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Hey guys. Looking for some info.

My buddys are going to give me a dyno day for my bday. well 3-4 runs at least.

so some of my questions are:

What tires should i use, Heavy 19's on all seasons, light 17's on all seasons, middle 18's on snows?

Should it be hood down air box closed, etc?

New spark plugs?

Should i do runs with no OV tune, different ov tunes, ov tunes with Tmap etc.

Thanks
 

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I would love to see a stock base model run vs. your top tune file. That would be pretty cool.
CK
 
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The only real benefit for you would be 100% stock and then with your mods for comparison.

Your tire and wheel choice makes no difference.
Opening the hood or having FANS BLOWING all over the front of the car is a cheat.

Changing spark plug is ALWAYS a plus. Even when you drive to do a race event the first thing you do is pull the plugs for new ones.

Make sure that they calibrate everything and give you a complete DATA sheet so you can duplicate the set up for future DYNO runs.

DON"T be surprised if they are lower numbers then expected. The only time that you see large gains is if you go on the bottle... :wink2:


Don't get caught up in the debate about "HEAT SOAK" just have FUN . Your DYNO operator should have suggestions if that becomes an issue between runs and can compensate.
 

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Find the highest octane pump gas you can find (93/94 octane) so you can run all the tablet maps without inducing knock, then head over to the dyno. Having a 100% stock dyno would be useful, but I wouldn't expect much gains from intake/exhaust mods. It also takes time time to change hardware, so just focus on the tune. On the same dyno day, you can run stock vs. 89, 91, 93 etc. octane tunes on separate dyno runs. It's best to stick with 1 dyno day with multiple dyno's in order to avoid potential differences in conditions & calibration between days. As for heat soak, the car will get heat soaked after a few runs, and after that the temperature should be consistently hot, thereby reducing variability. Ask for as many fans as you can get though, and come in as early as you can while its cooler. I'm not sure why blowing fans would be a cheat, as you want to simulate driving conditions and keep air intake temperatures as close to ambient as possible. If you don't use fans, the temperature under the hood gets crazy high, and the ecu will keep pulling timing (you will loose more power than the tune makes). You should get the most power on the first run while the engine bay is still cooler, but the dyno software should adjust power based on conditions (temperature and atmospheric pressure). Its better to not have it adjust the results much though, as the adjustment is not always accurate.

One more thing to keep in mind is how long it takes for tunes to settle in. The skayactiv knock control system actually does fine tuning of the ignition timing, such that it adds timing if no knock is detected or reduces timing if it is present in WOT runs (ECU learning). It can take several hundred miles to remove knock events that rob power, or add timing where it would be beneficial (assuming same quality of gas). If you flash a map, the power made afterwards will not be based on learned settings in this sense. So to keep things fair between maps, makes sure you do a fresh flash before testing any tune. Based on this concept, the tune you are running when you drive their will be most adjusted.
 

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^^^ Not really a fair assessment or accurate account of what the engine actually does though?
In what regard exactly? The engine doesn't stay in the same position collecting heat under the hood as it runs maximum load to redline... In WOT runs on the street, the car moves through the air...
 

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I was a Dynojet certified tech for a few years in the late 1990's (motorcycles). It's a great tool, especially when combined with an EGA (exhaust gas analyzer), but the ONLY thing it's good at doing is giving you a before and after comparison on the same day. The numbers are meaningless by themselves, any tech can fudge the numbers upwards of 20% and we frequently did on "dyno days" when people would come in for one run just to get HP numbers. Different days, different operators and you're introducing error where it's pretty much impossible to see nuance.

If you're going to get a few runs, make them count for YOU. Run what you think is "your best" (again, with an EGA ~ you have no clue how to improve without knowing what's coming out the exhaust), and make adjustments based on the faults found so you can do better. If no faults found, and I managed that a few times on my own bikes via "butt dyno", smile, call it good and either save the credit for another day or share the fun.


BTW, hood up/down, fans used are all non-issues so long as the same conditions are used on Each run. I'd *NEVER* run without fans, not worth the risk.
 

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^what are your thoughts on the different types of dyno? eg. mustang vs dynojet...
 

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No real opinion if you're using them as a before/after tool (best use).

Intertia (Dynojet) dynos measure acceleration, return numbers that are more "seat of the pants" (meaning, if you see a number go up with an inertia dyno, you'll probably Feel that as well).

Loading dynos measure Actual load.

It's possible to make a change and See a change on an Inertia dyno but not on a Loading dyno. An easy way to describe this if you were to change the final drive a little, suddenly you're accelerating a little faster but with a lower top speed. Both spit out numbers with calculation from a known (sea level, specific temp and humidity), which is an easy way to fudge numbers for the single-run guys.

I only ever played with Dynojet brand, they're the company that had the training and certification and I'm not really familiar with the rest in actual hands-on/real world applications. I can only drag out very dusty theory.. :D Looks like Mustang is an Inertia design, so there will be no real difference between them and Dynojet. You'll probably get different numbers, but if you did a repeatable adjustment you'd see the same percentage in change.
 

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Brian I owned a DYNO Jet and was factory trained for it. EGA are pretty much old school anymore...
I think somewhere I still have my Yamaha EGA tester as well.
You did forget to mention spark plugs...as a very important and valuable way to see what is really going on in an engine at WOT ..That is if
the readings are performed correctly?

It does not matter who did it or when a DYNO is run if you know what the deltas are the current programs can make adjustments for a previous run DYNO from anyone in the US anytime. That,s if the operator is willing to give you all the DYNO and program calibration setup info.

I use a DYNO to do EFI/ECU Calibration and adjust the Dyno program to give a close proximate to Real world operation.


These type of threads never go positive because we have so many experts...and so many have deep pockets with lots of cash to run to the DYNO every week or month..to gain lots of DYNO testing experience.. :laugh2:
Me I am still learning with over 300 Chassis runs (over 100 in one year) and at least 100 or more engine only Dyno test performed (when I owned operated my Performance engine machine shop) I learn new things all the time.

And Brian.. I forgot all the bike DYNO testing I use to do..wow, that's a going down the memory lane...
Last one I did was on my very built 133hp RG500 :grin2:

BTW the cheap DYNO and is not far off and real world semi accurate is a AutoMeter D-Pic. At worst it is 1-3% from results on it comparing a well set up and tested Chassis Dyno either portable of stationary. IMHO it is more accurate than the portable Chassis DYNO you see at car shows and some shops.
 

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Discussion Starter · #11 ·
WOW, thanks, This is alot of good information. SO I guess, in regards to changing the tune it wont help much if the engine has to adjust to it.

Changing plugs will get done. Fans will be used to some degree probably what the guy running it suggests.

I will keep track of all the info and temps i can .

as far as runs go, since changing tunes is off the table, i guess i can just go in full auto, manual shifting, and sport mode with both.
However i hardly ever use the manual shifting option so maybe just full auto, sport mode, full auto, sport mode.

I don'tt really care much about how high or low the numbers are, its just a gift my buddies are giving so its just a cool thing to figure out.
 

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WOW, thanks, This is alot of good information. SO I guess, in regards to changing the tune it wont help much if the engine has to adjust to it.

Changing plugs will get done. Fans will be used to some degree probably what the guy running it suggests.

I will keep track of all the info and temps i can .

as far as runs go, since changing tunes is off the table, i guess i can just go in full auto, manual shifting, and sport mode with both.
However i hardly ever use the manual shifting option so maybe just full auto, sport mode, full auto, sport mode.

I don'tt really care much about how high or low the numbers are, its just a gift my buddies are giving so its just a cool thing to figure out.
I think it will be a learning lesson for you for the second time you go get DYNO'd..
There was a couple things that are not exactly correct from other members but for the most part IMO your first DYNO pull will have some interesting results. I say just HAVE FUN


Here is a response (found on the internet) I have often used on a few forums, maybe this will be helpful?


Is Your Dyno Lying?
Measuring your horsepower depends on whose yardstick you use.


from CAR AND DRIVER MAGAZINE
BY AARON ROBINSON
PHOTOGRAPHY BY DAVID DEWHURST
May 2004


Horsepower is like good luck. It can't be seen, touched, or tasted, but you know when the inventory is low. How much do you have? Go measure it. The best place to put your luck to the yardstick is in Las Vegas. The best place to measure your horsepower is on a dynamometer. In both cases, results have been known to vary.

Turns out that different horsepower dynamometers will spit out different results on the same car depending on their design and how carefully the tester manages the variables. When ambient air temperature and pressure were all that yesterday's carburetors cared about, factoring in the variables was easy. But modern cars are gradually becoming too smart for what was once a simple test. Engines trying to squeeze out more horsepower are run by watchful computers with better sensors that are able to differentiate between speeding down a freeway with a cooling headwind and spinning the dyno drums in a stuffy room. The technology of today's cars needs to be factored into your readings along with variations from dyno type to dyno type, or your horsepower numbers may be hazy, too.

Recall that horsepower is a unit measuring the rate at which an engine performs work. By current industry standards, one horsepower equals 550 pounds lifted at the rate of one foot every second. Automakers figure a car's oomph by hitching the engine to a machine that puts a controlled load generated by an electric or hydraulic brake on the flywheel. They plumb the intake and coolant to external fixtures that simulate on-road airflow and then run the engine from idle to redline. The engine dyno measures torque at the crankshaft using a variety of means and then uses a math formula?torque times rpm divided by 5252 (a sort of gearhead's constant, derived by dividing . . . oh, never mind). Horsepower comes after the equal sign. Thousands of hours of testing produce a peak horsepower number that prints in the dealer's brochure.

For the rest of us, rather than unbolt the engine and rent a multimillion-dollar dyno room, it's much easier to simply drive the whole car onto a chassis dyno that measures horsepower where the tires meet the tarmac. Throughout the U.S. are shops with such machines, some even capable of handling four-wheel-drive cars. Ordinary citizens pay anywhere from $35 to $100 to run the car up to redline three or four times, the tires turning rollers monitored by the dyno's computer. Eventually, the computer spits out a horsepower graph that you can take to your next bar-stool drag race.

But before you pop the clutch on your tongue, consider that a chassis dyno doesn't measure horsepower at the flywheel but at the tires after various driveline losses have subtracted their drag. Friction from rubbing gear faces, inertia from heavy shafts, and the stirring of oatmeal-like gear lube all reduce the advertised horsepower reaching the tires and, hence, the dyno.

"There's no really accurate way to get engine horsepower from a chassis dyno," says Matt Harwood, marketing coordinator for Mustang Dynamometer, a major supplier of chassis dynos in Twinsburg, Ohio. Some tuners use the so-called 15/20 rule, which assumes a 15-percent driveline loss for manual transmissions and 20 percent for automatics. But, says Harwood, "I've seen losses as high as 35 percent." So unless it's printed in the brochure or was measured on a true engine dyno or by a tuner with tons of experience with your particular brand of car, any flywheel horsepower number quoted by a hot rodder under the shade tree is most likely just a calculated guess.

More important, did your car run on the dyno as it would on the street? If it's the latest model, chances are good it may not have, says BMW tuning wizard Steve Dinan. An afternoon spent at his Bavarian speed emporium in Morgan Hill, California, convinced us that cars are gradually becoming too computerized for the simple dyno test.

Dinan's cars are wired with a battery of sensors that report when the airflow over the bumper is too little, when the inlet air is too hot, and when the water temperatures in the block and radiator are too close together (most turbocharged and supercharged cars also "know" when their intercoolers aren't cooling enough). The computer reacts by backing off the spark and turning up the richness?and as a result, turning down the power?to prevent catastrophic engine meltdowns.

To prove his point, Dinan bolts to his Dynopack one of his 2003 Dinan M5s, heavily tweaked to make a claimed 470 horsepower at the crank (he expects about 415 at the wheels). With the hood closed and no external fan blowing air into the radiator, the car wheezes out just 334 horsepower at the wheels. An LCD data logger on the dashboard reveals the air-fuel ratio from the engine computer. Approaching redline, the BMW's computer richens the mixture all the way to 9.5:1 as the underhood temperatures soar.

That's one thick mix, practically charcoal briquettes blowing out of the tailpipe. But then, with the M5 running in fifth gear (the 1:1 gear ratio with the least friction, preferred by dyno testers), the computer expects 159 mph worth of cooling wind blast around the horsepower peak. It's getting nothing, and it knows.

Now Dinan opens the hood and turns on a small Home Depot shop fan blowing about 10 mph worth of air. The M5 is allowed to shed some excess heat and then run again. This time the computer finds another 37 horsepower, or 371. Things are looking up, but the M5's output is still nowhere near Dinan's expected number of 415.

"I can't claim something I can't measure," says Dinan, so the crew then wheels out the big gun: a $7000 electric fan that looks like it should be hanging on the wing of a Boeing 737. It blasts 38,000 cubic feet per minute of air at 75 mph down a narrow duct, right into the M5's radiator. The fan roars, the M5 howls, the computer twinkles, and the graph paper ticka-ticks out of the printer. It says 411.4 horsepower, the best run of the day.

"I'd pick up four or five more horsepower if I came back tomorrow morning and ran it at 70-degree room temperature," says Dinan. The room is currently 81 degrees.

"Basically, what horsepower would you like? I can give you anything from 330 to 420 with the same car," Dinan says. "Blowing air with a fan isn't the same as creating a bow-pressure effect over the whole front of the car. BMW can simulate that because it has billions to spend on wind tunnels. We don't, but we can come close by spending $250,000 to $300,000 on a climate-controlled room."

That's Dinan's next step. It's a huge expense for a boutique parts-maker, but BMWs aren't getting any stupider. The trend says the cars rolling into a tuner's shop will have more and smarter sensors with each passing model year. BMW may be at the leading edge of electronic engine controls right now, but the rest of the industry is sure to follow.

When it does, the "brag-ability" of dyno numbers will get even more dubious as dyno printouts become merely a reflection of what a particular car does on a particular dyno under a particular set of conditions. What happens on the street could be another matter altogether. As in Vegas, sure bets are in short supply when you measure horsepower.
 

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WOW, thanks, This is alot of good information. SO I guess, in regards to changing the tune it wont help much if the engine has to adjust to it.

Changing plugs will get done. Fans will be used to some degree probably what the guy running it suggests.

I will keep track of all the info and temps i can .

as far as runs go, since changing tunes is off the table, i guess i can just go in full auto, manual shifting, and sport mode with both.
However i hardly ever use the manual shifting option so maybe just full auto, sport mode, full auto, sport mode.

I don'tt really care much about how high or low the numbers are, its just a gift my buddies are giving so its just a cool thing to figure out.
You can change tunes, just flash (or re-flash) each one you are testing that day so that the effect of ECU learning is minimized. If you are running 94 octane, you shouldn't encounter much knock that needs to be taken out via long-term learning. However, it won't have ignition timing auto-advance like it would after several hundred miles of learning, so you get a bit less power right after a flash. If your objective is to compare tunes, then re-flash and avoid the effect of ECU learning before each dyno run.

Dyno testing automatic skyacvtiv's can be rather challenging, as the transmission will want to downshift at lower rpms even in manual mode from what I've seen (then you won't get a graph showing full engine load power levels from low rpm to redline in the same high gear). To avoid a low rpm downshift, you will need to go part throttle at lower rpms, which won't give a good reading of peak torque or maximum low-end power. The ECU also only calls for full-throttle AFR enrichment when the pedal is fully down (kick-down switch pressed), meaning you won't be getting that data until after ~3500 rpm (that is where it won't trigger a downshift with kick-down switch). I would ask Mat @ OVT how he does his automatic dyno's. I heard that 2nd gear won't downshift at low-rpm, so you can try that but it won't be very accurate results.
 

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Discussion Starter · #14 ·
You can change tunes, just flash (or re-flash) each one you are testing that day so that the effect of ECU learning is minimized. If you are running 94 octane, you shouldn't encounter much knock that needs to be taken out via long-term learning. However, it won't have ignition timing auto-advance like it would after several hundred miles of learning, so you get a bit less power right after a flash. If your objective is to compare tunes, then re-flash and avoid the effect of ECU learning before each dyno run.

Dyno testing automatic skyacvtiv's can be rather challenging, as the transmission will want to downshift at lower rpms even in manual mode from what I've seen (then you won't get a graph showing full engine load power levels from low rpm to redline in the same high gear). To avoid a low rpm downshift, you will need to go part throttle at lower rpms, which won't give a good reading of peak torque or maximum low-end power. The ECU also only calls for full-throttle AFR enrichment when the pedal is fully down (kick-down switch pressed), meaning you won't be getting that data until after ~3500 rpm (that is where it won't trigger a downshift with kick-down switch). I would ask Mat @ OVT how he does his automatic dyno's. I heard that 2nd gear won't downshift at low-rpm, so you can try that but it won't be very accurate results.
I was just messaging with Mat and he confirmed that Dyno testing the Autos is difficult. I think I am going to pass on this idea as the chances of getting accurate information seems to have just harder.
Thank you everyone for your valuable input.
 

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I was just messaging with Mat and he confirmed that Dyno testing the Autos is difficult. I think I am going to pass on this idea as the chances of getting accurate information seems to have just harder.
Thank you everyone for your valuable input.
Shops the do DYNO testing having problem DYNO testing any vehicle need to contact their DYNO rep and/or re-learn how to use their program or check for updates.
I suggest you talk to the shop and see what they say.
I did mine and had NO PROBLEM. I also have done a few BMW with ATX's which their ECU is way more complex than a MAZDAs
 

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I was just messaging with Mat and he confirmed that Dyno testing the Autos is difficult. I think I am going to pass on this idea as the chances of getting accurate information seems to have just harder.
Thank you everyone for your valuable input.
Shops the do DYNO testing having problem DYNO testing any vehicle need to contact their DYNO rep and/or re-learn how to use their program or check for updates.
I suggest you talk to the shop and see what they say.
I did mine and had NO PROBLEM. I also have done a few BMW with ATX's which their ECU is way more complex than a MAZDAs
Since you were a dyno owner/operator for many years, how would you get around the problem? There does not appear to be a solution from what I've seen on the Miata and Mazda 6 skyactiv forums, after many dyno operators were consulted. Based on the downshift problem, the dyno graph won't capture full engine load from low to high rpm. Its not the complexity of the ecu, but rather the transmission programming.
 

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Since you were a dyno owner/operator for many years, how would you get around the problem? There does not appear to be a solution from what I've seen on the Miata and Mazda 6 skyactiv forums, after many dyno operators were consulted. Based on the downshift problem, the dyno graph won't capture full engine load from low to high rpm. Its not the complexity of the ecu, but rather the transmission programming.
Sorry I can't help with this. It as as I said the shops need to talk to their DYNO supplier or sales representative.
As for the ECU well..there you go..if you have "full access" (many programs that are offered either do not or the calibrator has no idea how to do global adjustment when changing calibration regarding an ATX except minor cell adjustment) If your purpose is for maximum results then you are not using the DYNO as a tool and rather a reward run for the best which is just not logical unless you are drag racing and have a specif engine speed target to go through the lights.
IMHO Matt22 should more just try to go and get a first run for FUN! He already has to many changes that are not dialed in together so anything obtain is more then what he has right now for information about his engine output which is NOTHING!
 

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Sorry I can't help with this. It as as I said the shops need to talk to their DYNO supplier or sales representative.
As for the ECU well..there you go..if you have "full access" (many programs that are offered either do not or the calibrator has no idea how to do global adjustment when changing calibration regarding an ATX except minor cell adjustment) If your purpose is for maximum results then you are not using the DYNO as a tool and rather a reward run for the best which is just not logical unless you are drag racing and have a specif engine speed target to go through the lights.
IMHO Matt22 should more just try to go and get a first run for FUN! He already has to many changes that are not dialed in together so anything obtain is more then what he has right now for information about his engine output which is NOTHING!
If your suggesting that you can tune the auto transmission, no tuner has ever done so for any skyactiv platform. You would need to gain access to a different ECU, and special software/security to do so. I doubt you'll find any performance shop dyno operator that can do this in your neighborhood. Has anyone been able to program the skyactiv transmission to not shift gears on the dyno? Its one thing saying it can be done hypothetically, but another actually doing it... It's hardly worth getting a dyno if you can't assess the entire rpm range on the dyno, and produce less than accurate results from the rpm areas that can be measured.
 

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Unfortunately I didn't get the chance to do my comparison before trading it in on my Mazda6. I can say in my discussions with Mat at OVT, he did clearly say that the Knock Control Sensors (KCS) would need a solid 7 or 8 runs to adjust to each new tune. There is a learning process the ECU has to go through before you're seeing maximum benefit from the re-flash.

I personally could tell the difference between flashing the ECU and then 100 miles later; good 'ol butt-dyno.

My idea was always to take two cars; one stock Mazda3 2.5L and get the baseline numbers to yield a co-efficient, and the other my tuned 2.5L with a couple hundred miles on the tune. This way the actual dyno numbers don't matter at all. We'll say the dyno shows 144rwhp and we know the engine puts our 184hp on paper, then your co-efficient is roughly 1.28. Then pull your tuned 2.5L onto the dyno and run that. We say the dyno says the tuned version puts down 159rwhp, then multiply that by 1.28 and you would know the "crank" HP tune would be roughly 204hp.

Mat confirmed this would be the best way to do it if you were looking to identify crank HP numbers on the tune. It takes atmospheric conditions out of it, and everything is done on the same day. While the engine is not necessarily the same, the fact that they're all manufactured to produce 184hp at crank, you should have a pretty accurate number. That's not to say there's some margin of error, but this is probably as close to fool proof as you can get.

So you just need to get your hands on a stock Mazda3 2.5L and make sure your 93/94 octane tune has been fully "learned" by the ECU. Hope maybe that helps w/o getting too technical. (which btw, good write-up @Brian. )
 

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If your suggesting that you can tune the auto transmission, It's hardly worth getting a dyno .
No I did not. At least not on the MAZDA (yet) Please read my response more carefully.

There is a difference between a shop that simply does DYNO runs and a shop that uses their DYNO as part of a program to do performance of vehicle enhancing.

From what I am reaing form you ...it is my suggestion to find a different shop to help you with you DYNO Testing?

ALL DYNO TESTING is WORTH WHILE!! If done correctly.

Ok well I think I have pretty much said what I am going to say and at this point............GOOD LUCK to the OP on his FIRST DYNO RUN! :grin2:
 
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