[Juiced1]

We've put that cam in a bunch of 6gen Camaros with zero issues. With a set up similar to yours we made 545rwhp with the TSP stage 3 cam, headers, intake and E85.

[6spdhyperblue]

Do you guys still run vvt or full lockout

[Brandonc_06]

Originally Posted by Juiced1

We've put that cam in a bunch of 6gen Camaros with zero issues. With a set up similar to yours we made 545rwhp with the TSP stage 3 cam, headers, intake and E85.

Thank you. Looking forward to installing it!

[oldman]

Originally Posted by Nabush

You sure can manipulate numbers on a Mustang dyno...

From what I saw, Mustang dynos are very repeatable, several pulls with same tune were showing exactly same numbers...

When I was talking 530WHP at 6000 rpm this was with cam and heads on an A8, without MSD and TB. No way. 490-500whp max.

The as measured HP from a dynojet is as accurate as anything know to man. It takes HP to spin up a heavy roller PERIOD. As measured on a dynojet is as accurate as you can get and it is comparable to anywhere, anytime, to another as measured on a dynojet.

Am I saying the same car with the same mods will make the same true as measured HP? Nope, the car will put out different HP depending on conditions (and location of dyno). The is an highly abused SAE correction factor for that, which should be used under very limited adjustments (read that as a few %) and never on a FI engine. So why don't we all use as measured? Which is 99.9% accurate completely repeatable?

The Mustang dyno is a programmable load dyno and can literally spit out ANY number. It is VERY useful in tuning a street car on street gas especially FI cars as these cars tend to ping / detonate underload.

You get into real trouble when you want to race a dynoject against a Mustang dyno. As a dynojet is a true fixed load no way to cheat as measured, and a Mustang dyno is NOT.

It is near laughable when we get to Unicorn HP on FI using STD, STP et al.

[Juiced1]

Originally Posted by 6spdhyperblue

Do you guys still run vvt or full lockout

Yes, full lock out on the stage 3

[Nabush]

Originally Posted by oldman

The as measured HP from a dynojet is as accurate as anything know to man. It takes HP to spin up a heavy roller PERIOD. As measured on a dynojet is as accurate as you can get and it is comparable to anywhere, anytime, to another as measured on a dynojet.

Am I saying the same car with the same mods will make the same true as measured HP? Nope, the car will put out different HP depending on conditions (and location of dyno). The is an highly abused SAE correction factor for that, which should be used under very limited adjustments (read that as a few %) and never on a FI engine. So why don't we all use as measured? Which is 99.9% accurate completely repeatable?

The Mustang dyno is a programmable load dyno and can literally spit out ANY number. It is VERY useful in tuning a street car on street gas especially FI cars as these cars tend to ping / detonate underload.

You get into real trouble when you want to race a dynoject against a Mustang dyno. As a dynojet is a true fixed load no way to cheat as measured, and a Mustang dyno is NOT.

It is near laughable when we get to Unicorn HP on FI using STD, STP et al.

Where did I say the dynojet were not repeatable ? I perfectly understand a fixed mass to rotate will provide repeatable measurements. After all, what should I know, I only have a Master in engineering and a PhD in physics...

The issue I see with Dynojets is that the pulls are really short for most of them, you don't load properly the engine, which is obviously an issue with turbo engines. Moreover for tuning the adjustable load of a Mustang dyno is very usefull even on an NA engine to look for knock and or simulate very high loads.

It is common knowledge that most of the time Mustang Dyno, properly setup, yield lower numbers than dynojets by few % (max 5% ?) . There is no science behind the words " heart breaker" but yet they come from experience of several users.

[oldman]

Originally Posted by Nabush

Where did I say the dynojet were not repeatable ? I perfectly understand a fixed mass to rotate will provide repeatable measurements. After all, what should I know, I only have a Master in engineering and a PhD in physics...

Ah vitae, I always say engineers have the slow cars. Last time two German PhD came and talked to me about direct injection in a diesel, I was installing a stereo and boom box playing 99 luft balloon (as fate would have it). They said your nothing like we envisioned from your writing. Great guys, they do like the Fredericksburg beer garden. As an aside if you get a chance to watch the mock invasion of an island at the Nimitz Museum, it is something to see.

Originally Posted by Nabush

The issue I see with Dynojets is that the pulls are really short for most of them, you don't load properly the engine, which is obviously an issue with turbo engines.

I have noted that in my post, the Mustang dyno is better at tuning because of the load. So we agree

Originally Posted by Nabush

Moreover for tuning the adjustable load of a Mustang dyno is very usefull even on an NA engine to look for knock and or simulate very high loads.

It is common knowledge that most of the time Mustang Dyno, properly setup, yield lower numbers than dynojets by few % (max 5% ?) . There is no science behind the words " heart breaker" but yet they come from experience of several users.

Once again I agree. I was and am addressing that an as measured dynojet number is dead on 100% accurate no cheating possible. Does it reflect the real world? No as noted more eloquently by you, but I did refer to it, the load especially on street fuel is the same as on the street. Back in the bad days (the 80s and early 90s) many boosted cars would run more boost in the lower gears vs drive as the engine would be spinning against less load, meaning less chance of detonation. Hence the 1000 HP Supra, take that car off the dyno put 93 octane in it and try to drive it on the street and your down to 600 HP. That why the Supra crowd don't even place in the top 20 ever in the pump gas shoot outs. Because the engine is just too small for the octane limit of pump gas.


The nut of the problem is the 100% accurate dynojet numbers get corrected to SAE which is meaningless on a FI engine, secondly it was meant to be used under very small variances say 2 to 3% Then enter in STD and STP aka Unicorn HP and now the reading of a 100% accurate dynojet is so far off nobody knows what HP / torque the car is actually making. Of course the tuners could print the correction factor applied (CF) but then that would drastically undercut their HP claim. To make matters worst you have shops, that just manually enters false data into their dyno so that all their cars are like 10% more HP than any other dynojet.

Not to be outdone, the Mustang dyno guys (since this is a fully programmable dyno) can and do come up with fanciful numbers themselves. So as you have stated "properly setup" does not bring customers into the shop. At least the dynojet can display as measured, no cheating possible. I know how to run a dyno have made many dyno runs.

Oh and FWIW, I've worked my way through 3 college degrees by building cars and engines. BTW and make more money the Dean or Chair of my department. Too bad these guys can't teach, much less build cars.

Nutshell if there is ANY doubt and the shop has a dynojet, just ask for numbers uncorrected aka the actual HP the car made to the wheels.

[NickeyMatt1LE]

Originally Posted by oldman

Ah vitae, I always say engineers have the slow cars. Last time two German PhD came and talked to me about direct injection in a diesel, I was installing a stereo and boom box playing 99 luft balloon (as fate would have it). They said your nothing like we envisioned from your writing. Great guys, they do like the Fredericksburg beer garden. As an aside if you get a chance to watch the mock invasion of an island at the Nimitz Museum, it is something to see.



I have noted that in my post, the Mustang dyno is better at tuning because of the load. So we agree



Once again I agree. I was and am addressing that an as measured dynojet number is dead on 100% accurate no cheating possible. Does it reflect the real world? No as noted more eloquently by you, but I did refer to it, the load especially on street fuel is the same as on the street. Back in the bad days (the 80s and early 90s) many boosted cars would run more boost in the lower gears vs drive as the engine would be spinning against less load, meaning less chance of detonation. Hence the 1000 HP Supra, take that car off the dyno put 93 octane in it and try to drive it on the street and your down to 600 HP. That why the Supra crowd don't even place in the top 20 ever in the pump gas shoot outs. Because the engine is just too small for the octane limit of pump gas.


The nut of the problem is the 100% accurate dynojet numbers get corrected to SAE which is meaningless on a FI engine, secondly it was meant to be used under very small variances say 2 to 3% Then enter in STD and STP aka Unicorn HP and now the reading of a 100% accurate dynojet is so far off nobody knows what HP / torque the car is actually making. Of course the tuners could print the correction factor applied (CF) but then that would drastically undercut their HP claim. To make matters worst you have shops, that just manually enters false data into their dyno so that all their cars are like 10% more HP than any other dynojet.

Not to be outdone, the Mustang dyno guys (since this is a fully programmable dyno) can and do come up with fanciful numbers themselves. So as you have stated "properly setup" does not bring customers into the shop. At least the dynojet can display as measured, no cheating possible. I know how to run a dyno have made many dyno runs.

Oh and FWIW, I've worked my way through 3 college degrees by building cars and engines. BTW and make more money the Dean or Chair of my department. Too bad these guys can't teach, much less build cars.

Nutshell if there is ANY doubt and the shop has a dynojet, just ask for numbers uncorrected aka the actual HP the car made to the wheels.

Uncorrected dyno numbers can vary depending on weather and would be way less consistent than using a correction factor. Unless the dyno cell is temperature, pressure, and humidity controlled. Take a hot humid late summer afternoon. Upper 80 degree temps and 90% humidity. You make some initial pulls to get a baseline tune established. Then a front moves through and the next morning it's 60 and 50% humidity. A common occurrence here in the Midwest that time of year. Now that car still on the dyno would read higher with no changes using no correction factor. Now all of your data from the previous day would be out the window. Or trying to compare a similar or same combination that was tuned on the same dyno in the winter to one now being tuned in the summer. Accurately showing gains made by modifications to a vehicle requires a correction factor.

Dynojets have a load cell option just like a mustang dyno. Very useful on higher power cars. Especially turbocharged.

[oldman]

CF useful on NA cars under limited conditions, since they are so abused, I would rather not use them. Near worthless on FI cars BTW.

What is wrong with tuning the car for the current conditions? As really even with a small CF applied it really does not help with tuning. I must be missing something here...

Here is the most common example a base supercharger Procharger (I most familiar with) should get you 600 HP. Lets say SAE conditions outside, drivetrain loss with a M6 is really about 10% so I'd expect 540 RWHP as measured and since the conditions are SAE standard the CF=1.0. I drive the exact same car to Denver on a 105 degree summer day. The SAE CF is probably 15%, but wait the Denver shop likes to race dynos as it brings in customers, they use STD which is 19% and they use a rule of thumb of 15% drivetrain loss (even though it ain't). Then they quote and sell their much higher HP kit on the exact same car.

For ballpark let's say 7 PSI is 150 HP or 22 HP per PSI, say Colorado is down 1.2 PSI or 26 HP, temp well it has a big intercooler so temp might only be 10 degrees over what it was at SAE J1439 at 77 degrees, 10 degrees F based on the gas law of negative 460 degrees back of envelope that is about 6 HP less. So the actual engine in the car in Denver is making about 600 HP - 26 HP for pressure drop, -6 HP for temp = 568 HP. Lets just say 5% for grins and we get 570 engine HP, dyno is about 10% loss or 513 RWHP as measured no magic.

But the shop wants to corrected for the reasons you stated (actually to sell parts). 513 RWHP as measure corrected to STD = 610 RWHP, but WAIIIIIT a minute the shop is selling engine HP (higher number) so they crank in their rule of thumb (I've seen anything from 15% to 18% to 20%) 610 RWHP x 20% loss = 730 engine HP.... FOR THE EXACT SAME KIT.

SAE correction factor was meant for engines on a dyno NA to be compared under very limited conditions. There is no FI correction factor as an FI engine is less sensitive to altitude and temp. One can argue that these DI engines are octane limited not boost limited hench they can put out the SAME to the wheels in Denver vs LA, so why would one "correct it"?

Same thing happens in magazine dyno test, mostly these are hub dynos with a drivetrain loss of say 5 to 8 % They are using STD correction factors and then some ridiculous drivetrain loss factor to conclude the engine is make xyz HP over stock.. We both know that an SAE certified engine makes within a very small percentage the HP advertised. So who is correct the magazine, with their STD Unicorn HP and fictional drivetrain loss or the SAE certified number?

As stated the potential for cheating or whatever you call it is rampant, can't cheat on as measure HP on a dynojet. But you say my shop is in Denver during the summer and this is a NA car. Well does the customer live in Denver are you tuning in Dever, then why do you care what the corrected HP is? You are tuning the car for Denver and it makes what it makes.

Here says the max CF is 7%. So sorry for Colorado it can't be used. https://www.dynomitedynamometer.com/...horsepower.htm

You can do a search on this forum, I've published dynojet's statement on correction factors use on boost engines, nutshell it can't be done. I also posted dynojet's statement on why STP, STD CF were removed as they are HP readings true enough, but a Unicorn is a horse.


I just checked and Denver is like 2.3 PSI down and 23% correction factor. Note that SAE can't be used above 7% and STD / STP would be 3% LOL...

So why do dyno racers not put the CF applied? If you can answer that you will understand the nature of dyno racing. It a correction factor really being used to compare an engine and parts to some standard or is it used to produce fictional HP gains? As I always say ask for the uncorrected HP number is you want to know how much HP the car is actually making.

[oldman]

Here is the Dynojet VP's response to CF on boosted applications:
"The correction factors that we use in our dynamometer software are not
valid with forced induction applications. The most popular correction
factor, SAE CFJ1349 JUN90 and J1995 JUN95, does not account for the
conditions present in boosted applications. Atmospheric pressure is the
major component of this calculation, and anything that varies from the
standard (29.235 inHg) can easily be corrected for NA applications. When
you are forcing an "artificial atmosphere" into your motor, these
standards go out the window.

Technically any boosted car should be viewed as uncorrected if you want
to compare apples to apples. If we had a correction factor that just
took into account temperature and humidity, that may make things easier
to compare in boosted applications. If you are forcing 1 atmosphere
(14.7 psi) in your motor at 6,000 feet, or 1 atmosphere at 100 feet,
that's really the same difference.................IF you are measuring
manifold ABSOLUTE pressure, it's absolute, don't rely on a standard
boost gauge to give you an absolute value.

Regards,
----------------
Dan Hourigan"

[oldman]

Here is why a dynojet is dead accurate uncorrected:
https://mustangforums.com/forum/2005...dyno-runs.html

[NickeyMatt1LE]

From the standpoint of trying to race dynos or compare different cars on different dynos, yes there are too many variables to do that accurately. Altitude being a big one, tires, tire pressure, how the car is strapped down, vehicle weight, airflow in the dyno cell to name a few. If you are using the dyno to just read a power output on a given day with a given car, then yes uncorrected is the most accurate reading.

The point I am trying to make is I use a dyno as a tool for tuning and to measure power and torque gains made by modifications. To accurately do this I need consistency. Last week it was 80 degrees out and the weather station on the dyno was reading 80. Today it's 45, dyno area in the shop is 55 on the weather station. If I baselined a car last week then we did heads, cam, intake, e85, and I went to tune it today I would not have an accurate representation of power gain if it was set to uncorrected. Yes the car could still be tuned properly and I could still calibrate mbt, fueling, etc. I would have about a 2% higher end result (10-12 rwhp) then if calibrated on a day with the same conditions. When you do a specific combination of parts to the same model vehicles, it's nice to have the gain in power almost identical every time. Then if for some reason you saw a lower gain from said modifications, you could go back and troubleshoot to see if there is a problem. Other examples could be if we were trying a new cam lobe, or some different porting on an msd intake, or 1 7/8" vs. 2" headers. Without a correction factor, trying to measure small gains made by modifications like this would be very difficult unless you were to wait for the same exact atmospheric conditions.

Now coming back to racing dyno's. We often get new customers that buy modified cars from different parts of the country. They want to see if that dyno sheet they got with the car is in the ballpark of what it's still making. If it was previously done on a dynojet, with the same correction factor we could get an idea if it's still healthy.

Just some examples of where I think a correction factor is necessary.

[oldman]

Originally Posted by NickeyMatt1LE

From the standpoint of trying to race dynos or compare different cars on different dynos, yes there are too many variables to do that accurately. Altitude being a big one, tires, tire pressure, how the car is strapped down, vehicle weight, airflow in the dyno cell to name a few. If you are using the dyno to just read a power output on a given day with a given car, then yes uncorrected is the most accurate reading.

The point I am trying to make is I use a dyno as a tool for tuning and to measure power and torque gains made by modifications. To accurately do this I need consistency. Last week it was 80 degrees out and the weather station on the dyno was reading 80. Today it's 45, dyno area in the shop is 55 on the weather station. If I baselined a car last week then we did heads, cam, intake, e85, and I went to tune it today I would not have an accurate representation of power gain if it was set to uncorrected. Yes the car could still be tuned properly and I could still calibrate mbt, fueling, etc. I would have about a 2% higher end result (10-12 rwhp) then if calibrated on a day with the same conditions. When you do a specific combination of parts to the same model vehicles, it's nice to have the gain in power almost identical every time. Then if for some reason you saw a lower gain from said modifications, you could go back and troubleshoot to see if there is a problem. Other examples could be if we were trying a new cam lobe, or some different porting on an msd intake, or 1 7/8" vs. 2" headers. Without a correction factor, trying to measure small gains made by modifications like this would be very difficult unless you were to wait for the same exact atmospheric conditions.

Now coming back to racing dyno's. We often get new customers that buy modified cars from different parts of the country. They want to see if that dyno sheet they got with the car is in the ballpark of what it's still making. If it was previously done on a dynojet, with the same correction factor we could get an idea if it's still healthy.

Just some examples of where I think a correction factor is necessary.

agree with what you said, too bad this is not what most posted dyno runs do.

Same dyno, same car, assuming NA, yes absolutely SAE correction should be used. We are talking plus or minus 2% max. FI would still be better as measured. IMO

[RobbyBeefcake87]

Originally Posted by Nabush

You sure can manipulate numbers on a Mustang dyno...

From what I saw, Mustang dynos are very repeatable, several pulls with same tune were showing exactly same numbers...

When I was talking 530WHP at 6000 rpm this was with cam and heads on an A8, without MSD and TB. No way. 490-500whp max.

I'm not shitting on mustang dynos but since you mentioned the bs dynojet numbers, I had to mention that dynojet are pretty respected by many for accuracy. Sure there's some fibbing that can be done, specifically with disingenuous placement of where the dynojet reads ambient temps to skew things more favorably when corrected. A proper dynojet dyno reading is very legitimate, and while mustang dynos are great tuning tools there's plenty of manipulation that can happen there as well.

Anyways I think we're mostly in agreement.