Hub Dynos vs Roller Dynos
Hub Dynos vs Roller Dynos

Hi this is Jeff from Evans Tuning, Today I
want to talk to you about the myths that we’ve heard after owning and operating a Dynapack
dyno for the last 12 years. So the first thing I want to talk about is
the Dynapack dyno reading high. I’ve heard this since I’ve owned it 12 years ago. The
dyno reads high compared to this dyno, or it’s the highest reading dyno there is out
there. From my point of view the dyno is a tool. It’s what I use to calibrate and tune
your car’s computer. So being like any tool it has a purpose, and that purpose is to hold
the load on the engine so I can properly sweep all the fuel and ignition points, you know
in the maps and properly map out a car’s calibration or tune or you know whatever you
want to call it. The Dynapack when it came out was the only game in town as far as a
proper load-bearing dyno. Now there are some other options on the market right now you
know I own two Dynopacks. I have two 2-wheel drives that actually combine to make an all-wheel
drive. I have found you know I’ve traveled and tuned at a lot of different shops. I’ve
used multiple different dynos, I’ve been on the Mustang, i’ve been on Dynojets, Dyno
Dynamics, you name it and i’ve pretty much used it. From a tuning aspect, I still believe
the Dynapack has the best control strategy for being a load-bearing dyno. As far as it
reading high, I’ve found that our dyno reads about on par with an average reading Dynojet.
Now when you get in the mix of a high-power car, on a roller-dyno, you’re limited by
traction once you get up to a certain point. You might see pictures or videos of guys sitting
on the trunk of a rear wheel drive car, or on the front fenders of a front wheel drive
car, just so they can get enough down force on the tire so that it gets grip so it doesn’t
spin on the roller so they are going to get some sort of a reading out of it. Once you
get to that level where the tire slips, you’re always questioning how much power it is actually
putting out, you don’t really know and your load is changing under that kind of condition.
So your tune is questionable, you may not be getting proper load on the engine to properly
tune it. Case in point years back I had a Supra, it was making roughly about a thousand
at the wheels, at that point in time my first dyno couldn’t handle that kind of power. We
ended up having to tune it on a dynojet, and we made a bunch of pulls and the car it was
spinning on the rollers, I had four or five guys sitting on the trunk to make it hook.
I think it made like 860 or 880 or something like that on his dynojet. I did an upgrade
on my dyno years back, and that dyno can now read about 12 to 1400 horsepower by itself.
We ended up bringing the Supra back and putting it on my dyno. Now the wheels are off so were
connected right to the hubs so there’s no wheel spin. The car put out a little over
a thousand on my dyno. Now you’re going to go “it reads higher”, of course it
reads higher the tires weren’t slipping they weren’t spinning, everything is going right
into the hub and is able to be measured. And, I found that the same condition when we ran
35 pounds of boost on that dynojet we put it on my dynapack, the boost changed because
the load was accurate. The tune changed, i found that the tune was actually a little
bit lean where I never would have seen that or experienced that on a dynojet, and it would’ve
been missed. So you know that client could have left and ran that car at the track and
it could’ve been lean, it could have melted a piston it could have been catastrophic.
You know from a tuning aspect I really strongly feel that the dynapack, taking the wheels
off the car, is the way to go for tuning a high power car. Now there’s exceptions the
dynapack can’t read you know 2000 horsepower. There’s limitations. Mainline actually has
a new hub dyno out which we’re considering looking into down the road to do really high-power
domestics, I think those can read up to 5000 horsepower at the hub. So you can dyno a pro-mod
which is really cool. But for a tuning tool the dynapack is probably one of the best out
there. It leads me into people talking about the dyno reading high. The car gets tuned
on our dyno, case in point which trying to make an example here. A car base-lines on our
dyno at 200 horsepower and I tune it and I make 240 horsepower. Your car is going to make 20% gain in power whether it’s on a dynojet,
whether it’s on a dynapack, whether it’s on a mustang dyno, or whether it’s on whatever-whatever
kind of measurement you’re using to calculate horsepower and torque you’re going to see
that percentage gain. So you have to keep in mind, you know people go “I had my car
tuned here and I went and tuned here, and this guy made more power” -well not necessarily,
you need to do a baseline on that dyno to see where you’re at. You need to see how
much more you’ve gained, you need to see the percentage gain and you get retuned by
another place and are not willing to baseline you on the tune that you were previously tuned
on by another shop let’s say unless the conditions are unsafe or the tune is really poor that
you can’t. They’re not going to show you that gain, you have to wonder what the dyno numbers
really are, you’re not seeing the percentage gain. The percentage gain is the most important
thing to look at when you have a car tuned, the dyno is a calibration tool, regardless
of what dyno you have it’s used to tune the car. You need to pay attention to the percentage
you gain in horsepower and torque, which won’t change despite any dyno that you’re on, so
that’s what you need to be most concerned with. So one of the other common misconceptions
that we hear on a daily basis is “The dyno is not reading the power at the wheels”.
On our dynapack we take the wheels off it gets put on the hub, these pods, and the wheels
removed. So at the “wheels” some people consider it’s not the tire spinning on a roller
it’s not at the “wheels”. That’s completely illogical. The chassis dyno is measuring the
drivetrain loss, now there is going to be some loss of a tire on the roller, because
there is friction, there’s not enough friction that it’s going to make a substantial difference
putting the tire back on the car. You know I’ve heard this over and over and over and
over again and any dyno whether it’s hub or it’s roller, is measuring the drivetrain
loss. The loss from the flywheel through the transmission through the axles out to the
hub. Or on a rear wheel drive car, from the transmission through your drive shaft to the
rear to the axles to the hub. So either scenario rear wheel drive, front wheel drive, or all
wheel drive, or whatever you’re measuring the actual output through the drivetrain.
It has NOTHING to do with the wheels. So it’s at the hub or it’s at the tire, it’s the same
thing other than maybe a tiny bit of frictional loss from the tire contacting the roller,
which would be like a fraction of a percent, perhaps like .25 percent or something like
a quarter of a percent. It’s next to nothing. So another topic that i’ve had people bring
up to me via email, phone call, conversations, in person in the shop you know i’ve heard
well you know “my friend doesn’t want to come here told me not to get tuned on a dynapack
because the tune will be junk.” I don’t really know exactly what that means but as
far as the tune quality of the dynapack it lets you sweep all the fuel and ignition load
points on a map probably better than almost any other dyno i’ve been on. That allows a
tuner, not just me but any tuner, to go in and make very detailed changes to the map
and see cause and effect. I can hold the car at 3000 RPMs at 0 PSI and I can see the torque
and horsepower output live on the dyno screen. I can measure the difference of adding a degree
of ignition timing or taking it away, i can actually tell exactly what’s going on I
can find you know when you’re tuning ignition timing maximum break torque. It’s where
you find what’s going to give you the most power and then anything above that is actually
going to lead to knock conditions or it’s not going to make any additional power so
your running more ignition advance for no reason. But i’m able to actually see all of
those things on my dyno where you’re not going to be able to do that on most other style
dynos. So people saying you get tuned on a dynapack your tune is going to be junk or
it’s not going to be good I think that comes down to operator and i think that comes down
to the tuner that’s you know tuning your car. But from an accuracy, precision standpoint
being able to see exactly what is going on, the dynapack is in my opinion one of the best
tuning tools that I’ve worked with. The last topic I want to bring up is safety.
I’m sure if you go and YouTube or you go on Google, and type in dyno failures or anything
like that, you’re going to come up with a ton of videos or pictures of cars flying
off the dyno, going through walls, or God knows what. On a Dynapack, because you don’t
strap the car down as you would on a roller style dyno, you know, we take the wheels off
the car gets bolted on the hubs, the pods slide on once that happens there’s nowhere
for the car to go. It’s going to stay in that position. There’s no chance of it falling
off. You know owning the Dynapack for 12 years i’ve never even remotely had a car come
off the dyno, I dont think ive ever even thought about it happening. I don’t even ever remember
hearing of a car coming off a dynapack dyno anywhere ever, i’ve never even heard of
it, never seen a picture NOTHING. So from a safety standpoint keeping the car from flying
off the dyno is non-existent on a dynapack. The second aspect or safety concern is when
you have a tire on a roller, you’re spinning that tire super super high mile per hour.
Tires have speed ratings, I couldn’t tell you how many times i’ve seen and i’ve actually
had personal friends that are professional tuners have tires explode on the dyno at high
speeds. You know a tire blow out if that car isn’t strapped down just right it is going
off the dyno, that is unsafe, and when the tire explodes its shrapnel sometimes or it
whips around and it’s going to take out whatever is in it’s path, somebody standing near
it you know whatever is near it, it’s going to take it out because there is a lot of force
a lot of speed and a tires hard and heavy it’s going to hurt something. The last thing
that I think is crazy that people do is sitting on the cars to gain traction on the dyno.
If you have someone on let’s say a front wheel drive car sitting on the front fenders
and you have a tire blow out that tire is probably going to take their leg off, there’s
going to be no way to stop it. Likewise if you have a rear wheel drive car and you have
someone sitting on the trunk and that car gets loose the straps break, all the people
that are sitting on that thing are going for a ride and someone is going to get seriously
hurt. I don’t ever have to think about any of this, I don’t ever have to worry about
it, you know the dynapack in my opinion is the safest dyno or a hub dyno in general because
there are several other hub dynos on the market. But the dynapack is what we use and it’s
never a concern, never an issue. In my opinion it’s the safest if not one of the safest

41 thoughts on “Hub Dynos vs Roller Dynos”

  1. Doug Swartz says:

    Can't wait to make my appointment

  2. islandboi1988 says:

    One of the best tuners on the east coast right here! Great info

  3. that jamaican guy says:

    are you guys still making the j series stroker kit? I'm anticipating it for my second build after my kswap

  4. LaimisBMW says:

    Great vid. I can confirm every word after i bought my Dynapack dyno.

  5. gorrilaunit99 says:

    Do you sell prebuilt FI S2000's for private purchase?

    I'm very interested in buying a prebuilt/tuned Supercharged (Drivetrain and Supporting Mods only) S2000

  6. TheEscobar999 says:

    yeah!! its much better if the tire explodes when the client is on the higway back home… 😀

  7. TheTurbooneg says:

    it's major BS that he's on here having to defend his process and equipment for calibration of someones drivetrain setup when ive heard literally not one bad review by the tons of people that i personally know that have used him for their race cars(setting records) to their daily driver turbo/all motor cars. Definitely one of the best here and should be treated as such.

  8. steve nichols says:

    Great video Jeff. Any hub dyno should read higher. You simply don't have the tire/ roller interface. Again, thanks for sharing. we see 3-5% between our hub and roller dyno's.


    Not gonna lie I've been an opioids user for. Year methadone for 7yrs this guy is high AF

  10. MatthewWhiteBoy Mueller says:

    your dyno doesn't read high, it reads accurately.

  11. Brad Haas says:

    How do those hub dynos work? Obviously they don't flip over from the torque/HP going thru them.


  12. 1down5up says:

    I had no idea a hub dyno existed. I think this is the only way I would be fully confident about having a car tuned. It makes sense to wanna measure horsepower through the driveline but eliminate the variable of wheels/tires with differing weights, diameters, and rolling resistance. Not to mention inconsistencies in how the car is strapped down

  13. Floppy Ole says:

    either has black eye cause got hit or is strung the fuck out

  14. BigBoysClimbOnBigRing says:

    The older I get, the more I realize how much ignorance there is in the enthusiast culture. Listen to this guy.

  15. SI RICKO says:

    Damn i love these video so much good down info

  16. Aou Celloutus says:

    How can a Hub dyno measure same as dynojet????? Don't you lose some power to wheels and tires?????? Not talking smack, just really wondering…..

  17. Andrew Gallagher says:

    The Dynolog software that comes with the Mainlines would have to be the best in the industry.

  18. _ VesBraun says:

    easiest way to understand HP and dynos: your car can spin the roller a certain speed, that input can be translated to energy OUTPUT, measured in kilowatts, then we can translate that energy output into torque, and then HP as a function of torque. seriously, its not that hard. all dynos should read roughly the same.
    though the effiency of your air pump (engine) and drivetrain can be affected by PLENTY of variables, fuel mixture, altitude, fuel pressure, drive train wear, etc.

  19. _ VesBraun says:

    dynapack = safe & reliable.

  20. Dylan Neman says:

    totally agree, i always had the same thoughts about hub dynos

  21. Francois Combrinck says:

    Are you able to remotely tune a Infinity 6 ECU ?
    Sadly here in South africa tuners are simply not interested in even looking at it. And refers me back to Stone age ECU that is total rubbish
    Like this

  22. Initial Greg says:

    Have you dyno’d your arms? They look to be 500+whp on a heartbreaker

  23. nick strahan says:


    Not sure if you ever check your comments but I have a question:

    Do you guys calibrate by holding the engine at a constant speed while varying the throttle? Is the dyno's load control system capable of this? This would also put it at a much bigger advantage over dynojets, or other acceleration based dynos. Those machines rely on calculating power from the acceleration of the roller. The problem with that is you must accurately know the rotational inertia of the entire driveline to get the correct power value.

  24. vinzanity68 says:

    Thank you! I am new to dynos. I want to build a dyno from plans online. And I have always thought that hub dynos are more practical since you don't have to build a big (expensive) roller. Thank you for confirming that hub dynos are a better choice. 🙂

  25. omaduskilas says:

    I learnt a lot thanks!

  26. Meister_ 4wlc says:

    Which is better hub or rollers?

  27. Noorzuihadi Bachok says:

    Great knowledge…

  28. Okaythen001 says:

    His arm looks like it's bigger than his head

  29. ntme9 says:

    Without watching the video and knowing next to nothing about dynos, i would bet the hub dyno would be more consistent and accurate but read a bit higher than roller. I would think that a roller types flaw is its readings would be affected from differences in tire size, tread pattern, weight, and compound softness.

    I'm having a Whipple put on my pickup truck and the shop doing the work has a Hub type. It's the first time I've seen that and it got me thinking.

  30. ntme9 says:

    7:15 if you take a truck with 31s then you take the same truck with 37's you're telling me you won't see a difference??

  31. chucai says:

    great video . Agree of every bits you mentioned . and thanks for the explanations

  32. Ian Summers says:

    The point he’s missing about the wheels and tires is that they have mass.

    He keeps bringing up friction being the reason for lost power when comparing a chassis dyno to a roller, but then also says the lack of traction on a roller is an issue. These ideas conflict.

    You want more friction. More friction is more traction. Traction means more power getting to the roller. The real loss you would see using wheels and tires on a roller as opposed to a chassis dyno has to do with the rotational inertia of a big 35+ pound set up (times four) being added to the drivetrain. That takes torque to accelerate.

  33. Ric777888 says:

    I want a real world measurement. real world my tire is on. with tire off it distorts everything. if you only care about engine then yes hub is better. bottom line the rear wheel makes circles!

  34. LifeInGeneral says:

    Thank you clearing things up. There are a lot of tuners here in SoCal that don’t know what there talking about. The only tuners that touch my car is Church Automotive, Daniel Butler. And Bisi at Bisimoto in Ontario.

  35. JP says:

    How do people know a dyno is reading "high" or "low", what are they comparing it to?

  36. JP says:

    One downvoter uses a chinese roller dyno that reads in cubits

  37. Kane Saw says:

    Dyno correction factors too.

  38. Blaine Macdonald says:

    The only people that care are the people that want to post their numbers on the internet

  39. W .Khairi says:

    I am just wondering …Do you guys ever think about exhaust gases and their hazardous components , Especially for high HP cars and for cars without catalytic converters, SO do u ever consider this risk and how it effects your health on the long run?
    Since I love cars and pondering in jumping in this kind of business but I am kinda of worried about this aspect of the business.
    Thanks a lot.

  40. jt says:

    very true no bs here

  41. knurri says:

    Sorry…. I can't take you seriously when you keep saying "you know" and "um". You should have rehearsed what you were going to say before making this embarrassing video.

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