Dynojet vs Dynodynamics

I'm trying to make this comparison as un-biased as I possibly can, even still I am sure there are going to be individuals who say otherwise.

The car tested is a 2005 STi, fully built motor & heads with an FP RED.



For comparison I am using this chart that was posted from the dyno dyamics dyno. As far as I know this run was stated to be done at 22psi.

390hp 35Xtq @ 22psi (claimed) Dynodyanamics




After having to turn the MBC up just over half a turn to achieve the claimed 22psi target, this was the best run of the 4 done. On this run the peak boost hit 22.7psi peak netting 395hp and 351tq. If you notice both dyno's show the same dips in power at 2.5k rpms and again at 5.8k rpms.



395hp 351tq @ 22.7psi Dynojet




Just for those data lovers here is the screen shot from the Delta Dash log of the 395hp run.



Noted from the datalog:
-Absolute manifold pressure of 2.55bar or 22.7psi
-LTFT of 0
-Intake air temps >124f
-Advanced multiplier of 1
-No knock correction.





Here is the same graph above but in SAE correction (1.04 corrected)




Finally here is an overlay of all the runs completed from the first to the last one. We picked the highest of all 4 to use as our comparison



Thanks for looking and I would be more then happy to answer any questions.

Doug

 

so less than 5%...interesting

 

Its about 1.6% give or take on uncorrected numbers. Its 5% on SAE

 

Looks pretty dang close to me. Remember the Mustang numbers vs DynoJet when you tuned my car and got the baseline?

I see in the Knock correction it's pulling back timing (right???? as my logs were always ramp up and FLAT) and that AFR curve looks horrible. Or is that a result of boost taper (but still my old logs never fell).

So what were the retuned numbers? I'm assuming this car was retuned if it was at Topspeed?

 

Using uncorrected number is a bad idea, in my opinion...few people do that in this industry. Too much variations from summer to winter. If we posted uncorrected numbers, this particular car would have measured 8-10% lower base on our weather station SAE correction.

Our dyno defaults to SAE correction.

Good data points, however...thanks for sharing.

 

Look at those intake temps......whew it hot in there! Freaking heat index up here in SC today is 127! YIKES!

 

Thats why we posted SAE and uncorrected

And we didn't retune the car yet coolrex....the customer badly wants it done after this, so we put him on the schedule.

 

Take another look...there is no observed knock corrections on those logs.

I have never been a fan of the pump/filter system that most DynoJet's use. Our uses an NTK sensor mounted directly onto a tail pipe sniffer. It reads about 1 point richer than reality, but it's a good visual...and much different from the AF curve generated from the DJ.

 

We could probably make a lot of money talking crap about each other's tunes in front of customers, and then suggesting a retune.

We aren't into that...have fun.

 

Then why is knock correction varying so much?


At ~ 4200 rpms the knock correction is adding as expected. Then at 5500 rpms, 6500 rpms, and 7200ish rpms it drops again and again.

I understand boost is tapering but 'MY' car always tapered too but the Knock corrections didn't do that. It built up to max and STAYED there unless timing was being pulled.

Maybe it's meth tune vs pump gas tune? I never ran pump EVER unless I blew a meth pump seal.


NOTE maybe it better I said nothing but really I'm just trying to read the data logs and understand what's going on.

 

I didn't talk one word of crap my friend...I in fact defended you twice while he was here. I tried to send him out of here and told him the tune was safe and fine to run on, he insisted he wanted to redone.

I don't think you really wanna start attacking my character AGAIN! Be careful!!

 

@ Coolrex... on some cars I run the same knock correction curve. Its something I have been using for years, shared it with Scott who I am sure also shared it with Sharif. Typically subaru's are the most sensitive to knock around 5krpms hence why you see more knock correction being added there to increase the safety buffer.

@ Sharif... nobody here said one bad word to the customer about anyone there or the tune. He just wanted to stop by and check us out and have us look over his car. I only suggested that the afr's and maf scalling in the lower region was a bit off and could use a small tweak but the tune was safe and looked fine.

Forgot to add we have not used the pump sniffer here in a long time, these afr reading came from the exhaust stream.

 

Thanks Doug. So the way my curves were are likely due to 'me' telling you to push it and make what you can?

 

Thank you Doug. I was about to post the DA table advance clarify for CoolRex. Scott didn't share the logic behind it, but obviously the highest likelihood of knock occurs at trq peak (peak cylinder pressure), and diminishes as trq drops off. I know you know this, but just elaborating for the community.

Sorry for my earlier comments..they were out of line. Comparisons of dynos are great, but let's not compare tuners/tuning and what a customer may or may not want to do.

 

Hmmm, on Forged's dyno it was making nearly 21 psi at redline and on TS's it was making about 17...

We usually make sure our IAT is under 104 before we start a pull and at TS it was nearly 130.

This customer's map is pulling significant timing over 122 degrees and it doesn't put it all back until 104.

There was another car recently on both dynos, I believe it made 274whp on our DD and near 330whp on their DJ.

Siegel

 

I've tuned on a LOT of different dynos. Some tend to have MUCH more boost taper up top than others, and almost all have at least a little more than on the street. Our DD translates closest from dyno to street of any that I've used.

Siegel

 

↑↑↑ "our dyno dynamics"? I'm pretty sure your an Engineer.

AND

Now thats OVER 20%...these fun numbers are just getting more creative.

 

Boost at 7k rpms was 2.36 absoluted or 20psi. This is read off the factory map sensor which both you and I know typically reads a tad bit lower then other sensors.

Really your not serious that any significant timing is being pulled at 122 degree's.

 

Scott... this isn't a pissing match between the two shops.. I just wanted to post a graph and show the numbers, boost, temps... whatever they will never be perfect unless you have both dyno's under one roof.

 

This is something I've wanted to post forever and just never spent the time typing it up. Now that it's after 5 I can "play" a little. I'd be heading home, but it's monsooning here.

ABSOLUTELY ANY tune that's safe on the street should be easily "beaten" by a tuner on a dyno. To clarify; ANY tune that runs safely on the street is normally EASILY tweaked to make more on a "magic pass" on the dyno. With the hood up, intercooler cool or even wet, a big fan directly on the engine, and a load of 4th gear or less, a tuner darn well BETTER be able to make more power than what’s safe with the hood down, engine bay heat-soaked, fully-loaded with questionable gas, and uphill in 6th gear.

I’ve tuned on a LOT of different dynos. From essentially zero inertia Dynapacks (you have to remove the wheels and there is less inertia than having the wheels on) to HEAVY 4,000 pound Dynojet rollers to 2,000 pound, loadable Land and Sea’s to our low-inertia Dyno Dynamics at Forged. They ALL are not the same loading as the street. With the DD you can easily change the load to mostly “encompass” the loads seen on the street, but it’s still not the same. This doesn’t matter all that much with NA cars, but with turbo cars they can run SIGNIFICANTLY different on the street than they did on the dyno.

Almost all cars make more boost and run leaner on the street than they did on the dyno. Some dynos (such as Dynojet) do not have adjustable load. Your only option for load is what gear you run it in. Generally you run a car in the highest gear that keeps the top speed reasonable. When you take a car off the dyno and go to the street it RUNS DIFFERENTLY.

I have often been asked “are you going to put it back on the dyno after the street?” I often reply with “would you like it to run correctly on the street or on the dyno?” Obviously, it would be interesting to know what it would make on the dyno once road-tuning is done, but for the most part, it doesn’t matter.

If we take a car straight off the dyno to the street it will usually make at LEAST a pound more boost (in a high gear) and run up to a full point leaner. So if it made 20 psi and was 11.00 afr on the dyno and made 300whp, when you put it on the street it might make 21psi, run near 12.0 afr and make MORE than 300whp, until it blows up. To make it safe you have to add fuel and turn down the boost CONTROL (not the actual boost run).

If you were to take that car that now makes 20 psi and 11.00 afr on the street, and put it back on the dyno, it would (in theory) make 19psi and run 10.00 afr and probably make 275whp. ANY tuner should be able to turn it back up to 20 psi, 11.00 afr and 300whp. WOW, your old tuner must be a hack and your new tuner is clearly an amazing genius

“So why use a dyno at all?” you might ask.

Tuner's generally like to start tuning on the dyno. It's a nice controlled situation where you don't have to worry about other cars, cops, getting stuck on the side of the road, etc. It's much faster to "rough" in a tune on the dyno than on the street because you don't even have to look out the windshield.

The best description for what tuner’s do is “putting numbers in boxes.” ASSUMING everything is mechanically right and “normal” (LOLOLOL) all tuners really do is “calibrate” – tweak the input until you get the right output.

Most tuners know approximately what "data output" we expect each car to comfortably run; as in how much boost, timing and what AFR we think that setup should safely be able to run. The initial tuning is just tweaking the input to get the right output. You have to iterate (tweak, test, analyze, tweak again, test again, repeat) to find how much wastegate duty is required to make the boost you want, where exactly that puts you on the load maps to find what timing and afr to have where, etc. Within reason, more boost, leaner afr, and more timing make more power. Certainly the dyno can show you when running a little richer lets you run more timing and whether that makes more power than leaner and less timing, and finding the right cam timing can really only be done on a dyno. So, most professional tuners can also tell you about how much power the car will make once we've got a "typical" data output. That typical data generally has some safety margin in it to deal with reality. In reality you have to be ready for bad gas (or at least not great gas), hot engine bays, high-loads, mis-alignments of the moons etc.

Once we've got it running the timing, boost and AFR that we like, then we can “push” and see what the car will actually be happy with. We can see if it'll gain power with a little more boost, more timing, leaner, etc. Sometimes the moons align and a car will stay safe and happy a bit beyond what we expect. Sometimes the car’s not “quite right” and it makes less. It could have bad gas, one light injector, crusty plugs, a curse, etc.

Then most tuners make a "magic pass." They get a little more aggressive with the tune, hose down the intercooler(s), let the engine bay cool, etc etc. I usually tell my customers when I'm making what I consider a magic pass. I let them know that the car probably won't be happy with those settings on the street. Particularly if it's hot or they're wanting to be able to redline 6th gear...

If we take a car straight off the dyno to the street it will usually make at LEAST a pound more boost (in a high gear) and run up to a full point leaner. Subaru's that have been taking 8 seconds to go from 2k to 7k rpm on the dyno and moving 3.2 grams of air might do the same rpm in 6 seconds but move 3.5 grams of air. Basically THE DYNO IS NOT THE REAL WORLD!

That's why I always tell people that it's not how it runs on the dyno that counts, it's how it runs on the street.

So, again, you take a car off the dyno, you turn down the boost 3 or 4% wastegate duty, you add a few percent fuel and you start road tuning. Most cars require a slightly different shape wastegate curve and sometimes a SIGNIFICANT amount more fuel. Generally we get the car back to running what we think is safe and reliable and that's what the customer gets to take home. That’s usually about the same “data output” as we told them was what it would make in the real world.

If you take that setup to another dyno, or even if you put it back on the same dyno. It will run that pound less boost, and up to a full point richer than it was on the street…

More later, gotta take the break in the weather.

 

I'm still employed at Forged. I was there 3 nights last week and I'll be there a few times this week...

I'll see if we can get that customer to post up...

Siegel

 

Cliff Notes?? I am on the dyno right now and what does it have to do with my OP

 

Yeah do that

 

Guess the power finally came back on?

:drama:

 

I see what you did there but I've read your post twice now and I'm still not sure how its relative to the current situation. This was a simple discussion about two different dynos read. I drew my own conclusion from what was posted, I assumed everyone else could as well.

 

Alex:

The cars actually stay pretty cool on the dyno with the big fan. Its actually a lot cooler then say sitting at a red light for 3 min with absolutely no air going over the radiator.

 

I knew this would turn into a pissing match.

 

Funny. There is only 1 tuner that 'road' tuned my car after being on the dyno if it was ever even on the dyno at all. And I've been with 4 tuners on my old Subaru.

3 of the tunes ran just fine with the exception of my last round.....that round was purely inexperience with cutting the mappings in halves and lack of time to really learn and dial it in.....in other words I got impatient and went straight to the master as he was gonna tune it all along and I really just needed a good rough break in tune.

SS your replies have nothing to do with Doug's original post and is PURELY an intellectual ramble attacking the shop and such.

Kudos to Topspeed for actually keeping this civil and honest.......I can clearly read who did the first attack and who simply added fuel to the fire when it was pretty much done and over with.

 

Wow, didn't think I'd have to spell it out for this crowd...

The dyno is not the "real world."
When you take a car off the dyno you have to lower boost control, and add fuel to make it run the SAME boost and AFR as when on the dyno. Often you make it run a little richer, lower on boost and lower on timing than on the dyno for safety.

Car makes "best case" at Forged = 390whp
Car is road-tuned, requiring lowering boost control, adding fuel, reducing timing, etc.
Car is dynoed at TopSpeed indicating a little rich and "only" making 410whp.

The 390 at Forged should be about 440 at TopSpeed. Cranking the boost a little, leaning it out a little and adding a little timing should get it up near that 440whp for a "magic pass" at TopSpeed. Of course you wouldn't let the customer take the car and beat on it with a tune that only makes a clean pull with the hood up and a fan right on the intercooler. You'd have to "safe" it a little and bring it back down

Siegel

 

For those that don't have a great grip on correction factors, the main thing it's correcting is temperature.

When it's hot, uncorrected will obviously be the lowest, with SAE giving a bit more, and STD often giving a LOT more than that. STD might add another 5% or more to SAE.

When it's cold uncorrected will often be higher than SAE, but STD is often still higher than uncorrected.

Many people on this board probably remember that I always used SAE correction when it was under 90 at TopSpeed, but when it was really hot in the shop I always used STD. Using STD when it was cold seemed to give very inflated numbers, and uncorrected in the hot gives very disappointing numbers.

I do think it's interesting that if you search here for "topspeed dyno", most of the plots they post are in STD correction which is the highest, yet when they post their "un-biased comparison" they begin by showing an uncorrected plot and comparing it with our SAE corrected plot. They do show what it made with SAE, but don't even post STD correction. So when it's good for them, they use the STD correction, but to show how "closely theirs reads to ours" they show uncorrected on a 100+ degree day and then show SAE below. (Going back 6 months there aren't many posts, but the Supra was in STD even though it was cold, as was the Stock Turbo craziness car, and also coolrex's)

The last one that was tuned there and brought to us made 350.3 there and 308.2 at us = 13.67%

The sheet that I used to give people their Dynojet numbers had 13.4% in it...

Siegel

 

You know what... you should just drop all this and concentrate on your current engineering job.

Your really starting to sound like a broken record and its getting old. I might take what you say more seriously about the graphs for cars I post when you actually build something fast on your own... tune a 1100hp e85 8sec supra, 1000hp 8 second 4cylinder, a car that makes over 700whp or hell maybe even a 10sec street car... but you haven't.

You make long posts about how your the best and try and give 100 reasons and excuses as to why you are... but results and track times are what counts not long winded posts.

So when I post a graph, if you don't like it you can choose to look the other way.


/Rant

 

You've tuned ONE high hp E85 Supra. I tuned a 687whp 93 octane supra, not like either of those have anything to do with Subaru's.

The 1,000hp 8 second 4-cylinder has a lot to do with Shawn who works at Forged. I've tuned a few 700+'s, you've tuned what, 5?

I don't see anywhere that I said anything about me being the best... I also don't see any listing of reasons or excuses. I don't make excuses, and I actually drive a Subaru on track at least once a month. Why don't you bring Lucy out to Road Atlanta in 2 weeks? The one I'll be driving has had it's turbo kit entirely rebuild at Forged, so it's truly been entirely built by Forged employees. You drive and I'll drive and we'll see how it goes.

And as for results and track times, I believe that you and I are even on Subaru road-race track records at 3 apiece.

And if we're going to talk about results, TopSpeed has participated in exactly ONE competition in the last two years, Forged competes about once per month.

This was YOUR comparison, of course the last one we posted showed a 13.6% difference.

Siegel

 

Seriously Scott, you are just digging deeper into the hole. You really need to just stop.

 

Seriously... see my above post. I think you have lost it lately and live in some fantasy world... So take care as I feel I have nothing to prove to you of all people.


Oh... and nobody cares about your racing because you never have won anything.

 

LOL Scott thinks he can race/drive but as One Lap proved he can't.