True HP and DYNO

In the link in the first post, Marc gives many technical reasons as to why the FactoryPro dyno is more accurate and precise than others. Inertia (the principle that all DynoJet dynos are based on) hinders the results and Marc discusses why on his page. Besides this, getting the best out of a bike takes more than setting steady state or acceleration air/fuel ratios, which is only what tune link provides. I've yet to read a technical reason as to why Marc is wrong.

I haven't yet had a bike tuned with tune link, mainly because the tuners I know won't pay the up front and yearly fees for the software. However, I have had some of the best tuners in the country tune my bikes using the PCIII and other devices using DynoJet dynos. I am sure these guys can set the air/fuel ratio as good as tune link could and their results would verify that. What I have found is that Marc has gotten results that others could not, understands the needs of the rider more than anyone I've dealt with and considers situations which cannot be duplicated on any dyno, especially a DynoJet dyno. He did all these things while explaining everything to me. Has anyone else here paid for Marc's services before judging him?


Gary M
www.bmgracing.com
CCS SW AM #28
'03 Kawi ZX636R
'00 Duc 748R

Gary,

The current Dynojet dynos are not simply inertial dynos anymore. To use the Tune Link software, you need a DynoJet 250 with the load control. Load control is the key feature that allows proper tuning at various RPMs, gears, and throttle positions.

I am sure both dynos are precise....I know the DynoJet dyno is very precise.

Accurate? As long as the dynos are consistant, do I care if one reports more HP than the other? No. Not as long as I can measure the gains made by a bike.

Again, if Marc had the best dyno, people would be flocking to it. The DynoJet Tune Link software is revolutionary. Tuners like Dan Kyle use it. It allow one to make customs maps much more quickly without having to make hundreds of dyno runs.

Marc is a good tuner. But that does not mean he has the best dyno or that DynoJet dynos are crap. You have remember that Marc is trying to sell his products so you have to take what he says about products that compete with his with skepticism.

Scott

Of course, a dyno needs load control to program fuel injection and I'm sure most people know that a model 250 has an eddy brake. A DJ may produce hp readings that are accurate enough for tuning, but what about the limitations of the software and the lack other features?

Ask someone who uses a DJ250 how they determine the correct A/F ratio at any given throttle position or RPM. They can't, because a DJ250 doesn't display the HP at steady state. It only gives HP readings when doing acceleration tests. Setting A/F ratios using acceleration tests is not accurate enough for tuning EFI because of the delay in the O2 readings. Besides that, using the inertia to do acceleration tests doesn't provide the proper load for tuning.

What about Tuning Link? It requires someone to guess at the best A/F ratio and the software sets the FI map to provide that A/F ratio. It does not set the A/F ratio to the best power. No given A/F ratio makes the best power on every bike and even considering a single bike, the best A/F ratio varies for different throttle positions and RPMs. Additionally, a 4 gas analyzer is sometimes needed to optimize a tuning point (like when the exhaust is in reversion). DJ doesn't have 4 gas capability.

Inertia is hard on bikes and the eddy brake. Also, it takes time from the tuning by waiting for the drum to slow down. Tuning a two stroke is more of a problem and it will beat up the eddy brake on an inertia system. Some dyno manufacturers (like MJP) offer dynos with DJ like inertia drums, but the drum does nothing to help in anyway. It's only a option to more accurately reproduce the BS DJ numbers so the shop can more easily sell their services. The problem is that the general public is conditioned to the inflated DJ numbers. This is why MJP (with O2,4-gas, and a FactoryPro-like interface that displays Steady State HP) is selling many dynos to replace DJ250's throughout Europe. There are even a few MJP's imported to the US.

Marc could have included DJ power as an output, but he decided to only output true HP. I respect his integrity to not buy into the DJ BS, although it ultimately hurts his business. I also respect him for trying to educate the masses. It's much easier to conform than educate every potential customer.

DJ needs to makes changes to their dynos to be more like Marc's, but doing so would mean that they were wrong all along. I don't see DJ doing that anytime soon. Until then, the FactoryPro dyno will always be better for tuning than what DJ offers.

Being the preferred dyno for any race series rules enforcement or being the industry standard is meaningless.

Scott,
I'm still waiting for a technical reason as to why you think Marc is full of crap.

Gary M
www.bmgracing.com
CCS SW AM #28
'03 Kawi ZX636R
'00 Duc 748R

Sorry PPL to have started this post...Just throw it out there to get some opinions.

Was not hope for DJ? to be thrown into it ..Or his name used in vain.

It was happy reading though.

All the best. cheers and happy riding

Wan2Fly

Point A to point B is always faster when you Fly!

Factory didn't mislead me. I get my information from various sources, this includes tuners who use DJ's and other dynos and from info available from the Dyno manufacturers themselves. Marc isn't my only tuner, I have paid for the service of many tuners over the years.

Dave, are you saying the the 250i can display digital Hp readings in real time when using load control? The Tuning Link and WinPEP screen shots in the DJ brochure do not show Hp readings and this capability is not mentioned anywhere. Also, the DJ 250 tuners I've talked with say it can't be done. FactoryPro, Superpro, Land & Sea, MJP and Mustang dynos can do this and advertise the capability.

It could be possible that the tuners I speak with are using earlier versions of the DJ 250 that don't have this capability. If that's the case, then DJ is making improvements and that's good for all consumers. I have heard that DJ is now testing a fast 4-gas EGA module. Maybe they will also add this as an option (this would make DJ dynos more like a FactoryPro). It will come at an expense, though and price has always been DynoJets biggest advantage.

What is mentioned in the 250i brochure is this "...the Tuning Link monitors the current air/fuel ratio at over one hundred and forty different points. At the same time, the Tuning Link automatically calculates the correct fuel adjustment to achieve the user desired air/fuel ratio."

Using the 250i, how is the "user desired air/fuel ratio" optimized at any given point? How does DJ train their tuners to determine this?

Although I agree with others here that dyno's don't need to be precise, accuracy is what is important. The riders who make changes and return for dyno runs rely on consistency. Those who tune at home may find this magazine article interesting:
http://www.factorypro.com/magazine/mag_cyclecanada_Dynojet_dyno.html

(After re-reading this article, I noticed this statement: "Dynojet unfortuantely cannot calculate horsepower while applying a load through the eddy-current")

I do understand that FactoryPro is trying to better their marketshare by posting links such as this, but the info is from a print magazine, not from FactoryPro. Has anyone found anything, anywhere that says FactoryPro dynos aren't accurate, precise, consistent, or poor tuning tools?

I decided to write here to share what I've learned about tuning, and I am still learning. I also happen to think it is wrong to say someone is full of crap without any reasons to back it up.

Gary M
www.bmgracing.com
CCS SW AM #28
'03 Kawi ZX636R
'00 Duc 748R