Yamaha FZ-09 Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
990 Posts
Discussion Starter #1
Anyone have any data on different dynos?

Here's my 2 cents to start off...

I think that Dynojet is about 10% high at CF:SAE setting and 13% high at CF:STD setting (most people don't even use the STD, it's ridiculous)... but it's not that simple. The inertial sweep tests really seem to provide an extra boost in the HP readout for the big bikes. They have made great progress with the new Dynojet 250i with torque module and eddy current brake, and they are by far the most popular (partly because they are less expensive, and partly because everyone wants to see big HP numbers, partly because everyone wants what's popular or comperable).

OK, I guess they serve multiple purposes:

One is tune development (using an eddy current or water brake to hold settings, using a load cell to measure actual torque, using a 4/5 gas analyzer, development software, etc).

Two, is a "yardstick" for dyno days, or before and after.

So, what is everyone's experience with dynos, and maybe the lesser known DYNOmite model 800 Eddy Current Dyno, or the big Superflow Cycledyne Eddy Current Dyno, or the Mustang Dyno (Factory Pro Dyno). I guess there are a few more.

Personally I'm a big fan of Marc Salvisberg (for many decades, he's a brilliant tuner with many patents) and of course the Factory Pro Dyno. Any thoughts?
 

·
Registered
Joined
·
304 Posts
Old thread, but here are my $0.02

Not a big fan of the dynojet method of load control. They spent years trying to get an inertia dyno to produce consistent data, but in reality you can’t because it can only measure acceleration and on a bike, acceleration is rather fast. I’m not sure they tell you anything.
When they added the eddie current brake, they didn’t take all the weight out of the drum, so it still creates a weird load.
Dyno Dynamics make an excellent dyno and their software is excellent. Their step algorithm for bikes is very clever, and you get the feeling you are running a sweep, even though it covers a large area of the map.
They can take all your ECU signals via CAN as well as other sensors and you get your entire dyno session as data points for analysis and tuning. Using Woolich Racing kit I was able to completely remap a ZX14 from a 2hr session, come back a week or two later and it was spot on across the entire map.
Superflow make great dynos. I’ve only used them for engines, not chassis and not bikes. They have water brakes to a fine art. I think eddie current dynos do suffer from inconsistency if they get hot - water brakes not so much because you can control the temp. Water brake dynos are maybe 10-20rpm stable, so you see some “noise” doing fixed rpm tests with rolling throttle.

I’m currently building my own engine dyno for bikes. Trying to find a Telma or Frenelsa eddie current brake at a good price.
All the control logic is designed and the entire thing will run on CAN bus so I can datalog every aspect.


Small phone + crap vision = my excuse for typos
 

·
Registered
Joined
·
990 Posts
Discussion Starter #3
Thanks for the feedback... full disclosure, I have a FactoryPro dyno (so we always tend to favor what we have bought it seems), and familiar with the others... and I could never understand how DynoJet could correlate the load cell versus their mass/acceleration calculations. The FZ09 on the FactoryPro is about 98 true HP correlating to about 116 DynoJet (SAE not STD) reading on a 2014 250i with the new WinPep 8 software and new DynoWare RT hardware. STD would indicate higher (look at Dyno charts, anyone who uses STD calibration is probably looking to show higher numbers). Having said that, Dynojet has done a fantastic job in establishing themselves as the standard. What I don't understand is how they correlate that load cell with the acceleration HP calculation, as it's not just a linear percentage, but a whole different dynamic that results in a higher % for higher HP.

Bottom line seems that for accurate development work, the FactoryPro with the low inertia eddy current system, and integrated gas analyzer, is very helpful.

You can probably do this on the 250i the same way to a point, but set an RPM step and check all of the throttle positions to set AFR under load... you can see HP and TQ live... the gas analyzer will also let you know if the ignition timing is off (lower CO2 and/or higher NOX). By the way, if the timing is off, the traditional lambda wide-bands will show a leaner AFR as it cannot distinguish between certain gas ratios. On the DJ it's easier just to use auto-tune and paint all of the blocks with a new AFR... but something interesting happens with modern TBW bikes. If you hold lower power settings steady for 4-5 seconds, ECU will swap over to the vaccuum sensor maps, and they are sometimes out of wack. One example relevant to this site... Akra Ti exhaust system has an area on the OEM steady-map where it runs a little rich, and cruising in this area will show a slight surging that's not easy to detect, more like an unstable feeling... so painting the TPS/RPM maps to correct will cause issues of course. Same concept on any modern bike, the steady-setting maps will interfere -- running a DJ PCV Autotune all the time will help but you can't just load that area into the permanent TPS/RPM map as it has to account for the switch. It's always better just to properly tune.

With regard to the heat and the eddy-current comment... the calculation is based on RPM and Load Cell data with a very low inertia drum in the case of the FactoryPro... so it's live and very accurate... variable is grease in the bearings perhaps as this resistance is not transferred to the load cell, but there doesn't seem to be any perceptible resistance with the bearings (granted it doesn't get very cold here)... and there's a warm up sequence for the step pulls which would likely loosen up any small drag there.

The Supeflow has a much higher inertia drum, so it works well with the high HP bikes but seems challenged with the low power settings on smaller bikes in my opinion... but I haven't developed any ECU's on the Superflow. If I had a 400+HP drag bike, this is probably what I would want to use, with a 5 gas analyzer and lambda both. The inertia stuff alone would be fun on dyno nights but not very useful to properly tune it.
 

·
Registered
Joined
·
304 Posts
Excellent info! My experience agrees with all you have said.

Bottom line - if you want to properly tune a modern EFI bike with TBW, you need a low inertia dyno with good load control, properly calibrated load cell and software that you understand and can use.
My current project involves head and exhaust thermo couples (per cylinder), a very sensitive knock sensor, lambda probes on each port and a gas analyzer. Once I have the eddie current brake organized, I want to do some detailed TPS, MAP and Ignition maps. I’ve already found a fair amount of inconsistency between cylinders in the stock maps. The FTECU stock and Unrestricted maps seem a little worse. Once I have a solid engine map, I’ll start playing with response maps and the other “ridability” tuning. I think they are actually more important than peak output, but this torquey engine improves a lot if you better balance the cylinders (esp the MAP table).


Small phone + crap vision = my excuse for typos
 
1 - 4 of 4 Posts
Top