Which injectors for modest HP upgrad

[MWehmeyer]

Question that I didn't really see addressed in a search of the forum.



I have a 91 that started life as a non-IC. PO added an intercooler at some point. I was thinking of upgrading to 190's but wonder if that's the right decison. I'm assuming that I should always be looking for non-IC engine goodies.



TIA,

Mike

 

[dpuckett]

I have no personal experience, but adding 185s didnt give people any power increase in the past. In fact, some LOST power with 185s over stock nonIC. And, since the 190s are 5hp over the 185s, they may not net you much over your stockers.



What kind of boost and EGT do you see? With stock injectors and pump settings, you should be at or slightly above 20psi. WIth stock injectors and a PDR HX35-18, I could peg a 40psi gauge (and near 1400 deg) on my early 91. Still averaged 20+ MPG with 4. 10s. A previous owner had it turned up about 50%, and it lasted 300K.



Point is, you can gain much more from pump tweaks/ tuning alone than those of us with later trucks. Try that and see, unless you just want some new sticks.



Another ~30hp option is PODs, if you can stand a little smoke.



Daniel

 

[bgilbert]

Non-IC'd injectors are about the same as 190's. You would see no gain. Your only upgrade would be POD's (+~30hp) or a custom set $$$ (+??). As far as looking for goodies, don't even bother looking for something that says for non-intercooled engines. We're lucky enough to see something for a 1st gen period. You can use the smaller 7mm tipped injectors, you just have to use a copper reducer bushing 9mm-7mm. $8 each from PDR. This would be what you need if you bought POD's or a custom set. Custom set would be from any reputable shop that can build EDM'd injectors.

 

[MWehmeyer]

... .



What kind of boost and EGT do you see? With stock injectors and pump settings, you should be at or slightly above 20psi. WIth stock injectors and a PDR HX35-18, I could peg a 40psi gauge (and near 1400 deg) on my early 91. Still averaged 20+ MPG with 4. 10s. A previous owner had it turned up about 50%, and it lasted 300K.



Point is, you can gain much more from pump tweaks/ tuning alone than those of us with later trucks. Try that and see, unless you just want some new sticks.



Another ~30hp option is PODs, if you can stand a little smoke.



Daniel

Daniel - PODs are not an option because of the smoke :|



As far as boost goes - installed a 4" exhaust along with the gages - haven't seen over 12 pulling a 6% slope with a 9' high load dragging in the wind.



Haven't cracked 1000 on the egt even on the 6%.



Not looking to buy new injectors - looking for a modest HP increase without hurting mileage too bad - will be pulling a 24' 5er all over the west starting in August.



Getting 20 - 21 mpg on the hills and city - 22 on level interstate running around 60 mph with 355 gears (assuming - can't read the center number on the equipment list).



Pump is at stock timing and looks like all the factory covers are in place on the pump.



Mike

 

[dpuckett]

If you're only seeing 12psi tops, look at your AFC line from the pump to the head. Seems like i ran my 91 w/o the line for a while, and could still make 20psi. If your potmetal line is cracked, look in the discontinued parts forum for repair options. Go back 2 years, I think.



If that doesnt fix it, I'd say you have pump issues. And, more available power wont hurt you MPGs, IF things are up to snuff, and IF you go easy on the pedal.



-DP



PS- noticed your air filter, check your intake hose at next oil change for dirt in it.

 

[JLEONARD]

Even I was seeing over 20 psi boost with my stock injectors and only very modest pump mods.

For good power and not too much smoke try the Bully Dog +50s if you can still find them.

Some day I'll get a new boost gage so I'll know how much more than 30 psi I'm getting. And I can still get 24/25 mpg if I keep my foot light.

Jay

 

[Greenleaf]

This guy brought a Non IC unit to me with a manual transmission ( I can load that thing good) and he had 9 psi. I didn't tell him his air boost/signal line to the pump was busted off... ... ... . LOL He has a sour taste for the Cummins untill I got ahold of it.



-S