[Pushit2.0]

In my opinion this is why LSE chose the Dyno Dynamics(DD) Lowboy 450 Twin/Twin chassis dyno. We researched different types of dynos for 5 years before making our decision. We looked at all the DynoJet line talked with sales people the hole works, talked with Mustang dyno and looked at the hole line there also, looked into dynopacks but due to the hydraulic system and using water to cool the system, also only showing hp/trq at the hub instead of at the ground, and the problem of using a lift or floor jacks to get a car on/off the dynopack, and the fact that the dynopacks only weighs so much and is not bolted/secured to the ground. We made the final call on the DD after a lot of thought in what would work best for us has a company and provide the customer with the best results.

First it has small rollers and uses eddy current breaks to produce load. This along with an adjustable wheel base and the front/rear beds not connected with a belt will allow the DD to dyno cars that have power splits in the drive train; Porsche, Trail Blazer SS, Audi and/or cars that can not be converted to 2wd, Subaru, just about any auto, 3/S, etc.

Also how much power the dyno will graph and handle was a big factor. When steady state tuning cars the small roller will not smooth out or effect the power out put(that much), the dyno is very sensitive and shows every little change. Also displaying this live is what is needed in most cases so you can see your change right a way. The DD has a pressure sensor that when you spin the roller is pushes or pulls(pending rotational direction or on decel, yes it shows negative hp/trq) using the eddy current break to transfer rotational force down on the pressure sensor. This puts out a number called tractive effort in lbs. That is calculated into lb/ft of torque and then with the engine RPM it figures HP.

The computer is run off DOS so there is no windows to crash or freeze. The dyno also logs air intake temp(for NA cars) and has a 5bar map sensor along with a crazy ass LM11(a little below lab grade) O2 sensor that is all logged for every pull we do on the dyno and can be looked at anytime, and/or graphed live on the screen during the pull. Also the dyno can hold a load right where you want it to, have the engine stay at 3000rpm all day long(or what ever RPM/MPH you want) and tune with accuracy, after using dynojet, dynopacks, and mustang dynos its amazing how well DD does this.

The ramp rate is also nice, this is how fast the dyno will let the car accelerate. When tuning and doing sweep pulls you want to simulate the road as much as possible, so you adjust the ramp rate to let the car go faster or slower threw the gear, and with using ramp up/down you can figure out your drivetrain loss. Dynojet just has the drum that weighs this much, lighter cars its to much load and heavy car/trucks there is to little load, mustang dynos and dynopacks are closer but still vary load/rpm a little which, known from personal experience.

There are limitations to this though, each eddy current break can hold(stop) 600hp and graph 1200hp(sweep pulls) so our twin twin can handle double that per axel. Along with the hp limit their is temp limits because it uses electricity to produce load that is converted into heat. With 2 eddy breaks on each axel the heat is spread out more and the dyno will be less likely to over heat during long tuning sessions(which happen a lot around here). Also the way a car is strapped down on the DD with traction bars is a lot safer and less likely to spin the tires then other chassis dynos(rubber band the car over a big roller) except dynopacks.

I think the last point of LSE choosing the DD would be its nickname the Lowboy its only 18" tall so no lifts or pits are needed just a few ramps and back the car on. That is my take on it, Josh Ryan Pattie, chime in if you would like.

~John
One last thing a dyno is a measuring tool, how it is used and who uses it will have a big effect on HP out put, bring your car to the same place/dyno each time and take notes on how things were done ie atmospheric conditions, strap down method, temp corrections, cooling over the car, exhaust evacuation, etc. Bring it to the same place, run the same way, and your car should make about the same power with out changes to the car(pending mods and repeatability) and show increases/loss in power when mods/changes were made.