JPrewitt

Looking for advice on upgrades to bring my 89 D250 in around 350 to 400 HP.

Let me start by given you some stats: This has been a three year project '89 D250, with completing rebuilt engine (new Cummins head, 7 mm holes) and rebuilt trans (727).
Mods: H&M Fuel Pin (M3), Dynamic Timing Shim, 4 inch Exhaust, HC-35 Non-Westgate Turbo w/ 16 mm housing, 3600 RMP spring, 3 inch Cross Over, Tuned in VE pump to fit modes, all monitored by Edge CTS.

Project Goals: Looking for that 40 mile a day, head turner, daily driver, that will lite'em up and still get 20 MPG!

When replacing the head due to cracks, I had to replace my 9 mm injectors with 7 mm stock (not a smart move), now I would like to upgrade the 7 mm injectors nozzles with bigger Bosch nozzles, just not sure of which size (5 X .012 or .014). Not sure if I have enough air to run the .014. Any helpful words out there? 15 PSI lift pump and upgrades in Torque converter and flex plate in work.

JPrewitt

Let me ask this: What would be the best "leanest and meanest" injector upgrade in the chase of 300 +HP?

thrashingcows

Did you put in head studs? To get into the 350-400hp range your going to have to run some big boost numbers.

Personally I don't know what the attraction of those numbers are....350-400hp. I see threads started all year long with people asking about this type of combo. Over on CumminsForum there is a "performance thread" that has probably answered this question a dozen times.....make swing over there and see what others have recommended.

Having said that your going to need to move a lot more air to get up to those numbers. That 16cm housing is not going to cut it. Probably need a HE351 at the least. Going to need to move lots of fuel through as well to make use of that air.

j.fonder

If i were building for 350hp with a non-ic motor(155* bowl pistons) this is what i'd do - on a budget)

he351 turbo
marine 370 injectors - mildly honed
timing spacer (because you have it)
fuel pin - what you have will work
pump tuning - going to need to be about 1 turn from runaway
piston lift pump
powerstroke IC with 3" tubes and 24v intake
60# valve springs
boost/egt/trans temp gauge
aftermarket converter (Revmax/goerend/suncoast)

that will get you darn close.

j.fonder

for 400hp add this to the above

he351 compounds with either s369, s467, or s472
head studs
comp flow honed marine 370s

Rick 12v CTD

If I were to put compounds on I would o-ring the head. Second, if I were doing compounds I would without a doubt use the PDD towing compound turbos. I'm not sure how well the piping kit would work in a first gen though. There are a few important differences to note between 1 gen and 2 gen trucks which would impact how the turbo brace and piping is made.

The kit runs a k27 over a new s369sx-e with t4 1.0ar exhaust housing. I think it's darn close to a perfect setup for a VE motor.

Also, to make 350-400 studs aren't essential if you gate at 40psi but it's certainly not a bad idea as HG have been known to let go even at 40psi

Otherwise the only thing I would add to fonders post is a gov spring but you already have one. I don't know what a 3600spring comes off of, perhaps a TDI application. Either way, a 3200 or 3800 spring would do the trick also.

j.fonder

i agree on the s369. forgot about that setup when i was typing last night. i want to put one under my he351, which is essentially a holset version of the K27.

JPrewitt

Thank you all for the inputs, but maybe I should have stated that the HX-35 was last years upgrade; moving forward with the chase of more HP will have to be with the HX-35 as my quarterback turbo! I have my quarterback, I need to build my team around it!

j.fonder

ok, well in that case, compounds will be a must. so all of what was said above but with something like an s369, s467, or ht3b under the hx-35. on a budget, the hx-35/ht3b will make the numbers you're looking for and is a really common compound setup.

the difference between 350hp and 400 hp is big when it comes to our VE pump motors. especially if you're at all concerned with drivability.

Jim Lane

Additional cooling for your transmission.
How do you plan to control (traction) and stop 400 horsepower?
What will the torque figures be at 400 horsepower?

mhuppertz

Simple, throw in a set of Lucas POD's and a 16cm exhaust housing and you will put fear in the tuner community. That's hat I did.

j.fonder

i've seen worse recommendations.... wait, nope, no i haven't.

by fear, you mean fear of driving off the road as you "rolls the coals" in front of them?

ofelas

The old school way...still works well