I feel that it's time we try to come to a consensus on testing methods we all can accept when one of us feels like spending the money to pay for dyno time, especially when it's in efforts to share with the community.

I'd like to hear from people that do this kind of thing often... Vendors and various racing Mini teams. I just want to know how I should dyno my Mini so that my numbers are accepted by the community without having the testing methods shredded.

Be detailed!! Hood up or down? What kind of fan blowing? Blow it right onto the IC? or just something down in front of the radiator? How cold should the car be before running? Should it be up to operating temp? How many runs should you make? If you can't dyno after mods on the same day...how critical is ambient temp and humidity... should I wait till a similar weather day? Are A/F ratio's critical to examining everything? Do I need something that'll tell me IAT's for comparisons sake?

Once we've come to some sort of consensus (if that's possible )... Let's post it as a sticky for reference so that all Nam members new and old can try to subscribe to the same standards of testing!

 

Good idea Ben.
I'd like to see the information just for my own education if for no other reason.

Also do we want to add a consistent starting temp for the IC?

 

One more idea for you: should runs be in third of fourth gear? I have seen IATs go really high in normal mcs runs in 4th gear, simply because of the stress of a 4th gear pull to redline- at the price of lots of timing pulled and power lost. 3rd gear runs, on the other hand, seem to result in much less heat soak and less timing pulled.

Of course, I've heard that fourth gear is closer to a 1:1 ratio [of what, though, final drive?], and that that was ideal for accuracy.

In a non-boosted car, IATs climb a lot slower than on an MCS... and this hurts power.

I am personally on the fence about which is more ideal AND repeatable.

 

I'm all for it but ...good luck

 

I'm afraid that from what I've observed on many message boards that the only time people don't doubt figures are, from the dragstrip

Much more fun as well

 

You need to make sure the IATs aren't too high to start.... But fans? Not sure how to spec that.... Also, you should look at coolant temps to see that the car is at proper running temps.
If you log IATs you can see how effective the fan is during the run though...

Matt

 

in general when someone does a dyno for their own personal gain and posts it on the forum, MOST of the members will say "hey, nice numbers, thanks for sharing".

However, whenever someone posts a dyno to show that intake "A" is better than intake "B", it turns into a flame war. That just seems to be the pattern that I've noticed.

I agree that there should be an accepted set of criteria for doing dynos and evaluating HP/TQ curves, but people will always find a way to discredit the results. I guess that could be a good thing or a bad thing, depending on how you look at it.

 

the results should be flamed.

Matt

 

The reality is the Dyno is the MOST accurate way to see if the mods are adding up...whatever you get...you get....if you don't like it try another dyno...I have been to quite a few different ones....they are all very close...the Dyno started beign used for this vary reason...vendors were stating X HP per mod...and the Dyno has called them all out...you cannot get away with the blah blah of the "bolt on X HP" days of old...

I Choose the Mustang Dyno after seeing and feeling the results of tuning on a loaded dyno...I once didn't like them cause I was told they tend to read low...and well didn't want that...LOL...yet now learned what a benifit it can be to have load on the wheels while tuning...

Hood up...a very high CFM fan. load set to 3000 lbs. Depending on ambient temp sometimes I add and additional fan on the IC to insure the IATs are consistent spraying the IC with water inbetween runs to insure that its as close to operating temps as possible...which is near impossible due to the fact that inorder to create enough wind to simulate 50 let alone 80 MPH....well I'd need a dang dyno in a wind tunnel...so uhhh yeah...

A/F is very important....not jsut to say "hey, I made this much" but to know how your car is acting and whether or not you are tuned properly for hte mods you may have...of if none if your car is tuned at all....

Also know that if you watch your timing you will see how 91 terrible effects your cars ability to run well....it's horrible horrible stuff....and I recommend mixing in at least 3 gallons of 104 when ever possible...that's a MINIMUM heh eheh...not nessisary but it sure smooths the car out....

if you are going to tune and not just see what the car is making I reccomend pure race gas...not cause you will make more power but because it will give you CONSISTENT A/F ratios and you will be able to tune the car better cause the a/fs are not all over the place due to the ECU trying to compesate for knock

this is the answer I have for you from having spent the better part of the last year on a dyno...and there must be constant and equal variables for me...or else I am not getting data...just random #s...LOL...it may or may not be the Uber technical thing to say...but it works..and that is what matters to me...after all the #s have been crunched and the variables wieghed...take it to the dyno and see what it does...THEN the fun part comes in...to see what the car AND drive does...TAKE IT TO THE TRACK!!!

Hope that helps!

 

There are enough different types of dynos out there and enough variables that could skew the results, that you will always have people questioning your results, no matter how accurate they are, especially people with their own agenda. When I take one of my cars to a dyno, I mainly do it for my own curiosity and enlightenment, although I do tend to share the results online as well. If you set out to post your results with your own agenda or for bragging rights, you'll likely get shot down for one reason or another.

-Keith

 

here's the reality with dynos...if you wanna worry about the people who don't under stand the reality of them...is that the FINAL # isn't what matters if you are looking to see how much power a MOD made...

If you go to a dyno...you make 160 WHP...then you add said mod...now you have 180 WHP on the SAME dyno....that mod made 20 WHP...YAY!!

if you wanna make a big # for braging rights...then Dyno Jet has the rep for such things...

 

I guess my thinking here is that it's not so much a testing method for someone just to see what their car is putting down. We all know that diff dynos and conditions will show diff results.

It's the DELTAS that matter... a testing method that can be done in a before/after modifications manner so that we CAN see what certain impact mods have made.

My own selfish reasons for starting this thread is I want to be able to test what the new WMS exhaust does for my car as accurately as possible... and to be able to share my results when it's done with everyone here.

So what I've gathered so far...

Hood open for sure... fan on the IC (because no fan will simulate actual airflow being pushed into the hood scoop right?) Same dyno for before and afters.. Dr. Obnxs suggests monitoring IAT temps and coolant temps... making sure the car is up to operating temp, but not heatsoaked from a hard drive just made I presume right?

Tuls... not sure what you mean by a mustang dyno putting a load on the wheels, vs. how a dynojet works.. perhaps you can explain?

Randy Webb suggests 4th gear runs.. like you said, it's closest to 1:1 ratios. He also suggests doing 5 runs for repeatability, and monitoring IAT's.

We have bear in mind not everyone will have access to race gas. I have 93 octane..and I imagine if you're stuck with 91 it's possible to get octane booster to get you up a few points to be consistent with fuel used.

Keep the details coming guys... just something so we as consumers can really come closing to being able to see a reliable delta between mods.

 

and inertional dyno has a roller of known mass, or moment of inertia. When you hit the gas, it spins up to speed, and based on the rate of change of rotation per unit time, you know what torque has been applied, and hence, the HP of the motor (by using an RPM pickup). For a kick, there's a video of Hubie getting 430 WHP, and the dynojet goes "whee" REAL FAST!!!!!!

A load bearing dyno allows you to set the force that is applied agains the wheels, or the rate of RPM ramp (while varying the load).

Why would this matter? Well, there's a lot of stuf that spins in the drive train, the faster that you rev to red-line, the more energy that you put into your spinning all the stuff that spins, and this will lower your hp reading. If you do you tests in a step and hold (step 100 RPM, hold RPM, read HP, step, hold, read etc) you will minimize contributions to the driveline, and only be left with frictional losses. This is the closest you can get to an engine dyno reading without pulling the motor.

Some things to keep in mind, at 60 MPH, the car is going one mile a minute. A square foot "area" would have a flow of 5280 CFM, at 60! I don't know how much air actually flows through the IC at this speed, but fans blowing on the IC probably don't replicate real world airflows....

Also remember that you need some serious flow through the radiator as well......

The idea of reps is a very good one. With a G-Tech, I can get ~ 3 HP Standard deviation on 5-6 runs with "qualifying" runs. Those being ones where the car is at operating temps, and heat soak is less than 10 deg C.

But comparisons across dynos is a *****, just like Tuls says.... Deltas can be very good, but comps across dynos are hard.

Also, the timing retard can be real bad. Look for a thread on 91 vs 100 octane gas to see just how bad....

So if you want to see how good your new exhaust is, get a lot of dyno time so you can get the reps in, run the 93, maybe with some booster, and have at it!

Or get a G-Tech, so you can really beat your car for data.....

Good luck, Matt

 

well this is turning out to be qutie the good thread...YAY!!

heh he

SO F15Eweapon....I think you have already gotten what you need...honestly...if you wanna see what the web exhaust is really doing...like with ANY mod...strap yer Mini to a dyno....make 3 passes....see what she's makin....then...get your exhaust bolted up...and make three more on the same dyno....Making sure that whatever the factors you use are the same....

in the end...honestly the more simple you make yoru test the easier it will be to see the HP results....

being too technical is as bad as not technical enough....sometimes we get SO over the top we cause issues....and it makes for strange variables LOL

 

Ben. Let me know when and we'll hook a BIM-COM up to it.

Here's my question on that.
What are the 4 best parameters to map with the BIM-COM during a dyno run(s)?

 

If you do RPM, IAT, MAP, Mass Flow, Knock Window, timing for all four cylinders, upstream pressure, throttle position, driver demand, calculated load, speed and a few more, you get about 2.5-3 data points a second.

If you do timing, knock window and mass flow, you can get up to 10 Hz.

Depends on what your looking for....

I'd go with RPM, Speed, IAT, coolant temp, MAP, timing, knock window and MAss Flow.

If you really want fast data
RPM, IAT, MAT, Coolant, Timing. You'll know calculated load (100%) Demand (100%) and TPS (81 Degrees ( I think that's max).) Who cares on upstream pressure, ( although that's good for testing intakes).

Matt

 

Most accurate "dyno" = the seat of your pants when you hammer your right foot to the floor

But seriously, its good to see some concensus being reached. I'm gonna jump into the mod game soon I hope (finances allowing) and want to know what numbers are more realistic than others.

 

"However, whenever someone posts a dyno to show that intake "A" is better than intake "B", it turns into a flame war. That just seems to be the pattern that I've noticed."

change that to:
"However, whenever someone posts a dyno without showing repeatability and base runs, it turns into a flame war. That just seems to be the pattern that I've noticed."

the criticism of results is justified if there are holes in the data.

word of advice: re-do your first test at the end, even if it means you have to re-install parts. That omission was the fatal flaw in the intake shootout.

 

Well said......

I have dynoed at 5 different dynos and the results and methos have all varied... each operator felt that his way was the right way....what a surprise.... results varied by as much as 15%.

what I have come to believe is that if it is ego driven..you will always look for the most generous method and dyno.... if it is performance driven you will look for "scientific method." Get your base run.....note your environment.... and compare to your deltas..... If you are going to make claims .. a is better than b ... then I suggest you follow jlm's advice if you don't want "controversy."

I would look for a shop that has dynoed lots of Minis so that you can get a basis of comparison.... I would assume that they would use the same methods and you can get a feel for how your car is reacting to the new mod.

 

Since conditions are different (eg ambient temperature, flow rate of fan(s), octane #) maybe we should all publish the specific conditions for each dyno run. My best run with basic mods (15% pulley, CAI, MTH) was 193 whp and 176 lb-ft of torque but I used two fans, hood open, 93 Octane and ice bag on IC. Changing the condtions can have as much effect as changing the mods. Check out the DYNO article on the Dinan website.

 

This thread should not be dead bump bump bump