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What dyno to choose MainLine vs Dynapack

Off Topic Discussion

If it's not really about tuning or wiring. Then it belongs in here.

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Good morning to everyone .

I've been searching a lot on internet looking on both sides what have to offer , and i am a bit confused i must say this is why i make this post that maybe can help me choose ...

I own a small motor-sport shop company. At first i had a 4x4 Bapro dyno (Italian Company) that worked well at low power /normal car situation , but i was struggling to make accurate measurements or even get proper data-logging on high power (motor-sport cars) , so i decided to sell this one and buy the new HUB-Dyno Rotronics has to offer (French Company), The dyno is good with a decent Data-logging same for low or high power cars, BUT Unfortunately i had so many problems with this dyno (Which unfortunately i cannot mention here as i have a court agreement (yes this went badly for like 6 months back and fort with lawyer and experts pfff) , so the company got the dyno back and i got my money back ..

For the 3rd time now (and hopefully the last) i'm searching my "new" dyno ..

So I'm in "between" these 2 leader brands , Dynapack / Mainline for the moment i do not "care" if it is a Hub or a Roller dyno (well if i buy the Dynapack it has to be a Hub-dyno)..

I'm looking advice from guys that already owned a Dynapack or Mainline and see from their perspective what is "good" and what is "bad" with their dyno (it has to be some "bad" / downsides with every dyno nothing is Perfect ... )

For example i know that Dynapack it has an issue with Automatic cars not every automatic gearbox it can run on, On the other hand no such issue with Mainline (hub dyno) the rollers doesn't have such issue ..

A small preview on my company so you can have an idea on what i'm searching on. I work on Motor-sport car (Classic 24Lemans Cars / Formula 1 80s / prototypes / rally / time attack cars) I'm also tuning some "daily driven" cars (Vw group cars / Mercedes / Bmw ).

The dyno i will need it has to absorb something like 1200-1500hp (more is useless to me) but to have good repeatability and a very RICH data-logging ..

Sorry for the long post , Looking forward to you reply.



The fact that you've said you may need to support 1200-1500 hp may end up excluding the dynapack so this may make your choice very simple. First of all though you do need to understand that neither dyno really has a horsepower limit but rather a torque limit, so the ultimate limit on either dyno will depend on the engine torque and the final drive/gear ratio. On my old dynapack 8000 (4 x 4000 nm hub units) the most I could support was about 1000-1100 whp in 2wd but this required a final drive change to get there so it was a lot of hassle. They are problematic with some auto transmissions but to be honest most of the time they're absolutely fine. The issue normally comes up with a drag car that uses a high stall convertor where the torque multiplication is massive.

Since I had my dynapack they have released a larger 'DAQ5' unit that supports 4500 nm so that may be enough to get you across the line but you just need to understand how that torque limit will affect the cars you're tuning. Along with the max torque rating there is also a hub speed limit so you need to balance the two with overall gearing so it might not be as simple as it looks on paper.

As a product the dynapack is excellent and the hydraulic control is accurate and very fast (definitely faster than an eddy current absorber). Repeatability is also excellent and a demo I used to run on our customer nights was to run a car in steady state and turn the head lights on and off - the dyno could show the almost insignificant difference due to the alternator draw on the engine. The software is relatively user friendly but much more simplistic than what can be done with the Mainline, particularly in regard to the CAN capability on the Mainline. Despite dynapack literally being 5 km from my old workshop in Wellington, I found them remarkably difficult to deal with and this is a continual complaint I hear from other dynapack owners. At the time that I owned my dyno they also didn't seem interested in further development (we had been asking them about more advanced logging and analysis options for years which seemed to fall on deaf ears). I haven't really followed what they've done since I moved on so can't comment on the current capabilities.

The Mainline roller which we've had now for the last 4 years is excellent and the software capability is almost limitless. I will say that the user interface is written by an engineer and can be a little intimidating as there are so many options, however it doesn't take long to learn. As mentioned above, the eddy current power absorbers are a little slower than the hydraulics of the dynapack and ultimately I tend to see slightly more run to run variation on the roller than my old dp hub dyno. Mainline's customer service is absolutely out standing and Todd and Craig will bend over backwards to help any mainline dyno owner.

We've just taken delivery of our new mainline prohub 4WD dyno which I'm expecting will help with consistency as it eliminates the tyre contact patch on the roller. This is the smallest of their hub dynos yet has already been proven to support over 2500 hp in 2wd form so it would be more than up to your requirements. As a bonus last time I checked, the Mainline was quite a bit cheaper than the dynapack.

Ultimately both are excellent dynos and the biggest choice for you will be torque/power handling if you decide to go dynapack.

Thanks a lot for the answer here Andre , it was exactly what I was looking for to hear from someone how probably they owned one or the other Dyno both in your case :)

In my understanding I have to use those 2 dyno before I decide on which one I will get .. Before I buy something that will not fit my needs...



It's a big investment so it's always advisable to test drive the machine before you make your decision, even if that may involve some cost to travel.

Andre, now that you have had some seat time with your new ProHub dyno, can you provide some feedback as to how it compares to a DynaPack ?

To elaborate on my previous post, I’m looking to buy hub dyno, and am teetering between the ProHub and a DynaPack. I’ve tuned many cars on DynaPacks and prefer them to any other chassis dyno I’ve used but have never used a ProHub as they are fairly scarce here in southern California. So:

1. Smoothness : have you found that there is any advantage to the Mainline in regards to rolling smoothness ? With the DynaPack, even when you have made every attempt to center the hubs, some cars just bounce a bit. I thought that the Mainline CV setup may help ? Also, is the amount of work to bolt up a car about the same as compared to a DynaPack ?

2. RPM stability with engines that have very low inertia : I found that on some engines with low inertia, the DynaPack had a very hard time controlling RPM.

3. Target rpm when tuning : with the DynaPack, you can just type in the exact RPM and drive up to that set point. From what I can tell the ProHub software requires you to enter a wheel RPM. If this is true, do you keep a spread sheet handy to do the math, or possibly I’m misunderstanding how the Mainline works? How do you find it for mapping when having to target non-standard rpm break points, i.e. 2716 , 4639 , 5113 rpm, etc. ?

4. Engine cooling fan : do you have the Mainline fan, and would you recommend it ?

Thank you for your time, any other thoughts or insights into your experience with the Mainline ProHub would be greatly appreciated.

Hi Chris,

First up I'd say that both are excellent dynos and both will do a good job. There are understandably pros and cons with each. To answer your specific questions:

1. I don't think there's an advantage as such to the pro hub in terms of smoothness. This really all comes down to the adaptors being bolted on concentric to the hubs and if they aren't then either dyno will give you an uncomfortable experience. A nice feature with the pro hub is that they provide adaptors with a specific stud pattern (say 5 x 114.3) which means there's no fiddly washers to align and you're guaranteed the adaptor will be concentric. Of course mainline also offer the universal adaptors too. The work required is slightly higher on the mainline as the adpators are two piece - first you bolt the adaptor to the car and then the hub unit bolts to the adaptor.

2. The prohub probably has an advantage in terms of low intertia engines due to the additional inertia of the edddy current power absorbers themselves. That being said, I haven't as yet run a car with very low inertia so can't give you first hand feedback. What I would say is that the inertia of the pro hub allows you to test gear change cuts which is almost impossible on a dp.

3. The prohub set points are related to axle rpm but it's not a big deal since the engine speed relating to the axle speed is also shown. Not perhaps as simple as dp but certainly not a problem. You can control the hub rpm very finely so there's no trouble with odd break points

4. Yes we have the mainline fan and it's effective and well packaged. I still find that it can be insufficient for sustained high rpm/load steady state tuning but there'd be few fans that would cope better I'd think.

I will add that the mainline software is initially a little daunting and less intuitive than dp. You learn your way around very quickly though and the advantage is that it's incredibly powerful. I don't know what dp have done in the 6 years since I sold my business but over the 12-13 years I owned two dp dynos I was constantly frustrated by the lack of software features, particularly around data acquisition. The Mainline is insanely powerful in this regard, particularly if you have the CAN option to take the ECU data stream.

Lastly customer service at dynapack was terrible when I dealt with them. My shop was literally around the corner from dp's factory yet I get faster responses and better service now from Mainline who are in a different country. I found that there was a certain arrogance expressed by dynapack about their product and it felt like they were grudgingly doing you a favour allowing you to buy one. This sentiment has been echoed by the majority of dp owners I've met world wide. I believe that dp sold dynos in spite of their best efforts to the contrary and they were only successful because at the time they happened to have the best product. That however has changed and now products like the mainline do everything the dp can do and more. Mainline have fallen over backwards to help us out any time we have a question or a problem which is refreshing. I hear this from other mainline owners all around the world so it's not just because of our brand.

I'll add a caveat here: I haven't owned or used a dp dyno for 6 years now and I know they have new software and I believe thy've worked on improving their DAQ system including CAN and OBD2 comms. I have can't speak for these features because I haven't used them myself. Their customer service may also have turned a corner in the time I've been with mainline. I can only speak for my own experiences.

A couple of other factors to consider. If you're considering tuning high power engines then the prohub is 100% the right choice. The dp is torque limited and my old unit would shut down above about 4400 nm. That might sound like a lot, however once you factor in the gearing and final drive, this can be problematic with engines producing 1000-1200 hp in 2wd form. It's made worse if you have an auto trans and torque converter. For comparison even the smallest pro hub dyno will handle in the vicinity of double the torque of the largest dp dyno.

Due to the inertia inherent in the eddy current absorber there is a little more latency in control with the prohub compared to the hydraulic control of the dp. I'm splitting hairs but it's worth mentioning, particularly if you're already familiar with dp. Lastly, the pro hub pods are significantly larger and heavier than the dp pods. This may be an issue if you're limited on space.