2003 engine differences

[LMcCary]

I have a 2003 SLT Quad cab 4x4 with a 250 hp and 5spd and am disappointed with the lack of torque and power. What is the difference in the engine to keep it from being turned up to the 2005 or 2006 level by Smarty or other programmer.













2003 250hp 5spd 4x4 Ouad SLT Patroit Blue with no mods yet.

 

[DrDiesel]

I had a 2003 CTD. I installed a TST box and was very happy with what the box is capable of. However, the 2003 Exh. system is too small.

If you added a complete exh. system with a 4 inch from down pipe to tail pipe, removed the stock intake tube(Cool Hose and Amsoil Nano Fiber filter goes here) added a TST R49, an upgraded fuel(lift pump) feed system(Fass/Air Dog) you could very well reach the 325/610 mark without loss of reliability. The higher you set the TST the more upgrade components you'll need. (clutch/flywheel/fuel system ECT)

The TST box is very expandable for BHP/LBF. You would not go wrong with a TST box. I have one on my new 2006

Get the TST an exh. system Cool Hose and the nano filter. You love it... Money well spent. :-laf

 

[JHardwick]

If you added a complete exh. system with a 4 inch from down pipe to tail pipe, removed the stock intake tube(Cool Hose and Amsoil Nano Fiber filter goes here) added a TST R49, an upgraded fuel(lift pump) feed system(Fass/Air Dog) you could very well reach the 325/610 mark without loss of reliability.

That's a gross understatement.

 

[DrDiesel]

That's a gross understatement.

I know, but I`m a very conservative person..... :-laf

 

[Vaughn MacKenzie]

The only thing to be careful of when increasing power is keeping an eye on EGTs, since the SO engine doesn't have the gallery cooling like the HO and 600 series engines and can't take quite as much heat (don't sustain over 1200-1250). It does have the same piston cooling as all 24 and 12-valve engines, just not the additional gallery cooling.



Vaughn

 

[WBarker]

I have a buddy that has an 03 and we installed hot version of the juice and upgrade the intake,exhaust, and the fuel system and he made over 400hp on the dyno

 

[LMcCary]

Besides the piston cooling change, what else is different. I read somewhere that the 2003 injectors are not interchangeable with a later model.

I am updating the fuel system this weekend by adding a GDP pump and filters system. Later, hope to add some sort of box, like edge, TST or smarty. Of course I will be adding EGT guages, fuel press, etc. No sense of flying blind.



Thanks for your responses

 

[dcherill]

Is there a list of what changes were made during what model year for certain Items? I know that it would be a big list, but it is like the same questions all the time. (I was looking for the same questions when I got my '03, I just ended up with an HO).



knowing which years the exhaust changed to a full 4" system would be great. a site that I am a member of for my motorcycle has a HUGE list of what was changed over the years, check it out for a format that might work, I know there have been many more changes, but it could be a good place to start.



http://faq. f650.com/FAQs/F650HistoryDifferences.htm

 

[LMcCary]

Where are all the engine guru's? I can't believe that no one knows the differences in the 2003 SO to 2005 HO engines.

 

[rbattelle]

The significant differences between SO and HO, as I recall, are:



1. Different piston cooling jets (as Vaughan mentioned).

2. Lower injection pressure.

3. Different ECM programming.



Here are a couple threads on the subject:

Link

Link

Link

Link

Link

Link



Ryan

 

[LMcCary]

Thanks Ryan, that is more of what I was looking for. Besides piston cooling change, mostly programing difference.

Does any one know about the injector difference?

Why can't Smarty pull the same horsepower out of the SO as the HO?

 

[zippinbye]

From the first 03s until the 04. 5/Cummins 325/600, I recall three engine choices. The HO was a 305/555 I believe. Then there was a SO and an even lower output version reuired for CA, VT and I believe two other states. When I ordered an 04, of course it was supposed to be the HO. But when it arrived at the dealer, it was the extra low output tree-hugger engine, suitable for Volvo-driving Vermontonians! (apoligies in advance to Vermont residents and those who drive Volvos, but maple syrup and fine Swedish diesels do not make up for boxy cars that only turn left and governmental choking of the CDT engine!) Can you believe the sales guy said "it's all in the ECM, we'll just reflash and you'll have an HO!" My response began with F and ended with u. They ate it and pawned the truck off on somebody who did not know the difference, and reordered my truck. Thanks to those idiots, I ended up waiting way long for the first 600s and missed what was probably the best engine, a pre-04. 5 HO. The point being is that there are major differences between these engines that are not simple computer magic. While programmers and other enhancements will benefit any of them, a 250 with the same mods as an HO is still going to be a lesser powerplant, and as mentioned, is probably more prone to EGT concerns. As with many who have contemplated projects like a 4 x 4 conversion, dually/single rear wheel morphs or auto to manual transmision swap, you might be better off selling and buying a similar truck with the equipment you really want. A lot of people would not be aware of your "lessor" engine as you sell it, and many of the internet pricing references and printed "blue books" do not reconize the different output versions. Other than paying sales tax again (in most states), you would probably be happier with a 03 or early 04 HO. Then the mods could begin!

 

[LMcCary]

Before I go thur another purchase, another engine will go into this truck. Heck my '97 12 valve would eat this thing alive as far as raw power. This is a nice truck and I hope to keep it. But it will perform better, even if it requires a 12 valve transplant.

Strange thing hppen yesterday, I drove my old 78 dodge crew cab with a 96 stock 215 Hp with a 5spd, man that thing still zips compared to this new truck, and its near stock. (and throughly used)

I have been a mechanic all of my life, know most engine fairly well, but can not believe that this engine has no hope as far as performance. The rest of the truck is one of the best vehicles that I have ever owned. This is the first four wheel drive, and I like it, as it has already come in very handly, like the run to Colorado recently in the snow and ice pulling a 20ft. load trailer all the way to Craig Colorado, over rabbit ears pass.