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2020 F8 Scat Pack 392 6 Speed Stick
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Discussion Starter · #1 ·
Hi,

Been doing a bunch of reading upon how the new Hellcat CAI got the 10hp so why are the HP numbers the same on all 3 versions of the Scat Pack as both the T/A and Shaker are a CAI design?

Regards,
Jim
 

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CAI's typically don't add hp, unless combined with other performance parts. I did the hellcat lower airbox mod to my scat. Guess how many hp it added? 0. The factory airboxes are pretty great for factory. Only reason I did the mod was to lower IAT.
 

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The Hellcat (with the new hood design) can flow more air into the engine over the '15 - '18 closed airbox with the Air Catcher port (the latter item mainly to help keep IAT temperature lower)

the dual scoop Hellcat hood allows more air volume plus high flow the Hellcat specific air filter

Conversely, the Hellcat Redeye is detuned to 797 vs. 808 (same engine / supercharger as Demon) due to the smaller hood scoop area.

Demon is designed around 1/4 mi track, and won't hit high speeds (and speed limits of 168mph for drag radials) and allowed the large single hood scoop. The lift at speeds > 170 mph wasn't an issue with that model

For the Redeye, the Demon scoop would have created front end lift and loss of stability at high speeds (Hellcat and Redeye aren't governed), so the compromise was a hood design with more airflow over the earlier 'Cat design but avoiding the front end lift at higher speeds.

The Scat Pack Variants with CAI (T/A 392, Shaker) may not have significantly higher flow numbers that warranted re-rating the power output of the 392.

Similarly would be the T/A 5.7 and R/T Shaker (5.7) over the standard 5.7 airbox / air filter setup.
 

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2020 F8 Scat Pack 392 6 Speed Stick
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Discussion Starter · #4 ·
Hi again,

So if they decide in future years to offer the new dual scoop hood/CAI, then would the 392 see different power ratings or is it really not effect a non-SC engine as much, only helping intake air temps?

Just curious, thanks for the input.

Regards,
Jim
 

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Hi again,

So if they decide in future years to offer the new dual scoop hood/CAI, then would the 392 see different power ratings or is it really not effect a non-SC engine as much, only helping intake air temps?

Just curious, thanks for the input.

Regards,
Jim
Probably not. The stock factory air intake is capable of meeting the demand of a 6.4. Making more air available is irrelevant on NA cars that already have their supply needs met.
 

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'16 A8 Scat Pack
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CAI's typically don't add hp, unless combined with other performance parts. I did the hellcat lower airbox mod to my scat. Guess how many hp it added? 0. The factory airboxes are pretty great for factory. Only reason I did the mod was to lower IAT.
Same here. Lowered the IAT's, with a little better throttle response when the Summer heat hits.

Mine doesn't feel like it has any more HP or torque with the OEM HC box/tube and a OEM HC filter element.
 

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2015 RT Shaker (STP/A8/FORGED/NAPPA/NO SUNROOF)
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Yes, it's great for lowering IAT's.
 

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2016 R/T Scat Pack
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I'll be testing this out soon. A buddy bought his own dyno. We are going to do pulls with a fan in front of the HC tube open and with it blocked off.
 

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2020 F8 Scat Pack 392 6 Speed Stick
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Discussion Starter · #10 ·
I'll be testing this out soon. A buddy bought his own dyno. We are going to do pulls with a fan in front of the HC tube open and with it blocked off.
Hi

Be interesting to see if any real difference, guessing not much, but definitely post your findings

Regards,
Jim
 
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You had me at "buddy bought his own dyno..."

A Guy
 

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2011 gwe srt
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10hp gains are more sales gimmicks then proven dyno gains. Dodge took the scat pack and put an electric power steering motor on it and claims it freed up 15 hp. NO WAY. Think about that. You really think it took the equivelent of the motor needed for a 10k generator to spin your alternator putting out a max of 200 amps?? That 10k unit puts out 10,000 watts your 200amp alternator= 2200 watts Then factor in the additional draw off that alternator to power the motor and the fact it needed to be a bigger unit to make that power. Most likely chevs camaro hp rating was getting a bit to close to the challengers so they slapped a new number on it. Just look at how many of us get sucked into things like cai and cat backs and even in some cases headers that add nothing or AT BEST give half what the salesman says they will.
 

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for the '15+ 392 there are also tweaks to the shorty headers and the diameter of the exhaust system increased over the earlier years as well as the resonators are a straight - through design vs. the baffled style from '14 and earlier

that in addition to going from a belt driven p/s system to electric p/s

there was tuning to maximize the effects of the exhaust system being more efficient
 
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for the '15+ 392 there are also tweaks to the shorty headers and the diameter of the exhaust system increased over the earlier years as well as the resonators are a straight - through design vs. the baffled style from '14 and earlier

that in addition to going from a belt driven p/s system to electric p/s

there was tuning to maximize the effects of the exhaust system being more efficient
first time i heard that. I thought all 392s had 3 inch exhaust. Mine came with a cat back so i cant say for sure. First time ive heard the headers were different. Ive seen many posts about 5.7 guys wanting to go with 6.4 shortys but have never once seen that a certain year was better then another. Even so i cant see one shorty header giving more then a hp or two over a different shorty header. gains from shortys aren't that great to begin with so i cant see a whole lot of improvement there. So in other words the newer cat backs show less gains with an aftermarket cat back then the older ones with there more restrictive exhaust. I cant imagine one shorty header adding more the one or two hp over another shorty header. Just not much to work with there. Id like to see wheel dyno numbers between them. My guess is any two newer ones would vary as much as comparing my 11 to a 20.

heres a you tube video of my exact car. Not one like it but my car before and after a hearthrob cat back. That exhaust is not on the car anymore because it had terrible drone and was replaced by a different cat (zoomer) It put down 424 which id say is pretty darned good for even a factory 475 hp rating. Car was box stock.
 

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2018 Scat Pack SHAKER in Plum Crazy- GONE :-(
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10hp gains are more sales gimmicks then proven dyno gains. Dodge took the scat pack and put an electric power steering motor on it and claims it freed up 15 hp. NO WAY. Think about that. You really think it took the equivelent of the motor needed for a 10k generator to spin your alternator putting out a max of 200 amps?? That 10k unit puts out 10,000 watts your 200amp alternator= 2200 watts Then factor in the additional draw off that alternator to power the motor and the fact it needed to be a bigger unit to make that power. Most likely chevs camaro hp rating was getting a bit to close to the challengers so they slapped a new number on it. Just look at how many of us get sucked into things like cai and cat backs and even in some cases headers that add nothing or AT BEST give half what the salesman says they will.
As for the power steering, yeah I fully believe it. Spin that hydraulic pump at a few thousand RPM when it is designed for maximum results at idle and that is a huge drain. And Alternators only draw as much as needed, they spin free with no electrical load. So the result is no HP draw from steering unless you are, well, steering. And before with hydraulic, you had maximum draw when revving the highest, when you weren't steering.
 

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I'll be testing this out soon. A buddy bought his own dyno. We are going to do pulls with a fan in front of the HC tube open and with it blocked off.
“The hole in the headlight was actually put there because we required a certain amount of pressure drop across the intake system to generate 707 hp,” Cowland told AE. “Certainly if we took that away and we increased that pressure drop across the intake system, we would lose horsepower. We’ve never measured it by blocking it off or taking it away, but it could well be seven horsepower.” A second inlet point is located underneath the airbox.

Your testing could finally tell us how much it actually helps!

 
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^^^This

A Guy
 
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