etn550

This is the other half of my post which is what are best mods for around 100 hp increase and best economy? So far:

An electronic gage readout, Which ones are good value?

Smarty

BHAF

Delete Cat

50hp nozzle tips (Assuming quicker injection at lower pressures)

PDR Camshaft (Can I change lifters in frame?)

maybe a turbo mod. Which one?

Gear Vendors. Had one on a used truck worked great, hate the $3,500 price tag for new. What about cost of re-gearing the pumpkins? (Ram3500)

Rickson 19.5 wheels with 255 or 265 tall tires for mpg and no tire changes for 100k.

I'm trying to compare this against a 12 valve engine swap, if that is possible.

Please give all comments. Thanks!

Doug

soulezoo

For one, if you're going with the Ricksons, forget about the gear change... those will change it on its own to a big degree. Problem is, from feedback I've gotten from friends that have done this, is that they lose mileage.

If all you want is a 100hp increase, you don't need the 50hp tips.

For just 100 hp, you really don't need another turbo.

Why would you want to swap to a 12v?? They get more mileage because, in stock form, they are not pushing much fuel. By the time you modify it to get to the power levels you now enjoy (say 425rwhp), you'll lose the economy factor and the ease of driving factor. The mechanical engines can be wonderful; but, tuning is everything with them, and it is an artform. Poorly tuned can make life miserable and you are tuned for one way or another in a somewhat narrow range. I love how they start though. The CR's are just plug and play no fuss no muss.

rip 112

^^^ on the nail. All you would really need is

gauges
Smarty jr or sr if you want a lil more

then if you want more after that you can think about more hard parts, like injectors and fuel pumps (though I think a fuel pump and filtration upgrade would be necessary)

etn550

Smarty alone is all I need for power.

BUT I am looking for "Best" mileage. I believe those other mods will help mileage. Correct me if I am wrong please.

The pdr cam is reported by members to be worth 2 mpg.

The turbo is to get peak compressor efficiency around peak torque. A non emissions turbo diesel can have the turbo tuned so that at certain rpms (like around peak torque) exhaust manifold drive pressure is LOWER than inlet manifold boost pressure with net work to the crankshaft. With all of this emissions tuning and quest for HP we loose sight of the fact that tuning can be for mpg too.

The BHAF and CAT delete are for reduced backpressure. Might delete inlet heater grid too.

Sorry about the Ricksons. Seemed like a good idea. Stiff, narrow, should have been low rolling resistance in a 255 or 265. But they are a lot of $$ so I can loose that idea fast. Thanks for opinion.

I had a 12 valve tuned for mileage and towing. It was awesome. The mods were less money than a modern program box. Those injectors were cheap, lasted forever, and most diesel shops could deal with them. I had my p7100 flowed and balanced for $300. That pump is virtually indestructable. A 400 hp 12 valve can have a nice torque rise, meets my hp requirement and is simple.

Plus a 12 valve p7100 manual trans can be started and driven without electricity. A coat hanger can lift the shutdown solenoid and it will bumpstart and run with power brakes and steering. Kind of a neat feature.

So other ideas for best mileage??

etn550

I'm begining to think the fuel pump / filter upgrade is cheap insurance to protect very expensive injectors. That was a good call. Adding it to my list.

rip 112

Well if you are insisting on mileage, then I would do this

HTT 62-65-13, or any 62-65 or 62/68, IMO the HTT ss turbos have an advantage but are a little pricey.

Airdog AD II, this will give you ample fuel and better filtration along with water separation, plus a lifetime warranty.

Smarty sr, I am suggesting the sr because you may find higher levels better for mileage with the right tuning, and the turbo will like the higher settings too.

Monitor or gauges of you choice, I think you know why.

and eventually you will need a clutch and DMF removal (dual mass flywheel), in which I would then suggest South bend Clutch.

The cam is helpful, but can be more useful when more parts are added. IMO if you are gonna pull the motor apart to do a cam swap, you might as well do studs, springs, and maybe even so head polishing.

It can go on, and on, and on, but in all actuality to get better mileage the first 5 will be a substantial improvement over stock. Hope this helps.

etn550

Yes, thank you. Very good. This is what I am looking for. I'm going to start with smarty and gages then look into your turbo recommendation. I have used SBC for clutches on my past 12 valve and like SBC. I will handle the flywheel at the same time. I think i can weld up a straight exhaust with a big donaldson muffler myself. The airdog seems to be a favorite and it will support future mods if any. Are manual gages going to run about the same as the electronic readouts when all done? The electronic ones seem like they will monitor a lot for easy install just need to install EGT probe. And smarty won't be plugged in normally.

rip 112

On the exhaust, you have full 4" from turbo back, so really losing the cat (at your own risk) and replacing the muffler will give you a simpler and cheaper solution. (do some searches on Donaldson mufflers and Nelson, you will find pics and lots of info on this)

On the monitoring, I'm partial to gauges, just like the way they match the factory gauges and there is something about seeing a needle move that i like lol. Price wise you should be looking close to the same. If you haven't looked here, this is a favorite for me to refer because of their customer service and complete gauge kits so you can take alot of guesswork out.

www.dieselmanor.com

steelblitzkrieg

I may have missed it, but what do you expect or hope for as far as an MPG increase?

.boB

There are only two reasons to increase mileage - save money, or increase range.

If you want to increase range, the simplest and cheapest is to add another fuel tank. A simple 20gal tank will carry you about 350 miles.

If you're trying to save money, most available mods won't do it. Take the cam mentioned above. You'll gain 2mpg (on a good day). What does that cost? Don't forget installtion costs. How long will it take to break even?

That's the problem. Every mod has a break even point. Most that I have looked at don't make economic sense for me. But, I don't drive 50K miles a year, either.

Having done a lot or research and gained a lot of experiance over the years, here's a few simple things that provide an economical improvement:

1. Drive slower. My truck is extremly sensative to speed.
2. lighten the load. Get all the useless junk out of the bed.
3. Improve aerodynamics - lower the chassis if it's been raised
- Slope back cap, or flat bed cover if you're buying one
- front air dam. Keep it cheap and easy.
4. Reprogram the computer. The stock tune is a huge comprimise, designed to appease all drivers in all situations. A simple tuner like Smarty Jr can make big improvements.
- Turn the power down. That's right, down. It takes fuel to make power. More power = more fuel.
5. Tires: Big wide heavy off road tires will really suck down fuel. For mileage, use a low resistance narrow tread. If you don't tow much, you can use a slightly taller tire for possibly better mileage.
- I doubt spending the money on alum wheels will pay back in a reasonable amount of time.
- Overinflating or max inflating the tires is a bad idea. You will gain some fuel mileage. But you'll wear them out much more quickly, and there goes your gas savings. You'll also reduce the contact patch and adversly affect transient response. Bad idea.



Over the years, I'v found these mods to be complete money wasters on most vehicles (there are exceptions):
1. Cold air intakes and filters. You can spend hundreds of dollars, and see little to no improvement. Some changes - like the Home Depot Mod - provide improvement in limited circumstances.
2. New exhaust. You could spend hundreds of dollars on a complete 5" or 6" exhaust system. And yet, I'v not seen a single shred of proof that it improves mileage.
3. Bigger turbo. 10psi is 10psi, no matter which turbo you use. And they are darned expensive.

rip 112

10 psi may be 10 psi, but on one turbo it can be 800* on another it could be 1200*, does that make one of those exceptions??? In my experience having cooler egts have related with me getting better mileage, a more reactive turbo can always be beneficial. I agree on the intakes though.

etn550

I agree with what you are saying. The cam is around $550 and it would be my labor in 1 weekend, no problem. It would be paid back in 2 years or less excluding towing which would pay back quicker if 2mpg claim is accurate. Lower EGT has some value even if not bombed heavy.

I was on track for some low profile 255 19.5's on Ricksons and was told this was a waste. Looking at narrow and hard rubber.

I have ordered the smarty and will experiment with various settings including reduced power.

If the gearing can be set to peak torque rpm at empty cruise speed then I would verify and adjust the turbo match for those conditions. A good match point operating at 80% compressor efficiency can actually contribute to power by having less exhaust manifold drive pressure than boost pressure for a net positive pressure drop accross the system adding free power. In the research lab at CAT in the early 80's we made a turbo compound engine which has a second exhaust turbine after the first. Instead of having that second turbine drive another compressor wheel it drove a gearbox back to the crankshaft to add power from wasted exhaust energy. Cool stuff.

If I could get 3 more mpg empty I would be very happy. I have a very mixed style of driving. I do like some power on occassion, but I can run a whole month or a whole vacation towing with a very conservative driving style.

There ar a lot on here that can advise on making power. By dumping emissions requirements power and economy can be had up to some point. From there it is one or the other. Twins extend the power and economy dynamic a little bit further.

So I am interested in economy and like experimenting. Just my thing right now. I guess it would not be too much of a challenge to build a 800hp engine but I don't want to have something that could blow up. I would rather be the one that can get real good mpg. Just me and just a hobby to see what I can achieve. No real payback considered and no need for fuel more capacity.

Your aero mods are good suggestions. I plan on addressing covering the bed somehow. I wish someone made a sloping topper, like a hatchback!

Sorry for long post.

.boB

I know I'v seen one somewhere. It wasn't quite a hatchback. But it cut down pretty low in the back.

You could easily make one out of plywood. Then you would know if the theory is sound.

.boB

Although I'v looked, I'v never been able to find any data that says a lower EGT affects mileage or power in any way.

In the context of this discussion, I can't see that it would make any differance. Especially since the EGT's would be maxed only occasionally, and then for a very short period of time.

Rednax

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Commercially produced aerodynamic pickup bed cap

http://ecomodder.com/forum/showthrea...d-cap-583.html


Rich Taylor -- GMC Truck Division guru -- says that a grille-block, partial bellypan, and tonneau are good for pickup truck fuel economy.


According to Peterbilt Engineering Systems Manager Rick Mihelic, the truck engine must
overcome five primary forces in order to move the truck down the road. They are:

• Rolling resistance, or the loss due to friction between the tires and the road;

• Mechanical losses, which result from friction inside the engine and the drivetrain;

• Accessory losses, which result from running alternators, air conditioners, fans, etc.;

• Grades, or changes in road elevation; and

• Aerodynamic drag.

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