Uncorrected dyno numbers

[DavidHasselhoff]

Haven't heard of the laff.tuner but Wes @ TPS Performance. In prairieville is a very good tuner however he is not there anymore an can be no longer "hands On" I believe lanny chouest hired him and moved him to New orleans to be his personal tuner for all his exotics and is building wes a new facility at the road course they are developing on the westbank. So now he basically does remote tuning, which is fine...but Im less then fond of the guy running the shop at tps now. So really without any of that having to be said a little over 3 hours away from me (houma) you have johnson motorsports that I have been more then impressed with, heck The Tuner's first cousin is chris Johnson from what I've been told co wrote and developed SCT software back in the late 90s. Regardless off all the mumbo jumbo I've been more then impressed with my tunes from him, my numbers are great and more importantly my drivabilty is good also, if you just wanna run over there to check out the facility an stap ur car on to check the numbers you can, then obviously if you want him to crack another 10 -15 out of it you can pay to do so. Ur setup is very basic, so it was probably just a matter of loading in a base tune from sct without any need for fine adjustment, so any one who can operate a computer can click a stored file... it only the highly modified stuff i've seen Baton Rouge have issues with where you actually have to start adj fuel tables an such....so to clear my name you probably have a very solid tune from a Very Nice Tuning Shop!!!

My buddies shop down here will throw it on the dyno and see what she really makes. It's a mustang dyno so it'll read lower, but they can show you how good your "custom" tune is for free and then you can decide if you want them to tune it for you. They'll let you sit there and watch them as they tinker with the tune and dyno tune it as many times as needed before they hand you your car back.

 

[DavidHasselhoff]

Go look in the snakebite thread. I posted my #s and all and the issues I'm having right now. You'll see somewhat of what I'm talking about.

 

[Islandcat]

you know someone who has a shop in new orleans? I couldn't find anyone in new orleans when i was looking for someone. Let me know who it is and contact info and i might give him a call. The tune i got is fine so far except for one thing........ The throttle is too sensitive in first gear and if i get on and off of it quick, it will lurch (surge ) 2 or 3 times before it gets itself right. Besides that i am happy with it, but i guess now i could have done better.

 

[DavidHasselhoff]

you know someone who has a shop in new orleans? I couldn't find anyone in new orleans when i was looking for someone. Let me know who it is and contact info and i might give him a call. The tune i got is fine so far except for one thing........ The throttle is too sensitive in first gear and if i get on and off of it quick, it will lurch (surge ) 2 or 3 times before it gets itself right. Besides that i am happy with it, but i guess now i could have done better.

Well I thought the tune was fine too until I took it to another dyno (my friend's shop) and dynoed it there. My street tune made more power than my race tune....Send me a pm and I can give you the details. Only problem is you're going to have to pay for another dyno tune, which IMO is complete and utter BS....

BTW the shop has done a few GT500s. They fixed a FRPP whippled 2010 that was having major issues after he let ford install it on their car.

 

[Robert M]

The car compensates becasue it is metering the air that is coming into the engine and that reading and load level is applied to a fuel and spark tables in the ECU.
The "correction factors" are an attempt to equalize differences that would be caused by dynoing on the same dyno, in different weather conditions. For example, if you dyno during the summer, and it's 100 deg out and 50% humidity, your numbers uncorrected numbers would be much lower than if you hit the rollers on a cool, dry day. It also makes comparing different dynos i different areas easier, but that can get pretty sketchy since no two are exactly the same.
The correction fastors equalize the temperature and humidity to "ideal" conditions, as well as converting the numbers to seal level numbers. That being said, corrected numbers are not worth piss at high altitudes for forced induction cars as it always over inflates them.

So in other words, the dyno "at the time of testing" is correct + or -, and the output of the car "is what it is" at that time with those current conditions. The "correction" is guessing what the car would dyno with cooler temps and less humidity and using a formula to do this, however, the numbers that were produced on the dyno are the current real world facts if the dyno is infact correct.

Another correction should be closing the hood and keeping the warm/hot air under the hood while dynoing, as it is in the real world. I can't think of any cars that would drive around with their hoods open while letting the hot (power robbing) air escape. The only exception would be if the air intake was "completely" sealed to a cold air hood, then the air intake would not be exposed to underhood incoming heated air as most are that I have seen.



R

 

[CuZzO99L]

you know someone who has a shop in new orleans? I couldn't find anyone in new orleans when i was looking for someone. Let me know who it is and contact info and i might give him a call. The tune i got is fine so far except for one thing........ The throttle is too sensitive in first gear and if i get on and off of it quick, it will lurch (surge ) 2 or 3 times before it gets itself right. Besides that i am happy with it, but i guess now i could have done better.

I haven't heard of any tuners in N.O. either.... i remember you used to have 504 dyno a long time ago....shreves automotive, don't know what happen to him either. I know you got Southern Hotrod. That does mostly mopar stuff. But hey if your a good tuner you should be able to tune anything in my opinion.

 

[DavidHasselhoff]

I haven't heard of any tuners in N.O. either.... i remember you used to have 504 dyno a long time ago....shreves automotive, don't know what happen to him either. I know you got Southern Hotrod. That does mostly mopar stuff. But hey if your a good tuner you should be able to tune anything in my opinion.

Shreve's is now DV8, the place I'm talking about. He moved his performance shop into his resto-mod shop and does both now. Steve (Shreve) is a damn good tuner. GO THERE!!!! Don't go to SHR....they ride Mopar dick like it's going out of style.

 

[CuZzO99L]

Noooo Shit!!!!!!!! That's awsome to hear!!!! Man Steve tuned my truck 4 years ago an I've been spankin ass ever since!!! That's kool! Please pm me his info so I can get my truck back to him, cuz I was about to trailer it to MS to get my tune checked for peace of mind!!! Thanks!!!

 

[DavidHasselhoff]

Noooo Shit!!!!!!!! That's awsome to hear!!!! Man Steve tuned my truck 4 years ago an I've been spankin ass ever since!!! That's kool! Please pm me his info so I can get my truck back to him, cuz I was about to trailer it to MS to get my tune checked for peace of mind!!! Thanks!!!

Sweet. Just let them know Ryan with the Black GT500 referred you so I can get $50 off my dyno tune...since my current one is ****ed. 504-287-4110. It's called DV8 now. It's located right by the new orleans airport back by all the performance shops off marietta street. Don't forget to tell em I sent ya. :coolman:

 

[IronTerp]

What is the difference in dyno results when someone says "SAE vs. STD" or "incorrect"? Is it the way that the specific dyno is set up to measure hp and tq? some are set for SAE and some are set for STD? or how would what is "real" at the rear wheels change with an equation/calculator. If a car dyno's xxx at the rear wheels, how is that considered incorrect given the location that the car was dyno'ed? unless that specific dyno is known to be incorrect when compared to other dynos locally on the same day, same temp., same car, etc.?

This is new to me, so I am interested in learning........

R

Either Correction factor (STD or SAE) is fine and both are excellent, accepted measuring systems. SAE is considered the "standard" on SVTP although many dyno shops use STD because you will get higher numbers, (and make customers happier?). The numbers are derived by a simple click of the mouse on the dyno's computer which throws the specific formula into the calculation. Most Dynojets actually have 5 different measurement systems for calculating RWHP/RWTQ.

Here's the formulas for SAE and STD:

SAE conditions: T = 77 oF, PD = 29.235 in Hg, RH = 0%, sea level, ηm = 0.85.
STD conditions: T = 77 oF, PD = 29.921 in Hg, RH = 0%, sea level, ηm = 1.00.

Where T = Ambient Temperature, PD = Dry Air Pressure, nm = Default Mechanical Efficiency.

Uncorrected is just that, uses actual sea level, temperature, dry air pressure, etc. Not generally a common way to measure because it makes it near impossible to compare to other dyno results in different locations on different days.

Insofar as horsepower at the wheels vs at the flywheel, at the wheels would utilize parasistic losses from the power used to turn the gears in the transmission, turn the flywheel, to the rear differential and axles, and finally to the rear tires themselves. Generally we will see a 12 to 15% loss in horsepower from the flywheel to the rear tires. Thus with the GT500, the reported stock Flywheel HP is 500 and typical RWHP is about 435 which equals to about a 13% drivetrain loss.

 

[Robert M]

Either Correction factor (STD or SAE) is fine and both are excellent, accepted measuring systems. SAE is considered the "standard" on SVTP although many dyno shops use STD because you will get higher numbers, (and make customers happier?). The numbers are derived by a simple click of the mouse on the dyno's computer which throws the specific formula into the calculation. Most Dynojets actually have 5 different measurement systems for calculating RWHP/RWTQ.

Here's the formulas for SAE and STD:

SAE conditions: T = 77 oF, PD = 29.235 in Hg, RH = 0%, sea level, ηm = 0.85.
STD conditions: T = 77 oF, PD = 29.921 in Hg, RH = 0%, sea level, ηm = 1.00.

Where T = Ambient Temperature, PD = Dry Air Pressure, nm = Default Mechanical Efficiency.

Uncorrected is just that, uses actual sea level, temperature, dry air pressure, etc. Not generally a common way to measure because it makes it near impossible to compare to other dyno results in different locations on different days.

Insofar as horsepower at the wheels vs at the flywheel, at the wheels would utilize parasistic losses from the power used to turn the gears in the transmission, turn the flywheel, to the rear differential and axles, and finally to the rear tires themselves. Generally we will see a 12 to 15% loss in horsepower from the flywheel to the rear tires. Thus with the GT500, the reported stock Flywheel HP is 500 and typical RWHP is about 435 which equals to about a 13% drivetrain loss.

Thanks:thumbsup:

Me personally, I would be interested in "correct/real" numbers related to where I lived in the U.S. "Correcting" numbers with different calculation formulas would seem to be a bid deceiving both to myself and those who see my numbers if I post numbers that are not "real world" for my location. I agree that "wishful" numbers are nice, but that just means that more $$$ need to be spent on mods to make them real numbers, and the next dyno of "uncorrected/wishful" numbers are the next goal, but calling them correct? that is not correct. With these thoughts I am not saying that anyone on here would post "incorrect/higher" numbers than reality in their location, but I'm sure that it would be a temptation since those numbers may be higher in some/many cases.

Right now it is in the mid 40's here in central Fla., 31 degrees Tues. and Wed. night and low humidity. Right now would be the perfect time for me to go dyno my Super Snake, the numbers would be Great!!!! BUT, 85-90 percent of the year it is hot and humid. What would be more realistic numbers for me to quote/post? dyno numbers from the few days per year when the weather/temp is more "perfect"? or reality?, hot humid, sucks? That being said, it would be nice to have a comparision of what temps and humidity really do to performance, real numbers.

R

 

[FEARSNO1]

well if it is any help to you, i help run a dyno shop here in Lafayette, that has a dynojet, we don't have a tuner, but have remote tuned many many times, from all kinds of people, including VMP,Amazon racing, and Jon Lund, just pay for the dyno time, normally 125 bucks or so, and you pick your tuner and pay him directly, I do the datalogging and uploading etc. it very simple and easy, and you have the comfort of using one of the best tuners in the country.

pm me if your interested and i will help you set it up

 

[Islandcat]

Well i took up Fearsno1 on his offer and brought it to his shop. We got Jon Lund to remote tune it for me. We ended up making 551 HP and 545 TQ SAE corrected when he was finally finished. That was on a 91 octane tune too. I am very happy with the results and the improved drivability of my car. So Thanks alot Jon Lund and Fearsno1!

 

[Robert M]

Well i took up Fearsno1 on his offer and brought it to his shop. We got Jon Lund to remote tune it for me. We ended up making 551 HP and 545 TQ SAE corrected when he was finally finished. That was on a 91 octane tune too. I am very happy with the results and the improved drivability of my car. So Thanks alot Jon Lund and Fearsno1!

Ok, so you have quoted SAE corrected numbers above 551h.p. and 545tq. Below are the numbers that you quoted as "uncorrected" earlier in this thread. The "corrected" numbers show considerably less than the "uncorrected", that is a large gap between then and now......... 30+h.p. and 30+tq. Why is that? Was more realistic higher temps and humidity for your area added to the calculation? or what changed for the loss?

Original quote-----------------------------------

My horsepower was 583, torque was 578, but these were uncorrected number in 50 degree weather with about 20 percent humidity. My mods were just a 2.6 pully and tune. I figured with just those mods i should be 520 to 545 sae horsepower, but i cant figure out how to convert my numbers lol.

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I'm just trying to figure this out.............

R

 

[FEARSNO1]

Well i took up Fearsno1 on his offer and brought it to his shop. We got Jon Lund to remote tune it for me. We ended up making 551 HP and 545 TQ SAE corrected when he was finally finished. That was on a 91 octane tune too. I am very happy with the results and the improved drivability of my car. So Thanks alot Jon Lund and Fearsno1!

glad i could help out, and most important glad your happy with the results. i extend the same deal for anyone local that wants to do a remote session with there tuner of choice, no worries about hurting my feelings about someone else doing the tuning cause i don't tune, but i can dyno and datalog the shit out of a car. LOL

Ok, so you have quoted SAE corrected numbers above 551h.p. and 545tq. Below are the numbers that you quoted as "uncorrected" earlier in this thread. The "corrected" numbers show considerably less than the "uncorrected", that is a large gap between then and now......... 30+h.p. and 30+tq. Why is that? Was more realistic higher temps and humidity for your area added to the calculation? or what changed for the loss?

Original quote-----------------------------------

My horsepower was 583, torque was 578, but these were uncorrected number in 50 degree weather with about 20 percent humidity. My mods were just a 2.6 pully and tune. I figured with just those mods i should be 520 to 545 sae horsepower, but i cant figure out how to convert my numbers lol.

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I'm just trying to figure this out.............

R

the humidity was really high last night when we did the dynoing, and the temp was in the 70's, so that is the reason for the higher numbers, we did a baseline over the tune already in the car and made 5 hp and 6 tq over it once finished. and we also improved the driveability of the car.

Brandon