Whay dyno machine to get

[virus77]

A buddy of mine wants to get a dyno in the shop soon and I was wondering what type we should get. Any posts about you experiances with them or any real reasons to go with a certain brand would be appreciated, also if you guys can give some info on how much it ended up costing, thanks.

[USsil80]

have they looked at the dyno packs... that way you don't lose any floor space ..

[getnrowdy23]

no!!!!!!!!!!! those suck and are not acurate!!! they dont take the weight of the wheels and tire into account nooooo dont do that!

[virus77]

Ive heard dynodynamics and dynojet from people so far, any opinions?

Can a MOD move this to 240sx general, I placed it here on accident.

[D1 guy]

dynojet is the only way to go. Its better than any other out there. All you need is a wideband o2. It comes with all the other software.

[veilside180sx]

Actually most people that are really finicky about stuff I know, run Mustang dyno's.

[ETTInnov04]

+1 for mustang dyno. Mustang's read closer to what you would actually put down on the street. It uses a edy(can't remember how its spelt) current brake to simulate resistance. The dynojet on the other hand is the industry standard, for one it typically reads higher than the others so its great for dyno queens. And I'm not sure but I believe it uses weighted rollers, which we all know once you get something moving its easier to keep it going.I'd go mustang for the purists but if you have to go dynojet.

[s13sr20chris]

+2 mustang eddy current dyno

[getnrowdy23]

+3

[knightrider]

no!!!!!!!!!!! those suck and are not acurate!!! they dont take the weight of the wheels and tire into account nooooo dont do that!

i dont see how the weight will affect the accuracy, other than helping it. but i will put one down for dynapack, we have it at our shop and they are great, you dont have to strap down the car, permantly install it in the floor, and it is very accurate and you dont have to deal with wheelspin or jumping off the rollers. also you get a much more accurate power curve

[rochesterricer]

DO NOT believe all the **** talking you hear about Dynapacks. One that is properly setup will actually read slightly lower than most dynojets. With a Dynapack, you can load the engine properly and you don't have to worry about wheelspin affecting the numbers. For the real down low on properly setup Dynapacks, contact Jeff Evans at Evans Tuning http://www.boosted-hybrid.com/

[virus77]

Ive actually spoke with mustang dyne and dynapacks spokesperson and so far im leaning towards mustang, its quite a bit cheaper and a proven dyno at the expense of occupying a bay.

[GTR Shop]

no!!!!!!!!!!! those suck and are not acurate!!! they dont take the weight of the wheels and tire into account nooooo dont do that!

What a load of SH1T!!I have done MANY hours on a hub unit...On a steady state run, you can see the kw change that having the indicators blinking makes.They are the ONLY dyno in the world that can produce the same numbers run after run, with no chance of a car spinning tyres on rollers or coming loose.Also only dyno that can hold an engine at load within 20rpm/min of the set rpm.They are made 2 mins away from our shop.. their old Cheif R&D man does work for us.... so I know 'enough' about them.

DynoDynamics.. now THEY are rubbish.. 18% difference in power between 2 gears.. yeah.. really accurate... they can't even calculate power from torque and rpm correctly

As far as dynos reading higher.. lower etc... which one is right????Mustangs and Dynojets seem to be the odd ones out.. there was a test done in Australia on about 5 different dynos witht he same car... published onthe net somewhere..

[JimmyMethod]

i dont see how the weight will affect the accuracy, other than helping it. but i will put one down for dynapack, we have it at our shop and they are great, you dont have to strap down the car, permantly install it in the floor, and it is very accurate and you dont have to deal with wheelspin or jumping off the rollers. also you get a much more accurate power curve

The weight of the wheels and such is part of the loss between flywheel power and power at the wheels. Effective power is what your actually putting between the rubber and the asphalt.

[rochesterricer]

The weight of the wheels and such is part of the loss between flywheel power and power at the wheels. Effective power is what your actually putting between the rubber and the asphalt.

The problem is that wheelspin screws this up. Dyno numbers are never good for comparing, because even the same make and model dynos can read differently in different places or even a different times of day, due to varying conditions. Dynos are tuning tools, nothing more. For tuning, repeatability is the most important factor, and hub dynos always have better repeatabitly than roller dynos.

The only TRUE test of effective hp is the racetrack. Always remember that.

[s13sr20chris]

The only TRUE test of effective hp is the racetrack. Always remember that.

i would say an engine dyno with climate control does pretty darn well.

[rochesterricer]

i would say an engine dyno with climate control does pretty darn well.

Not of EFFECTIVE hp. Your results on an engine dyno do not change when you get a different wheel/tire combo.

[InsanityInc]

Not of EFFECTIVE hp. Your results on an engine dyno do not change when you get a different wheel/tire combo.

And racing on a track isn't going to tell you how much horsepower you have either...

[rochesterricer]

And racing on a track isn't going to tell you how much horsepower you have either...

I guess what I'm trying to say is, most of us don't build cars to generate a number on a dyno. The hp figure is ultimately irrelevant, because the goal usually is to go fast on some sort of racetrack. To most of us anyways. I guess some people do live for the dyno though.

[atomicfire]

i dont see how the weight will affect the accuracy, other than helping it. but i will put one down for dynapack, we have it at our shop and they are great, you dont have to strap down the car, permantly install it in the floor, and it is very accurate and you dont have to deal with wheelspin or jumping off the rollers. also you get a much more accurate power curve

YOU LOSE

Just kidding, weight is all the dyno is about. On earth because of gravity, weight is related to the mass somewhat. I know theres density and whatnotbut in general you can expect that the more something weighes, the more massive it is.

Because the dyno calculates power by comparing how fast the known mass in the dyno rollers, wheels, and tires accellerate (jerk) the mass is an important factor in figuring out your horsepower. Take the mass\weight of the tires and rims out of the equation makes it unseen mass that your car has to spin, taking away from your hoursepower readout.

Hope this helps you out.

EDIT: +1 for dynapack

[s13sr20chris]

Not of EFFECTIVE hp. Your results on an engine dyno do not change when you get a different wheel/tire combo.

your right, but under the assumption that engine building and chassis building are separate on a race car, it is the ideal way to build horsepower/torque curve you are looking for. not only does it eliminate the wheel/tire combo but also the whole driveline! this is truly ideal when builing an engine.

i am with you on most of this though. its all about winning races. its not about getting the big number. if that were the case this would be the supra owners club.

[Dattebayo]

For safty reasons I would have to go with dynapack.

But Mustang dynoes are like a standard around here, so close second for the preferred alternative.

[PantherRacer]

hp differ's on temperature, wheel size, how someone feels, how you shift, etc.etc.etc.

If and when I start my shop I'm gonna need a dyno too...sounds like mustang is the way to go...

[rochesterricer]

That is partly my point. Wheel weight and size DO NOT actually affect hp, but they do affect how fast the car accelerates. This is why inertial dynos like Dynojets can be fooled by such changes. That is why I feel Dynojets are not truly accurate, because they can be fooled by things like wheel size and flywheel weight.

[InsanityInc]

That is partly my point. Wheel weight and size DO NOT actually affect hp, but they do affect how fast the car accelerates. This is why inertial dynos like Dynojets can be fooled by such changes. That is why I feel Dynojets are not truly accurate, because they can be fooled by things like wheel size and flywheel weight.

Uh... they aren't being fooled. Chassis dynos measure RWHP, which means the actual horsepower you're putting to the ground, after you've spun everything in your driveline.

[PantherRacer]

Ok, I made the assuption that scince wheel size directly affects how your engine revs under load etc. (smaller wheels= higher revs)that it would affect hp also, scince hp is made at a certain rpm...guess not

[rochesterricer]

Uh... they aren't being fooled. Chassis dynos measure RWHP, which means the actual horsepower you're putting to the ground, after you've spun everything in your driveline.

Yes they are. You need to actually look up the definition of hp to fully understand this. This is why a lighter flywheel does not produce any hp gains on anything but an inertial dyno like a Dynojet. Eddy current or hydraulic brake dynos are not affected by such things.

A dynojet works by measuring the amount of time it takes to accelerated a known mass(the roller). Therefore, something that affects acceleration but not hp can fool the dyno. Other dynos actually measure the force or work produced, which is the definition of hp. While an inertial dyno calculates what hp should be.

All of these things are pretty well established.

Ok, I made the assuption that scince wheel size directly affects how your engine revs under load etc. (smaller wheels= higher revs)that it would affect hp also, scince hp is made at a certain rpm...guess not

Smaller wheels change your gearing and, therefore, allow you to accelerate faster. They do not affect hp though.

[Thee 240sx Owner]

+1 for Engine dynos... :-D