How much power could I expect to gain from adding a turbo to a 6.9L? I've been told that these injector pumps have no way to increase fueling when boost is present, so Im thinking it wont help much.
Also, is there a name for the holes that connect the prechambers to the cylinders? and is it possible that making them bigger could improve power or throttle response?

 

You can turn the pump up manually to inject more fuel. I am sure somebody will be here soon to tell you how. From what I have been told it adds a lot of power. Just know that the stock 6.9 can only take about 15 psi of boost.

 

wouldn't that just make it smoke all over the place until the turbo spooled up

 

A proper turbocharger will build boost as the fuel flow ramps up so in reality you have access to more power with less or smoke. I have an older turbo kit that I got used and I can drive smoke free even under moderate load. Newer turbo kits are usually wastegated and can do even better.

I would not go past 10 PSI under any conditions with a 6.9L that has stock head bolts or head gasket leaks can result. Having said that, even with ARP head studs, I have yet to go past 10 PSI. No point since there is enough power already for my needs.

Here is the article on how to adjust the fuel pressure:
"Fuel injection pump adjustment article"

But unless you add a turbo you WILL end up with a lot of smoke and higher fuel consumption and dangerously high EGTs.

Officially the power can go up to 250Hp and close to 500 Ft/lbs of torque. In theory, more might be possible, but to date I have not seen any actual dyno resuts that show much better. I doubt my truck is actually putting out 250Hp.

 

Iman901,
What you say is partially correct about the fuel.

If you set the fuel real high, then just stomp the throttle at low RPM, yes you make a lot of smoke.

But if you take off easy at part throttle, increase throttle application as the turbo spools, you can make around 50% more power with very little smoke.

IDI engines are non computer controlled, you have to be the computer.

I would recommend you install a pyrometer before you turn the fuel up.
It is possible to melt pistons, easier than you think, with increase fuel delivery.

 

[/QUOTE]huge difference between turbo &non t. for me a turbo is a MUST have. but i use it to tow up hill both ways with snow over my head.................if you run empty all the time, then it depends on your cash level if its worth it to you.

,listen to dave!

 

i turned up the pump on my 94 F-350 7.3IDI and have found tat the power level has gone up quite a bit. but i also installed a dual ram air intake and k&n air filter, i also installed dual 2 1/2 to single 4 inch exhaust. i plan on installing a ATS turbo kit on my truck soon, and was told tat the turbo kit would bring me up to 350HP and 650 LBS/FT of torque.......but tats wat i was told. but the basic rule to any diesel is more air more power tats if your fuel is turned up though. JUST WATCH TAT PYROMETER ause it will get hot!!!

 

turbo it pyro and add another air snout then play with turning up the pump... my 87 will out pull my in laws 93 both auto but mine has turbo and he's a 7.3 he may get me off line sometimes but when we hit the hills loaded(last load was 7,000 pounds counting the trailer) I could blow past him we both was shooting out the black smoke but at least I was gaining speed ....

 

The turbo will help tromendesly (it did on my 7.3 and Im sure the 6.9 would be close to the same) Your question on it smoking before the trubo spools up, Yes, You might get a quick puff of smoke on take off but my new banks trubo spools up very quick and I have no smoke at any throttle position (I didn't turn my fuel up yet) and It used to smoke alot before the turbo. Now it runs great.

It was kinda doggie before since the truck weighs 8,000 lbs and any load I had sent me up to almost 12,000 lbs or more. Now it pulls much better,I get on the highway much quicker loaded or not, It supprisingly has great takeoff power at standstill since it spools very quick.

Another thing, Going up hill and/or very stong head winds at 70 mph was almost full throttle sometimes, now I may give it a little over 1/4 throttle in any weather/road conditions. It works great!!! Im told it lowers your egts and I do get better fuel milage while under heavy loads. I bought the one at Bankspower.com. They have a whole page of info on it and it is JUST FOR THESE engines. (along with the 6.2 and 6.5 but that kit is a little different for gm) It is already wastgated at 10-11psi so you will not overboost and came with all the hardware needed to install it.

For the banks turbo I got,
Less smoke, Lots more power (the equivelent of an UNMODIFIED 7.3 powerstorke up to 2003.)
Better acceleration at any speed (Makes passing much easier)
Pulls loads alot better with better mpg
Lower egts (if pump set to factory specs)
Quick spool turbo with wastgate already set at 10psi
Much bigger and complete exhaust system
Built spacificly for Our trucks.

I have a very small color brochure if you want any scaned pictures, let me know. It will give you the specs compared to stock.

 

This is a tough question to answer...in my opinion
-yes a turbo will give you more power than any other mod you can do
-but a 6.9 will NOT take much in the way of boost, without a stud kit
-pyrometer is a must
-price of a turbo kit is cost more than some these trucks are worth
-but when towing in high altitude, there is no subsitution for what a turbo can do for your engine....but watch that pyro

Hope this helps?

 

Turbo, Turbo,Turbo,Turbo,Turbo REPEAT....Turbo, Turbo, Turbo............

 

I second that!!!!... and whatever you do......!!!!!! LISTEN TO DAVE !!!!!!

 

And as the pyrometer goes that everyone keeps talking about, My kit inclued that with the boost guage as well. As posted above, I guess the turbo could be more than the truck is worth but if its the truck you Like and don't care about selling it or its value, who cares if it cost more than the truck is worth. (except for insurance issues) Also, Going on vactaion in 2 weeks in the mountians that have a few passes at about 12,000 feet above sealevel. Can't wait to see how well it pulls.