Dodge Challenger Forum banner

Difference between 5.7 and 6.4

103K views 125 replies 49 participants last post by  tommasom 
#1 ·
Hello, I have a 2011 RT 5.7 auto. I have only 2 years on my lease left and may get out of it early so I can get into a 6.4 SRT8 auto earlier instead of waiting the two years.

-Is there that much of a difference between my RT and the new SRT8. I have never driven the SRT8 6.4, and would love to know?

-The numbers for my car are 376hp and 404tq. The numbers for the SRT8 are 470hp and 470tq. It is more, but it doesnt seem like a huge difference. It is about 100hp and 70tq more...

thanks
 
#2 · (Edited)
Having owned the R/T, 6.1, and now the 6.4, yes there is a tremendous difference.

Key differences:
- adaptive 3-mode suspension
- Brembo brakes
- engine (yes you will notice a huge difference)


What I would suggest is go test drive a 2012 392. Nothing typed out will be able to explain the driving experience difference.


Sent from my Autoguide iPhone app
 
#4 ·
It depends on if the R/T has a 6speed or not and then the mods that have been done...
With my mods, on my '09 R/T 6 speed...I make more RWHP than the 392(I make 417hp on a Dynojet vs. my 364RWHP baseline)and most 392's only make 400ish for RWHP stock with no programming available...I have LESS $ in my R/T than the 392SRT8 costs...even with suspension & brake mods, bolt on engine mods, and programming of the PCM. If I do a VVT Cam and ported heads...I will be close to 500 RWHP...and still be under the cost of the SRT8-392 without supercharging or forging the motor. Just depends on what's important to you and where you want to go...better off buying a used Challenger 6-speed and modding the hell out of it.
 
#5 ·
-The numbers for my car are 376hp and 404tq. The numbers for the SRT8 are 470hp and 470tq. It is more, but it doesnt seem like a huge difference. It is about 100hp and 70tq more...
100hp bump makes quite a difference, you'll have no problem noticing a difference :)
 
#6 ·
The 6.4 is a huge difference. I had a 09' supercharged R/T and my 6.4 is way faster than my old R/T. I also made the switch from a manual to an automatic, because I wanted to do better at the drag strip. The HP numbers don't tell the whole story. The real difference is the torque, which is more than 90 ft/lbs more than the stock 6.1, and makes the 6.4 a beast. This 6.4 comes out of the hole like a rocket compared to my old 5.7. My car just dragged on Friday and got a corrected E.T. of 12.2. The actual E.T. at +2000 Density Altitude was 12.5 with drag radials.

The best suggestion I can make is to test drive a 392 turn off traction control and go WOT on a straight road. Your head will be slammed into the headrest. Judge for yourself.
 
#10 ·
The 6.4 is a huge difference. I had a 09' supercharged R/T and my 6.4 is way faster than my old R/T. I also made the switch from a manual to an automatic, because I wanted to do better at the drag strip.
Sounds to me you didn't drive a stick very well if it is way faster!!!:icon_biggrin: I would think a supercharged 5.7 should hang pretty easily with a 392!!
 
#7 ·
I'm with all the guys above. I too have had a heavily modded 5.7 with SC and a 6.1, this 392 is awesome. It's just an all around better car than the old RT or 6.1 was/is. HP #'s won 't tell the full story. Hard to tell you without driving it. There are few cars out there that accelerate from a dead stop like this heavy beast. I have a Hennessey Viper and coming out of the whole my 6.4 is there. Different story though once we get above 45mph. All in all this 6.4 is one of the more satisfying cars I've owned. I buy hotrods all the time but this will be one I'm keeping.
 
#83 ·
I'm with all the guys above. I too have had a heavily modded 5.7 with SC and a 6.1, this 392 is awesome. It's just an all around better car than the old RT or 6.1 was/is. HP #'s won 't tell the full story. Hard to tell you without driving it. There are few cars out there that accelerate from a dead stop like this heavy beast. I have a Hennessey Viper and coming out of the whole my 6.4 is there. Different story though once we get above 45mph. All in all this 6.4 is one of the more satisfying cars I've owned. I buy hotrods all the time but this will be one I'm keeping.
I love my new 392, but having owned 4 Vipers there is no way the 392 keeps up with any of my previous Vipers out of the hole (unless I was on old tires). Better have someone other than Hennessey tune that poor thing... Or, get some new tires.
 
#8 ·
Huge difference!

I just traded my 11 rt for a 12 srt...i dont care what anyone says. People say you can take an rt and make it a srt clone by doing suspension and some hp upgrades. Nope I had suspension on my rt and it wasnt nearly as responsive as the srt it. The srt is night and day. Its a completely different animal.
 
#11 ·
There is no comparison between an R/T and a 392. The 392 is a superior car in every way, and is worth the extra cost IMHO.
 
#15 ·
You tell em Spark.

Plus the op has a lease so I don't think a supercharger is in his future = 392 more better...
 
#16 ·
My first time at the strip, here's the difference. Left lane me with R/T six speed and a 91 tune, right lane 392 auto. Yeah, I can't drive worth crap I guess, but great driving isn't gonna make up this much time. I'll let the right lane reveal himself if he wants to. He was way faster. I still love my R/T though.
 

Attachments

#20 ·
I don't know how true this is, but I have been told by an 392 guy that driving his car makes the 5.7 feel like a 4 banger. He said the only thing the 5.7 has going for it, is it's exhaust note and mileage. Torque is non-existent compared to the 6.4. The 6.4 will go sideways and smoke the F1s off the line at will. That is a true muscle car type engine, where the powers down low. 5.7l only gets into the power band around 3k, which makes it more like a Civic (not exactly, but same concept). Meaning, you need more revs to extract the power.

With that being said, I will NEVER drive a 6.4 because than I will get the torque bug and will want to trade in (which I cannot).
 
#23 ·
With that being said, I will NEVER drive a 6.4 because than I will get the torque bug and will want to trade in (which I cannot).
Same here! I love my R/T, but I know if I drove the SRT I would be scheming for a way to get my hands on one from that day forward. The much larger price tag and higher insurance rate is a good incentive to keep me away from them too!



Sent from my DROID BIONIC using AutoGuide.Com Free App
 
#22 ·
The power curve and additional of the 6.4 - there's no denying there would be a difference.

In the past, the 6.1 was more noticeable in the top end, but the 6.4 has more down low, mid and upper end and the mileage improved for the 6.4 over the previous SRT engine.
 
#24 ·
100 hp not much of a difference??? what???

tons of 6.1 guys switch to the 6.4 just to get 45 more hp....i test drove a 6.1 and the 6.4 is notable...going from a 5.7 to a 6.4 will be a big deal

i drove a RT at the SRT track experience....you;ll notice the power difference right away....the RT is great, dont get me wrong...id never rip on it, but the SRT is much better
 
#25 · (Edited)
Just under 3 grand for an Arrington 4.05 stroker kit. Port your eagle heads and stick on a ported 6.1 intake nd your RT will be a kick ass 392. Also consider a used 09 or 10. They are tuneable and you can get rid of the Chrysler crap tunes that they reflash your car with after you buy them.

Edit. Sorry... I didn't see that you had a 2011.
 
#29 ·
5.7L vs 6.4

i will probably piss off a couple of 392 owners. I am giving my opinion as a person that has owned both vehicles, both black, automatic, srt wheels, CAI, and Corsa on both cars....RTPlus was 2011 fully loaded (minus stripes) and my current is a 2012 SRT8 fully loaded black minus stripes....side by side they look exactly the same (minus the 392 badging). In my honest opinion the RT Plus was about the same performance getting up on the access ramps or normal highway speeds and acceleration....I am not talking about track performance because i have not ever been on a track, but as far as normal highway hauling ass, both are very similar. HOWEVER, the brakes, and handling on the SRT are better. If you find a good deal go ahead and step up (and if you can afford it)....if not, the RT is just fine....Also the insurance difference is minimal if you are a middle age fart like me.....the SRT is the SRT and the RT is an exceptional performance for dollar spent.
 
#32 ·
RippTyde,

I'm not saying I agree with my friend, but he may be slightly exaggerating some of these claims. I don't really know though, because I haven't driven a 392 before. I was a passenger and the guy barely got on it. My friend is all about numbers, and now that he has a 392 is thumping his chest like a Silverback Gorilla.

You have stated before you can roast your tires at will. Not everybody can do that. Some have killed backpressure with certain catbacks, or O/R pipes. We all drive on different roads, different temps, different wheel setups, etc. It is not typical for an R/T to be able to light them up without some assistance (revs). I envy your car, as it seems to be a factory beast or you have not touched your factory exhaust. My guess is you've retained your backpressure by doing so.

60ft/lbs may not seem like a lot, but most owners of the 392 (some of which had a 5.7 or 6.1 before) always mention torque. Maybe the computer difference allows for the driver to feel the torque more? I don't know if they reduced torque management or not, but you can't deny people seem to notice it. Again, most people who are happy or excited tend to exaggerate.
 
#36 ·
All Challengers are cosmic. What it comes down to is what do you want to spend to have a different experience. That's true of much in the material world.
 
#38 ·
It feels to me like some of you R/T guys are pointing tommasom down the wrong path. Such as posting video's of your supercharged R/T. Really? How does that help him decide when not comparing stock versus stock. Or better yet, get with someone with a blower on their 392 from Arrington or RDP putting out just under 600 RWHP then compare. I owned a supercharged R/T and loved it. I love my 392 even more, mostly because it is faster and handles better. That has been my experience. Be proud of what you have but I feel you shouldn't have to "defend" your car by making false claims just because something else may be overall better. Some of the claims on this thread are just plain wrong and aren't spoken from experience. Too many "theories" and not enough facts. I'll say again, my 392 is heads and tails better than my R/T was, even with supercharger. Be proud of what you got. I know I am.
 
#42 ·
I would be glad to debate with you on a new thread :) and you are right, I did start start out comparing my supercharged car and that was just my experience since I supercharged it just after it was bought. I respect the opinions of others but I don't like the numbers being thrown around as some kind of, well according to the dyno sheet, talk. To me, track time is what counts. I was actually shocked when my 392 HP numbers came in lower that my then supercharged R/T but my zero to sixty time went down by a whole second. I am still learning how to shave off tenths in the quarter mile, and I have yet to race in the winter with much better DA. Hopefully that will all come together at the end of the year. Have a happy 4th of July!
 
#44 ·
an RT is a nicer car and I am positive we have a lot of 392 owners who will never take their car to its limits. If you daily drive and are on a budget, nothing wrong with an RT or even an SE. They are all challengers. I do like to race mine and to me its always best to start with the highest platform and go from there. Of course there is that no tuning issue.
 
#45 ·
an RT is a nicer car and I am positive we have a lot of 392 owners who will never take their car to its limits. ...
The PCM swap is really helping with the tuning issue. Before I started pouring performance money in mine I went and looked at buying a 392. The tuning issue was a major negative blow for me. I like to mod my stuff the way I want it to be. I had already paid for wheels/tires, custom interior, stereo system, etc and would have lost a ton if I tried selling it. I've basically taken my R/T and am turning it into exactly what I want - interior, suspension, brakes, power, etc.

In the end I will probably end up spending more on my R/T than if I had just bought a factory floor 392, but I'll also have exactly the car I want and not based on the options Dodge offered. The end game for me is probably going to be a forged 426 at some point just because I've always wanted a 426.

But yes, most people won't even remotely come close to limits of the car.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top