How do i turbocharge a ford ranger?

[Bob Ayers]

Bob, please contain you posts to 1 at a time. theres no need to flood a topic like that. and also please do not assume things you do not know (how many turbo systems i may or may not have built or worked on in my life).

I don't know any other way to post, but 1 at a time!!!

 

[Wicked_Sludge]

did you happen to notice that you posted 3 times in a row?

 

[Bob Ayers]

did you happen to notice that you posted 3 times in a row?

Yes, 1 at a time!!!!!

 

[Dave R]

BSFC is brake specified fuel consumption. we can use .6 (the lowest common level for turbo charged engines).

It's Brake SPECIFIC Fuel Consumption. And what web page did you get the .6 number from? I know it's not from your years of dyno experience.

 

[Dave R]

Bob, please contain you posts to 1 at a time. theres no need to flood a topic like that.

Admonishing users is my job, not yours.

and also please do not assume things you do not know (how many turbo systems i may or may not have built or worked on in my life).

Then answer the question yourself.

 

[Wicked_Sludge]

And what web page did you get the .6 number from?

you might try doing some research of your own.

 

[krugford]

Bob: He was simply stating that instead of posting three seperate posts, you should just have gone back and edited you're first post to include your additional responses if there are no new posts below yours. It doesn't really matter now, just for future reference.

Fitting a turbo to an engine is done depending on what you are trying to achieve. He said that you could use a turbo off of a Mack truck. While this would be an extreme case, he was right. Technically you could use a turbo off a Mack truck. Is this engine capable of fully utilizing this large of a turbo, no.

Properly sizing the tubine and compressor sides of the turbocharger is very important and you'll need to look at turbine AND compressor maps. Turbine maps are based on corrected mass flow VS expansion ratio. Not exhaust flow and engine rpm. Exhaust mass flow has a lot less to do with engine rpm than it has to do with load level on a forced induction engine. Compressor maps are based on pressure ratio VS corrected mass flow.

You're going to need to find out how much air you need to bring into your engine in order to keep your trapped equivalence ratio near stoich based on how much fuel you want to inject. It will be your fuel flow rate that determines how much power you can output. Turbochargers don't create power, they merely lower your smoke limit by putting more air into the cylinders to help oxidize the increase in fuel. They do in fact, represent a sizeable load on the engine.

As for the injectors, assuming a 100% duty cycle is a litte speculative. I also wouldn't design to run at 85% either as this would be borderline and wouldn't leave margin for future expansion. How big of an injector can you get that still fits in the standard bore? I believe what Wicked Sludge was trying to point out was that you might have to upgrade the injectors. If stock is 14 lb/hr, then you can easliy figure out how much power that is capable of producing running at maximum. Do you know if there is a factor of safety built into that 14 lb/hr number? If you are running at 14 lb/hr, where are you running in terms of duty cycle?

I realize that you will not be designing your own turbo from scratch so I would suggest getting one from an engine that is roughly the same displacement that operates roughly in the same rpm range as your donor engine and use that. There should be mutliple options out there.

-krug

 

[Bob Ayers]

Bob: He was simply stating that instead of posting three seperate posts, you should just have gone back and edited you're first post to include your additional responses if there are no new posts below yours. It doesn't really matter now, just for future reference.

Fitting a turbo to an engine is done depending on what you are trying to achieve. He said that you could use a turbo off of a Mack truck. While this would be an extreme case, he was right. Technically you could use a turbo off a Mack truck. Is this engine capable of fully utilizing this large of a turbo, no.

Properly sizing the tubine and compressor sides of the turbocharger is very important and you'll need to look at turbine AND compressor maps. Turbine maps are based on corrected mass flow VS expansion ratio. Not exhaust flow and engine rpm. Exhaust mass flow has a lot less to do with engine rpm than it has to do with load level on a forced induction engine. Compressor maps are based on pressure ratio VS corrected mass flow.

You're going to need to find out how much air you need to bring into your engine in order to keep your trapped equivalence ratio near stoich based on how much fuel you want to inject. It will be your fuel flow rate that determines how much power you can output. Turbochargers don't create power, they merely lower your smoke limit by putting more air into the cylinders to help oxidize the increase in fuel.

As for the injectors, assuming a 100% duty cycle is a litte speculative. I also wouldn't design to run at 85% either as this would be borderline and wouldn't leave margin for future expansion. How big of an injector can you get that still fits in the standard bore? I believe what Wicked Sludge was trying to point out was that you might have to upgrade the injectors. If stock is 14 lb/hr, then you can easliy figure out how much power that is capable of producing running at maximum. Do you know if there is a factor of safety built into that 14 lb/hr number? If you are running at 14 lb/hr, where are you running in terms of duty cycle?

I realize that you will not be designing your own turbo from scratch so I would suggest getting one from an engine that is roughly the same displacement that operates roughly in the same rpm range as your donor engine and use that. There should be mutliple options out there.

-krug

Good post Krug!!! It's refreshing to read a post that's not full of BS!!!

Normally, an injector's MAX flow is rated at 80% duty cycle.

 

[Dave R]

you might try doing some research of your own.

Well, after spending a few years in the dyno room of the Tonawanda Motor Plant, I should think I have learned a few things.

Where did you gain your first hand knowledge?


Let's try something else with your little new found formual.

If we assume the stock 4-14#/hr injectors, a fairly safe 80% injector rate and the .6 BSFC listed above....you get a max output of 74.67hp. Wow, how does Ford ever make these trucks run?

 

[anupaum]

If we assume the stock 4-14#/hr injectors, a fairly safe 80% injector rate and the .6 BSFC listed above....you get a max output of 74.67hp. Wow, how does Ford ever make these trucks run?

There's something funky with that math . . .

Here's the formula I'm familiar with:

InjectorSize = (HorsePower * BSFC) / (#Injectors * DutyCycle)

BSFC should be around .55, and I wouldn't go higher than an 80% duty cycle. With this formula, I come out needing 19 pound / hour injectors for my 130 horse engine. Honestly though, I've never seen anywhere NEAR an 80% duty cycle on any of the datalogs I've done while tuning. (With my foot REALLY into the throttle while racing uphill, my injectors are humming along at 60% or so, and it's not running lean, either!) On one hand, that demonstrates how gentle I am with my truck--which, if it sees 4 000 rpm means that someone ELSE is driving--and on the other, how the math enables us to properly size injectors before we ever drive the machine!

Of course, all of this depends on fuel pressure, too. Once we boost an engine that has a rising rate regulator (like the factory fuel pressure regulator on my truck), one psi of boost = 1 psi of additional fuel pressure. This is why George is able to run 15 or so psi in his machine using the same injectors I'm using at 5 psi.

Also, weren't the stock injectors 15 pounds / hour?

It's easier to tune for a good idle with small injectors because there is more room to play with pulse widths when the need for fuel is small. The engineers at Ford are WAY smarter than I am. Since I've begun this journey into the realm of abnormal aspiration, I've developed healthy respect for those guys!

 

[krugford]

The problem with that math is that he's assuming both a BSFC (from Wicked Sludge's first assumption) AND a fuel rate to determine a power output. IF that engine is using 44.8 lb/hr of fuel and only outputting 74.67 hp, then you would have a BSFC of 0.6 lb/(hp*hr). A BSFC of 0.6 would most likely correspond to a partial load condition on a modern engine, not a rated power condition. BSFC is load dependent at a given RPM.

 

[Wicked_Sludge]

krugford is right. BSFC varies by load (it also varies depending on aspiration, a n/a engine usually has a BSFC closer to 0.4-0.5). that formula is just to give you a general idea of what kind of power a particular injector size can produce.

anupaum, thats the same formula i posted. fuel injectors are given their ratings at a certain fuel pressure. increasing the fuel pressure forces more fuel through the injector, effectively "increasing" the injectors flow rating. a variable FPR is a good way to "get by" with smaller injectors. the downside to this is you loose some of your fuel metering efficiency.

 

[anupaum]

krugford is right. BSFC varies by load (it also varies depending on aspiration, a n/a engine usually has a BSFC closer to 0.4-0.5). that formula is just to give you a general idea of what kind of power a particular injector size can produce.

That makes sense.

anupaum, thats the same formula i posted. fuel injectors are given their ratings at a certain fuel pressure. increasing the fuel pressure forces more fuel through the injector, effectively "increasing" the injectors flow rating. a variable FPR is a good way to "get by" with smaller injectors. the downside to this is you loose some of your fuel metering efficiency.

At higher loads, this seems logical. Given that most folk don't spend a whole lot of time at WOT, but quite a BIT of time at part throttle, smaller injectors seem like a better way to go for me.

 

[Dave R]

A BSFC of 0.6 would most likely correspond to a partial load condition on a modern engine, not a rated power condition. BSFC is load dependent at a given RPM.

Yes and no. BSFC is ONLY a measure of an engine's efficiency, period. In other words, how much gasoline an engine burns to generate x amount of HP. The BSFC 'improves' when an engine is unthrottled (WOT) and running near to peak torque but other than that it don't move much for any specific engine.

N/A or forced induction has NOTHING to do with an engine's efficiency.

.6 is rather poor, especially for a modern EFI computer controlled engine.

And BTW, most of the engineering world refers to it as SFC. It's only called Brake SFC because that is the way it was done in the old days.

The problem with that math is that he's assuming both a BSFC (from Wicked Sludge's first assumption) AND a fuel rate to determine a power output. IF that engine is using 44.8 lb/hr of fuel and only outputting 74.67 hp, then you would have a BSFC of 0.6 lb/(hp*hr).

There is nothing wrong with the math, unless your trying to say that Wicked's formula is so screwed up that it can't be used to solve for another variable. He came up with the .6 value, from somewhere, I merely pointed out that inputing real world variables for injector efficiency showed that Ford couldn't possibly be making these engines produce more than 74.67hp without over stressing the injectors. Since it's pretty obvious that they are making them work, then something must be wrong with the formula.

 

[Wicked_Sludge]

did a little research, i was wrong about the 14lb injectors (though, thats the stock size used on the non-ffv 3.0). the 2.3 uses 19lb injectors.

the BSFC for a n/a engine is generally between 0.4 and 0.5. ford uses a safety margin of 85% duty cycle for their injectors:

144 x 0.45
4 x 0.85​

the stock injectors are good for 144HP of n/a power. not a lot of slop built into the system and definitely not enough for a power adder like a turbo.

sorry about the confusion