How to better mpg on Detroit 60Series?

Trouble65-You really need to make your air intake and feul pressure is right. The best way to keep track of your air filters is with an air restriction GAUGE,those filter idicators are garbage.I have seen people talking about drilling the restrictor fitting which is a good thing to do but you guys should know it is not just a drill to a size situation.Every truck has different return line sizes etc. that can affect the pressure the engine sees.The correct pressure to get to is no more than 65psi. at 1800rpm. no load on the engine.I have never had to modify the check valve to get to 65psi.You also spoke of your exhaust vavle adjustment being loose...that is not really common they usually tighten up over time,maybe someone really set the top end up badly.If you would like a good DD shop in Houston go to S&S thier truck shop is on the north side of I-10 across from the Budwieser plant.They are a very big DD distributor.If you are only running aroud Texas I would be considering running rib type(steer)tires out back instead of lug type.If you are running LP 24.5's you could gear 3.7 and be safe 3.55 may be just a little too much for that engine program.If you want to check at what RPM your power/response starts for your engines program do the following.(you must have a turbo boost gauge)Drive the truck with a load, with the trans. in 1:1 let engine get down to 1200rpm. and stand on the trottle,wide open watch the boost guage and tach,when you seen the boost jump up note that engine speed.What ever that RPM. that will be the RPM that the engines power band starts.That is the RPM, I would gear the truck for at the road speed you want operate at.I hope this helps

 

PaulE,for what it is worth I have run 900hp.+ with marine injectors etc. and never touched that check valve for anything other than to make sure it was clean and working.With some of my bigger programs I actually had to go back to close to a .80 restrictor so it would keep the injectors full.

 

DD14, i have drilled fitting on stock DDs only. i did my DD3 with press gauge, ended up with .109 for 65 psi. did 2 others .104 and .98 both 65 psi. im amazed how sensitive DDs are to this mod. a few thou makes quite a diff... have had friends go .112 without using gauge and just go. not what i would do but it worked ok no problems that i know of.... thanks for info

 

DD14, are those marine ECMs for 900 hp ? are DD ECMs easier to get inside than CAT ? brief description if you woudnt mind .

 

My ECM was/is not a marine,lets just say I have a "direct connection".I do not think they are easy to get into and if you could you would want to be a DD engineer to deal with it,there are so many timing tables and values in there it is insane.It definetly isn't a matter of changing a few codes.For what it is worth there are some "off road" programs available I'm recalling to about 775 hp. but that is with a 14ltr.I can look for numbers I believe i have some build sheets for these engines.I am also sure the 14ltr. marines went to about 1000hp.One nice thing is about the DD ECMs is you can have multiple programs my one has 3 one for everyday about 750hp.aad one for play at 900+hp. and 2500rpm. and one for smoke tests.Those are hp#s to the wheels.Hope I answerd your question.

 

On you remarks about the feul pressure,it definetly is better to set them up with a gauge but if you had time and patience you could experiment with seeing how low you can get the pressure until it starts cavitating the injectors to a point the lower the better,but at idle that feul pressure gauge with the needle tapping off the low side pin will drive you crazy...and after a while break off the needle.

 

DD14, thanks for the info, im a gearhead, i love this stuff. im always wondering "what if i did "............ makes my head hurt... reading all i can here looking to learn more.

 

all of that negative or suppositions simply is to do a test. it cost arounds $40-60 i havent heard anybody in the other 4 forums whine about doing this (check valve) elbow 90 but i can assure you hundred of series 60 with diesel in the oil. come on give me a break! that is because all the presure in the head, the only thing i can tell you is ,that you lying to the computer that injects more fuel. remember that theres a sensor in the filter base and that regulates the flow of the fuel. its simple to understand its not rocket science. if you have a spare valve you have nothing to lose but much to gain.

 

There is a sensor in the what filter base that regulates the flow of feul to what?I guess I am going to learn something new.I wonder who is doing the whining and where,but just to keep things clear the CHECK VAVLE and the 90deg. elbow (restrictor fitting) are two different things.Sure for $40-$60 you don't have much to loose but a gain??If I can get high feul pressure low enough at 2500 rpm. to not completely fill the injectors that check vavle aint holding anything back!Sorry if I offended you.

 

the truth is im not offended but now you are going to learn something new. i saw this and learned it since california sent all the trucks(mandatory) to go to the dealers to check the hp and smog. i dont remember around 1992-2001 ( all types of brands of trucks were there). but in the series 60 simply they put another sensor in the base of the filter (but that sensor has a number and nobody can touch it). all of the drivers had problems because of the power and if you dont believe me just ask anybody from California. after doing this trick i put this happy face to this driver and to this date i never received a complaint