[Enslaved]

Originally Posted by Eldi Z

OK. Well, if you can look at a WoT pull, lets take 4th gear as an anchor, somewhere between 4500 - 6000 RPM. Have a look at Spark advance, AFR range. Would be interesting to see the data.

Small snip of a very short 4th gear pull this morning in the zip file. File size is very limited on the forum.

Timing is extremely conservative (imo) and still getting some knock down low, which is looking more and more like blower or header noise to me than real knock. BUT - I'm a turbo guy, and this platform is still foreign to me. Running 93 and have added boostane to see if it eliminates it - it does not. Screen shot of a different pull - can still see the light KR in the same region. I assume the knock learning will eventualy nip this, but dont know for certain. Any advice to diagnose would be appreciated.

Going to hit the dyno tomorrow to get some reliable 4th pulls. Will be getting a wealth of data from those runs, naturally.

That said, depending on the situation it's somewhere around 8-12 degrees in the suggested rpm range.

[Eldi Z]

Cool. I will have a look at the log later.
KR is often dependent on the KR sensitivity settings in the tables, so mechanical noise can indeed casue this.
Tomorrow at the dyno, it is a good opportunity to run a complete log and cover all of the parameters. If the dyno shop is using external professional Knock sensors, I.E. Plex https://www.plex-tuning.com/product/knock-detection/ then you could find out if it is real or fake.
The OEM sensors are not quite as accurate as Plex.

Will you have your remote tuner standing by in the background, or even monitoring your session at the dyno?
This could prove effective because he will able to calibrate in RT while seeing the results.

BtW, I used to be (and probably still am in a way..) a Turbo guy myself - used to have a small 2.0L / 4 Cyl. VW-Audi 20VT platform. My other car today (daily) is also a turbo - BMW with a B48 2.0L 4 Cyl. engine, making relatively high power for this platform with a few supporting bolt-ons and an effective calibration.

Good luck at the dyno and please post the results and let us know details how it went and the conclusions and plans moving forward.

[Eldi Z]

Had a look into the log. Found peak Torque at 3800 RPM 884 Nm (652 Pounds) at the crank. Boost at this point is 7.5 PSI. Spark Advance extremely conservative at 8.0 Deg. Lambda 0.82 - rich enough.
At the wheels this torque level would be 554 Pounds (15% Drivetrain loss for Auto).

Interesting if the dyno shows similar figures.

[Enslaved]

Had a look into the log. Found peak Torque at 3800 RPM 884 Nm (652 Pounds) at the crank. Boost at this point is 7.5 PSI. Spark Advance extremely conservative at 8.0 Deg. Lambda 0.82 - rich enough.
At the wheels this torque level would be 554 Pounds (15% Drivetrain loss for Auto).

Interesting if the dyno shows similar figures.

You weren't too far off.

540hp/537tq on a Dynapak setup.

No changes made during the session, just back to back runs.

She was running a bit rich. Boost crept higher than I expected, but I have read that it's common. Tune by Ted (JRE) remotely and only on the street. Not too bad for what it is. Repeatable, IAT's seem reasonable and lots of area under the curve. Funny little dip towards the end of the curve, not sure what that's about.

Anyways, it certainly feels like it's got more in it, but I'll defer to Ted when we talk next week.

Graphs and log attached.

[RobZL1]

Nice to see those injectors and HPFP getting some good use! Ted will get you squared away for sure.

[Enslaved]

Originally Posted by RobZL1

Nice to see those injectors and HPFP getting some good use! Ted will get you squared away for sure.

Oh yeah, they work great. The timing was perfect for my build. Thanks again to you (RobZL1) and the others who let me know about it.

As for the car, yeah - I have no doubts that Ted has an ace in his pocket. In a perfect world, I'd snag the dyno for a few hours with him on the phone and dial it in. For dealing with this over email and a knucklehead like me(me plus lord knows how many other tunes in paralel he's doing), the car drives amazing. Driveability is phenomenal and the car rips.

If the weather holds and there are gains to be had from additional tweaks, I may just hit the dyno again before the salt hits the roads.

[Eldi Z]

[QUOTE=Enslaved;11500932]You weren't too far off.

540hp/537tq on a Dynapak setup.

No changes made during the session, just back to back runs.

She was running a bit rich. Boost crept higher than I expected, but I have read that it's common. Tune by Ted (JRE) remotely and only on the street. Not too bad for what it is. Repeatable, IAT's seem reasonable and lots of area under the curve. Funny little dip towards the end of the curve, not sure what that's about.

Anyways, it certainly feels like it's got more in it, but I'll defer to Ted when we talk next week.
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Great! This leads to the conclusion that HP Tuners logs provide an excellent prediction of what can be expected on the Dyno. The Torque results seen on the Dyno in your measurement are only 2.5% off (lower...) compared to the HP Tuners .hpl.
Would be interesting to get such validation (or refute) from others who logged torque and dynamic MAF / Airflow and compared to the dyno results during the same run.

[Enslaved]

Being torque based, all the inputs and math involved in the ECU it's not surprising to me that it's pretty close. Naturally, it's output is only as good as its input - i.e Input resolution and calibration. Kudos to the nerds at GM, and kudos to Ted for his torque maps lol

[Eldi Z]

...And another piece of important detail picked up from your dyno. This was a DynaPack, meaning, that the measurement was right at the Hubs and this means the most conservative numbers possible - lowest parasitic losses.
Guess that a Mustang dyno would tipically show ~ +3-5% higher readings than a DynaPack (like you measured on) and a DynoJet would show the highest numbers overall with ~ +10-12% compared to DynaPack. Makes sense?

[Enslaved]

Originally Posted by Eldi Z

...And another piece of important detail picked up from your dyno. This was a DynaPack, meaning, that the measurement was right at the Hubs and this means the most conservative numbers possible - lowest parasitic losses.
Guess that a Mustang dyno would tipically show ~ +3-5% higher readings than a DynaPack (like you measured on) and a DynoJet would show the highest numbers overall with ~ +10-12% compared to DynaPack. Makes sense?

I hear ya. I just think its a bit more nuanced than that. Plus, I think you will start a huge flame war with the dyno accuracies Everybody and their brother has had an opinion on this subject since the first dyno was created.

In the GM dyno wings, we calibrated (and I'm sure they continue to) our dyno cells with 'gold standard' instruments that were traceable to NIST. Even then, the accuracy and repeatabilty were generally ~1% of the standards(s) - full scale in some cases, % reading in others. However this could vary depending on the range of the unit. I mention this because I suspect most dyno's out there are likely NOT calibrated at a reasonable frequency. Calibration drift is a very real thing, for many reasons. Moreover, with all the variants out there (eddy current, intertia, hydraulic) you will have error between them, as you mentioned.

Add in the mix, wheel size/weight/traction, dyno operator setup and configuration, ambient conditions (let's not forget calibration and accuracy of the dyno's ambient sensors), and probably a few other variables I'm leaving out - you have a healthy scenarion for varation in output. Quite frankly, It's impressive that the dyno manufacturers have things as close as they do. It just means they've done the best they can to eliminate humans from the equation as much as reasonably possible.


At the end of the day it comes down to drivability, seat of the pants feel and track times (if that's your thing). Big numbers are easy to acheive - it just takes money and a sliver of knowhow. Drivability tuning,imho, is where the hard work is and what matters the most on a street car.

Anyways, sorry for the rant

[Eldi Z]

Originally Posted by Enslaved

I hear ya. I just think its a bit more nuanced than that. Plus, I think you will start a huge flame war with the dyno accuracies Everybody and their brother has had an opinion on this subject since the first dyno was created.

In the GM dyno wings, we calibrated (and I'm sure they continue to) our dyno cells with 'gold standard' instruments that were traceable to NIST. Even then, the accuracy and repeatabilty were generally ~1% of the standards(s) - full scale in some cases, % reading in others. However this could vary depending on the range of the unit. I mention this because I suspect most dyno's out there are likely NOT calibrated at a reasonable frequency. Calibration drift is a very real thing, for many reasons. Moreover, with all the variants out there (eddy current, intertia, hydraulic) you will have error between them, as you mentioned.

Add in the mix, wheel size/weight/traction, dyno operator setup and configuration, ambient conditions (let's not forget calibration and accuracy of the dyno's ambient sensors), and probably a few other variables I'm leaving out - you have a healthy scenarion for varation in output. Quite frankly, It's impressive that the dyno manufacturers have things as close as they do. It just means they've done the best they can to eliminate humans from the equation as much as reasonably possible.


At the end of the day it comes down to drivability, seat of the pants feel and track times (if that's your thing). Big numbers are easy to acheive - it just takes money and a sliver of knowhow. Drivability tuning,imho, is where the hard work is and what matters the most on a street car.

Anyways, sorry for the rant

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Actually, you are perfectly correct, but within these errors and variances, we still do get some sort of reference that we can rely on, in order to assess the power figures.
And yes, for a street car (which is my goal as well), drivability is key, while chasing the last bit of WHP at the highest points of the RPM band is (to me) of lesser importance.
Saying this, curiosity of what can be achieved with my hardware and software calibration drives me to research the various measuring tools available and their potential effectiveness in reporting the results.

Bottom line, back to your next steps: Would be interesting to see how Ted @ JRE gets you dialed in towards your next dyno session.
From the log, seems that spark for instance, is extremely conservative at ~ 8 Deg.
In my case, I run the stock LT4 1750cc unit + LT4 fueling as well (@ 93 Pump gas), spark being at 14-14.5 Deg. while boost is capped at peaks of 7.5 PSI - Usually more like 7.2-7.3 PSI @ WoT. Lambda stabilizes at ~ 0.82

[JSH]

Originally Posted by Eldi Z

==================================
Lambda stabilizes at ~ 0.82

I shoot for 0.82-0.85

[Eldi Z]

Originally Posted by JSH

I shoot for 0.82-0.85

Guess you are talking about Pump gas E10 and I guess on an LT4 ?
Forged material + lower C/R allows for a leaner mixture.

The LT1 with its cast pistons and tight ring gaps is likely less forgiving, so a little richer for safety and yes I saw some calibrators feeling comfortable even with 0.86-0.87 and then are usually more careful with spark advance and boost.

[JANNETTYRACING]

Rigorus testing since 2014 on Boosted LT1 has reveiled that MBT is achieved at .82 which is a 12.05 AFR for reference.

Where LS Port injected engines MBT is .78 or 11.46.

Fuel is a piston coolant as well, leaner mixtures put undue heat stress on components that over long term will drastically accelerate wear and can lead to detonation.

All this is verified via an ECM 1500 Lambda meter.

https://www.bmotorsports.com/shop/pr...fX4j6V_TWIMBYQ

There will be some error in other brand/pricepoint wide bands.