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2020 Jeep Grand Cherokee Trailhawk, ProCharged 5.7L Hemi
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I like the sound of a good Whipple style supercharger, but the 5.7 is so fragile with their weak pistons (Piston ring land groves built high on the piston, and tight ring gap clearance), and the Whipple with their instantaneous power would be a little harsh on my stock internals. IMHO

The ProCharger builds power gradually and is a easier on the engine.

... now, If I had a forged lower half before I started, it might have been a different story. :LOL:
 

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2020 Jeep Grand Cherokee Trailhawk, ProCharged 5.7L Hemi
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All this talk of headers has them moving up my mod list. I know the 5.7 makes good power but is choked down on the exhaust side. I have a 6.4 intake manifold sitting in my garage waiting to get the msd box to control the svr. I really want to dyno my Jeep stock but want to do it after I put the 32” tires on. I tow a decent amount so I want as much low end torque as I can get. Gonna start saving up now.
32s would have been cool, but they wont fit on my 2020 Trailhawk without cutting the fenders.

I have 275/55R20 which are 31.9 inch tires and I still had to put some heat to the front bumper and curl them in a bit closest to the tire to keep them from rubbing at turn.

I have a 23 foot Travel Trailer that I have pulled around without issue, I am sure that the Holley intake may have hurt my low end torque a little, but I get it all back and then some with the ProCharger. And, at 3k the power really comes to life.

You are definitely going to want that control box for the 6.4 intake to take full advantage of available torque. (y)

Once I finish with the tune, and Overkill Racing gets their 4-wheel dyno repaired... I really want to see where I'm at.
 

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2018 Grand Cherokee Trailhawk
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I like the sound of a good Whipple style supercharger, but the 5.7 is so fragile with their weak pistons (Piston ring land groves built high on the piston, and tight ring gap clearance), and the Whipple with their instantaneous power would be a little harsh on my stock internals. IMHO

The ProCharger builds power gradually and is a easier on the engine.

... now, If I had a forged lower half before I started, it might have been a different story. :LOL:
I didn't consider that. Isn't that basically the same issue that the Subaru EJs have? I have minimal experience with Chrysler anything (my 5.9 Limited was the only other Chrysler I've owned), so coming from GM a lot of this is new to me. I'm used to the 3800 which takes unreasonable amounts of abuse without complaining. I'm not necessarily opposed to centrifugals, but I'm a fan of the "OEM+" look with minimal mess in the engine bay. Do the 6.4s have the same weak internals?
 

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2020 Jeep Grand Cherokee Trailhawk, ProCharged 5.7L Hemi
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I didn't consider that. Isn't that basically the same issue that the Subaru EJs have? I have minimal experience with Chrysler anything (my 5.9 Limited was the only other Chrysler I've owned), so coming from GM a lot of this is new to me. I'm used to the 3800 which takes unreasonable amounts of abuse without complaining. I'm not necessarily opposed to centrifugals, but I'm a fan of the "OEM+" look with minimal mess in the engine bay. Do the 6.4s have the same weak internals?
The 3800 Supercharged engines were also tune from the factory, only made 225 to 260 hp, depending on the series (2 or 3). The crank, rods, and pistons, not forged, but stronger than the NA versions.
AND, only had 8.5:1 compression.

AS I understand it; the 5.7 hemi has a very tight top ring gap and the ring land on the piston sits very high on the piston. So too much boost, or heat can cause the ring gap to close breaking the piston at the top ring land grove.

I do not know the specifics for the 6.4 Hemi, but I read once that they are even more fragile than the 5.7 Hemi's (but I could be wrong)(it could be because of the higher compression ratio). BUT, where I can make 175 hp at 7 PSI with my 5.7, the 6.4 can make 215 hp at 7 psi using a ProCharger. As long as we tune smart, we shouldn't have any issues.
 

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The Series I 3800s were the low output ones with an M62, and don't share too much (of anything) with the Series II design. All of the S2s were 240 HP and the S3 was 260 HP, mostly owing to the more efficient Gen V blower as nearly everything else was identical. For what it's worth, the Supercharged S3 (L32) did get forged connecting rods, however there was been much debate as to whether they were really any better than the original Series II rods. At one point, in an older Regal GS I owned years ago, I ran the naturally aspirated (L36) shortblock with the supercharged top end, while that build wasn't as "extreme" as my current one, the 136k mile (at time of swap) NA block saw that thing 100k more miles to the junkyard due to rust. Those engines were way better than they had any right to be. My current build on E85 makes me laugh every time I drive it, and comparing it against performance cars I've owned (01 C5 Vette and my Stinger GT2), it's a bigger riot than any of those.

Speaking of E85, I wonder if that would help with the longevity of the 5.7 under boost. The cooling effect is massive. Although, given the fuel economy I get my Regal on corn, I'm not sure how much I'd enjoy that in the Jeep.. lol.

I did some research on what you were saying, and yeah, it does seem that the 6.4 has it even worse than we do. Do you have a meth setup on your build? Your note about tuning is an extremely valid one, and I'm wondering if bad tuning is taking out some of these engines, too.
 

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Speaking of E85, I wonder if that would help with the longevity of the 5.7 under boost. The cooling effect is massive...

Do you have a meth setup on your build?
E85 isn't even available where I live, so it wasn't even considered.

No Meth.

I have to admit, I am a car guy, but I am not building a race car (Jeep). I just wanted "More Power Baby"... lol

My Jeep is the Trailhawk, I wanted a Grand Cherokee Trailhawk with the 5.7 Hemi. I live in the Sierra Nevada Mountains so I get to play on the mountain roads, it gets used in the snow, and I take it off road on occasion, but nothing too extreme.

It is my daily driver, and I want something that I can play with.

... I'll have to find a new project pretty soon, this one is about done. :oops:
 

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I feel you on that! Basically if they made a Trailhawk with even a detuned Trackhawk 6.2, that would be my ideal GC. Since they don't make that, I'm on board with the whole "let's get more power out of this thing!"

I could have bought an SRT or a Trackhawk, but I also like something resembling off road capability :). The Hemi Trailhawk fit that as close as possible.
 
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