Injector recommendation for 1990?

[Bschwarzli]

Hey Guys,

Question. The current set up on the 1990 is a 1997 HX35 with the original 1990 18 cm H1C exhaust snail. I run about 32 psi having only changed the fuel screw and addition of an intercooler, ASA intake, 4" exhaust, timing at 1.79, 60 psi springs, and exhaust manifold. My pyro can reach 1300+ if I want it to, but that is mostly when towing and slightly lugging it.

But this has been in there now for 3 years. And as the weak link getrag is now gone and I have a 5600, I want a little more. Plus the fact that the H1C housing is so corroded at the flange that is no longer seals, I have started looking into a Super HX40 vs just replacing the H1C housing.

Question is, with the above mentioned, what injector would be recommended? Would the stock 1990 9mm units flow enough to drive the 40? Or would something like a DDP stage 1 or 2 type injector work? Maybe PODs? Bosch 190s?

I do not want smoke and I would still like to retain a good fuel economy (yes I know mpg is dictated by ones right foot! ) so I am looking for a balanced engine. I suspect the current injectors could work but with the 40, it could likely use a bit more.

Thoughts? Suggestions?

Primary use is towing 11K lbs as well as daily driving only in summer months. HP wise I currently put down 274/720 at the wheels as it sits. Would not mind a bit more kick for the long hills but I also do not want to get into studs, head gaskets, etc so no not looking for a 150 HP + injector.

Thanks!

Robert

[skilletky]

Stock non Intercooled injectors can make a pretty good amount of power. Maybe just a different turbo, fuel pin ( or grind your own), and maybe mess with your timing more.

[RCCUMMINS89]

I'd see where you like it after another turbo.

[Bschwarzli]

LOL @ your avatar skillet! Thats good!

As for your suggestions guys, I am wondering too if that would also make the most sense. I know I cant adjust the fuel screw anymore as I am 1/8 turn away from it walking its own RPM up (that was fun to watch! ) so I would need other methods....

Anyone ever run a Super 40 with factory injectors?

[cmann250]

I was going to put a Super40 on my '89, but I found an HX35 suited me. My HX is stock with the 12cm gated housing, I have a '94 model intercooler, a Cummins low pressure piston lift pump, an injection pump set up closer to yours, and I made 274/503 due to the stock 260k mile 727.

A hybrid HX35/40 or the Super 40 will be my next step if I ever feel the need to take another step. I know I could use more air, but it hasn't melted and it burns pretty clean.

Either way, please keep us up dated because I'm at the same point on the journey.

[Bschwarzli]

Hmmm. Interesting. When I swapped from 727 to getrag I gained 20 HP even. I cant recall the TQ number though. Nothing else changed at that time.

Will for sure keep you all in the loop.

[RCCUMMINS89]

you probably gained more torque than anything else. A manual allows the motor to put down the power where it wants to.... an automatic is like a hydraulic pump, the higher the prm the more efficient (to a degree) meaning a nonlock up auto starts putting the power down after our pumps done.

[cmann250]

I was on a Dynojet and the operator applied a couple different loads. Maybe an inertia dyno would give a different torque number?

Like RC mentioned, my curve was smooth as can be and both curves were the same shape.

[RCCUMMINS89]

due to nothing more than rpm..... a manual in many cases will put down a lot more torque and close to the same hp.

[galakinokis]

long time ago i had 3 or 400 hp injectors in my 91. timing was up a tooth or so, ran awesome down the interstate. not really hot rodding it, but the sweet spot was about 73. Now i have stock injectors and 70 is screaming.

[Tacoclaw]

I would think an auto would provide with an increased torque number but a lesser HP number. Considering the TC's job is technically torque multiplication, and the engine is able to get to a happier RPM faster, I would think it would provide superior torque at the rear wheels at low speeds but the stick would destroy it at midrange and upper RPMs with it's loading abilities and efficiency.

[RCCUMMINS89]

The drum's acceleration is read out in torque. An automatic is not efficient until upper rpms...............this nets a more matched tq/hp number to what a manual truck would do..........in the upper rpms.

At lower rpms, where our trucks are more efficient a manual puts the power down, where an auto puts down a lesser percentage.

So, on a stockish....non lock up auto.............it will put down a lower tq number and closee to the same hp number as a manual.

[RCCUMMINS89]

Let me re phrase this.............

Think of an automatic as a hydraulic pump................the higher the rpms (engine rpms) the more efficient it is.