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Dyno Gurus Advice Needed!!!

Posted By: MRMOPAR622

Dyno Gurus Advice Needed!!! - 09/04/12 05:13 PM

Dyno operators advice needed. When we have our engines dynoed how do we know the dyno is calibrated/setup right? Looking at the instrumentation on the dyno is there a certain gauge or gauges we can look at to make sure our dyno results will be accurate? We hear a lot of talk about "Happy Dynos" we even have a post on here referring to "Happy Dynos" I did not want to hijack that post with this question.

Hopefully some of you dyno gurus can step in and tell us the correct procedures for setting up the dyno.
Posted By: Brian Hafliger

Re: Dyno Gurus Advice Needed!!! - 09/04/12 05:40 PM

You can look at the correction factor, usually if the weather is good and elevation is between 0 and 2000ft. the CF will be 1-1.04.
You can ask them when the last time they calibrated it...or if you business means alot to them they may calibrate it in front of you?

As delivered, our DTS reads slightly low compared to what they recommend, and much lower than what a Superflow CF would read but everytime we check calibration it's the same, so I feel no need to change it. Ours is less than 1/2% off.

It's also good to find others who have used the same dyno as you, and find out how they run at the track vs. the power they made.
Brian
Posted By: Dunnuck Racing

Re: Dyno Gurus Advice Needed!!! - 09/04/12 05:58 PM

It is not a big deal to do a calibration check. You hang a weight on an arm and check to see if the torque reading is where it should be.
I check calibration on mine every time I turn it on. Ask them to check it in front of you,if they won't look for someone else.
On Superflow dynos ther is a dial by the operators left knee to make minor adjustments. An unscrupulous operator can turn the dial up to add power and make you think he is a great tuner. Make sure the torque reading is zero or maybe Plus or minus a lb-ft of torque with the engine not running
Keith
Posted By: Cab_Burge

Re: Dyno Gurus Advice Needed!!! - 09/04/12 06:57 PM

I'm under the impression that there is a friction table on the DTS and the Studka dynos that can be adjusted for the flywheel wieght, IE aluminum 17 lb wheel or a 40 lb steel wheel The DTS uses a large diameter steel plate bolted to your flywheel, the Studka driveshaft bolts directly to the crankshaft usually with no flywheel or flexplate I had one customer who I had built a 484 C.I. RB pump gas street motor that he had supplied a really bad set of Mopar Stage IV heads that had the seats sunk really bad, it made 496 HP on the best pull with changing a bunch of parts. He made a comment to the dyno operator that he was really hoping to make 500 HP with that motor, the dyno operator shut the motor down and went into one of the tables in the software and made some changes to them, the next pull made 504 HP I ask the dyno operator several months later what he did to do that, he siad he change the friction table, IE flywheel weight I told him to never do that on any of my motors agian Even if I begged him to, he said okay On the local Studka dyno the current operator had been running it without calibrating it, once he did the calibrattion,maybe 20 minutes max to do it, with his shops race motor on it the dyno showed a hundred HP and comparable torque loss on that motor I had dyno tested one of my motors on it and then took the same motor with no changes to a DTS dyno in Klamath, OR which is at 4300 Ft above sea level versus 2500 Ft above at the Studka dyno, my motor showed 100 HP less on the DTS dyno After bringing back to the Studka dyno with the 17 lb flywheel still on the Studka operator wanted to use my flywheel, 8 bolt Hemi pattern, on his motor to see how much differences the flywheel would make on there motor. The Studka does have, I think, a friction table, it may be label some other name that escapes me right now Using the flywheel makes a lot of difference on the throttle response on the Studka dyno, both the DTS and the Studka have electric operated throttles, the DTS does a btter job of not letting the motor rev sky high when you go to WOT to begin a pull, the Studka lets it go way above the preset RPM you set to start the pulls at before it slows it down so you can start the pull at or below that preset RPM Have fun and keep in mind that all dyno are a measuring tool to use the measure changes that you make on the motor that day You should try different tests in the car when your done if you want to max the combo out
Posted By: RAMM

Re: Dyno Gurus Advice Needed!!! - 09/04/12 07:17 PM

Quote:

It is not a big deal to do a calibration check. You hang a weight on an arm and check to see if the torque reading is where it should be.
I check calibration on mine every time I turn it on. Ask them to check it in front of you,if they won't look for someone else.
On Superflow dynos ther is a dial by the operators left knee to make minor adjustments. An unscrupulous operator can turn the dial up to add power and make you think he is a great tuner. Make sure the torque reading is zero or maybe Plus or minus a lb-ft of torque with the engine not running
Keith



Not on a 902. J.Rob
Posted By: sr4440

Re: Dyno Gurus Advice Needed!!! - 09/04/12 07:25 PM

Quote:

Quote:

It is not a big deal to do a calibration check. You hang a weight on an arm and check to see if the torque reading is where it should be.
I check calibration on mine every time I turn it on. Ask them to check it in front of you,if they won't look for someone else.
On Superflow dynos ther is a dial by the operators left knee to make minor adjustments. An unscrupulous operator can turn the dial up to add power and make you think he is a great tuner. Make sure the torque reading is zero or maybe Plus or minus a lb-ft of torque with the engine not running
Keith



Not on a 902. J.Rob



Not on a superflow powermark either.

Joe
Posted By: DJVCuda

Re: Dyno Gurus Advice Needed!!! - 09/04/12 07:40 PM

Quote:

Quote:

It is not a big deal to do a calibration check. You hang a weight on an arm and check to see if the torque reading is where it should be.
I check calibration on mine every time I turn it on. Ask them to check it in front of you,if they won't look for someone else.
On Superflow dynos ther is a dial by the operators left knee to make minor adjustments. An unscrupulous operator can turn the dial up to add power and make you think he is a great tuner. Make sure the torque reading is zero or maybe Plus or minus a lb-ft of torque with the engine not running
Keith



Not on a 902. J.Rob



I just had my 430 on a SF 902 and it did in fact have the weights on the arm - to check calibration - if thats what you are referring to.
Posted By: RAMM

Re: Dyno Gurus Advice Needed!!! - 09/04/12 07:42 PM

I was referring to the infamous "KNOB". J.Rob
Posted By: DJVCuda

Re: Dyno Gurus Advice Needed!!! - 09/04/12 07:45 PM

Quote:

I was referring to the infamous "KNOB". J.Rob



yeah - sorry i saw no suck knob -
Posted By: Dunnuck Racing

Re: Dyno Gurus Advice Needed!!! - 09/04/12 08:43 PM

Sorry I should have been more clear about the tune up knob.
I knew it was on the 901 models,and thought it was on the 902 console also.
ANY brand and model should be easy to check calibration on or I would not trust it. Checking the calibration at a certain level should be easy. Checking that it is accurate throughout the range and actually adjusting for such is a little more involved.
Keith
Posted By: 68DartRB

Re: Dyno Gurus Advice Needed!!! - 09/04/12 09:11 PM

Don't want to hijack - but what about wheel dynos like a dynojet vs dyno dynamics? It always seems the mustang and dynamics dynos are stingy compared to the dynojet? Calibration or just the nature of the beast on roller dynos?

Attached are 2 dyno runs with my E55 AMG (Diamler days - so kind of Mopar..lol). Both runs were the same day one dyno dynamics (new computer tune) and a few hours later on a dynojet so the conditions were almost idental. 53hp difference but the Torque was almost the same 542 vs 535???

Attached picture 7364570-E55Dynojet001.jpg
Posted By: 68DartRB

Re: Dyno Gurus Advice Needed!!! - 09/04/12 09:12 PM

Dyno Dynamics:

Attached picture 7364572-EurochargedHarrisonDyno.jpg
Posted By: AndyF

Re: Dyno Gurus Advice Needed!!! - 09/04/12 09:31 PM

It is a very simple process to calibrate the dyno. They all come with some sort of weight bar which is used to dead load the sensor to make sure that it is reading properly. Once the load sensor is checked then the weather station is used to input the current conditions.

There are a lot of keyboard clowns who yap about "happy dynos" and such. Most of them have never run a dyno before and can be ignored.

It does make sense to use a dead load that is roughly the same as your peak torque, but it isn't an absolute requirement. But if you have the option, that is one thing to do. If your engine is going to make 600 ft-lbs of torque then you hang 600 ft-lbs on the load sensor for calibration. That way you know you're calibrated for your engine. It doesn't have to be exact, just in the ballpark.
Posted By: Dunnuck Racing

Re: Dyno Gurus Advice Needed!!! - 09/04/12 10:20 PM

Quote:

It is a very simple process to calibrate the dyno. They all come with some sort of weight bar which is used to dead load the sensor to make sure that it is reading properly.

While this is true for checking to make sure the load cell is calibrated,there are are several other steps to checking and properly adjusting the electronics that feed and read the load cell.
I check the calibration arm weight setting every day I use mine. I check for proper voltages at the load cell and circuit board once a month. It is pretty rare for these settings to move much but with all the vibration and heat associated with testing it does happen.
I remember a post about a very popular shop being very far off on some things in another forum a couple years ago.
I check mine frequently to avoid confusion by false data since I prefer to be able to compare engines I have had on here to each other.
It also would not do much good to tell a customer he makes more power than he really does ,that would lead to issues with convertor and gear selection.

Keith
Posted By: RobX4406

Re: Dyno Gurus Advice Needed!!! - 09/04/12 10:24 PM

Quote:

There are a lot of keyboard clowns who yap about "happy dynos" and such. Most of them have never run a dyno before and can be ignored.




Please explain how an engine can go from one dyno one day, to another the next, same basic weather conditions and make 45-50 less hp. This wasn't a 700+ hp deal it was a 400 at the first and 350-355 second. Engine sure didn't run like it had 400hp in the car!

People do know how to alter/massage the software.
Posted By: AndyF

Re: Dyno Gurus Advice Needed!!! - 09/04/12 10:30 PM

There are a ton of reasons why an engine can lose 50 hp between dynos that have nothing to do with dyno calibration.

A well thought out dyno cell can easily be worth 50 hp over a poorly designed dyno cell. Even if the dynos in each cell are properly calibrated, there can easily be a large difference in power.
Posted By: RobX4406

Re: Dyno Gurus Advice Needed!!! - 09/04/12 10:39 PM

Quote:

There are a ton of reasons why an engine can lose 50 hp between dynos that have nothing to do with dyno calibration.

A well thought out dyno cell can easily be worth 50 hp over a poorly designed dyno cell. Even if the dynos in each cell are properly calibrated, there can easily be a large difference in power.



So XE268h cammed, stock head/compression 340's make ~400hp? Sure they do...

The second reading is a lot closer to reality than the first one.

Tuning tool, yes. Believing the numbers some kick out without proving it with real world performance, not so much. Seen too many dyno tested 600hp cars at 3000-3100# run 120-122...
Posted By: MR_P_BODY

Re: Dyno Gurus Advice Needed!!! - 09/04/12 10:55 PM

One VERY SIMPLE way is too have the engine room on
A/C... if its sucking in cool air it can be 50hp or
more
Posted By: RobX4406

Re: Dyno Gurus Advice Needed!!! - 09/04/12 10:57 PM

Quote:

One VERY SIMPLE way is too have the engine room on
A/C... if its sucking in cool air it can be 50hp or
more




Nope, cells had same ~ambient air temp and humidity, DA within 100ft.

One place even had a "mea culpa" regarding their numbers and in that they were short a good percentage of what it was really off.

If you don't believe there are happy dynos/dyno operators out there, then OK. Some guys out there know how to tweak the software, alter correction factors.
Posted By: Dunnuck Racing

Re: Dyno Gurus Advice Needed!!! - 09/04/12 11:04 PM

Quote:

Quote:

One VERY SIMPLE way is too have the engine room on
A/C... if its sucking in cool air it can be 50hp or
more




Nope, cells had same ~ambient air temp and humidity, DA within 100ft.




This is also why we use corrected numbers.

Keith
Posted By: Brian Hafliger

Re: Dyno Gurus Advice Needed!!! - 09/04/12 11:41 PM

Very true. The engine can run in terrible weather, but the CF will compensate for that. It will however affect the overall tune of the engine...in other words if you tune for terrible weather, and the run it in good weather it'll be very lean.

Get to know your dyno guy and others that have used him. Then make your decision.
Posted By: MRMOPAR622

Re: Dyno Gurus Advice Needed!!! - 09/05/12 12:23 AM

This is very helpful information so far. If we can all learn at least a little we will know we are getting honest numbers.Also having honest numbers on Horse-Power & Torque & weight of car is a Big + in getting the converter set up right.
Its also nice to know the new engine or new engine build is making the Horse-Power you paid for it to be.
Posted By: Big Squeeze

Re: Dyno Gurus Advice Needed!!! - 09/05/12 12:56 AM

Quote:

......There are a lot of keyboard clowns who yap about "happy dynos" and such. Most of them have never run a dyno before and can be ignored.....



....and there are a lot of keyboard clowns who yap about how much power their motor made on the dyno and such that apparently have never put one of their engines into a car and raced it and don't have an answer to why they won't post up a dyno sheet just because they think their crap don't stink because they write a few tech articles for a magazine......
Posted By: Performance Only

Re: Dyno Gurus Advice Needed!!! - 09/05/12 12:58 AM

i've dyno'd engines at several different facilities over the years that range from state of the art to the most basic bare bones types. i know of one shop that has a duct from their A/C going into the carb hat. they tell me horsepower sells engines. it does, but only when you can get the same power at the track.
it's one thing to calibrate the load cell, but that's only one of several things that will determine a correction factor and final numbers. i've been in facilities that don't even have a clue as to what a phsycrometer is. a dyno is only as good as the information that's fed into it. garbage in, garbage out. over the years i've seen many a member claim great dyno numbers, only to fall way short of expectaions at the track, one of those is fairly recent.
the best advice i can give is to ask the operator if the load cell is calibrated, check to make sure the baromter is accurate, take a wet bulb (phsycromter) reading, use the correct s/g reading for the ful being used, use a consistent rpm/ second while tuning, don't change in the middle of tuning. make sure the dyno repeats with no other changes being made. hopefully you'll get good, consistent numbers that the track will substantiate. i left a couple of other things out but you get the idea.
Posted By: Dunnuck Racing

Re: Dyno Gurus Advice Needed!!! - 09/05/12 01:50 AM

Back to the O P,if you find a dyno/ operator you trust and your car does not perform as well as it should there are things to consider.
Most dyno setups have very nice ignition and fuel systems on them. If you put a 600 hp engine in a car with stock fuel lines and a points distributor you may never run to its full potential .
there are other factors at work but you get the idea.
Posted By: LA360

Re: Dyno Gurus Advice Needed!!! - 09/05/12 01:53 AM

Quote:

i've dyno'd engines at several different facilities over the years that range from state of the art to the most basic bare bones types. i know of one shop that has a duct from their A/C going into the carb hat. they tell me horsepower sells engines. it does, but only when you can get the same power at the track.
it's one thing to calibrate the load cell, but that's only one of several things that will determine a correction factor and final numbers. i've been in facilities that don't even have a clue as to what a phsycrometer is. a dyno is only as good as the information that's fed into it. garbage in, garbage out. over the years i've seen many a member claim great dyno numbers, only to fall way short of expectaions at the track, one of those is fairly recent.
the best advice i can give is to ask the operator if the load cell is calibrated, check to make sure the baromter is accurate, take a wet bulb (phsycromter) reading, use the correct s/g reading for the ful being used, use a consistent rpm/ second while tuning, don't change in the middle of tuning. make sure the dyno repeats with no other changes being made. hopefully you'll get good, consistent numbers that the track will substantiate. i left a couple of other things out but you get the idea.



Just out of interest, what is a Phsycrometer Dan? I have never heard of it
Posted By: Cab_Burge

Re: Dyno Gurus Advice Needed!!! - 09/05/12 02:05 AM

Quote:

Quote:

i've dyno'd engines at several different facilities over the years that range from state of the art to the most basic bare bones types. i know of one shop that has a duct from their A/C going into the carb hat. they tell me horsepower sells engines. it does, but only when you can get the same power at the track.
it's one thing to calibrate the load cell, but that's only one of several things that will determine a correction factor and final numbers. i've been in facilities that don't even have a clue as to what a phsycrometer is. a dyno is only as good as the information that's fed into it. garbage in, garbage out. over the years i've seen many a member claim great dyno numbers, only to fall way short of expectaions at the track, one of those is fairly recent.
the best advice i can give is to ask the operator if the load cell is calibrated, check to make sure the baromter is accurate, take a wet bulb (phsycromter) reading, use the correct s/g reading for the ful being used, use a consistent rpm/ second while tuning, don't change in the middle of tuning. make sure the dyno repeats with no other changes being made. hopefully you'll get good, consistent numbers that the track will substantiate. i left a couple of other things out but you get the idea.



Just out of interest, what is a Phsycrometer Dan? I have never heard of it

A dual bulb sling phsycrometer are used to determine the humidity, my first weather station had one instead of a cheap humidity gauge. You where instructed to wet one bulb and sling it around in the air your racing in for thirty seconds or so and take a reading on the difference between the wet and dry bulb, use the enclosed chart with it to get the humidity. Do that three times quickly to validate your results It use to be harder to keep weather records, now its push some buttons and store it
Posted By: Old School

Re: Dyno Gurus Advice Needed!!! - 09/06/12 01:12 AM

Quote:

Quote:

......There are a lot of keyboard clowns who yap about "happy dynos" and such. Most of them have never run a dyno before and can be ignored.....



....and there are a lot of keyboard clowns who yap about how much power their motor made on the dyno and such that apparently have never put one of their engines into a car and raced it and don't have an answer to why they won't post up a dyno sheet just because they think their crap don't stink because they write a few tech articles for a magazine......



exactly what he said...
Posted By: sr4440

Re: Dyno Gurus Advice Needed!!! - 09/06/12 05:04 PM

When someone leaves my dyno, they have a CD with all the data on it, RAW, corrected and every factor that went into getting those numbers. Along with a copy of the windyn software to look at it any way they want.

As far as slinging a phsycromter around, nope I don’t do it. The SF Powermark was made this decade and all weather readings are taken by sensors, in real time. In fact, if the air was to change in the middle of a pull (unlikely) then the correction factor would change. (raw numbers wouldn’t)

Since you are going to a dyno to collect data on how your engine runs, I can’t see a reason why you shouldn’t leave with a ***load of info.

Joe
Posted By: MRMOPAR622

Re: Dyno Gurus Advice Needed!!! - 09/06/12 09:41 PM

Since you are going to a dyno to collect data on how your engine runs, I can’t see a reason why you shouldn’t leave with a ***load of info.

That's what I am looking for when I have one dynoed...useful info.!

I know nothing about running or setting up a dyno,but wanted to get a little info. to make sure it was being done right. I have heard a lot of talk about Happy Dyno's and it never hurts to have a little knowledge of what's going on. I would hate to buy or have a engine built and they dyno the engine and it shows 800 hp and it only makes 650 hp.But after reading most post I feel my chances of getting a fairly honest dyno test results are a lots better.
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