Interesting dynojet article

[Nash]

Originally Posted by turbotalon1g

Yea, i was in a hurry and taking a shit.
So next time i will put a little more thought into it more than i need to hurry up and wipe my ass so i can answer the door.
hey, cowboy the thread is about dyno's not shit analogies, learn to read dickwad.

There's need to call him a dickwad, and learn to use the fucking shift key.

[xveganxcowboyx]

Word. I was expanding on his analogy to try to help clear things up. No need to be harsh. It makes me cranky

[FattyBoomBatty]

Maybe you've got PMS.

[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.

[niterydr]

Good post John!

Like he stated we bought our dyno for its versatility, repeatability, tuneability, and any other ...ability I can't think of right now.

Every dyno reads differently. It is about what you use it for that makes the difference. Our is used as a prototype machine. We use it to design and test parts, and to design and test engines. We tune street and race cars with it, and we find it to be very accurate and easy to use, that is why we purchased it.
I can actually see if a change I made to a timing map made a difference LIVE, that is a fact that dynojets can not do.
I can see and graph different conditions by changing the smallest of things (like spark plug gap).
Accuracy is all about who is operating the equipment. We strive to be as accurate as we can, to give honest and real results.

I race cars, I do not race numbers. When the light drops, the bullshit stops.
I use numbers to realize potentials of vehicles and setups. They are nice for comparision sakes, but tend to make people over-confident and down right defensive about things.

I did not want this to turn into a dyno debate, just an interesting article I found on how dynojet came up with its "HP" formula and the wondeful job the creater of dynojet did marketing the product and bringing it to the masses.

[Halon]

I'm not in anyway saying your dyno is bad. Apparently it is one of the better dynos out there. Never said your dyno was bad. All I'm saying is I wish the numbers of all the dynos were closer, maybe standardized or something, because it does lead to confusion when I show people my chart and they say "damn that's weak" and then I go to explain that these dynos read low, and to do this math to figure out about what it would maybe be compared to theirs. Just kinda confusing. That make sense?

[niterydr]

Originally Posted by ju-on

I'm not in anyway saying your dyno is bad. Apparently it is one of the better dynos out there. Never said your dyno was bad. All I'm saying is I wish the numbers of all the dynos were closer, maybe standardized or something, because it does lead to confusion when I show people my chart and they say "damn that's weak" and then I go to explain that these dynos read low, and to do this math to figure out about what it would maybe be compared to theirs. Just kinda confusing. That make sense?

Makes perfect sence.
Don't worry, many of the industry leading facilities are switching dyno manufactures...that is another "fact". Dyno Dynamics is getting more and more popular across the US.

[turbotalon1g]

Sorry to mr. V-Cowboy.
Sometimes i have to use my bro's laptop and the left side of his keyboard is fucked up.
I personally don't care about dyno's, its nice not to have to change anything on my car dyno, just drive it on and do it to it.
And i couldn't give a shit about numbers and you could all tell from the
run-ins i have had this past season.
I just tell people i made 239hp on a DD which reads a little lower than a dynojet, i then give them the est./guess dynojet number and proceed to whoop some ass.
Either way to people other than us, we just have a little 4-banger in some unknown car.
Sorry again. Hope i used teh SHift Key enough.

[Goat Blower]

So is this an informational thread, or a promotional thread?

[Pushit2.0]

This was just showing what a dynojet is and how it calculates Hp/Trq, mass vs acceleration. And people asked why DB and LSE bought the DD dyno's so I posted why we did. And a lot of people still do not know how the 2 new dynos in the area work/operate so I thought I would post it up so people knew how the DD displays/figures out hp/trq.

~John