Bombability of HO vs Std '03

[RedRam1]

Guys,



My buddy, who lives in Texas, just bought an '03 4x4, quad, slt, 5 speed, 3:73 geared, std output CTD. He has had the fever since driving my truck when he visited last summer. I tried to talk him into ordering an '03 HO 6 speed, but he apparently got a h@ll of a deal buying his truck off the lot.



I have told him about the TDR being an invaluable source of info on these trucks, and have encouraged him to join. He is tickled to death with his truck, he traded a '98 2500 chevy 350 gasser, and is amazed at how much better his CTD pulls his boat and camper. Although he is satisfied with the power, he remarked that his truck did not feel as quite strong as mine - I'm running an EZ & 275 RV injectors in my '01. 5 HO. He is not nearly the gearhead that I am, and does not understand (yet) that the fuel injection systems on our trucks are two completely different animals. My buddy is relying on me as his official CTD advisor, so until he joins the TDR, I am acting as the middleman. Some or all of my questions have probably already been adressed, so I'll apologize in advance if I'm rehashing a lot of old info - I confess to not following the third generation forums very closely.



Here are my questions:



What 'plug and play' type of modules are available for '03s, and which ones seem to perform the best?



I have read that most, if not all boxes currently available work by raising the pressure in the fuel rail. Does the high pressure/commonrail injection system seem to be able to tolerate the increased pressure? Do any boxes change the injection timing?



I am also curious as to how the std output '03s run compared to the HO's. A guy I work with bought an '03 HO, and it seems to be very close in power to mine, I would have to say I still have the edge, but not by too much. I have not driven a standard output '03, so I can't comment on how they run.



What are the differences in the standard & HO motors for '03? Does the HO get it's extra power via ECM changes, or is soemthing different about the pump or injectors?



Finally, I know that with 2nd gen trucks, ETCs were somewhat more bombable than ETHs. What about the '03's? Is one any more bombable than the other? On otherwise stock trucks, which one would benefit more from say an EZ, the std or HO?



Sorry for the long winded post, I'm stuck here at work on a Saturday, and it's kind of slow!

 

[boonsur]

To briefly cover your questions:



Physically, the (SO/HO) engines are praticaly the same. The HO gets oil "squirt" tubes which help cool the pistons. There may be some beefier components, but the SO should be plenty capable of some mods. Most of the power differences come from the computer controls. Also, the trannys they (HO's) are mated to are built stronger, to better handle the increased power.



So far, most of the boxes are just raising the fuel pressure. There are quite a few posts going about this. Sounds like it can wreck things fairly quickly. IMHO, I will wait until someone comes out with a reliable one that changes timing, etc. (not sure, but I think a lot has to be learned about the new computers).

 

[RedRam1]

Thanks, Boonsur. I have been surfing the 3rd gen forums, and obviously am going about things backwards - should have checked out the threads before posting.

After reading the posts on raising fuel pressure, I agree with you that if it were my truck, I would hold off a while. A box that raises fuel pressure seems to be a lot higher risk than plugging an EZ, VA, etc. into a VP44 equipped truck.



I wonder if it putting an '03 HO ecm on a std. output truck would get you to HO power levels? I am also still very curious as to how the std. output motors run. My buddy in comparing his truck to mine, is relying on his memory from ~9 months ago when he drove my truck. I have never driven a std '03, but based on my test drive of my co-workers '03HO, I would guess that an '03 std output would feel approximately as strong as a bone stock '01-'02 HO. Is this about right?

 

[Prairie Dog]

I would think the 03 H. O. would feel stronger than your stock 01 - 02 as they get about 255+ H. P to the ground (on dyno) as compared to the earlier H. O. 's flywheel rating of 235 - 245.

 

[RedRam1]

Prairie Dog,



You are correct about the '03HO feeling stronger than a stock 01-02HO. As I stated in my original post, my co-worker's '03 HO feels just SLIGHTLY less stout than my EZ/275 injector equipped '01. 5 HO.



What I'm wondering is how a stock '03 STD output feels compared to either an '03 HO or my mildly bombed '01. 5. My buddy in Texas (I'm in GA) says his new std. '03 does not feel as strong as my truck, and is soliciting my advise on how to make his truck run a little better. Since I have never driven a std output, I don't know how far apart we are. It is also possible, since it has been almost a year since he drove my truck, that he is remembering it to be stronger than it really is.



I have never dynoed, but would guess my truck would put down in the neighborhood of 265- 275 hp at the rear wheels. You stated the '03 HO's are at 255+ rwhp, what about the standard output '03's, has anyone seen on one of these on a dyno?

 

[timjones]

Red, your gonna lost 50+ hp in drive train friction. this is a more or less, the more hp you make the more you lose. A 305 puts to the ground 260hp. -55 hp. A 250 then should lose about 50hp or about 200 to the ground. A 400 would lose about 75hp.

 

[JohndeereG]

Originally posted by RedRam1



I am also curious as to how the std output '03s run compared to the HO's. A guy I work with bought an '03 HO, and it seems to be very close in power to mine, I would have to say I still have the edge, but not by too much. I have not driven a standard output '03, so I can't comment on how they run.

I can't help you in determining what Mods to make, as I am doing "research", also.



However, I can share my experience between my 03 HO 6 spd versus my brothers 03 SO 5 spd. For the most part, all things are equal except for the engine/transmission combo. Because his 1,4,5 gears are the same ratio as my 1,5,6 gears, I feel that I can make a fair comparison--which there is a noticable difference in towing, daily driving and fuel mileage. Hypothetically, you are following a car that pulls off the road. The HO will pull the low rpm grunt up to operating speed much better and usually without down shifting. I average 19+ mpg regardless of the type of driving but my brother's range is 15-17 mpg.



My 2 cents

 

[RedRam1]

Thanks, Johndeere. Based on you and your brothers experiences, it sounds like my buddy's recollection is correct... his std '03 probably is not as strong as my EZ/275 equipped '01. 5 ETH. I TOLD him to get an '03 ETH/DEE!!

Since the primary differences in the '03 std vs. HO seems to be in the computer controls, I wonder if Cummins/Dodge will come out with a replacement ECM to boost the std '03 to HO power levels? Seems like they might, since they offered the DC/Cummins approved ECM for the 2nd gen Isb trucks that boosted power to ETH levels. This would be a safe way to get a little more power, probably would not even void your warranty.

 

[JohndeereG]

Originally posted by RedRam1



Since the primary differences in the '03 std vs. HO seems to be in the computer controls, I wonder if Cummins/Dodge will come out with a replacement ECM to boost the std '03 to HO power levels?

There is a little bit of mechanical difference between the HO and SO CTDs. Cummins describes the difference as:



"What did we do to make the HO engine 305 horsepower and 555 lb-ft torque? First we beefed up components such as the pistons to handle this power level. We used gallery-cooled pistons which receive an oil spray to for cooler temperature and longer life. Then we modified software to create the greater horsepower and torque, while staying within all engine and driveline parameters. "

 

[RedRam1]

Johndeere,



I understand about the minor mechanical differences between the '03 std. and HO motors, however, there were also minor mechanical differences between the '02 and earlier ETH & ETC motors. These minor differences did not stop Dodge from offering the 245hp/505torque ECM for ETCs.



You would think that even DC would have to admit that the '03 ETC could handle the extra hp/torque without problems. I can see why they would be reluctant to offer a similar type of reprogrammed ECM for '03s though, 305/550 may be too much for the 47RE to handle. My buddy has the 5spd in his '03, so he would be ok of this option were ever offered.