Best mods for 12 valve Cummins towing and freeway speeds
 

Hello everybody newbie here I hope this is the right place to post this thread if not please correct me and point me in the right direction!! I have a 97 12 valve Cummins everything is pretty much stock I have done the AFC mods as in getting more rack travel And what not I have not fine tuned it yet!!i bought it with no fuel plate!! I already lost the gear housing cause the kdp!! At least that's over with!! I am looking to get around 400 HP I will be towing a big text trailer with mining equipment and also I pull fifth wheels that are usually gvwr 15000!! At 60mph I'm at 2200 rpm I would like to travel at 75 in a good rpm range and get best fuel mileage also what have you done with your intirior I hate mine!!! any pics appreciated thanks for the help I really appreciate it!!!

a 62/65 turbo is ideal for towing, you could go with a 62/68 which is the latest design. your gearing seems a bit weird. you may want to get 373 as it sounds like you may have the 410's. basically tuning and a turbo will get you to 400 horse. you can do sticks, and dv's and then tune it properly. first thing is get a plate back in it for tuning purposes. 0,10,100 are all good plates. i prefer a custom 0/100 ground by hand out of a stock plate and tuned accordingly. pulling that much weight you may consider egt control mods like a exhaust manifold and intake piping, don't waste money on a cold air intake. afe bhaf works best. get the dry type with a pre filter and you will be good to go. intake horn etc. crazy carl makes a nice 3.5 inch system. 3.5 intercooler pipes and a huge 3.5 horn. made 405 on a similar truck as yours with just a 4 gsk, 64.5/71 bd special turbo, crazy carls piping and a htt exhaust manifold. and tuning. thats not an ideal tow set up but you can make same power with the smaller turbo no problem.

So if you could dumb this down a little bit for me I am very interested in the same kind of deal for my 96 3/4 ton but I dont really understand whats being said. Your talking about changing gearing? whats egt, and afe? Sorry for my ignorance. :argh:

Twins and what you said?
 

what about a ht3b turbo under a hx35???? With some dvs and 4 gsk's and 60 ibs valve springs and 4?inch down pipe And exhaust!! Plus intake horn??? and then 3.73 gears what else??

The ht3b combo works but it's pretty out dated and more work/ heat/ loss of room then really necessary when you can just buy one turbo that is newer tech and does what you want in a simple package. With the ht3b tho yes you will achieve what you want. It will spool quick easily make 400 horse And support up to around 600-650. I personally would go with a better single now to make the 400 horse and compound later if you want more power. And Ya check your gear ratio. Seems a bit high for what you want.

And kruze.96 read the beginners thread. Then if you got questions start a thread or you can pm me

So the hx35 can't go over a hx35 If im thinking clear although couldn't that lower egts and help keep load off the one cause I have two hx35 but could you tell me where I'm not thinking right!!! Also what size of "single" turbo would you recommend for the weight I will be pulling!!! also I am goin thru front end steering like crazy even moog parts what would your recommendation be on that? And I found some 354 gears for my truck would that be to low or just add more hp and call it good??

The only way to run 2 hx35's is sequentially. Which is with a very expensive custom header running 1 turbo per 3 cyl. Not worth the hassle for a hx35. If I were you. I'd buy a bd killer b which is a 62 (61.5) turbo. Come with a full install kit and includes a 4" hx40 downpipe. There are other options but bd makes a nice simple set up. And will supply plenty of air. There are many many different options and ways of doing what you want but this is the most straight forward from a single reputable vendor. As for gearing it won't add any power. What you want for towing is for your rpm to be around 1800-2100 so you will need to do a ratio calculator and find out what gearing you need to make your truck run that rpm at the speed you want to cruise towing.

I also got no idea on front end parts on a dodge. I'm a Chevy guy. Moog is a good company. There are also lots of companys out there that I know make upgraded versions of the problemed dodge desgins but you'd have to look into it.

Please clarify your question, I'm not sure what you're saying is going on.

If you are wanting to spend money to drop rpm at highway speeds what about a gear vendors over/under drive

You have to really want to spend money to go that route.

A re gear will work fine. Plus cummins get best mpg and power at 1800-2000. Don't give him silly ideas lol

The question is, are you going 60mph in the sweet spot or 75? I prefer my numerically higher gears myself. I'd rather just make more torque than play the gearing torque multiplication game.

OK I'm knew here an I have a question on my 98 12v. I'm thinking about rebuilding it. I know it has to b bored. So so question is what piston should I run in it. I do a lot of hauling. An what else do u suggest I should do with rest of motor as far as set up for towing.

Why does it have to be bored? I shudder to think what abuse a 12V would have to be subjected to for boring to be required.

First off I'm new to diesel. Don't know much about them yet but learning. I drove the truck with the #3 injector leaking bad I was only getting 6 to 8 mag out of it. So I pulled motor out to get tyranny fixed. So I went ahead a pulled head off to c if piston was burnt. As someone suggested. When head was off the #3 piston was as clean as a new one. So then I check cylinder for ware. It has some scratches u can fill. So now I'm stuck u what to really do.

both of my blocks needed a boring, one was too worn to bore actually. and if you want a tight engine boring is the best way to get that. re honing a standard size will bring the tolerances out. which can affect performance. depends how worn your engine is though, if you have like 0 wear then a hone will do. as for pistons it depends if you want to keep your stock injectors or not. i went with mahle power paks .020 over in my case. they are a performance piston but definitely don't break the bank. you will have to switch to a marine style injector 155 angle. if your just towing 370 marines would offer a good performance boost and match your new spray angle needs as well as being budget cheap apparently. i noticed a good weight difference between my stock pistons and the power pass which i assume will translate to a bit more power. as for the rest of the engine depends on your budget and what you actually plan to do with the engine. like chargers, intended power, what fuel set up you want to run, etc

OK I'll check into that. Another question is a buddy of mine has a older 1st gen 12v motor.
I'm wondering if that motor would work in mine. Can I change the p-pump an turbo off mine
Onto that one until I get mine rebuilt.

Absolutely.

OK thanks. So it all interchangeable r they any horsepower different. Sorry for all question I'm a diesel dummy. I'm new to diesel.

HP is definitely different, but you can always put your injector pump on the older engine and be pretty damn close.