Dynamometer Types and Number Validity

Charles said:
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NWroten said:
How often and/or what is used to calibrate a dyno? I've seen CAT scales that weigh big trucks calibrated for accuracy, but never heard of anyone doing this for engine or chassis dynos. Thanks, love the site, Neil
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The scale need to be correct to avoid folks from getting big fines when pulled over.

A dyno at your local shop has ZERO regulations.

Now a dyno at a government certified testing facility of some sort, something that GM uses to post hp results of their cars, I would assume is checked and validated ..
 
JasonCzerak said:
That's all good, assuming your not spinning the charger outa it's map! :)

Well, I'm using logic here based on what I know so far about turbos, this is where my turbo knownled starts to get fuzzy.

However, If you are already at the top of said chargers efficiently for shaft RPM at sea level to make ends meat, it's not going to do very good at 14,000 feet, correct?

Or does all that efficiently and shaft rpm stuff change linearly with altitude and other weather conditions.
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If you're overspinning the charger at Sea Level and you care about making power at higher elevations or turbocharger life, then you should learn to properly size a charger for an application before you tackle anything else.

I realize that plenty of people don't care if they are spinning the wee out of the charger(s) for a given power output. Especially those constrained by rules on charger size. For anyone else, you should have picked a larger unit if it falls on it's face anytime you leave the beach.

(Larger compressor)
 
JasonCzerak said:
The scale need to be correct to avoid folks from getting big fines when pulled over.

A dyno at your local shop has ZERO regulations.

Now a dyno at a government certified testing facility of some sort, something that GM uses to post hp results of their cars, I would assume is checked and validated ..
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Yet, ironically, it is precisely GM and the like that post the most inflated dyno numbers of all. Oh, unless you only cared what the engine made without a belt, any accessories, a trans, or anything else to make it actually capable of doing anything useful, or even running on it's own for that matter.

I'm glad you brought that up, because OEM power ratings are at the very top of the useless dyno garbage pile.
 
Charles said:
If you're overspinning the charger at Sea Level and you care about making power at higher elevations or turbocharger life, then you should learn to properly size a charger for an application before you tackle anything else.

I realize that plenty of people don't care if they are spinning the wee out of the charger(s) for a given power output. Especially those constrained by rules on charger size. For anyone else, you should have picked a larger unit if it falls on it's face anytime you leave the beach.
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ha! thanks for validating my point!

you are correct about correct sizing. i'll say on my beach in Minneapolis. no need size it for death valley. LOL

it's tough to take someones word for "streetable". to size a turbo for a DD
 
JasonCzerak said:
ha! thanks for validating my point!

you are correct about correct sizing. i'll say on my beach in Minneapolis. no need size it for death valley. LOL

it's tough to take someones word for "streetable". to size a turbo for a DD
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My truck is very street friendly. I drive it every single day (it is my sole daily driver), and I still work it everyday hauling lumber, steel and equipment trailers.

Yet at ~1100' elevation it had zero problem making between 90 and 100lbs of boost on the dyno with a wastegate duty cycle of 28%... I was actually shooting for 70 to 80lbs and just didn't yank enough wastegate out to control it up top. I have no doubt it would make over 100lbs anywhere in the continental United States if you wanted. (Although I couldn't guarantee the engine would stay under it)

Sizing a charger setup for DD friendliness that will make the power in Death Valley all the way to Denver Colorado shouldn't be mission impossible.

:1tooth:
 
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Charles said:
Yet, ironically, it is precisely GM and the like that post the most inflated dyno numbers of all. Oh, unless you only cared what the engine made without a belt, any accessories, a trans, or anything else to make it actually capable of doing anything useful, or even running on it's own for that matter.

I'm glad you brought that up, because OEM power ratings are at the very top of the useless dyno garbage pile.
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I had a 1972 Buick Electra 225 that I was going to pull the 260 hp 455 out of, when I noticed it had a sticker that said "This engine is rated at the back of the transmission with all accessories including the a/c on." I was like HUH? What the heck does that number tell me?
 
The world knows that God only ordained one dyno and it belongs to the Apostle Dunbar *bdh*:bow:
 
Charles said:
My truck is very street friendly. I drive it every single day (it is my sole daily driver), and I still work it everyday hauling lumber, steel and equipment trailers.

Yet at ~1100' elevation it had zero problem making between 90 and 100lbs of boost on the dyno with a wastegate duty cycle of 28%... I was actually shooting for 70 to 80lbs and just didn't yank enough wastegate out to control it up top. I have no doubt it would make over 100lbs anywhere in the continental United States if you wanted. (Although I couldn't guarantee the engine would stay under it)

Sizing a charger setup for DD friendliness that will make the power in Death Valley all the way to Denver Colorado shouldn't be mission impossible.

:1tooth:
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It's kinda funny tho. you base you entire argument around a turbo charged engine, and only correctly sized turbos at that, to validate the accuracy of corrected vs un-corrected numbers and a typical dyno jet. The majority of super charged and N/A motors would totally invalidate all your points. You can't rule out other types of motor here if you want to ensure your measuring tool is accurate.
 
Gm's dyno numbers are right on if not conservative in my experience with their gas motor vehicles. Ford, well, they are all over the place.
 
JasonCzerak said:
It's kinda funny tho. you base you entire argument around a turbo charged engine, and only correctly sized turbos at that, to validate the accuracy of corrected vs un-corrected numbers and a typical dyno jet. The majority of super charged and N/A motors would totally invalidate all your points. You can't rule out other types of motor here if you want to ensure your measuring tool is accurate.
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Um..... we drive turbo diesels, this is a diesel site. My bad for assuming we would also be talking about them in this discussion.

Oh wait, I'm the OP. I can tell you for sure, this thread is about turbo diesels, not n/a gassers, electric motors, or solar cells.



Your logic there is no different than telling me my micrometer is no good, and my points about it's accuracy when measuring a pipe of approximately 3" DIA are wrong, because the same accuracy could not be expected if we were to try and use the same mic to then measure the diameter of a pipe of the same dimensions but one made from rubber. And we're going to take the measurements at 0 degrees F and then at 200 degrees F. And you would childishly point to the vast disparity in measurements as proof that correction for temperature and other environmental factors MUST be taken into account....

Only in this analogy, the turbodiesel would be akin to a steel pipe, and the n/a gasser the rubber hose. Sure the steel pipe will expand and contract in the extreme cases of 0 degrees and 200 degrees. But for people with a firm grasp on reality, it's just a 3" freakin pipe. Not 3" @ 70 degrees F.....

Were talking about turbo diesels here. Not rubber hoses.

But thanks anyway.
 
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Charles said:
Um..... we drive turbo diesels, this is a diesel site. My bad for assuming we would also be talking about them in this discussion.

Oh wait, I'm the OP. I can tell you for sure, this thread is about turbo diesels, not n/a gassers, electric motors, or solar cells.
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There are non-turbo ford diesels ya know....

This specific site is "Competition diesel". There is no "turbo" in the name. If this was TDR, then you may have a point; but in this case you don't.

Then again, when I think about it, why would a ford have a diesel that can even compete in any competition. So we couldn't be talking about fords on this site.. There for the rest have turbo's, I think you may win this argument after all.
 
JasonCzerak said:
There are non-turbo ford diesels ya know....

This specific site is "Competition diesel". There is no "turbo" in the name. If this was TDR, then you may have a point; but in this case you don't.

Then again, when I think about it, why would a ford have a diesel that can even compete in any competition. So we couldn't be talking about fords on this site.. There for the rest have turbo's, I think you may win this argument after all.
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so you're telling guy who started the thread that this thread is not about what he started it about.... Now that's smart.

And your comments regarding Fords... You're an ignorant a-hole... Crawl out of your little freakin hole and look at what Ford are accomplishing now!
 
:pop: Standing by for A-1 poo flinging now
 
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I liked the Super Flow dyno that was over in Fortuna. Drive in the room, close the door and the big fans take care of the smoke. When that thing applied the load, you better be ready.
 
StrokerDude said:
so you're telling guy who started the thread that this thread is not about what he started it about.... Now that's smart.

And your comments regarding Fords... You're an ignorant a-hole... Crawl out of your little freakin hole and look at what Ford are accomplishing now!
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Dude, it's a joke about fords. Been around this site much? Since when has everything on this site been serious when poking fun at other brands? BTW, real professional language there, I'll be sure to respect everything that come from your mouth from here on out.

The thread starter never specified in this original post, this had to be diesel. it was assumed based on this site? sure I suppose. Then he goes one to assume all diesles have turbos, I pointed out his flaw and I'm the bad one? I also pointed out the fact that if you spin a turbo to the edge of his map, his points are also then flawed, still some how I'm the bad one here.

There is a reason for corrected and un-corrected numbers.

Funny. John @ Floor it came up to Minneapolis with his load dyno last summer. 80 degree day out. No big fan flowing air though the intercooler either. It's a damn shame I made some changes between then and the normal dynojet I have a long record with. I dynoed 578hp. A few months later I managed to get to the race track. my ET can't count due to manual trans and slow launch with slipping clutch. however I managed 2 106mph runs. At my weight of 7220 (cat scale certified). the track day was similar, 80 degrees sunny. Not sure of the altitude differences, i could look that up tho. However the compd HP calculator comes up with 583hp. Holly crap. how did that happen? I'd say that's rather accurate. Not sure if that's corrected or not on John's dyno. Can't seem to recall right now. Anyone know what john spits out for correction factor?


The year prior, i ran the 1/4 at 100mph. That's 490hp from the CompD calculator. i dynoed 512 on this same dynojet with in a month or so. It's been to long to recall the weather conditions. the dynojet is corrected 512, I can find that sheet and do the un-corrected math.
 
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