Ok ive had my truck since aug no engine probs 92.5 3/4 4x4 had a getrag but that blew up so i swapped a NV4500 in, put on 255/85/16 on alum 7' rims, in oct. I installed boost and pyro (after turbo) guages, empty at 65 mph its at 725 and 3 psi 2400 rpm ,hauling 18 foot trailer w 4200 sport fury 800 5 psi,12 max of boost lock coller still on fuel screw,after a week with guages turned up the pump 1 1/2 turns got 17 psi and same egts, put the 16 cm housing on same egts and boost. trucks averaging 18 mpg hwy/city

this week end i pulled a light 14 ft trailer with 2 quads bunch of furniture and a dirt bike to calgary. egts were going nuts hitting some times up too 1000 it was nuts and sucking fuel like nobodys business barley could do 65 mph so i pulled over and turned the fuel screw down a half turn truck was gutless like a volkswagon and still 875-900 egts at 65 mph pulling 8 psi i was mad!! so i had to stay at 60 mph 800degress 5 psi to keep it in contol got 15.5 mpg what is going on??? injectors??? i have always run the same diesel and howes treatment any ideas?? or is this normal I do alot of towing with my truck and want to at least do the speed limit it drives me nuts getting past by chevs and fords, thanks guys thow any ideas you have

***edit forgot has fresh clean k and n with 4 2 1/2 holes in the air box- made the truck spool up faster and have better response

 

My first guess is that you have an air leak which has recently developed, and that explains the high EGT's and low boost and power on the last trip. It is also possible that you have an exhaust leak before the turbo.

My second observation is that for a particular engine and trubo combination, it is impossible to increase boost without increasing EGT's at a given engine speed. So, when you say that you turned up the fuel, and your boost increased but EGT's did not, there is something wrong. Additionally, the 16cm housing should have lowered EGT's and raised manifold pressure, maybe not a huge amount, but enough to notice. This makes me suspect that there is something wrong with your manifold pressure guage and or pyrometer.

Check all of the plumbing from the turbo to the manifold, and take it from there. You will be able to get better performance out of her . . . Just have to be methodical and it will all turn out well.

Good luck,

Alec

 

Mabye it was the 7" rims.
Check the air filter.

 

For each housing size you go down, you will see roughly 2 - 2.5 psi more boost pressure assuming nothing else is changed....you will see more if you tweak your pump at the same time of course....
I'd first check for boost leaks...pull all the rubber boots on the turbo/intercooler system and inspect them closely...roll the rubber between your fingers like rolling a cigarette...look for signs of cracking, kind like the old tires get, sort "dry rot" kinda thing.

If you have the ability to make up a simple rubber fitting to go over the turbo intake and plug the other end with a cap then install a valve with air guage on it. Pressurize the system with no more than 20 psi and watch the guage.....it will leak down slowly because not all the valves are closed but it should be a slow drop in pressure. If you see a fairly quick drop then you've got leaks in the IC. Go hunting with some soapy water in a squirt bottle and keep pressurizing while you squirt and listen.

Your pyro readings are not that excessive to be honest. You are working the truck/engine/turbo and you will see some EGT rise. At 17psi boost on a post-turbo pyro install you would add roughly 170 -180*F to the EGT gauge reading. So, if your pyro says 1000*F add, say, 180 for safety sake and you get 1180*F. You can do that all day long with no trouble. You will have to watch water temps as they may start to rise if you hold that temp/load for extended periods but in terms of EGT's that is well within the "good to go" range. In fact you can run 1200*F - 1250*F all day...again you need to watch your coolant temps as that EGT temp will begin to "staturate" the engine/cooling system with heat...eventually the cooling system will start to fall behind and your water temps will rise...that is the cue to ease up on the throttle.

You don't mention if you tweaked the AFC cone....personally I'd tweak that first, before the full fuel screw. The AFC cone will determine the RATE of fueling increase at a given boost pressure.
So, you can set the AFC to max fueling and then tune the spring to hold off the extra fueling at low boost a bit longer till the turbo can get up on boost a bit before the fueling rate increases.
Drive it a few days like that and keep track of your readings....then, work on your full fuel screw a bit at a time. I recommend no more than 1/4 turns at a time...drive and watch the guages, adjust as needed.
Keep in mind that the amount of fuel increase from the fuel screw, sends a larger portion (or percentage) of the fuel increase to the low/mid range RPM band and less to the high-mid and WOT range.
So, if your AFC adjustment is not quite enough for your liking you can even ease that back a tad and bring up the full fuel screw a 1/4 turn.

If you are using additive as you mention, you are doing your pump/lines/injectors a major favor too....good on ya bud...

Hope that helps with your situation 440FURYHobie...

pb..

 

Thanks bushy looks like its time to pull the AFC cover and do some tuning, awsome reply thanks!! keep you all posted