Dyno testing

ir3333

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Watched a Dulcich / Friedberger video last night. They ran a warm 350 on the dyno with no fan and then added a fan. Total hp dropped 30 hp with a fan. That's quite a bit.
What would the total losses be if you add air cleaner, alternator, fuel pump and full exhaust?
 

33IMP

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EM has done other parasitic loss videos.
Alternator: not much.
Fuel pump: not measurable.
Air cleaner: depends a LOT on which filter housing and element. Test of 19 aircleaners showed everything from 100 hp loss, to 5 hp gain (velocity stack actually made power) The great majority of quality a/c setups, horsepower loss on a 700hp engine was negligible. Flow DOWN into the carb was better than airflow across it.
Water pump: less than a bad fan.
Exhaust.: again, depends a LOT on motor power, size, mufflers, pipes et all.
Just did a test of a 598 Chevy for cutouts. The mufflered exhaust they used robbed the motor of 50 hp, and more than 80 lbs torque. (Imo, they did it on purpose to make the cutouts look good)
Yet they did a test of 4" race mufflers on frieburgers blown 1100 hp 555 cu in big block, and they cost less than ten hp.
In my humble opinion, the wrong fan will cost more hp than the right exhaust.
 
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MOPAROFFICIAL

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Total accessories claimed around 75 hp
at 6000rpm last I heard. Varies with motor and accessory equip/design.
They didn't switch to electric fans in production factory cars for nothing.
Fuel milage and power go up.
 

ir3333

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so it would be reasonable for an engine to dyno 390hp but in a driving car it might be around 340 at the crank?
 

TT5.9mag

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Test of 19 aircleaners showed everything from 100 hp loss, to 5 hp gain (velocity stack actually made power)
The famous salad bowl. I was at Westech two weeks ago and my girlfriend saw the salad bowl and couldn’t believe it. She was star stuck over the dumb thing.
14ADCC21-0E23-468F-9554-7A044C6B6E7A.png
 

a-bodyguy

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Crazy as it sounds in 1982 i ran no fan on my street driven 70 duster guessing 11 to 1 had 180ish cranking comp general kinetics hft 300r 507 lift 243@50 108 lsa rhoads lfters torker 340 650 dp nitrous it all came about i blew water a pump killed the radiator it was a clutch fan. Fixed the radiator new pump tried no fan it only started to get hot after 10 min of idling if i was stuck in traffic id shut it off the car was possessed i swear. I did run it with no front bumper the chebby folks could not believe it did not over heat it also had 3.23s 727 with L60 14s 26.99 tall it trapped 108 in 2nd gear something else the chebby guys could not believe . I tried to run no fan on 2 other A bodys both 340 cars they over heated quickly no dice crazy right? yes the temp gauge worked right! ran full timing no pinging good gas back then
 

AJ/FormS

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No. Clutch fan was best, (about 10-15, don't remember exactly) plastic flex cost 25, fixed stock direct drive cost 30.
That's what I thought, old news.
Who would run a 7-blade, all steel, hi-attack angle, factory fan ;
without a clutch?
I run that exact fan on a thermostatic-clutch; and at 3457 pounds my lil street-367 went 93 MPH in the Eighth @900ft elevation. By the math, that is 430 hp. Ima guessing, that fan cost me nothing, even on 3 shifts, accelerating thru 4 ratios and trapping around 6150.... on a 230/237/110 cam.
but if this is right,
and the dyno engine was running a mechanical water-pump; then the pump costs
30 less 10 to 15= about 15-20hp all by itself.
Ya think there is an agenda on that show? I mean more than the obvious?
It's sorta like the anti-flat-Earthers, desperately hanging onto their opinion and ramming it down the innocents. If you watch that show often enough, yur gonna see other trickery. I put them on ignore years ago.
>One of my peeves is only publishing hp results up to the rpm of peak power. Whereas the power may hang on another 400 or 600 or even 800rpm at up to 95% of the peak. Why in the world would you shift at 5400, the peak, if you still have 95% at 5800 or 6200 or even 6600? Rev that beast!
Here is one of my favorites, but from HughesPerf.; Lookit that Power peak, then extrapolate the torque curve another 200 to 400.
My guess is that;
at 6200rpm, she might still be making 355ftlbs=419hp=96% of peak.
by 6400 the Torque might be down to say 340= 415hp = 94.8%
Ima goin' to shift that at 6800 and watch the hood jump, cuz when it drops in at 5000, that is max torque right there.
Badaboom!
land_dyno.jpg
 

33IMP

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Funny thing, I run the exact plastic flex fan they lost 25 hp with. I use a manually controlled pusher electric as well, primarily for cool down between rounds. I use the plastic flex for one reason, it keeps 500hp cool. It's a primarily raced/occasionally street driven car, and cool is more important to me than 25 hp.
I could probably use a much bigger puller fan, an electric water pump, and drop a hundred pounds of exhaust, and pick up three tenths. Why? It's a bracket car, three tenths quicker means dick, I'd rather drive at 170° than 215.
I use the electric fans and water pumps on the race car. Really helps cool down between rounds.
 

92b

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Watched a Dulcich / Friedberger video last night. They ran a warm 350 on the dyno with no fan and then added a fan. Total hp dropped 30 hp with a fan. That's quite a bit.
What would the total losses be if you add air cleaner, alternator, fuel pump and full exhaust?
Way too many variables to put a number on that.

Air cleaner: Depends on how carb is affected by using the air cleaner. We seldom test with out an air cleaner because nearly all applications we dyno run with an air cleaner. Different air cleaner setups (Filter base and lid) can make significant swings in air fuel ratio and power. It’s best if you plan on using an air cleaner to bring to the dyno what you plan on using. If you are open to different options then bring those also. We have seen both gains and losses going from air cleaner to air cleaner to no air cleaner.
Alternator: We did a little testing on a 602 crate motor with and without alternator. This was with a fully charged battery and a small alternator. Alternator manufacturer claimed big power with increased voltage to the ignition. I predicted it would loose a little power with the alternator. Result was less than 1 hp difference (within the margin of repeatability). 1. alternator no belt. 2. alternator with belt but wire unhooked. 3. alternator with belt and wire hooked up. Things that could change the results. The battery was fully charged and only the ignition was drawing on the battery so the alternator is not doing any work. Small alternator had little rotating mass so inertia play no significant part. With less than 6200 rpm and a good combustion chamber design and a properly working hei distributor no benefit is realized from a higher voltage. Change any of that and the results may be different.
Fuel pump: Sometimes we will initially run the motor with the dyno electric pump then switch to the mechanical pump that will be on the engine to make sure all is working properly. Can't recall ever seeing a loss in power with a properly working pump.
Full exhaust: That is a can of worms. Short version. Exhaust may or may not change things drastically.
Fans: We have tested a few fans. Generally the more air they move the more power it takes to turn them.
 

92b

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That's what I thought, old news.
Who would run a 7-blade, all steel, hi-attack angle, factory fan ;
without a clutch?
I run that exact fan on a thermostatic-clutch; and at 3457 pounds my lil street-367 went 93 MPH in the Eighth @900ft elevation. By the math, that is 430 hp. Ima guessing, that fan cost me nothing, even on 3 shifts, accelerating thru 4 ratios and trapping around 6150.... on a 230/237/110 cam.
but if this is right,
and the dyno engine was running a mechanical water-pump; then the pump costs
30 less 10 to 15= about 15-20hp all by itself.
Ya think there is an agenda on that show? I mean more than the obvious?
It's sorta like the anti-flat-Earthers, desperately hanging onto their opinion and ramming it down the innocents. If you watch that show often enough, yur gonna see other trickery. I put them on ignore years ago.
>One of my peeves is only publishing hp results up to the rpm of peak power. Whereas the power may hang on another 400 or 600 or even 800rpm at up to 95% of the peak. Why in the world would you shift at 5400, the peak, if you still have 95% at 5800 or 6200 or even 6600? Rev that beast!
Here is one of my favorites, but from HughesPerf.; Lookit that Power peak, then extrapolate the torque curve another 200 to 400.
My guess is that;
at 6200rpm, she might still be making 355ftlbs=419hp=96% of peak.
by 6400 the Torque might be down to say 340= 415hp = 94.8%
Ima goin' to shift that at 6800 and watch the hood jump, cuz when it drops in at 5000, that is max torque right there.
Badaboom!
View attachment 1715989236
Hard to make a comparison with graphs that have the data layed over each other but are on two different scales. I don't know why they do that. The whole purpose of a graph is so you can make a visual comparison. I'm not blaming you AJ I know you didn't make the graph. Sorry for rant.
 

AJ/FormS

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I actually prefer this kind of graph, it reads really nice. The expanded Torque curve amplifies the difference from one rpm to another that relates better to what you are feeling on the gas-pedal. When making comparisons, you just have to be aware of which scale you should be using.
 

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