No need for "me" to explore, because my opinion is different than yours. The dyno is a tool, just like the drag strip. I just happen to prefer the drag strip. I have experience using both and the strip is what I like better.
Stock 340 dyno tests?
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Yes and corrected to "WHAT" standards? With the drag strip, there are only two standards. ET and MPH.
I imagine most cars don't ever see the track.
Newbomb Turk
Well-Known Member
You can correct to several different standards. It depends on what you are trying to accomplish.
Off the top of my head, the “standard” most engine dyno’s and flowbench‘s use is 60 degrees, zero humidity and a 29.92 barometer. That is pretty much the standard.
There are other correction “standards” in use, but all they do is change the “corrected” number coming off the software. This is done so you can test year round and you will know if you made an improvement with a 28.32 barometer, 90% humidity and 100 degrees when the tests you made earlier in the year had a 29.00 barometer, 30% humidity and 50 degrees.
If you don’t correct to some “standard” you won’t have a clue if you made or lost power just due to weather changes.
So you should also know all the above data PLUS what standard was used PLUS you should have the uncorrected numbers off the dyno. Because that is exactly what the engine makes for power on that day with that weather. It’s pure science. Is it perfect? No. But it’s closer than going to the track and guessing.
I asked the other guy who thinks a dyno is a waste of time but he didn’t want to answer so I’ll ask you.
How do you test headers at the track? Most headers are a bear to change. On the dyno it’s simple.
How do you do lash loops at the track? You are looking for 5 HP gains or losses. Lash loops give you a clue as to how close you are on cam. It’s near impossible to see 5 hp at the track.
How do you do timing loops at the track? Unless you have a data logger (that has to be well instrumented) you won’t know how much timing you need at peak torque and what you need for timing at peak hp and rpm. Also near impossible to test at the track.
Intake manifolds are about the same. Easier than the typical header, it’s still cumbersome to yank and seal an intake in the car. And to do it correctly you need to do an A-B-A test just to verify your results.
I know that people think the time slip says it all, but it doesn’t. Clearly you can’t test with the engine in the car at the track like you can on a dyno and get even reasonably accurate results.
And I’m not even taking into account the car and all its issues, the driver and his issues, weather and all the rest.
Any decent engine shop has a dyno. It’s not because they are stupid. It’s because the recognize the value of the tool.
Its interesting to see people who live and die by cylinder head flow numbers (which most likely uses the same correction scheme as the dyno does) absolutely claim the dyno numbers don’t mean a thing.
It couldn’t be the car is in need to a serious tune up that the dyno numbers don’t match. Or it could be that the corrected numbers are so far away from the weather at the track that it skews the numbers. That’s not the fault of the dyno. That is an end user issue.
Ive seen correction numbers 200-250 hp higher than the measured numbers a few times. It happens.
There are companies out there that have weather stations and software that allows you to enter the correction factor from the dyno numbers and it measures the current weather and then it gives you the actual hp at that weather.
The dyno is an invaluable tool. You can learn much more, much faster than going to the track. Last time I rented the track for one day it was almost the same money as a day on the dyno.
"Can correct to several different standards". No kiddin. That was my point. A lot of times people get dyno numbers without that information. Almost useless then. We're on the same page though. I agree the dyno is a fantastic tool I simply prefer the strip. You can see fast cars and titties at the strip. You cannot see that in the dyno room.
Jeebuzz, I've never seen so many words say so little, while this thread starts to auger-in....
1) A dyno is more CONSISTANT, NOT more accurate.
2) The strip is more REALISTIC, NOT more accurate
DV had a 3rd party dyno an engine He'd finished while His were tied up, the results were amazing, and He knew they shouldn't be. He called the guy out for using the compensation to generate happy numbers, read; happy customers. You'd better know the dyno guy & be able to trust 'em if You want "accurate" numbers
The track is gonna give You real results,..for that day, baro-temps-humidity-tailwind/headwind-good lane/bad lane...a single cheesburger from the $1 menu vs a triple baconator, where'd You fill-up this time,.. if You actually know Your car You know, & what You've got now vs B4, if You're serious/a Pro You've got weather station/data/correction happy ****, I'm sure there's an "app for that" nowadays.
Most guys & gals ain't none of those things, they really aren't going to get any accuracy, but they can get the engine broken-in, timing & mixture dialed in, & maybe detect issues before they run over a crank or such..that's the best argument for a dyno, and We've had a Member here that got kinda boned all-around to that end as well.
Now put the wheels back on this thread damnit!!!!
1) A dyno is more CONSISTANT, NOT more accurate.
2) The strip is more REALISTIC, NOT more accurate
DV had a 3rd party dyno an engine He'd finished while His were tied up, the results were amazing, and He knew they shouldn't be. He called the guy out for using the compensation to generate happy numbers, read; happy customers. You'd better know the dyno guy & be able to trust 'em if You want "accurate" numbers
The track is gonna give You real results,..for that day, baro-temps-humidity-tailwind/headwind-good lane/bad lane...a single cheesburger from the $1 menu vs a triple baconator, where'd You fill-up this time,.. if You actually know Your car You know, & what You've got now vs B4, if You're serious/a Pro You've got weather station/data/correction happy ****, I'm sure there's an "app for that" nowadays.
Most guys & gals ain't none of those things, they really aren't going to get any accuracy, but they can get the engine broken-in, timing & mixture dialed in, & maybe detect issues before they run over a crank or such..that's the best argument for a dyno, and We've had a Member here that got kinda boned all-around to that end as well.
Now put the wheels back on this thread damnit!!!!
Swinger 340
Well-Known Member
HP may be a factor, as in the equipment added to the motor to extract.
Swinger 340
Well-Known Member
The dyno is a good tool. It will tell you, about where you are at, but the track will tell you where you are at. A simple explanation.
Newbomb Turk
Well-Known Member
This makes no sense.
Newbomb Turk
Well-Known Member
By their very nature, the dyno is more accurate than a track. Every single time. I explained that above.
Apparently anything more than two sentences is considered too wordy.
Seemed to make perfect sense to me.
Honestly I think this part of the thread is getting silly between the use of a track or dyno.
Enjoy the day people!
Dartswinger70
Well-Known Member
AS long as it lays rubber like the car at the end of this video its all good...for those that lack a sense of humour fast forward to 2:17...
agree, the chassis needs to be tuned to the horsepower to run THE numbers the engine is capable of producing.
You wasted 3 paragraphs to assert that You believe dyno numbers. Who's dyno? Which dyno?
You don't comprehend the difference between consistent & accurate? Dialing the mill in, knowing the torque curve, all fine. Absolute numbers?......You can take that to 5 different dynos & get 5 different "accurate" numbers....so whatever Dude...
To me it seem like some track guys have dyno trust issues, guess cause a dyno operators can fudge the results bit, and I guess from a bunch of braggarts that say they dyno X hp but come up far short of that on the track, can't really fudge an et/mph. But is ridiculous to trash dynos as an unreliable tool, I imagine anyone serious about their engine doesn't wants fake unreliable dyno results.
Newbomb Turk
Well-Known Member
Not my experience at all. Yours may differ, but i doubt you’ve ever spent a day on the dyno in your life.
Find a dyno with a good operator who isn’t concerned with getting a big number and if your car is right it will run what the OBSERVED numbers are IF they match the weather on the day you are testing the car.
Evidently you don’t get the difference between observed and corrected numbers.
That’s was the argument back on island and everybody would shoot holes in your choice. Be right or wrong, you were always the sucker. The one exception was the “HeartBreaker” so named because it always under valued the engine’s performance a lot.
Newbomb Turk
Well-Known Member
I just answered this. You have to look at the correction factor at the time of the dyno pull. If you are correcting 6% on a 500 hp engine that means the observed number is 470 hp. So long as the day you are testing the car with weather that matches the 6% correction factor then the car will run what the dyno says it made.
Some guys just don’t want to learn, or to know or even to understand. Once you get your head around the correction factor and WHY it is used then dyno numbers make all the sense in the world.
Sorry for the long post. The surface readers will skip over this one because it’s too long.
I can’t figure out who would want BS results. Car flippers?
LMAO
Every last dyno operator has have spoken with makes these claims
(The I don’t give a ****, my **** is right and I don’t give a ruck what you think because it’s accurate. Your engine makes what it makes on my dyno and that’s all there is to it.)
and trashes the other guys dyno, worth, work, accuracy etc…
Newbomb Turk
Well-Known Member
You from NY? If so, how close is the weather (at any time of the year) to 60 degrees, a 29.92 barometer and 0 humidity? NY is a decent sized state, with a coast line so I’m sure somewhere you might get weather like that but I suspect in most places you don’t.
You use the corrected numbers for that dyno on that day with that weather.
You use the observed numbers for that day and that weather if it matches the weather at the track. If you can’t get the numbers to match, there are weather stations that take the corrected numbers with the correction factor, measure the weather and the correct the power number to reflect current weather.
If you aren’t willing to do that then your Dyno experience will probably be disappointing.
Newbomb Turk
Well-Known Member
See post 197. I can’t explain it any better than that. How often do you see guys comparing measured numbers to measured numbers? You don’t, because the weather makes those numbers unusable for that kind of measurement.
Like I said, virtually every flow bench software program uses the exact same correction protocol and very few people question that.
I do know that the way some benches measure airflow can make then read slightly differently than the way some other benches measure air flow. But it’s not more than 1 or maybe 2% and 2% would be on the high side.
Was, past tense, I have escaped the (not so) great (evil) Empire State!
I can meet two out of 3! LOL. There is never a 0% humidity factor.
I don’t think that humidity factory is possible. I was an Islander.
Long Island.
When I walk into a dyno room, no matter how built it and what it is thought it can do, the results are never met except by the operators and there reasonably accurate unless they have worked with the builder before where they call the numbers.
Naaaaa I’ll skip rereading it, reasons below.
95% of people I cross measure numbers like there measuring dick size. Yep! I’m walking away…. IDGAF
The way the dyno guys talk, well… it’s ducking unbelievable really, another group I don’t pay attention to very hard or if at all. There to busy chest pounding there **** is the best and the other guy doesn’t have a F’in Clue to what they’re doing.
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