New Owner Intro & Questions

[JJump]

Hello First Gens,

I'm new to the TDR-thank you for the great web site! I recently purchased a '93 350 LE Club Cab with a 5 speed Getrag, 4. 10 rear axle & duals. The truck happened to come with a 30 ft 5th wheel travel trailer & the whole combo was set-up to work together when new. The clock shows 110k miles & it's a clean machine (so is the trailer). This is my first diesel vehicle and so far I'm pretty happy with it. But from reading the performance figures some of you folks are posting, there is a lot of untapped potential available.

The combo weighs in at 13,700 lbs (trailer 7100, truck 6600) So far I've pulled the trailer about 1000 miles, mostly interstate, running between 62-65 mph indicated (235/85 x 16 tires)in moderate rolling terrain through Alabama, Tenn, Ky, MO, and IL. In those runs I've averaged about 11mpg with my best being 12. 5. Maintenance records are a bit sketchy but I don't believe it was abused. Since purchasing I've replaced the air , fuel, and oil filter along with an oil change. I took it into a local diesel mechanic to have him check it out & he checked/reset valve lash (most ok, a couple tight but not too tight). While he was under the hood he gave a couple tweeks to the pump too. It appears that he might have lowered the idle slightly, advanced the pump about 1/8", and raised the governed top speed a couple hundred rpm. After he did his adjustments the truck definately has a lot more kick (a lot more!!) in the mid range & gave it a top speed unloaded of 80mph, but it didn't appear to make a huge difference in the MPG-last weekend, pulling the trailer I went 215 miles on 17. 5 gallons of fuel... . about 12. 25 mpg. Before the adjustments there was only a puff of black smoke at start-up. Now I see some black/grey smoke in the side view mirror as I'm going through the gears with a heavy foot, but the smoke goes away as the turbo catches up. It seems to be making a bit more noise now too-kind of a groaning while pulling the trailer up a hill.





What I'm really after is better fuel efficiency-I want to run with you guys! From what I understand, my trailer load is nothing compared to what lots of folks do. I'd really like to see 16 mpg while towing the trailer & close to 20 unladen. I realize that will take some mods & that's ok. I'll be looking at some gages (tach, pyro, & boost) in the near future. I hope to gain the information, contacts, and skills to realize my goals through my subscription to the TDR. Any advice gladly accepted!



Thanks for listening

 

[Greenleaf]

Caution is Advised!!!!!!!!!!!!!!!!

WE, the members of the first gen forum, together with TDR as a whole, are not responsible, in whole or in part, to the addition of better performance,increased horsepower and the increasingly large grin which you will or may be currently experiencing.



If you should begin to experience difficulties in performing daily duties without a daily fix of TDR/first gen forum, lying awake late nights in wonderment of increased performance and more SMOKE ... ... ... ... ... . GET HELP IMMEDIATELY.



Keep this and all other high performance diesel powered vehicles out of the reach of children.



And welcome



Scott

 

[JLEONARD]

to the addition of better performance,increased horsepower



Scott,

That's funny, but you should edit and replace addition with adiction. .



Oh, yes, welcome aboard JJump



Jay

 

[Bluebird]

Welcome home!

Welcome JJump to the best Diesel community on the planet. Looks like you jumped-in feet first. Nice rig and trailer set-up. If you don't find what you need here, I don't know what other life forms you will have to contact... for the answers

Patrick.

 

[jbolt]

Additional Warnings

Use with adequate ventilation

 

[farmall]

Hello and welcome. To be honest with you, I think expecting 16 mpg loaded is not going to happen. I avg. 18. 5 empty with a auto transmission and between 11 to 12. 5 loaded, depending on how heavy. It is probably possible to get a little better, but I would think you are about where most people are towing. Don't forget what that travel trailer lacks in wieght, it more than makes up for in wind resistance.



Bill

 

[Bob Beauchaine]

Welcome aboard the RWHP train I know you'll like your fellow 12 steppers your addiction is NOT curable - but who cares.



As far as power and mileage go just look around the site and you'll get some great ideas. Your 4. 10's are great for towing but as you get up there in speed you'll find the mileage drop off some. I have always believed that your right foot is the best mileage control you've got.



Bob

 

[Philip]

If your truck does not have a pyro setup in the exhaust. I would reccommend it real fast. With the fuel turned up and no way to track it. You could get into trouble towing.



16 MPG towing the load you listed. Not likely. My best milage towing to date was 14 MPG with a gross of 15k running 70 MPH. But look in my sig. You will see I am running 3:08's also.



Welcome to the TDR.

 

[Crash_AF]

Yep, as others have said, the best mod you can do is gauges... after that, if you're not afraid of the cost, have the gearing changed out from the 4. 11s to something in the 3. 55 or 3. 08 range and up your horsepower to compensate.



If you don't want to drop the coin to change rear gears or want to keep them for added grunt, consider a gear vendors (or other aftermarket) overdrive. Anything that will reduce cruise RPMs will net a mileage gain.



Good luck with your truck and welcome to the TDR, I'm sure you'll find it the best $35 you've ever spent. (I know I have)



Later,

Joe H

 

[dpuckett]

mileage

First, have your injectors pop tested. If they are popping open at too low a pressure, they will allow in more fuel, not atomized as well as it should be, thus netting less than optimal mpgs. Not to mention clogging of the tips if the previous owner(s) never added any Power Service or Stanadyne. I had a 93 that was popping 800 psi low after "only" 150K. I think anything less than 19-21 empty points to a problem somewhere, unles you just HAMMER the p*ss out of it from every green light. The 4. 10s dont help a whole lot, but if you just go a little slower, you should get in the high teens empty. Mine has 5 injectors popping at 3100 (spec is 3550), one stuck open (okay, pops at 650psi), and I get 18-19 around town. AS for your towing mpgs, I got 12-14 towing 22-24K GCVW at 60 in 4th with 3. 54s (EGT control, not power concerns), total height of about 10-11 ft, so 16 with your TT isnt too much to ask for, but that depends on how high it sits too. If it is 13' 6" you will drop 1 or 2, but 12 mpg sounds a little low to me.

SEcond, get a pyrometer and boost guage set up on your rig. A) get a 40 psi guage, you will peg a 30 psi guage with just some pump tweaks and a smaller housing; and B) put the thermocouple in the manifold. THey SAY a 300* difference or figure 10 deg for every psi of boost, etc, etc. Case in point. I had my t-couple in the exhaust pipe for a week or so before moving where it bleonged, and I rarely hit 900 deg, 28 psi WOT. Found a shop to drill and tap the manifold; moved probe there, and I could easily hit 1300 deg, and go farther had I had the gumption to do so. 28psi only equals a 280deg difference. Hmmm. .

Third, get a smaller exhaust housing on the hot side of your trbo. Sounds like a 16 NWG (Non WasteGated) would work for you , and be most cost effective. What exactly did the mechanic do to the pump? You cant just turn in the full power screw without smoking up a storm; other adjustments have to be made to reduce smoke, if that is your goal (and it sounds like it is). If he cant/ wont tell you, FIND SOMEONE ELSE TO WORK ON IT. It is worth a long drive to get it done right the first time, or do like I did, and learn about it yourself, that way it ALWAYS gets done right the first time.



Good luck with your "new" rig, and welcome to the TDR. Best $35 I've spent in a while.



Daniel

 

[dpuckett]

injectors

I just htought of one more thing. If you're after better mpgs and a little extra umpff, go to www.f1diesel.com They make EDM (electronic discharge machining) injectors. They have me sold on them, just have to some up with the $$$ to get them. PW or POD injectors will add some extra HP/ Tq, and there are a few places that advertise here (PDR, for one) that sell them in balanced sets, but I still like the idea of a really fine fuel spray and cleaner burn.

 

[BushWakr - RIP]

Hey welcome to the asylum, were the inmates run the show... .



Pastor Bob

Our Lady Of Acceleration Church... .

 

["Mad Max"]

Welcome to the party!

Welcome abord the Cummins express! The inmates-I mean fellow TDR members in here have either already done or are about to do any and everything doable on these rigs.



However, if you keep reading these threads you will get inevitable hooked - It happens to everyone, just like it has happened to all of us... . something about checking in and never being able to leave... (isn't there a song about that... . ) either way, diesels don't suck. If you've ever tweaked a small block 340 or a 440-6, just wait until you tap into this place. ANYTHING you can think of is in here, and the congregation has large amounts of experience..... and we love to read these threads until the wee hours of the night causing everyone at work to wonder why our eyes are all bloodshot... ...

... and all Bob's children said yay!



Anyway, glad to have you with us!

- Sam

 

["Mad Max"]

Seriously tho - gauges

Ok, ok, in all seriousnessness (it's laaaate), you'll want to baseline your rig. Sounds like you got the engine tuned up and checked the main functional items. Now you'll definitely want to invest in some gauges - it is the only way to know what is really going on. Sounds like you're in the right speed range for the gears, but I'm wondering if your exhaust is blocked off somehow. It sounds like you've got a good starting point, but I'd think you'd be doing lots better in the mileage dept. What is your mileage without the trailer, at say 55 mph? You'll feel a 'sweet spot' in the rpm band, usually around 1800-2000 rpm, where the engine seems to settle down and cruise along without trying to rev or lug down. With your 4:10's I think at around 55-60 mph is where you'd find your best mileage, especially towing.



I'm getting about 14 mpg towing a car on my 20" trailer, and I'm not known for a light foot. I do go easy though because the engine makes mucho power, but the trans is old, so I go pretty easy when accelerating. I can cruise at 70 mph all day whle towing, but I also have 3:54's out back. Unloaded I can get as good as 21 mpg.



Also, WHEN you upgrade your hardware (any you will sooner or later... it happens to everyone), and you double your hp and tq, you will notice that your cruising mileage will remain the same. After a weekend power bash up at PDR a few weeks ago, I nearly doubled my engines power, but my mileage stayed the same so long as I wasn't Porshe hunting... .

Power On Demand - That's what I call Diesel Power - When you need it it's there, when you don't, go easy and you'll get good mileage. Best of both worlds, and it's niiice.

(woah, I wrote a book... at this hour that's pretty good considering I can't see the keyboard any more... . )

- Sam