Chassis Dyno

[ccrp]

I had a DJ 224xLC and I loved it, simple and great repeatability. Will not eat tires even if you hold rpms quite long but it could be a lot faster in settling in until it holds a certain rpm. Maha's are much faster here.

Sold it and will get a Dyna Pack now. lot less noise issues (no rolling tire or drum noise) and its holding power is unsurpassed. hydraulics are so strong you could actually stop engine at WOT within one revolution. Beauty of it, you don't need it you can roll it away or take it to a race.

rigging up, I tried myself, hardly any longer then putting it on the DJ. And definitely no traction issues like on two roller setups

[LSxpwrdZ]

AFR wasn't my problem on the dynojet... it was timing. The timing it took to get peak power across the board did not coincide with my track tune. The pulls didn't last near long enough to get good readings either. Especially on huge stalled autos! You can really hunker down a car on a loaded dyno. I had alot of trouble out of a turbo car on a dynojet also. I had done some basic tuning on the street before we strapped it down and it was seeing 14-15 psi of boost on the street and on the dyno the maximum it saw was 11 psi. I have no idea why or how because a wastegate spring will hold boost no matter what load is on it but it did what it did.

[CRTD]

So does anybody have any info on the Dyno-Mite?

[VYSSLS1]

ive had DDs for 10 years, love them, easy to use and always worked well for me, if you can afford one you wont go wrong...

[edcmat-l1]

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

Again, I'll state, I like eddy current dynos as well. They have some advantages over inertia dynos. My problem is when someone states that merely the use of an eddy current dyno somehow results in a superior tune. It's much more about the tuner than the dyno used. That's ALMOST like saying using one software editor over another results in a superior tune.

At the end of the day, the dyno is just there to let you make changes while stationary, and let you record the results. It's up to the operator to understand the limitations of the equipment, and to keep the consistency.

[DSteck]

I never said it results in a superior tune. I prefer loaded dynos because they make things easier and more straight forward. Operators around here only use inertia dynos to make WOT pulls. The rest I have to do on the street. The shop I work at now with the loaded dyno... I could finish a car without it ever moving (well, not an auto) and to me, that is valuable (some moron won't run a red light and smash into me on the dyno, which has almost happened more than once).

[Justin@VMP]

I have owned a Dynojet 224 for about 7 years. I have owned the eddy current add-on for about 5 years.

You don't need the eddy current for mass air stuff, but it certainly helps, and may be necessary for certain speed density stuff. I do a lot of 600-800rwhp Fords and you can slow down the pull and get more data points with the eddy current. When I do an older GM vehicle that needs the VE table mapped out I can do that too. I have my software set up to do % load over the whole sweep, target a certain RPM or MPH (work vertically in VE table cells), or load the vehicle based on speed to simulate the road.

In inertia form the dynojet is pre-calibrated from the factory (you accelerate a given mass over a given time). In eddy current form it can be ran in inertia mode or loaded. The calibration procedure involves an arm and weights, beyond the basic "zeroing" procedure.

The beauty in the Dynojet is the simplicity, industry standard numbers, repeatability, not many parts to break, and inexpensive to fix if they do break.

The large roller provides a good contact patch for most vehicles and doesn't chew up tires or deform them. Some of the smaller and dual rollers can do this.

[DSteck]

That is one crapper about the dual roller Mustang dyno I usually use... It eats soft tires pretty bad.

[ccrp]

not only one set of drag radial or slicks went up on dual rollers..........................scary moments sometimes

one of the beauties of a single roller dyno. Or better Hub dyno

[edcmat-l1]

I never said it results in a superior tune. I prefer loaded dynos because they make things easier and more straight forward. Operators around here only use inertia dynos to make WOT pulls.

In not exactly the same words, you said almost exactly that.

but I've only used their inertia dynos which are only good for half-ass WOT tuning.

All I'm saying is, after a few hundred cars, there are things you can do with them that you probably don't even realize right now.

[DSteck]

In not exactly the same words, you said almost exactly that.

No, I didn't.

[edcmat-l1]

No, I didn't.

Practicing to be a politician?

[DSteck]

Practicing to be a politician?

No, just standing my ground against somebody trying to put words in my mouth.

[edcmat-l1]

No, just standing my ground against somebody trying to put words in my mouth.

but I've only used their inertia dynos which are only good for half-ass WOT tuning.

I'll quote it again un case you missd it. How is this not insinuating an eddy current dyno tune isn't better? If that's all inertia dynos are good for, then surely YOU MUST THINK BASED ON YOUR OWN QUOTED OPINION THAT THE RESULTS ACHIEVED ON AN EDDY CURRENT ARE SOME HOW SUPERIOR. You said it, not me.

[DSteck]

Again, you're changing things around based on what you want to see. I called it half ass WOT tuning because cars with huge stalls just blow through the pull resulting in considerably less data versus being able to push back and make a nice, long pull. Six speed cars and cars with pretty low converters aren't bad but it is a pain in the ass to mess with a 800whp car that flashes the converter and then ends the run in two seconds. Beyond that, I like being able to stretch pulls out in any car to get more data and pump heat in to make sure the IAT modifiers aren't too aggressive or not aggressive enough. I purposely ran my Z06 on extremely long pulls for the sake of stress testing. It spins the rollers up way too fast on inertia dynos and won't roll into full boost at the same rpm. For me, an eddy current makes my life easier and eliminates the need to try and keep a high horsepower car on the road while data logging it.

I never said the end result is different. For me, it is the process.

[Frost]

An unlocked stall will flash HIGHER on a loaded dyno; it's not going to slow down the sweep at all (except OVER flash, which is not where it's needed anyway), just make it sit at flash (slip) longer and cause more slip up top. That's the reason stalls get locked on the dyno, not for the number it can create. Past that, if you have a single-disc stall converter, you don't really want to make a locked pull under any additional load.

I can tune a VE on one without using the dyno or the car's brakes (though I often use one or the other here and there where appropriate) and can get it through it much quicker than you would likely suspect. That's a lot more than "half-ass WOT tuning".

[LSxpwrdZ]

Either way back to the point of the post... the loaded dyno IMO is better because you don't have to use special tricks to hit a cell or load the car a certain way. On my dyno there are various different methods of holding, sweeping or even applying a constant amount of load to achieve whatever you could imagine as far as load to the rollers. It is especially nice to do RPM column's in a VE table but even that doesn't cover the table correctly which is why I like to do sweeps across RPM columns at various load points to verify fueling is correct.

I was in the same boat about purchasing a dyno a few months back before I bought my DD and having used all of the above mensioned I'm happy with my purchase of the DD. But like Ed said the quality of the tune is in the tuner and the equipment is only as good as the tuner/operator... It's just my opinion that it's MUCH easier on the tuner with a Eddy Current/Load option.

[edcmat-l1]

An unlocked stall will flash HIGHER on a loaded dyno; it's not going to slow down the sweep at all (except OVER flash, which is not where it's needed anyway), just make it sit at flash (slip) longer and cause more slip up top. That's the reason stalls get locked on the dyno, not for the number it can create. Past that, if you have a single-disc stall converter, you don't really want to make a locked pull under any additional load.

I can tune a VE on one without using the dyno or the car's brakes (though I often use one or the other here and there where appropriate) and can get it through it much quicker than you would likely suspect. That's a lot more than "half-ass WOT tuning".

That's basically what I was saying in a post that was deleted.

[Alvin]

Of all the people commenting here I wonder who has actually used one and therefore qualified to speak about them.

I have one.

[CRTD]

So what seems to be the preferred roller configuration? As far as holding power, not killing the tires, maint/durability, and safety.