Heath Turbo Master

[chrisk1500]

Therefore : More boost = Less MPG... I guess I over simplified.

Unless you are towing up a grade with no boost and black smoke billowing out the tailpipe....in which case more boost would lead to more power which would lead to less pressure on the APP by your foot, which would lead to less fuel which would lead to better MPGs.....

 

[RadioMan]

.....which would lead to better MPGs.....

It's always something - Isn't it?
Like everything else, I guess, a question of balance - And what you want out of the system.
I try for the best fuel economy I can get. But then again my bucket truck just moves from place to place at a leisurely pace. Others want to get from Point A to Point B as rapidly as possible --- Especially if Point B is just a 1/4 mile away

 

[chrisk1500]

Just playing devil's advocate.....always a situation where the 'laws' are broken...

 

[RadioMan]

Is this better?
More boost at level cruise = Less MPG

The stock vac system drops boost to near zip when cruising, but how much difference would one see with like 5 psi boost at cruise? Or is the diff actually insignificant??

 

[chrisk1500]

IMO - no difference....but it has been a long time since I was 'stock'.....IIRC MPG was no different after TM - not significantly anyways....

My 'cruising' boost is around 7-9 psi....this is with a cruise speed of around 75-80 MPH....

 

[Dieseldad97]

I'll add my findings here. I ran around for years with NO turbo at all. Been about a month or so with a T/M and I have not noticed any loss in mpg. I guess if I were to hammer down all day long it would be less, but I drive like I always did before and mpg are the same.

 

[buddy]

Ive noticed a little drop in economy at cruise since I got a chip that increased boost. With my hypertech chip I would have like 2-3psi at 65-70mph, and then I put in a stock chip from a 95 K2500 L65, and boost in all cases went up, as well as power, but my 55-70MPH mileage seemed to suffer 1-2MPG when boost was at like 5psi. my max fuel rate with the stock L65 chip was lower than the Hypertech chip, but I still had more power. It could have been the chip telling the IP to dump more fuel too, I dont know. I havent done much with my new Engh Chip to know yet, but boost pressure is a little lower at cruise.

Although I still tracked a little over 18MPG combined with that stock L65 chip, and thats driving 75-80MPH on the interstate, spirited stop and go in town, and some 45-55 to and from work each day. (my other car is a Z28, so its very hard for me not to want to get up and go from a stop)

Im also surprised the ECM doesnt have programming to defuel if it doesnt detect the increased boost it asked the turbo to send. I understood its fuel dependent, but figured there is some feedback, since the ECM's intent is to send more air to increase the air/fuel ratio. Maybe I can design that for myself since all the sensors are there.

I'm also a little fuzzy on how the ATT can flow more air at lower PSI when volume of the intake is constant. Or does it just provide sufficient, with a more efficient turbine on the exhaust side that lets more free flow out reducing backpressure?

 

[Matt Bachand]

Well, when I changed my oil the last time was when I had a head rebuilt, and my routine was off, i never did my lube and air cleaner service.

The turbo-Master defanately feels peppy and powerful no lag issue with a clean air filter

 

[Dan Hunter]

Yeppers, a dirty/clogged air filter is an impedance to volumetric efficiency.

 

[JiFaire]

Getting better economy is a fine equation...

When I put in my TM and MaxeTork, my mileage went up - both pulling AND empty.

When I'm empty, the amount of fuel required to cruise is controlled by my foot, not by the chip - but the boost is slightly higher at 65mph than it was before, without the TM. I get better mileage from what seems to be higher boost and same fuel ... ???

When I'm pulling, I'm able to dump in 'way more fuel (thx to chip), but also get 'way more air (thx to TM). I get better mileage there, too.

You need to remember that you don't make boost without fuel... some amount of load is required. How much fuel it takes to make that amount of load move is dependent upon the efficiency of the engine, which is affected by the boost pressure/volume mapping.

It's a rubics cube... you change one thing, it changes everything else. Understanding that makes designing improvements for the 6.5TD a matter of systems dynamics more than anything else.

 

[buddy]

I think the chip has a lot to do with fuel output, since it takes your foot input and sends out to the FSD what to have the IP do.

the boost adds efficiency in most cases, since it is waste heat that youre powering it with afterall, and not all backpressure is bad, it builds torque to give you more horsepower. The more complete combustion then providing more power obviously and the backpressure creating torque so you can cruise at lower RPM, instead of needing RPMs to give you higher horsepower.

Like you say, its a dynamic thing with a lot of variables.

 

[Turbine Doc]

If youre actually using less boost, you might have lower temps since the ECM knows youre getting less air from your MAF so it tells your FSD to tell the IP not to use as much fuel, but then youd have less power.

I hadn't noticed anybody picking up on this FYI no MAF on F engined trucks, and on S trucks with them 98+ it was an passive sensor for economy only, acutually in my testing the money comb grid in mine was detrimental to power, so I eliminated it and am 100% F truck configured for airflow, with exception to S precups which will go away with project engine waiting to go in my truck.

 

[Turbine Doc]

I think the chip has a lot to do with fuel output, since it takes your foot input and sends out to the FSD what to have the IP do.

the boost adds efficiency in most cases, since it is waste heat that youre powering it with afterall, and not all backpressure is bad, it builds torque to give you more horsepower. The more complete combustion then providing more power obviously and the backpressure creating torque so you can cruise at lower RPM, instead of needing RPMs to give you higher horsepower.

Like you say, its a dynamic thing with a lot of variables.

Program chip or flash has everything to do with managing fuel request from APP, how much fuel delivered is function of lift-IP-& injector health, healthy IP is capable of 80ish mm^3/1000 if requested; add in some time/wear & tear IP or injectors, dirty fuel filter-weak lift & you get far less than the request.

56 mm^3 is stock S program, 63mm^3 is stock F program, early reflashes/chips netted about 76mm^3, 80mm^3 + is what latest tunes have, also important but overlooked are start of injection timing curve, trans shift points, in addition to boost & fuel curves.

 

[buddy]

I have several chips now, all with different fuel rates. SSDS' fuel miser seems to actually takes the first amount of pedal and lowers the fuel output of it right off the bat so you dont hot rod around wasting fuel in 1st gear. Looks that way on the scanner anyway and feels it.

 

[Matt Bachand]

I have several chips now, all with different fuel rates. SSDS' fuel miser seems to actually takes the first amount of pedal and lowers the fuel output of it right off the bat so you dont hot rod around wasting fuel in 1st gear. Looks that way on the scanner anyway and feels it.

That would defanately save of fuel, must feel like limp mode a little bit?

 

[Turbine Doc]

I have several chips now, all with different fuel rates. SSDS' fuel miser seems to actually takes the first amount of pedal and lowers the fuel output of it right off the bat so you dont hot rod around wasting fuel in 1st gear. Looks that way on the scanner anyway and feels it.

Was same with HP4 program with GM-8 turbo, but better control more APP more fuel alsmost linear with throttle like real throttle cable more pedal more fuel, no lag; now if I get on it with ATT slight lag, she will almost blow black as a tuned up DMAX until turbo spools up, if I drive it normally not so much, this is one of things I want Bill to see if he can improve upon now that ATT is my turbo of choice.

 

[buddy]

Yeah its annoying going from my Z28 and hopping in the truck and not going fast with the typical GM first 10% of the pedal 90% of the acceleration. I havent used the fuel miser much at all, still evaluating the power one from Engh. Plan to trade them off depending on the days activities and was really curious to see how they work differently, and Engh's went on sale for just $275 no tax or core return. Its like a 5 minute swap time on chips.