basically trying to top the dyno out,” Craig says. “One of our customers, Rotormaster, has had its PH2000 dyno to 2400hp already, and we’ve had several other customers go over 2000hp.
“The car and the dyno performed perfectly, but unfortunately the lights in the dyno room shattered due to the force created by the upward-facing headers! We made 2117hp, but unfortunately had to get off the throttle and abort the run. It’s important to note that while you can run up cars like this, you can still test a 100hp car s if you need to, as well.”