http://www.turbodieselregister.com/f...threadid=71525

 

Hi Dennis....

You are gonna have so much fun with this truck it should be illegal....
No need to mention gauges, that has been well covered...

I suggest you try to get your hands on some 185 injectors (they just went up in price by 100% thanks to Bosch, Cummins and DC, or so the rumor goes.)
You can get some updated injectors for near the same cost as the old 185's.
You're looking for the 190 HP injectors. We have some at PDR.

Why?? Well, one thing you want to do is ease the load on the injection pump. Ok, so how does a larger injector do that.....
Well, it flows more fuel due to it's tip size/design.
You can leave your pump settings basically the same and still gain alot more performance. Your gauges will tell you were you're at with temps right....

I've tried the stock 18.5cm turbo housing, the 16cm and the 14cm non-wastegated housing.
Running the exact same pump/injector/settings you will find...
The smaller the housing the faster it will wind up and "get up on boost". You will also find that it will give you real good (low) EGT's at the lower/mid range as well, and then further up, it will show accelerated EGT rise rates due to it's small internal size and the inlet to it being smaller.

The larger the housing, the slower it will spool up in general. Just pretend that the 12cm will spool up to max boost in 1.5 seconds, the 14cm in 2.0 seconds, the 16cm in 2.75 seconds and so forth. (THESE ARE JUST EXAMPLES AND NOT FACTS)
Also the larger housing will allow your EGT's to rise a bit faster at the lower/mid range and then pull the temps back down in the mid/upper range as the turbo "comes up on boost".
You need to decide your particular application, were you want your HP/Torque etc.

Of the sizes I've tried, I have come back to the 16cm three times and that is were I'm at right now.
If you have the correct injectors, pump settings/fueling/timing etc etc, you will find the 16 to be a spunky little housing with the "wind" for the upper range such as on the highway.
BTW, the 16cm and the 18cm have an almost identical performance/air flow at the upper end. So, you get the 18cm "legs" at the upper end, with the 16cm spool up.
Even that can be tweaked to improve it if you want. You can make the 16 spool quicker, in fact very near a 14cm if need be. That is of coure, a proprietary modification that we do at PDR.
If you choose the 14cm try to get a wastegated housing. That will help keep you from going to far up into the "high drive pressure" range which results in higher EGT's.

Clear as mud??? Hope that helps put things in perspective a bit...

pastor bob.

 

Hi Bob,
I've enjoyed reading your post! I am getting a big lick out of driving the truck, but I tell you, holding that big cup of coffee in the morning is an exercise in balance and counterbalance!

I've found a 12cm housing courtesy of a fellow on the list, but am not going to put it on until I get everything together (gauges, etc), and read up a lot more on all of it. Since I'm so new to this and the potential cost if I screw up is high, I want to be sure I'm doing it right!

That's a good explanation of the pros and cons of the housing size. Even as a former college English major, I understand it!

Mostly, I'll be using my truck for daily transportation, some occasional motorcycle hauling (in the bed) and trailering. Every now and then a car hauler. Highway speeds I'll keep at 80 or less, and so far I rarely stomp the throttle.

Denis

 

That's a helpfl thread, CB. Thanks!

 

Thanks for the valuable information Pastor Bob.

As I have been looking at injectors, I've seen that Piers lists both the Bosch 185 Performance injector and the Bosch 190 Performance injector. I assume that those are the two mentioned above. What are the primary characteristic differences between the two and if they are similar, why is one more than twice the price of the other? I'd have assumed that if one went up, the other would have as well.

I'm getting ready to add the 16cm housing to my '92 and some pump timing will follow that and then probably some injectors.

 

Is the line going to the afc housing important? Mine broke when I tried to remove it. Can't tell its broke til u try to remove the top, it slides back and might have a lil gap in the hose.

 

Yes, it is extremely important. That line provides boost to the top of the AFC diaphragm, which pushes down the fuel pin to give you more fuel when the turbo is making boost. You cannot develop full power without it!

 

I'm makin all kinds of smkoe now, I wounder how much it'll be when I get that replaced I just rembered the 92 has a new pupm on it. Mabye its time for a swap. Mabye its a newer one with more power.