Dyno Numbers

[Dean]

Originally Posted by MikeSTI

does the Mustang dyno record boost levels? This I think is the key and no one has answerd that. If Matt gets 230 @ 15psi and I only get 213 but maybe only @ 14psi I would think that would be the difference plain and simple.......................just wish I got more info on this sheet other then:

Max Power =
Max Torque =

but with out knowing if I'm acully getting "Max" boost or the many other factors I dont feel I got the "Max" of what I paid for

Boost would be helpful, but timing out of the ECU, and any knock readings etc. might be even more useful. I beleive Dyno tuning is much more expensive than dyno runs. I don't have any experience with what the current going rate is, but I would bet a hour of dyno tuning would likely be $100+

[ryan4601]

nate from ss told me that dyno tuning is 180 and hour.....im planning on heading back there to get my car tuned out at some point in the near future. Nate told me that hopefully i should be able to pull closer to 250 at the wheels on 91 pump.
ryan

[MikeSTI]

Originally Posted by nKoan

They did three pulls, one warm up and two recorded pulls.

The warm up was generally ~20hp lower then the higher of the two recorded pulls because the engine is not taken up to redline. The other two recorded pulls, unless something went wrong, would generally be within 7-8mph from each other. This variance can be from a lot of things, but the lower number is usually gotten when the engine is super hot (everyone here is reporting the higher of their two numbers, I assume)............

I guess the funny thing about this would be the best pulls where are last pulls........with that being said I have to think heat is not as big of a factor, <wink> eventhou we know it is, or my first 2 pulls should have been better then the third? right....or at least the second pull sience the first is a warm-up

[MattR]

Originally Posted by MikeSTI

car ran at Idle 5 min. before being dyno'ed, AC was off as was the stereo........

Mine idled at least 3 minutes before, I don't think that had much of an effect, the car hadn't been run before starting it and letting it idle, so I don't think the idle was a big deal.

[Nick Koan]

Originally Posted by MikeSTI

I guess the funny thing about this would be the best pulls where are last pulls........with that being said I have to think heat is not as big of a factor, <wink> eventhou we know it is, or my first 2 pulls should have been better then the third? right....or at least the second pull sience the first is a warm-up

Actually, the sequence usually went warm-up, 1st pull, check engine temp and if the engine temp was too high, rest for a few minutes while spraying water on the intercooler (from a water bottle, not the built in IC spray) with a fan strapped on it, then do the 2nd pull.

But the engine temp sometime wasn't very high after the 1st real pull, so the second on was done right away.

[Nate@s-s]

Hey guys,
just to answer a few questions about the dyno, what it can log, and temperature etc.

Our dyno uses a digital weather station that compensates for temperature, humidity etc. So the readings throughout the day would be standardized (more info on that in the link that Tyson posted, btw good find Tyson) . Heat soak however is a large issue, we make sure to temp the engine/IC before every run to try to keep things as consistent as possible.

The dyno cannot log boost, they have an option for it and after looking at it I preferred to use our deltadash software for any boost / timing logging as its going to be more accurate. We do have wideband afr logging with the dyno though. These are things we can do, but Saturday was a baseline only day, we can do more logging etc if you want, just give us a call and set something up.

The strange thing is how some of the cars from Reno were producing larger numbers than average. I believe nick is spot on with his explanation on timing etc (the ecu may be very very eager to add timing at your elevation) but the only way to know for absolute is to run a log of the ecu timing on a Reno car. If dean doesn’t object maybe I will run his again before we start on the mod work and log timing etc and see where we are at.

As far as Matt w the cobb stage one, despite that cobb's dyno is set to read a little higher from what I have been told.( most dyno manufacturers set the dynos to read closer to a dynojet for the US, mustang doesn’t, although the end user can request a custom config so that it does read a little higher. Dyno Dynamics does turn theirs up from the factory etc . ) But Matt also was in a front-end accident a while ago in which his timing covers were hit, we found later in the evening that he had what sounded like a very out of adjustment couple of valves on the passenger side head, which could have a great deal to do with why his car reads low. But.... a stock wrx on a factory calibration produces between 150-155 HP on a mustang dyno on average so that actually puts Matt’s car about where it should be.

Oh and for those who want to know, the drivetrain losses on a wrx are approx 75HP, so a 150 atw is 225 at the crank.

Any other q's let me know, I hope everyone enjoyed the trip to the shop. One thing not to forget though, every car will read slightly different, I have seen throughout the years "gifted" cars that put down more power than they should have stock, although I don’t think Dean's and Tyson's cars were (I believe it has more to do w the elevation etc) that could be the case w the STI's as their ecu's are tuned more on the ragged edge to begin w.


Thanks,
-Nate

[Dean]

Originally Posted by ssquarednate

If dean doesn’t object maybe I will run his again before we start on the mod work and log timing etc and see where we are at.

Permission granted... Knock yourself out... Probably don't even have to put it on the dyno to see where timing is running...

I'm pretty convinced the timing advance is the most likely culprit. As long as we did not cause any extended knock on the drive down, the ECU would have no reason to start retarding it.

Wheras all the guys racing around in the Sac. heat for the past week were probably not pegged in advance.

[Nate@s-s]

Those are my thoughts exactly,
I will run a log w it on the dyno at the same time so we see where we land.

-Nate

[MikeSTI]

so Nate would it also help to reset the ECU before we come down for other dyno's to try to keep the ECU settings close to the same each time? because everyone seems to consider my car a Cali car but I live in Reno......is my horse power even lower when I get home :?

[Nate@s-s]

I will know better after I look at the logs from deans car,
it may possibly help, but when you reset the ecu you also reset the learnt correction factors, which take a little to get back up to good levels.
I definitly think that the 10 HP difference your car had between other stock STI's ( 223 etc ) could have been in the ecu, fuel etc . but until we can see why the wrx's from up there were reading so high we wont have a for sure.
I will keep you up to date on it,

thx
-Nate

[sperry]

Thanks again for putting together the dyno day / BBQ! Good times!

[Nate@s-s]

No prob Scott,
Thanks for the Buisness!!


-Nate

[MikeSTI]

yah, thx so much for everything I had a really great time down there. Looking forward to any of those updates

[MikeK]

Nate (or anyone who knows),

I have a question about the dyno ... does it take into account the different gear ratios being used? For example, if there were 2 WRX's that produce identical power, but one had a close ratio gearbox, would the dyno take this into account and produce identical numbers for each? Or would the car with the close ratio gearbox appear to be more powerful?

Actually now that I think about it, the WRX and the STi have different ratio gearboxes. If you were testing in 3rd gear in a WRX (a ratio of 1.366) and 4th gear in an STi (a ratio of 1.346) does this mean that the STis appear more powerful than they are compared to the WRX?

Thanks!
Mike.

[sperry]

Originally Posted by MikeK

Nate (or anyone who knows),

I have a question about the dyno ... does it take into account the different gear ratios being used? For example, if there were 2 WRX's that produce identical power, but one had a close ratio gearbox, would the dyno take this into account and produce identical numbers for each? Or would the car with the close ratio gearbox appear to be more powerful?

Actually now that I think about it, the WRX and the STi have different ratio gearboxes. If you were testing in 3rd gear in a WRX (a ratio of 1.366) and 4th gear in an STi (a ratio of 1.346) does this mean that the STis appear more powerful than they are compared to the WRX?

Thanks!
Mike.

IIRC, because the dyno is load based, it's not a matter of how fast you're turning the dyno's drums, it's actually a matter of how hard you're turning the drums. I think the dyno brakes the drums and measures the amount of braking force required to keep the drum at a particular RPM. Meanwhile the dyno is watching the car's engine RPM so it knows where the motor's at in its powerband, effectively removing gear ratios from the equation.

[MikeK]

How does it know the engine RPM? I didn't notice any other sensors being connected up (not that I could see much from outside of course)

[sperry]

Originally Posted by MikeK

How does it know the engine RPM? I didn't notice any other sensors being connected up (not that I could see much from outside of course)

It's usually monitored via a timing light on the crank pulley, or can be monitored by plugging something into the car's electrical circuit (the cig. lighter will do) and counting ignition pulses (on our cars, every 4 pulses is one revolution).

[Nate@s-s]

Scott, you are correct in your explination of the gear ratio etc, on our dyno we read timing from the crank pulley w an optical sensor, we mark your pulley w a reflective strip that the optical picks up as the pulley spins.

As far as the high reno wrx readings we have been getting,
I did some more testing on deans car today, the car has been pulled in and out of the shop 5-6 times since the dyno day, but not driven any longer than that, then onto the dyno early this afternoon when I began testing. What I found was it looks as if the cars were knocking slightly on the dyno saturday night, as the timing was being pulled on deans car as soon as I put it on the dyno, but this does show how the wrx ecu learns.

First run: ecu pulling timing like mad
154 hp
159 tq

Second run: ecu started adding timing again at this point
157 hp
163 tq

Third run: still adding
159 hp
163 tq

Fourth run: still adding , getting close to knock though
161 hp
167 tq

Fifth run: added as much as it could, car was starting to knock slightly, adv. mulitplier was very low.
162 hp
168 tq

Sixth run: The ecu was now pulling timing back to get out of knock
158 hp
162 tq

Seventh run: ecu stable
160 hp
165 tq

I made a couple runs after this, all stayed the same, hp/tq figures were within fractions of the previous run.

hope this helps! I know it was an interesting experiment for me.

-Nate
S-Squared

[sperry]

That's awesome Nate! And thanks to Dean for letting his car be the test subject.

Now Nate, you have my permission to go ahead and really pound on Dean's car... see if you can get it down into the 130's hp/tq. Maybe scortch a piston or two to lower his compression. Or bust out the pliers and pull a few blades out of his compressor fan in the turbo.

[ArthurS]

So when you dyno cars from this point...will you have to run it 7 times to get the best result? As you can tell. I don't know jack about dyno's...

<----Still learning.....

[sperry]

Originally Posted by ArthurS

So when you dyno cars from this point...will you have to run it 7 times to get the best result? As you can tell. I don't know jack about dyno's...

<----Still learning.....

It's not the dyno that was changing between those runs, it was Dean's ECU adapting to conditions.

Idealy for tuning, Nate should be able to reset the ECU, then trick it into advancing the timing as far as possible in one run. Shiv over at Vishnu has a trick for doing it (I posted this in the 100 octane thread already):

Originally Posted by Shiv at Vishnu

Just a little trick that has been shown to accelerate the factory ECU's ignition timing learning process.

Background: There is something called "Ignition Advance Multiplier". It represents, by some complicated algorithm, the average learned positive knock correction applied to the ignition maps. It's represented in 1/8th degrees increments. 1 being the lowest and 16 being the highest (1/8 to 2 degrees in absolute terms).

The "happier" (knock free) the car is, the higher the number will be. Conversely, the lower it is, the more knock prone it is. This number, after ECU reset ore ECU swap defaults to 8 and usually creeps up to 16 (if well mapped) through normal driving. Depending on driving characteristics, this can happen within a few hours or a few weeks. Well, here's a way to make it happen in about 5 seconds ....

First: With the car fully warmed up, reset the ECU. This can be done by killing power the ECU or by simply pulling off the neg. battery terminal and pressing the brake pedal for a couple of seconds.

Second: Drive to a nice open road without traffic. Don't go on boost until you get there. Put the car into gear (3rd gear works the best) bring the revs up to 2600rpm. Push the go pedal down slightly so boost stays right around 2-4psi. You will need to MAINTAIN 2500rpm and 2-5psi for approx 5 seconds. You can do this by left-foot braking gently as to prevent acceleration. During these few seconds, the advance multiplier (which you can't see so you'll have to trust me) will go from 8, to 12 and then to 16. Works like a charm. And on our reflashed ECU, is worth an immediate 10-20 horsepower

In an attempt to save a lot of dyno time between reflashes (when the advance multiplier resets itself), I do this little trick after every reflash. In a typical dyno session, it's not unusual to reflash the same car up to 5 times. On the dyno, all I need to do is tell the dyno to hold revs to 2600rpm. Then I just lay on the throttle until I see a few psi of boost... Bingo!

Warning: This little trick artificially speeds up the learning process. This is only a good thing if the re-mapped ECU is mapped properly. If there are trouble-spots where knock is present, this trick will make it even more present. So be careful!

Cheers,
shiv
www.vishnutuning.com

That way you can test the tuning changes to the ECU w/o worring about drastic changes due to the ECU's learning ability.

[Dean]

Just spoke to Nate and he gave me the secret defrost switch sequence to put Scott's car in Limp Home mode. 57HP, 48Lb-Ft. Torque...

I'm not speaking for him, but as I said earlier, Dyno tuning is entirely different than what we did Saturday. Saturday was kinda like Friday Night Drags at the local track. Drive what you brung. No qualifying, practice, etc. like you would have at an official event. It is impracticle to do many runs or hook up all the Gizmos on a Dyno day.

If my numbers are right, they did 17 or so cars in about 10 hours. It wouldn't have been much of a dyno day if we could only have done 6 or 8 cars IMHO.

I would guess that from the time it rolled into the garage until it rolled out, those runs and all the hookup and logging probably took Nate 2 hours or more. I want to thank him for taking the time, and helping us all understand a little bit better.

My guess remains that since Mike was out front occasionally winding it up and having some fun caused some knock etc and the ECU adjusted accordingly. Tyson, Matt and I who were poking along at the back not getting into the revs much and thus not knocking much didn't detune as far.

[MikeSTI]

I just need to remember next time that I have it dyno'ed there, with future mods added, that my car has the potintal to put down = to Matt's car........when compairing whp with the added mods and not just the whp I put down that day or I may have a +17 hp difference.

[Evo Mike]

the S-squared dyno day was pretty awesome... Mad props go out to Tyson, Dean, and Matt, for dyno'ing such awesome numbers. Dean's car must really love that cat back exhaust, tyson's car just knows it's bling with those SSR rims, and as for matt's STI.... The pig stickers just add +5hp each at the wheels.

Mike, you're wondering why your STi dyno'ed lower than matts??? your answer lies in the pig stickers :shock: Other than that, i have no explination. Oh yeah, maybe their cars are just the special ones that ppl talk about comming from the factory... or maybe not............ :wink:

[Dean]

Originally Posted by MikeSTI

I just need to remember next time that I have it dyno'ed there, with future mods added, that my car has the potintal to put down = to Matt's car........when compairing whp with the added mods and not just the whp I put down that day or I may have a +17 hp difference.

I would say the opposite is true. Tyson, Matt and I can expect lower numbers as shown by Nates new numbers for my car.

My car evened out at 160Whp/162Ft-Lb. which is 12 down on WHP, and 15 down on Torque.

It probably makes sense to drive around in Sac using lots of torque etc. for a while to stabilize the car before any Dyno Day type test.