how much HP, opinions

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Jwithing

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Here's a link to an old thread of mine a few years ago when I went to the dyno. Lots of good conversations about numbers there.

 

seabrook

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No just stock but thanks for the complement. Probably just the angle the pic was taken on. I want the sleeper look and it has been a BLAST. They NEVER see it coming until they see taillights. The stories I can tell and it only has 34k miles on it now. LOL
lol oh yeah sleeper trucks are the best!! your truck is bad ***!!
 

Chas0218

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:birgits_tiredcoffee the fan clutch would explode if you tried to pull 30 horsepower through it. I'd believe it from a 1950s fan mounted straight to the crankshaft...
You have to look at it as drag on the engine, rotational mass, added friction on other components you'll easily free up close to 30hp especially a fan that is engaged. Other perk is longer water pump life
 

kurek

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You have to look at it as drag on the engine, rotational mass, added friction on other components you'll easily free up close to 30hp especially a fan that is engaged. Other perk is longer water pump life

Sure but in this house I like to obey the laws of thermodynamics; for example if you had a restriction on your intake that was "costing" you potential horsepower it would be because you can't burn enough air/fuel to make that potential. Pretty standard stuff, no laws broken, the fuel isn't being burned and the heat isn't being generated.

But if you're burning enough fuel and air to make "X" horsepower and your accessories are eating 30, you need to account for 22kW of heat somewhere. That's either a tornado under the hood of excited air or it's an alternator charging a flat Nissan Leaf or it's a fan clutch that's hotter than the sun...

Those big portable 4-foot diameter industrial air movers use about a ten horsepower engine for reference. :cheers:
 

1dbcoleman

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I have taken my 08 5.7hemi 4x4 mega cab, bored it 30 over stroked the crank 4.050 6.125 rods. 396 cubic inch, Cams, head work pistons and all that cool stuff and then put it on a dyno just like anyone would want to do if they want to talk about hp. 338 to the wheel. Hemi does not make that good of hp with internal changes. If you want hp throw in good arp bolts and stick a turbo or supercharger on it. Way less work. As for the 545rfe. Good luck. You will never stop blowing out overdrive. 4 transmission in 12 months and that using the best stuff available
 

1dbcoleman

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Get rid of the clutch fan. Spot weld the pulley to the hub for security 20210613_184107.jpg
 

Docwagon1776

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I know going with an electric fan over the mechanical will net you 30hp give or take.

Lulz, no. There is no way you are spinning a clutch fan, especially while the truck is in motion and wind is coming through the radiator due to truck moving through the air, fast enough to eat up 30hp. Roughly half that, tops, with the fan at full tilt and the truck sitting still.
 

Wild one

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Get rid of the clutch fan. Spot weld the pulley to the hub for security View attachment 484228
You don't need to spot weld the pulley on. You're the very first guy i've ever heard that's welded the pulley on.Throw that ****** RFE tranny in the garbage and 8 speed swap it.That tranny is costing you power,as those mods should put you at least 400 to the tires.There's something wacked with your build,as most stock 8 speed 5.7's put down damn near as much as you are with a built 396.Who ported the heads and what cam are you running? My cammed/bolt-on 8 speed 5.7 puts down 400rwhp and 415 lb-ft ,and jumps to 500 rwhp and a mind boggling 572 lb-ft at 3200 rpm on just a 100 shot
 

1dbcoleman

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So we spotted it because the last one popped right off the water pump while causing down the interstate.
 

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1dbcoleman

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You all do realize this figure is measured at the crank, out of the truck ,before any parasitic loses. At the wheel it is about 20% less.
It is at least 20% and more if it's 4x4 and bigger tires.
 

1dbcoleman

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You don't need to spot weld the pulley on. You're the very first guy i've ever heard that's welded the pulley on.Throw that ****** RFE tranny in the garbage and 8 speed swap it.That tranny is costing you power,as those mods should put you at least 400 to the tires.There's something wacked with your build,as most stock 8 speed 5.7's put down damn near as much as you are with a built 396.Who ported the heads and what cam are you running? My cammed/bolt-on 8 speed 5.7 puts down 400rwhp and 415 lb-ft ,and jumps to 500 rwhp and a mind boggling 572 lb-ft at 3200 rpm on just a 100 shot
W
This one is liable to get some mixed reactions, but I'm just seeing who's got what for opinions and why... unless someone has done it and checked, then you'd know for sure.
But anyways, I have a 2011 1500 sport 5.7/ 5spd auto that got a set of shorty headers due to replacing the good ol' warped manifolds and broken studs... but it also got a CAI, clutch fan delete / electric fan swap, one of these ( https://www.amazon.com/Performance-Retro-muffler-09-18-Aggressive/dp/B07YQ8C2CZ/ref=sr_1_6?crid=14DW886PZLJJP&keywords=ram+muffler+direct+fit&qid=1642575081&sprefix=ram+muffler+direct+fit,aps,169&sr=8-6 ) and a Superchips tuner 93 octane tune.

They usually list these trucks as being 390hp depending on the site. First question, is that realistic? Second question, whether the 390 is accurate or not what would be a good ballpark estimate of what it might be at given the above?
They are rated at the manufacturer for that HP. As all of you on here already know, the only way to know for sure is to get it on the dyno. And even then depending on who does the dyno test or have different ones do the runs they most always are different. Just make sure to take a lot of what these guys are saying with a grain of salt
 

1dbcoleman

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W

They are rated at the manufacturer for that HP. As all of you on here already know, the only way to know for sure is to get it on the dyno. And even then depending on who does the dyno test or have different ones do the runs they most always are different. Just make sure to take a lot of what these guys are saying with a grain of salt
So far no one on here is talking about having to add any kind of shot to get the horsepower they want. And there is nothing "wack" about my build, it's a bit rude on here to have an attitude about what uou have compared to anyone else on here. It's all OK to have our own opinions.
 

Wild one

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So far no one on here is talking about having to add any kind of shot to get the horsepower they want. And there is nothing "wack" about my build, it's a bit rude on here to have an attitude about what uou have compared to anyone else on here. It's all OK to have our own opinions.
Dyno's are only a tuning tool bud.First mistake you made was to tell everybody they needed to weld the pulley onto the shaft,nobody but you has ever had to do that when removing the clutch fan. 2nd mistake was posting your dyno numbers from a built 396,i'd be embarressed to post those numbers. But when all is said and done,dyno numbers don't mean squat,true test is what's your 396 run in the 1/4.You still haven't answered the question of who's cam are you running,and who ported your heads,as the 2 don't seem to be working very well together in your case.BTW whoever told you the Hemi doesn't respond very well to internal changes,is misleading you big time.They respond to internal changes every bit as good as any other late model engine does.Just because you have a very poor head/cam/compression combo,doesn't mean everybody else will make the same mistakes as you have.
 
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Wild one

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double post
 
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RLJ10X

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I’ve heard numerous times the quarter mile is the true test. Yeah, it’s what the driver and his car can achieve on a particular strip, on a certain day.

But there a lot of variables that go into a drag strip run. What if the guy’s tires or shot? Or his suspension set up is off? Or altitude, humidity, temperature, headwind? Track condition? Horse power, which is just a mathematical formula anyway, is just one of many valuables.

Every fuel pump in the US is calibrated. The same thing could be done with dynos. Could be,but it won’t; because it’s just not that important.

If someone wants to believe his engine has X amount of HP, there’s a pretty good chance that he’s at least reasonably close.
 

Wild one

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I’ve heard numerous times the quarter mile is the true test. Yeah, it’s what the driver and his car can achieve on a particular strip, on a certain day.

But there a lot of variables that go into a drag strip run. What if the guy’s tires or shot? Or his suspension set up is off? Or altitude, humidity, temperature, headwind? Track condition? Horse power, which is just a mathematical formula anyway, is just one of many valuables.

Every fuel pump in the US is calibrated. The same thing could be done with dynos. Could be,but it won’t; because it’s just not that important.

If someone wants to believe his engine has X amount of HP, there’s a pretty good chance that he’s at least reasonably close.
DA (density altitude) correction will get you close,is it perfect"no",but at this point in time,it's about the best we can do,to equalize tracks and timed passes.You're right,it won't compensate for poor tires/suspension/track conditions or a bad driver etc.Alot of the truck records are set by the Texas guys at Houston in the winter,when the DA can be under -1500ft,there's a good chance you'll have a hard time matching their numbers if you're running at tracks where the DA is consistently above 3500+ft,as they have close to a mile advantage in DA
 
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