IDI or DSL - is there a difference?

[Brutis]

I just started on the forum a couple of days ago. This is my first post - Hope I do it right. It's great and I've learned a lot. I just bought my first diesel. It's great, runs great, but I'm new to working on diesels.

I recently bought a 1990 F-350 dually with a 10' box. It has a 7.3 motor. I have been under the impression that it was a IDI. It's obviously non- powerstroke, non turbo. However, I was thumbing through a manuel yesturday and was looking at the engine identification page and the engine code was M. According to the manuel that makes it a DSL not an IDI.

I want to start doing some modification to boost mpg's, but I want to make sure I start off with the right info. Can I put a turbo on my motor? What's the difference btwn DSL an IDI.

I'd appreciate any input on these subjects, including how any of you have improved power and (especially) mpgs on the same motor. Thanks a lot.

 

[91crew]

Thats just telling you that you have a truck with a diesel motor. That diesel motor would be the IDI.

 

[Brutis]

Thanks. Is there much that can be done with those motors? It's my daily driver, so I'd like to get the most mpgs out of it - also, being a guy I'd like more power!

 

[dyoung14]

Thanks. Is there much that can be done with those motors? It's my daily driver, so I'd like to get the most mpgs out of it - also, being a guy I'd like more power!

turbo gets you the most power for the money, what gears does it have? and does it have ab overdrive transmission in it?

 

[Brutis]

I might be wrong, but I'm pretty sure its 4:10. It has the E4OD tranny. I see you've got custom ram air. I'm working on that right now.

 

[91f2504x4]

The best thing you can do for that truck to increase mileage is install a turbo and then put your right foot on a diet, the lighter that foot is the better mileage you will get. But if you are like me the turbo will lead to the right foot being heavier because you like the sound of the turbo and then there goes your mileage.

 

[dyoung14]

I might be wrong, but I'm pretty sure its 4:10. It has the E4OD tranny. I see you've got custom ram air. I'm working on that right now.

yes it seemed to help alot i could tell a big difference, when i actaully get an egt gauge that i trust im going to experiment between a ram-air and a cowl induction intake and see which one lowers egts the most and which one makes more boost, my guess is the ram-air intake will win

 

[dyoung14]

The best thing you can do for that truck to increase mileage is install a turbo and then put your right foot on a diet, the lighter that foot is the better mileage you will get. But if you are like me the turbo will lead to the right foot being heavier because you like the sound of the turbo and then there goes your mileage.

and 4:10 gears arent helping that much ether altho i have never drove an e40d truck so i have no idea how they act with low gears

 

[91f2504x4]

Just curious what that truck weighs with that box on it, I can tell it's 2wd so thats a little less weight but that box still doesn't look light. Maybe you can try the old homer simpson trick, get out your old pickaxe and put some speed holes in it

 

[Optikalillushun]

ram air, good exhaust and turn up the pump are good places to start.

when i turned up my pump after the ram air i actually picked up a few mpgs if i keep my foot out of it. i also had new injectors i put in while i was tinkering which helped. pump and injector condition will dictate power to a point so dont over look them either. things like return lines and glow plugs are cheap and easy to change so if its giving u a little hassle starting then it may be a place to look into.

 

[Chevyboy_0]

Exactly as everyone has said, exhaust, intake and turbo if the funds permit, the easier the air gets in and out will make a good difference in the way the motor reacts and runs, but before you get crazy with anything make sure you get some good gauges, cause "Knowledge Is Power!" and I just plain don't trust the stock ones

 

[RLDSL]

Your tag in your door jamshould tell you the axle code, look in the stickys at the beginning of this forum and there is a breakdown of the axle codes so you'll know for sure what you have.

As far as mods, It looks like with the installation of my new brownie box ( auxiliary transmission ) I'm getting about 13.1 mpg towing ( grossing a little over 16k ) up from 11.5 before the brownie install. Total fuel saving goodies on there are ATS )088 turbo, Hypermax cowl induction, Amsoil synthetic lubricants throughout, Spicer 5831 3 speed brownie , Howes Meaner power cleaner in the tank, a very steady right foot, and the urge to need to be there yesterday having dissapated at least a decade ago

 

[k_williams1982]

But if you are like me the turbo will lead to the right foot being heavier because you like the sound of the turbo and then there goes your mileage.

Is that where my mileage went? I might as well weld the pedal to the floor then...

As for the topic, I have 4.10 gears and a C6. On the highway @ 60 mph and empty, I'm getting around 16-17 mpg with the pump up two flats and running about 2,500 on the tach. In town, I'm getting about 14-15 mpg because I can't stand to be beat off the line by the ricer next to me (or to lay smoke out for that BMW convertable that had to ride my rear bumper out of the last signal). I am running a set of 315/75R16 (35") tires though, which "changes" my ratios to be about 3.73 gears with stock size tires. I bet the biggest chuck of your mileage is going to hauling that box on the back of the truck.

 

[subway]

something that no one has mentioned is just making sure your timing is set right. you need a meter to do it properly but the pump and injectors start wearing to the retarded side timing wise as they age. simply fixing the timing can be a big boost putting your engine back into the propely tuned range.

 

[Smokey73]

I think these things see peak power on the highway at around 2400-2600rpms. The best mileage comes in at about 1800, no matter the gears or tires