realistic goal? 359 HP?

[JDMills]

I Have been thinking about my long term goals for the D350. Not having experience with a bombed engine, I am left to daydream. .



If my goal was one Hp per cubic inch, would I be wise to :



go for a 35 or 50 psi boost gage?



Stock or Ported/modified turbo housing?



Run the original head, or plan on swapping it for the later ones with better injector options? (any opinions on how much the original injectors are able to support )



get another head as It will be helpful, and port it before installation?

(do I remember Joe D. saying that the late '93s had a '94 head on them? and that they flow better # then the first generation heads?)

Is a reground camshaft going to be required?



Should I quit while I am ahead and try to be more realistic? Or does drive-ability continue to improve up through the mid 300 hp range?

Last question: Is there any simple correlation between Hp/Tq? In that My truck is a 160/400 so it produces about 2. 5 ft. lb per Hp. Is that the general rule? does it stay constant as Hp is increased? If It was a general rule of thumb, then would I be hitting around 900ft. lb of Torque if I ever get to my goal?

Jason

 

[hdm48]

Reliable? streetable? economical? Fun to drive? Realistic?



YES to all of the above



Get a 50lb guage. Porting does help keep the temps under control and lets you use more of the power you have longer on hills pulling loads.

You are not intercooled(?) so everything helps.







Dave

 

[Bob Beauchaine]

Look at my numbers. I have never had the head off mine and it is a daily driver. Both Dave and I are running some pretty healthy numbers but we got there using slightly different routes. It's all about fuel and air. I still get better mileage than I did when the truck was new 17. 5+ city and 21+ highway. You just need to keep your foot out of it unless you need that little bit extra



Bob

 

[JDMills]

Dave, Bob,

Thanks for your information. I guess I have allready accepted that I will need a intercooler. . and so I will do some reasearch on the diesel dynamics III injectors, if that is what you are both using. I am interested to notice that you both are using 14cm turbo housings. why not the 16cm? is that all that is needed at this power level?

Bob: I will have to do a search on the 230 Hp pump.

I am getting excited about this adventure, yet I dont want to just throw parts at the truck, hoping to learn how it all works while I am at it. May be even do some porting on the head. .

Ha 21 Mpg would be sweet!

Jason

 

[BushWakr - RIP]

JD,



It can be done and it can be fun... . what more can we say...



Bob.

 

[Bob Beauchaine]

My first mod was the 14cm turbo - it's been on for almost 10 years and gives me the response I need for towing. I just have not seen a need to change it. As for the DD3+'s well I am super happy with them. The pump came from Wentland Diesel in Milton-Freewater OR but there are a host of pump builders out there especially on the west coast. Good Luck



Bob

 

[MrWinkey]

What transmission and clutches are you guys running?



I was thinking about a Piers HX35 or 40 for a turbo. I just killed my getrag so I figured while I'm doing mods I might as well bolt on a new turbo & injectors after I get the clutch in.



How long have your guy's high output pumps lasted?

 

[dpuckett]

My "high output" pump has 270K and counting. It was turned up at Cummins by a previous owner (think I'm #4). With a stock housing, worn out H1C, and paper filter, it would make 28psi at 6500ft. Now makes 40, with the mods in my sig.



JDMills- go for at least 40psi gauge, preferrably 50. Dotn forget the PODs, Bully Dog's 60 hp injectors, DonM's EDMs . There are a LOT of options out there compared to even a few years ago. But, without an intercooler, much more than stock will run you too hot. WIth stock injectors, I could max out my temps, and have pedal left. How the engine never burned down w/o gauges is beyond me, but then, the good pastor has seen the high teens for temps Start out with air in/ exhaust out- high flow filter (aFe, BHAF, I'd stay away from K&N, due to past filtering issues, but I dont want to start too hot a brand war here. ) and 4" exhaust. I have a muffler and flex pipe off a semi with a 318 Detroit; have to get a few elbows to complete the picture. Beyond that, keep the transmission overfull by a qt, DONT LUG IT. Get a tach, and keep it above 1500rpm at all times. The engine can handle it, the rest of it cant.



Daniel

 

[dpuckett]

OFitzgerald-

I'm running a Getrag and stock clutch, but not near the numbers of some. Look into a NV4500, though they have their problems as well. The turbo depends on your goals. The PDR HX35 is a god upgrade from the stock H1C, but some have outrun it, as well, thus necessating an HX40 or bigger. THere are several HX35/40 hybrids, allowing you to keep your exhaust and housing, yet flow comparable to the 40. I would stay at a 16 or bigger housign, esp if you are cursed with 4. 10s, like some. The 12 makes for quick spooling, but it chokes fast, and doesnt really support our head and turbo designs. I run 10 psi down the road at about 62; engine sounds like it's laboring more, and I seem to have lost a MPG or two. I had a similar experience on a 93 that I towed with- good response, but a little lower MPGs, plus, towing, there really is no EGT advantage.



Daniel

 

[JDMills]

Daniel,

Good information, thanks. I am still in the planning stage, but it sounds like I dont need to change the camshaft, and head porting is optional, helpful but not necessary. I might give it a try any way, but not for a while. Also, I guess I will see what can be done with the stock injectors, a intercooler, good air, and a free flowing exhaust. Then move to a smaller turbo, and pump adjustments. All of which will begin after a pyro/boost gage.

Your statement about not lugging the truck is good to know. It reflects my uncles statement, to the same effect, but you are more specific. Say will pump adjustments be needed after a injector change, to optimize their benifits? I bet I know the answer to that question.



Jason

 

[dpuckett]

About the only pump tweaks you may need to do is to tighten up the AFC spring, to cut low end smoke, if the freight train look isnt your cup of tea. Of course, you COULD turn it up, justifiable by the higher flowing injectors needing more pressure to atomize the fuel properly. But then there is the smoke issue. I had to tighten the AFC a little after my EDMs. Come to think of it, depending on the pop pressure of the new vs old injectors, you may need to bump your timing a bit if the new ones pop higher.



May as well do the head gasket; stock one's gonna blow if you top 250hp. And since you have the head off, it would be a good time for porting or a new updated head, with the 7mm injector holes. And since the 9s wont fit, you can get a set of DDIIIs or EDM Mach 2s. THen a 4" exhaust, HX35/40 hybrid... ... . Makes for lotsa when passing V8s. At "only" 360, I wouldnt worry about the cam. Now 400, it may not be a bad idea. Never know when the EGTs will get out of hand towing up in the Rockies.

 

[JDMills]

Daniel,

thanks for your help building a recipe for power. Just decided yesterday to pull the truck out of storage when it gets warmer, and enjoy its sight, and sound. Time to shed the winter beater, and more while driving!

Jason

 

[dpuckett]

Hey, dont thank me; thank the Pastor, Piers, nascar mark, Old Smoky, et al. THey are the ones who have gone through this stuff through the years, doen extensive R&D, and reporting on what works and what doesnt. I just have a good enough memory (for now) to remember and condense it all.



Daniel