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Q: on a boosted Application in a G3 #2931523
06/09/21 06:58 AM
06/09/21 06:58 AM
Joined: May 2004
Posts: 12,379
Taxes & Virus's R-US, NY
Dragula Offline OP
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Dragula  Offline OP
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Taxes & Virus's R-US, NY
What is the optimal cubes? Is it better to have the biggest stroke, or go with a certain ratio?


'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: Q: on a boosted Application in a G3 [Re: Dragula] #2931559
06/09/21 10:17 AM
06/09/21 10:17 AM
Joined: Nov 2003
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NW Indiana
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fbs63 Offline
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I Personally think it depends on what type of forced induction your using. Roots or screw superchargers make instant torque. Turbos and Prochargers depend on rpm to make more boost so extra torque in the beginning of a pass does not hurt.

Re: Q: on a boosted Application in a G3 [Re: Dragula] #2932694
06/13/21 02:40 AM
06/13/21 02:40 AM
Joined: Feb 2021
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Souderton
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Taylor Offline
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Originally Posted by Dragula
What is the optimal cubes? Is it better to have the biggest stroke, or go with a certain ratio?



Just my observations over the last few years , people who build 426 Supercharged CI G3s don't seem to run any faster then those who build 392-411s , and in theory if your making 1500Hp with 35X-37xCI you should make 1800 with 420-430ci , granted
I know it's not a direct correlation HP/Ci/Airflow , but you can't tell me that Extra 50-75Ci creates 300hp worth of friction at that level of a build.
Looking at what Rob Goss has done and what the blown FS cars run with the 2.9L Whipple I think 355-400CI is the optimal CI, with 411 being the "big" end for the G3 platform ...The FS cars are 354/355Ci running 7.50s at 3500 lbs race weight , Rob's Billet G3 is "400"ish I don't think you can get enough Flow out of the G3 heads to support 426-440ci supercharged certainly can't get enough cam lift to support big HP#s with the off the self heads and shaft rockers, Thikit(sp) and individual rocker set ups will get you up in to the .700/800s lift and 400/430CFM .
My TFX hemi is 503ci (504 if you round up) with a F3x140 Procharger uses every bit of that low 500CFm at .9XX lift to make 2750hp. which is 5.46HP/ci vs the FS 4.20(ish)HP/ci
The FS cars run 4.09 bore with 3.40 stroke with 6.30 rods , not sure what Goss's combo is, the older 5.7 stroker 392/394 CI set up, 3.917 - 3.937 x 4.05 makes good power if you can keep the block from breaking, and personally I think it has to do more with the hockey puck height piston than the block and 1.4X rod ratio.....with 6.10 rods your looking at 1.125 pin height and 6.125 rods you are looking at 1.09 pin heights , the FS cars run a 1.27/1.28 pin height. the Hellcat/Demon/Redeye run a 1.28 hence the issue with the 9.24-9.28 deck height of the G3 blocks limits stroke and the 4.46 Bore spacing limits bore to 4.09/4.10 and still have .200 cylinder wall. anything less and you're giving up HP potential. My uncle had a 362ci 5.7 with a Kenne Bell and a Big mouth TB lay down 1150hp thru a TH400 in a 2008 Charger about 3 weeks back over at a friend of his dyno shop,
I've seen a few of those 394ish based 5.7s around the East cost running 7.30s/180MPH which works out to 3.50 HP/ci , ones is a 86 Fox Body Mustang @ 2750 the other one is a 84/85Daytona RWD conversion ....I know one of the guys my uncle bult a 397 with a 4.5L whipple for is a 73/74 satellite that was running low 9s, I know that car was close to 4klbs and they broke a few early 5.7 blocks. the 426CI 6.1 that was in the car never faster then the 397 combo , it ran about the same .,the best run was .1 slower next engine for that pig most of it was bought from Schumacher, block ,heads Plan is to build a 360/370ci short rod with 1.3X Pin height and 6.2something rods.

Last edited by Taylor; 06/13/21 02:54 AM.

04 Ram 4x2 11.66@ 122 4750LBS ...phat pig Moves for fully loaded truck with NA 345ci Hemi
2020 1320 Challenger....stock daily driver.
Re: Q: on a boosted Application in a G3 [Re: Taylor] #2933941
06/16/21 01:56 PM
06/16/21 01:56 PM
Joined: Nov 2006
Posts: 2,252
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furious70 Offline
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stepping back from those all out engines - practically speaking staying with 5.7 displacement allows you to use economical and easier to package T4/4"dp midframe single turbos that can support ~700hp with nothing more than maybe gapping the rings on an Eagle engine. Anything larger and you'll need twin turbos or step up to a T6/5" dp large frame single turbo. The size is substantially different - I used an old dump truck tv7x series T6 to mock up in my Coronet. The T4 VSturbo I bought is several inches smaller in length and diameter.


70 Sport Fury
68 Charger
69 Coronet
72 RR
Re: Q: on a boosted Application in a G3 [Re: furious70] #2933997
06/16/21 05:03 PM
06/16/21 05:03 PM
Joined: Feb 2021
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Taylor Offline
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Originally Posted by furious70
stepping back from those all out engines - practically speaking staying with 5.7 displacement allows you to use economical and easier to package T4/4"dp midframe single turbos that can support ~700hp with nothing more than maybe gapping the rings on an Eagle engine. Anything larger and you'll need twin turbos or step up to a T6/5" dp large frame single turbo. The size is substantially different - I used an old dump truck tv7x series T6 to mock up in my Coronet. The T4 VSturbo I bought is several inches smaller in length and diameter.



I agree , it seems today the practical street/strip person is in the shadows of the "outlaw wanna-be Stirp/street person.
not sure who the guy is, but there's one that comes to mind with a stock Eagle short block, it's in an older Jeep wagoner/Cherokee 70's-86 body style. A well thought out Eagle long block will go mid 650s to 800s with a good tune and rings gaps opened, the pre Eagle for get it, 600-750ish is tops , if you don't squeeze the top of the piston off you'll break the edges and swallow cast pistons fragments. only real issue is with the Eagle 5.7 is the walls are thin compared to the early 03=08 5.7. not that it would matter under say 800 hp

I think it's too easy for people today to step over a well built 345-370CI boosted 5.7 and go right for the 390CI+ builds, fundamentally the cost of the short block is the same......... bigger isn't always better,

Last edited by Taylor; 06/16/21 05:04 PM.

04 Ram 4x2 11.66@ 122 4750LBS ...phat pig Moves for fully loaded truck with NA 345ci Hemi
2020 1320 Challenger....stock daily driver.






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