03 vs. 04 Hemi

[Dreamcatcher]

Is there a difference in the 03 and 04 5.7 hemi engine? The engine not the computer. I see parts available for the 04 hemi but it never mentions the 03 year model. Is it just a tuning issue or is there a difference in the engine itself?

 

[lxmodguy]

theres no difference

 

[Dreamcatcher]

I was just curious to why most after market parts say 04 - 07 and 08- to on up. I haven't seen any that say 03. I had a 03 truck I was going to use the hemi. I sold it but have never seen the 04.It just seems that more people seek the 04 and newer engines. Thanks for the reply.

 

[lxmodguy]

Technically I think the engines were in trucks first sold in 03 as 04 models.

 

[mr.belvedere]

I think 04 was the introduction of MDS in the truck 5.7's.

 

[Dreamcatcher]

I think 04 was the introduction of MDS in the truck 5.7's.

What is the MDS?

 

[Hemi Rebel]

What is the MDS?

Multiple displacement system. Trucks didn't get it til 06

 

[lxmodguy]

Multiple displacement system. Trucks didn't get it til 06

Yup. Same with Cars, the cars first got hemi's in 05. The ECM's in 03-05 stuff sucked. Early 05 cars had the 04 ecm in it which was awful, you fight it trying to get it to hold a tune, almost no parameters you can adjust. As I stated earlier, ever engine from from 03-08 is identical other than the MDS which can be eliminated with some plastic block off plates that dodge sells (because they are the same as 6.1 engines)

 

[Dreamcatcher]

Interesting , one reason for asking was the guy that bought my salvage 03 ram said he was going to put a supercharger on it. I told him even before he bought it that I don't think its possible. For one thing no one lists these type of parts to fit an 03 hemi. And for the other thing I don't think you could tune an ECM to run with one even an after market ECM. And even if it were possible the ECM and harness would be outrageous. If your going to try all that you might as well go find a hellcat engine. But I may be wrong. I don't know that much about the newer mopars. I have done similar builds with LS engines and Fords 5.0 but thet have a huge after market and you can do it for next to nothing money wise. But all in all you still don't have a mopar when your done!

 

[lxmodguy]

yes, its literally costs about a third of the price to do an LS motor. the 03 and 04 ecm is worthless for a hemi. you can run a hemi with a holley setup for around 1500 electronics.

 

[DwsPrime]

I know this is an old post but I want to interject that you can do a decent tune on a stock ECM from 03 if you take them time to wire in an SMT6 or SMT8, etc. It's harder to get it right using the crap ECM BUT it can be done.

 

[Dreamcatcher]

Can you explain SMT6 or SMT8 please. Not sure what this is or does. And thanks for your input.

 

[DwsPrime]

SMT6 and SMT8 are piggy-back units. http://www.perfectpower.com/index.php/products/piggy-back/smt8

 

[kb67mopar]

I run an 03 hemi in my car and am running it with an 04 ECM. The main difference between 03 and 04 is 03 didn't run EGR. Also in 04 they swapped valve springs as the 03's were more prone to breaking. I run a hotwire harness and a ram 2500 manual trans tune. It runs fine and works well. If I was going to modify or put on a supercharger I think I'd run a megasquirt hemi system from DIYautotune.com. Then you or anybody else with knowledge could tune it without spending big $$ on custom tunes.

I've been toying with selling my system and upgrading to the megasquirt so I could drop in a lumpier cam and maybe add boost in the future.