I recently bought a Dynojet 224XLC in ground chassis dyno and installed it in my garage at home. It's not a business thing for me, just something for my friends and I to use / goof around on. In that vein, anyone that's a member here is welcome to use it. Just pay me whatever you think it's worth when you're done, or owe me a favor down the road. No big deal either way.

No time restraints, no gaggle of on-lookers, no shop employees staring at you silently wishing that you'd get out so they can go home, etc... Assuming you can maintain traction on the drum, the dyno will read unlimited torque and horsepower. I've had a handful of cars in 900-1000 RWHP range on it and haven't had an issue with traction. I'm sure I'll have that problem eventually, but so far so good for now. Maximum wheel speed is 200 MPH.

My dyno is what most people think of when they hear the word dyno, a 24 inch diameter knurled drum recessed into the floor. The drum weighs approximately 3000 lbs, and the dyno software is able to calculate horsepower and torque from the rate at which your car can accelerate the drum. This is typically called an "Inertia Dyno" and is the vast majority of whats out there. However, my dyno has an electronic eddy brake attached to the drum. This option nearly doubles the cost of the dyno, which is why you don't see very many dynos with electronic load control in the wild.

Some of the benefits of the eddy brake are:

-Chances are your car doesn't accelerate down the road the exact way that it will accelerate a 3000 spinning drum. You can enter the vehicle weight, frontal area, and drag co-effcient into the dyno software; and the electric brake will apply additional load based on the weight of the car and wheel speed. This simulates driving down the road / track. I have tested it on my car based on how long it takes me to go from 2000 RPM to 7000 RPM on the road, and then again on the dyno. The difference is less than half a second over a 16 second test.

-The eddy brake lets you place the engine under the same load that the engine sees going down the road or race track. All engines act a little different under different loads, turbo cars especially. Maybe your car will tolerate 17 degrees on timing while accelerating a 3000 lb. drum, but out on the track it will only tolerate 15 degrees of timing because your car is heavier / harder to push than the 3000 lb. drum. On an inertia only dyno, that's a chance you take. With the electronic load control, you can mimic the same loads the engine will see when driving, and hopefully arrive at the best tune combination for your application.

-Say you have a stutter / stumble at light throttle, 2200 RPM. You can tell the dyno to hold the drum speed when the engine equals 2200 RPM. When you hit 2200, no matter what you do with the throttle, the brake will apply / release to keep the engine at 2200. That allows you to watch a laptop without crashing, have the hood open and wiggle things while the problem is occurring, etc... You can also do this based on wheel MPH. Same problem, a stumble at light throttle on the freeway. Tell the dyno to hold the wheel speed to 72 MPH, and away you go.

-Road test without actually needing a road. You can drive the car on the dyno more or less like you'd drive it on the road / track. Shift gears (violently if you want to), accel, decel, etc... No risk of crashing while road testing, tickets, other nimrods pulling out in front of you, etc... And you can watch a scan tool or data logger without worrying about keeping one eye on the road.

-You can steady state the car. IE; 3000 RPM, WOT, and the eddy brake will apply enough load so that engine can't increase RPM; while showing real time torque and horsepower. Leave your foot on the floor, and click the laptop to add a degree of timing. You can watch the power / torque respond to that in real time. You can do this at any RPM or any MPH. Great way to find MBT.

-RPM or MPH step tests, custom load tests, etc... Hold the engine at 2000 RPM for three seconds, then let it come up 500 RPM every 3 seconds. This can be MPH based as well. The software also allows for custom tests, which allow you to configure the dyno set up anyway you'd like. Maybe you'll be pulling a trailer and want to apply 20% of the eddy brake's capacity to the entire run to simulate that. Load changes over time, over RPM, over distance, etc... The only real limit is your imagination.

There's a whole host of things it does beyond power and torque. Power generation stuff is fun, but the electronic brake allows you to do some really neat things with the car.

If anyone from here wants to play with it, I'm in Garner, NC near the 40-42 interchange.

joshkinzey AT gmail DOT com is the best way to get ahold of me.

 

that’s very cool of you to do. I’m in the northeast. New York State to be exact. If I’m in the area I’d take you up on the offer.

 

Very cool!!!

I have Dynocom DC PODS in my shop. They are Eddy Brake dyno pods. I would like to do an in-ground, but really... with what I do it doesn't matter if it takes me a fex minutes to bolt on the hub adapters.

How is your software? I've had several issue with the Dynocom software and on the Dynocom users FB page, there are constantly issues. Mostly software, but some stupid things that seem to repeat like cables, handheld, grounds... I just wonder if the DJ people have similar issues.

 

Believe it or not, I’ve had zero issues with software or support. Every once in awhile I’ll have a hard time finding a clean RPM signal, but other than that the whole thing has been more or less flawless. I did have an issue with the air brake not releasing, but it turned out to be my fault for hitting the MAC solenoid with more PSI than was recommended.


I’ve been making pulls on it since July of 2020; so it’s still relatively new.