Chassis Dyno

[CRTD]

Was at the PRI show over the weekend and saw three chassis dyno systems that interest me. We plan to purchase one over the next year. The three that looked promising to me were the Dyno-Mite, Dyno-Jet and the Mustang Dyno.

For street performance, and drag racing apps what are some comments from users out there? No AWD at this time. But, maybe in the future.

[DSteck]

I've used Dyno Dynamics (AWD, and it was awesome), DynoJet, and Mustang. The Dyno Dynamics is great, but isn't on your list. The Mustang dyno is awesome because of the control you have. Loaded dynos just allow a much easier time. You can change how fast a pull lasts, simulate road conditions, and lock wheel speed They are great tuning tools. The eddy current DynoJets might be OK, but I've only used their inertia dynos which are only good for half-ass WOT tuning.

[Matt Compton]

I own a Dyno Dynamics.I love mine. Only regret is I should have ordered AWD when I did order. If you can suck it up and go AWD you'll pull in more Business.

[CRTD]

Dyno Dynamics had nothing at the PRI show. And i have not heard of them. But i could certainly inquire with them. There was a Dyno Com there. But it really looked like a cheap junky thing.

One of the differences that intrigued me was the roller size, type and configuration. As far as holding power (traction), safety, durability, etc. If i remember correctly the Dynojet had a large single roller, the Dynomite had a twin roller with grooves that ran the length of the rollers, the Mustang had a smaller (than Dynojet) single roller.

And service after the sale. That always means a lot. It doesn't matter what it is capable of, or what the price is, if they don't answer the phone when there is a problem.

I am waiting to get some literature from them all.

[mecanicman]

Mustang 1100 is a nice piece. I have used others, but this is my favorite.

[DSteck]

You can get a double roller Mustang dyno. It WILL eat soft tires though.

[Alvin]

I have a loaded 224xlc dynojet and love it. You can't beat dynojets repeatablity. I had to do a AWD TBSS a few years ago, went to a dyno dynamics and it dynoed 255 then went to a mustang dyno and it dynoed 350 in the same day.

As far as half ass inertia only tuning.... Another internet myth. I have yet to see a supercharged or naturally aspirated car change anything while loading them. That is REAL world experience. The 224xlc has enough brake to literally stop a 800 rwtq car. The only cars I've ever seen the tunes change on is laggy turbo setups.

[edcmat-l1]

The eddy current DynoJets might be OK, but I've only used their inertia dynos which are only good for half-ass WOT tuning.

Spoken like a true rookie.

[LSxpwrdZ]

I've not had good luck tuning on inertia either... my WOT pulls on the street proved better times and trap speeds at the track than a tweaked tune from my street tune I did on my personal car on a dynojet 248x.

We have a Dyno Dynamics analog dyno and love it! They are crazy low reading also haha. My other car is a Formula with a custom cam and a few bolt on's and it made 395rwhp on a DJ 224 at the Holley LSFest back in September... on my dyno it only made 348rwhp.

Anyway back to the dyno's, Dyno Dynamics is based right up the road from me, they are based out of Lexington, KY but is an Austrailian company. Haltech standalones are also in the same building. You can't go wrong with one of these dyno's. They are built like a tank and just flat out work awesome for tuning on.

[DSteck]

I have a loaded 224xlc dynojet and love it. You can't beat dynojets repeatablity. I had to do a AWD TBSS a few years ago, went to a dyno dynamics and it dynoed 255 then went to a mustang dyno and it dynoed 350 in the same day.

As far as half ass inertia only tuning.... Another internet myth. I have yet to see a supercharged or naturally aspirated car change anything while loading them. That is REAL world experience. The 224xlc has enough brake to literally stop a 800 rwtq car. The only cars I've ever seen the tunes change on is laggy turbo setups.

The Dyno Dynamics was always a heart breaker for people... but damn was that thing dead nuts reliable and durable. The display just looks like it runs off an Atari, granted I haven't used one in about four years so maybe they prettied up the GUI.

I like the ability to set the length of a pull to be longer if need be, especially on cars with huge stalls. I also ran really long pulls on my car just to push the setup and purposely let it run hot. Not to mention loading the engine at part throttle and locking vehicle speeds. I'll take a loaded dyno over an inertia dyno any day.

[edcmat-l1]

The Dyno Dynamics was always a heart breaker for people... but damn was that thing dead nuts reliable and durable. The display just looks like it runs off an Atari, granted I haven't used one in about four years so maybe they prettied up the GUI.

I like the ability to set the length of a pull to be longer if need be, especially on cars with huge stalls. I also ran really long pulls on my car just to push the setup and purposely let it run hot. Not to mention loading the engine at part throttle and locking vehicle speeds. I'll take a loaded dyno over an inertia dyno any day.

I like the loaded eddy current dynos as well, but to say all you can do is half assed WOT tunes on a DJ is totally false. Maybe you just haven't spent enough time on one.

FWIW, we ran a 900 rwhp turbo car at the track this weekend, and even though it was colder, and the tune was done on the crappy DJ :sarcasm: the A/F at the track was virtually identical as when I tuned it on the crappy inertia dyno.

FWIW2, you can do alot more with an inertia dyno, if you know how to use them. For one, if it has proportional air control, you can drag the brakes and hit cells you normally couldn't hit using just the inertia. Something infrequent users usually know nothing about.

The eddy current (especially Mustang and DD) dynos are nice for being able to hold a car to a certain RPM, and running up and down a column or across a row.

[DSteck]

The last place I regularly tuned for didn't want to use the brake until the rollers had slowed down all the way. It was just a basic DynoJet. None of the dynos I use belong to me, so I have no say in how they get used.

The standing mile Z06 I did for them was done on that same inertia dyno. It ran the same AFR in the Texas heat even though it was tuned in chilly St. Louis. I'm not saying you can't dial in WOT, but I much prefer using loaded dyno to easily control the sweep. Some cars blast through a fourth gear pull way too damn fast.

In comparison to an eddy current dyno, they can't do as much and don't offer the same amenities. I will run to the Mustang dyno as first choice any day of the week.

[Phil'sC5Vette]

Im looking to buy a mobile dyno unit

[CRTD]

Turns out Dyno Dynamics was at the PRI show. They did not have a dyno indoors like the others. And the one they had outdoors was unmanned when we went by. They did call me yesterday. Sounded good. They stated their roller was the smallest out there and that it offered very little inertia resistance. In essence you could stop the run right away if you wanted. Is that a big deal?

So how can one dyno give more generous (or reduced) reading than another and not be faulty or mis-calibrated? Is it purely a sales gimmick? If i used a torque wrench that was that far off i would be upset. And torque wrenches are only a few hundred dollars. Not tens of thousands. How much can we rely on the accuracy of these machines? Or are they just a measuring stick. Only to be compared against itself. A lot of people take pride in those numbers.

[DSteck]

You can calibrate the Dyno Dynamics to read similar to other dynos, just like you can calibrate any dyno. I don't remember the exact parameter, but there was some multiplier that was set to something stupid and that was why the one I used to use always read so low. After it was fixed, we put my Z06 on the dyno bone stock while it was pretty hot, and it made 430rwhp three times in a row. Pretty close to what a DynoJet would read for a stock C6Z.

[edcmat-l1]

You can calibrate the Dyno Dynamics to read similar to other dynos, just like you can calibrate any dyno. I don't remember the exact parameter, but there was some multiplier that was set to something stupid and that was why the one I used to use always read so low. After it was fixed, we put my Z06 on the dyno bone stock while it was pretty hot, and it made 430rwhp three times in a row. Pretty close to what a DynoJet would read for a stock C6Z.

You can't and don't calibrate a Dynojet. That's part of the beauty of the machine. It's simplicity. Only way to skew the numbers on a DJ is to intentionally feed the weather station misinformation. I.E. blowing a hair dryer on it, putting the stack in an AC room, away from the dyno, etc.

[DSteck]

The dyno still has to be programmed. At some point in time, somebody wrote code to convert the changes in drum speed into a power value. I'n not saying you do it live but it happens at some point in time.

I'm also lumping the display of raw, std, SAE, smoothed, etc numbers into that category. While not something that can be manually changed, I know people who report whatever correction factor reports the highest number.



At the end of the day, I don't give two craps about the number. I just want to see a curve that is relatively smooth. Unfortunately customers typically only care about a peak number.

I will still choose an eddy current over inertia dyno any day.

[Matt Compton]

In my area we have me with the DD 1 Mustang and 2 Dynojets. I have gone from my dyno to the dyno jet within 1 hour and got within 2hp. I have also gone and been 20down. really depends on the day. Use it as tool to deliver the best possible product you can. Yes the DD has a "market horsepower" function. It is mainly to combat the inertia dyno impossibly high readings. I have an engine dyno as well and have gone from there to the chassis dyno to the track and the ET and MPH are closer with my "LOW" numbers than they are from the local inertia dyno. To CRTD don't let that small roller thing fool you. Yes they are small (I do bikes karts atv's on mine) but don't ever do a panic stop or abrupt stop on one. You'll ruin the rear tires. And if you go DD get a twin retarder,Much more capacity and control than a single. I hear good things about their "tuner" line too. I'm going to look at one of those when I get ready to open a satelite store.

[Alvin]

The dyno still has to be programmed. At some point in time, somebody wrote code to convert the changes in drum speed into a power value. I'n not saying you do it live but it happens at some point in time.

F=ma is a complicated thing! That's the beauty behind it. Mass takes the same force to accelerate no matter if you here, on a mountain, or on Mars.

Most of the load type dynos use a load cell with a strain pack on the side of a Z cell. Turning on and off florescent lights is enough to skew them. Whats funny is most of them think that just zeroing them is good enough.

[DSteck]

F=ma is a complicated thing! That's the beauty behind it. Mass takes the same force to accelerate no matter if you here, on a mountain, or on Mars.

I didn't know friction stopped existing. I also wouldn't assume a perfect calculation of the rotational moment of inertia for the drum. I'd bet there's fudge factor built into the calcs at some point.