I keep hearing how much heavier the hemi is in this thread, mostly by RIPP, but what is the actual number? I think a 4.0L out of a TJ is only 47 pounds lighter than a 5.7 Hemi. I don't know how it compares to the 3.8.
Reading the whole thread, my point is made by people that took the opposite position than I did, which is, the supercharger doesn't do much of anything at low rpm's for the 3.8L and that stock the 3.8L is a gutless wonder at low rpm's. In other words, the supercharger fails to make a difference in the rpm range where the greatest improvement is needed.
As for as the outrageous costs of a hemi, that is from boutique shops like AEV and Burnsville Offroad. You can find a very low mileage hemi in a good condition from a wreck either at a salvage yard or ebay and if you are mechanically inclined, can put it in yourself. The total price will be approximately $7,000, compared to over $20,000 at a boutique shop. Don't believe me that the prices are inflated? Look at the outrageous price that was thrown out there for replacing a head gasket on the 3.8L of $3,000. Even paying a private mechanic shop, the price should be more than a few hundred, and once again, can be done for much less than that.
I would venture to say that the difference in weight between a 5.7L hemi and a 3.8L is less than seventy five pounds if the aforementioned 47 pound weight difference of the 4.0L is true. That difference in weight will mean absolutely nothing to the person that wants to wheel or tow better with his Jeep and will only come into play if you are racing. Racing Jeeps, now that is funny. If the weight difference was a thousand pounds, then it might be a factor, but for less than the weight of a person, it isn't going to matter when wheeling or towing.
RIPP and his supporters mention that the hemi makes power differently but will even out or fall behind on the top end and talks about efficiency of the 3.8 and non-efficiency of the hemi. Well yes, I am in agreement the hemi makes power differently, which is exactly the complaint of the 3.8L is, is that the way it makes power is not normal for a slow moving offroad vehicle.
If no low end torque and peak horsepower coming in at high rpm's were acceptable or even desirable, then we would all have engines from crotch rocket motorcycles in our Jeeps. Hey, they make a lot of power with a small amount of displacement, are very efficient, and spin ten to fifteen thousand rpm's. Let's not forget how light the engine is too.
If horsepower and torque did not matter in a Jeep and gears were the be all end all, then a 5 HP Briggs & Stratton would be sufficient right?
I think RIPP MOD's supercharger does what it was designed to do very well, but it reminds of an answer to a question that was not asked. It could be marketed better by avoiding outrageous statements and comparisons to a hemi and by advertising more of what it really does instead of trying to give misleading information about things it falls short on. I guess what I am saying, it would be credible to advertise it by saying "The 3.8L sucks at low rpm's and there isn't anything that can be done about it, but what we can do is build on it's strengths at the mid to upper rpm range in a cost efficient do it yourself friendly package."
2014 JKU Copperhead Pearl
Too many mods to list. Too awesome to sell.