Gen 3 HEMI Torque upgrades?

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Daemonkey

Daemonkey

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So, a little context. Right now I have a built 360 with a 268 cam that makes 438 lb/ft at 2500 rpms and it peaks at 467 lb/ft at 4500 rpm (to the crank). I was thinking of swapping in either a 6.1L or a 6.4L, my questions is what upgrades can I do to the HEMI to make that amount of low end torque at the crank (even better if it was to the wheels) without having to go with a supercharger.

I've seen dyno videos, posts, and the videos on shopHEMI.com but most of those are supercharged. Is it really that difficult to get that power down low? And yes, I love having that much power down low.
 
Based on that 5.7 cam swap, it makes less torque than my current engine even at peak. No doubt the 6.1L and 6.4L can make more power but, I'm looking for power below 3000 RPMs where I normally drive at. It just seems that most signs point towards supercharge to get the low end torque I'm looking for.
 
Daemonkey said:
Based on that 5.7 cam swap, it makes less torque than my current engine even at peak. No doubt the 6.1L and 6.4L can make more power but, I'm looking for power below 3000 RPMs where I normally drive at. It just seems that most signs point towards supercharge to get the low end torque I'm looking for.
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There is a new SA Design book just published that might help you. It answered lots of questions I had.
"How to Build New Hemi Performance on the Dyno"
It gives horsepower and torque graphs for intakes, heads, cams, blowers, nitrous, etc.
Cartechbooks.com is where I got mine from.
 
If you put a 6.4 car engine with variable intake manifold, you'll have all the low end torque you need. That engine is a beast. Could research and enhance that with the right cam. You could put that intake on a 6.1 also. You don't necessarily need to control the intake with the ECU. There are plenty of guys in the LX / LC world who have put the var. intake on a 5.7 and hooked it up through external electronics timed to engine RPM signal.

Another possibility is to use the 6.4 truck engine. It has variable intake also, but I believe makes even better torque than a car engine. Also, by using the truck engine, you virtually have a Hellcat block and heads, with only minor differences. Do a little research on the torque specs of the car and truck engines to confirm this. Pulling this out of my head right now from prior readings. Don't have the time to research this for you but I believe this will point you in the right direction.
 
only the big gas 6.4 is the same block as the hellcat. the only difference is the hellcat block is orange and the truck block is black.
you can buy a new bge block for 1295ish as i did. buy a stroker kid to make it either 411 or 422 cubes. custom cam amd vvt locked out will be over 500ft lbs and 500hp. witb 20mpg plausable depending on cam.
also the 6.4 heads can be bough new but with cast valves for 1500 a set no.core charges. is what i bought. same as hellcat there as well besides valve material and intake bolt pattern is same as 6.1/5.7/6.4. out flow the apchies to boot by 10cfm across the board.
 
turbofreek said:
only the big gas 6.4 is the same block as the hellcat. the only difference is the hellcat block is orange and the truck block is black.
you can buy a new bge block for 1295ish as i did. buy a stroker kid to make it either 411 or 422 cubes. custom cam amd vvt locked out will be over 500ft lbs and 500hp. witb 20mpg plausable depending on cam.
also the 6.4 heads can be bough new but with cast valves for 1500 a set no.core charges. is what i bought. same as hellcat there as well besides valve material and intake bolt pattern is same as 6.1/5.7/6.4. out flow the apchies to boot by 10cfm across the board.
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I would love to see a detailed thread of this built. Hell some of us barely know what a 6.4 IS
 
well mine is a turbo application. so i wont get any dyno numbers without the turbos on it. but i have a build thread
 
oh and those prices are what i paid for my bge/hellcat stuff. any questions id be glad to answer them.
 
I’m putting a 2013 srt8 5speed in my 67barracuda have you heard of anything on how to reprogram the speedometer as it normally runs of wheel speed sensors

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NA Torque is basically based on cubic inch and how well you fill the cylinders VE% per revolution and hp is all the revolutions added up. So just like hp torque is made by air flow. Most average street engines will make 1.15 - 1.25 lbs-ft per cid. To go over that you'll see engine with big roller cams high flow heads carbs etc... and its under 3000rpm will start to diminish for high rpm power.

So really its hard to make NA torque above the average build can do. But the good thing is hp is what moves and accelerates your car.
 
My Cuda is now a hemi direct from the dealer. I have lots of low end torque. Too much for the stock tires. I can roast em from a stop into third gear. No power braking required. 485 ponies compared to what my built 340 (450 cam) is amazing.

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