Manipulated Dyno #s- I'm Sick Of It! Video Inside

[Spaz Racing]

There R alot of head porter's out there these days. Some good...... some not so good. But I guarantee 4 the money U won't find a better head then mine that U can make good power with small cams. Thous keeping it a true street bike. I have built 235hp 1397's but U can't run them on pump gas either

[Johnnnycheese]

Im not talking about making any changes to the stack.Im saying if you compare any dyno on sae on any day from a shop that hasnt messed with the stack they should all be close......
I know what point chuck is trying to get across and I believe that there are guys that do it to sell there product....On my dyno the power is the lowest of all other big builders yet my motors mph and et great for the low numbers.......your only cheating yourself if you mess with the stack....
YOu have a starting point and you see your increase no matter what the final number is....Take it to the track and run a number with it.....that proves it all.........

I have to disagree.
I had 5 stacks all sitting in the same place and not one had the correct Absolute altitude reading.
some had me at 1700 feet below sealevel others at sea level I am at 732 above
I agree if you start with something on that dyno and end with it on the same dyno it is apples to apples and the gain is real in% but..............
How do you tell a customer that his 1397 only makes 180hp????
I would not be in bussiness very long
the only way I knew my numbers where off was the track numbers told me so (MPH does't lie)
I want a real correction factor period. and there is only one way to do that and show it on a sheet. get your absolute reading correct.

[DarkFalcon]

There is or used to be drum mass calibration issues as well. As I recall, default values for drum mass were frequently being encoded when actual values should have been entered. If actual is higher than default, then the dyno will read low; if actual is less than default, it will read high.

[gazza414]

There is or used to be drum mass calibration issues as well. As I recall, default values for drum mass were frequently being encoded when actual values should have been entered. If actual is higher than default, then the dyno will read low; if actual is less than default, it will read high.

that's 1 DF

[DarkFalcon]

Are there more?

[enginetuna]

Yeah, hair dryer in front of the stack whilst blowing cold winter air at the bikes ramair intakes.

[DarkFalcon]

ET, the question was asked in the context of software.

[Chuck Wilburn]

Yeah, you can mess with the drum calibration and it won't show with high correction factors. 

[whtrthanu]

alot of ways to cheat.....................................................yourself!!!!

[bobu]

Hey Chuck  you know that turbo you sold me and installed that we both blew head gaskets with and you shaved my cyl & head because of , was it the same one that the man from aberdeen burnt pistons with? You know, its the one that you told me didnt need to be able to adj. the boost on. 

                                                                                                         Im a little sick myself
                                                                                                        Tommy Cole

[Chuck Wilburn]

No Tommy, the man from Aberdeen brought me that turbo to install.  It ran fine until he asked me to turn the boost up after I already showed him on the dyno where he was running close to lean and the injectors were at 100%.  It was his decision to turn the boost up and he paid the price.  Not that it's any business of yours.  If you have more to talk to me about your bike, you know where my shop is. 

Now instead of being an ass trying to bash me on a forum, lets tell the whole story.  First head gasket blew after you picked the bike up from me.  I said lets put studs in it and a new gasket.  You pay for the studs/gasket, I'll do the work for free.  Gasket blew again on the dyno before you picked it up, I took the bike down again for free, straightend up the cylinder/block from you running it hot, put a cometic gasket in, added a .030 spacer plate all for free.  Cost you 10hp and now you're not happy.  But I clearly remember you saying do whatever it takes to make it stay together- I did.  Your bike runs fine now but you want to cry.  What about Stedman?  Yeah, I know all about that too- could he not make you happy either?  Evidently not or you wouldn't have come to my shop after leaving his wanting to sell back your turbo.

[bobu]

You are rite chuck nobody can make me happy with that turbo.  I was mistaken in that i thought he bought it from you.But you sold me a turbo with no boost adjustment and i believe you knew it. I have no intention of ever goin to your shop again, too many trips there already. I aint hard to find either.

[Chuck Wilburn]

I had never had that turbo on anything.  I took it on consignment from Don Mason out of Ohio.  Give me a call, I'll be glad to give you his number.  If you have a problem with the turbo, why aren't you bashing Velocity- they made the thing, not me.  It has the adjustment for the boost, I can't help it if it won't work.  Thats why I spent a lot of time on the phone with Velocity trying to starighten it out.  Once we realized that there was no getting it down, the next best thing I could do was set the motor up to handle a little extra boost.  That's what I did, all free to you, and now the bike runs perfect so what's the problem?

Just so you know, your little "ambush" here doesn't bother me in the least.  At the end of the day, I can sit down across form you at the dinner table, look you straight in the eye, and still enjoy my meal.  Good luck to you.

[gnd111]

You are rite chuck nobody can make me happy with that turbo.  I was mistaken in that i thought he bought it from you.But you sold me a turbo with no boost adjustment and i believe you knew it. I have no intention of ever goin to your shop again, too many trips there already. I aint hard to find either.

 

[thebbbusa]

This is exactly why i take most dyno claims with a grain of salt.  Unless you've done a before and after under nearly the same conditions on the SAME dyno, you really don't know what you've got.

My 03 ran 152hp in 5th gear (I think) last winter in the lower 50s.  I did some mods (full exhaust, pciii map, airbox) and got back on the same dyno, this time in sweltering 95 deg heat and only got 6hp, bike practically overheating.  Now the butt dyno says I likely picked up more than that, as the bike runs pulls completely different now.  (Unfortunately I don't recall if my numbers were STD or SAE)

So, like I said, unless it's same bike, same conditions on same dyno, you just never no.

On another note, I hear that most guys pull runs in 4th, which gear should it be done in, and which one reads higher/lower?

[Chuck Wilburn]

I pull in 4th for most bikes.  I only go to 5th/6th if it's abig hp bike to keep from spinning the tire.  I've heard guys say the dyno will read higher in higher gears but I haven't seen that to be true.

[whtrthanu]

If you pull in 4th or 5th it will be almost the same. 5th gear will make maybe 1 more hp.....
If its a harley it will always make more in 5th.....you want to get the bike to pull around 150mph...It will also give you a bit longer to see how the a/f is

[Competition CNC]

Very interesting thread.   Its just like racing, if theres a way to cheat some people will.
I wonder how many weather stations are just plain set up wrong.   You see some dynos consistantly reading higher than others, and I wonder how well they were set up to begin with.

Whats the procedure for setting it up when you first get the dyno?  Or is it self configuring?

[entropy]

Chuck,
great thread!

Q:  I see a whole lot more (reproducible) detail on my Innovate AF logs than I see on the Dynojet AF trace.  Have you ever tweaked a Powercommander map on your DJ using the logged AF?????

[Chuck Wilburn]

Don't have a data logger on anything but that's not a bad isea.

[enginetuna]

Very interesting thread.   Its just like racing, if theres a way to cheat some people will.
I wonder how many weather stations are just plain set up wrong.   You see some dynos consistantly reading higher than others, and I wonder how well they were set up to begin with.

Whats the procedure for setting it up when you first get the dyno?  Or is it self configuring?

No, plenty of shops just run and pay no attention to weather and tyre slip, both hugely important.
It can be calibrated but also they can go faulty.  I'm on my 3rd one in 3 years.  If you never check you could quite easily be up or down 15bhp or more on a hayabusa.  You really must have a 2nd realiable weather station or at least check the local weather report and see if you are anywhere near.
Its no good just saying "i don't tamper with it so its right" because if the calibration is wrong then the figures are wrong.  Don't rely on setup from dynojet.

[enginetuna]

Q:  I see a whole lot more (reproducible) detail on my Innovate AF logs than I see on the Dynojet AF trace.  Have you ever tweaked a Powercommander map on your DJ using the logged AF?????

I have built powercommander maps from logged wideband data and emailed them back to customers at race meetings.  Do the same regularly for my motec customers.
The lambda is another item that needs checking and replacing.  Don't rely on that as being accurate because they can be wrong.

As another side issue, i hear a whole lot of BS about ramair on the dyno.  My fan blows about 70mph at the front of the bike.  Comparing this to logged data off the motec system on my superbikes and supersport bikes, the motec logged data is never more than 0.3 off on AF compared to the dyno.  So don't worry about throwing in a whole heap more fuel.  BUT, i've never logged at 200mph (max about 170mph) so all your bonneville guys please don't come looking for me if it blows.

[Chuck Wilburn]

Ward just told me the best way to calibrate your dyno BP.  You need to know your exact altitude- then call the local airport and get the BP from them- then subtract your altitude.  BP is given at sea level, that's why your altitude plays a factor.  We're right in line with our local airport- if the planes didn't pull up on takeoff, they'd plow into our building!  So, I used the airports altititude of 346ft.  BP they gave when I called was 30.24.  Subtract my altitude- .346= 29.89 BP.  My dyno was at 30.2 so it was a little on the low-hp side, once corrected it will add roughly 3-4hp to whatever I dyno.  I'm not going to correct it for a while though because I'm testing things and that would through off my tests baselines.

[Chuck Wilburn]

Just got a call from Dynojet....  Seems like my video is causing a lot of trouble.  They're overwhelmed with phone calls wanting to know how to do what I did on the video.  They're afraid that more people want to jack up their dyno just to get higher numbers.  That was never my intention making this video.  I see their point- we don't need 100 more shops doing this than already are so I'll be removing the video later today.

[enginetuna]

SAE will still be a long way out if the air pressure is wrong.  XXXXXXXXXXXXXXXXXXXXX  -  section removed  -  XXXXXXXXXXXXXXXXXXXX.  You will see about 20bhp  between them on a busa.
Chuck isn't saying everyone with high bhp is doing this, he's just informing those that don't understand to pay attention to this.

I've removed my bit on how to do it as well.