[FatTortoise]

I am wondering if there is a difference in performance that you can feel if you put in better fuel injectors..

How many fuel injectors are on the Vulcan FF engine? 4?

Also, what does a "fuel rail" do?? If I put one of those on there aswell, should I expect some performance?

I knew that the Vulcan FF has some better Fuel Injectors, and Fuel Rail.. but will getting better ones increase anyting?

 

[silvapain]

well, I know that the gen III FFV's used 25.4 lb/hr injectors, but only run at 14 lb/hr using regular gas. There are six injectors - one for each cylinder. The fuel rail is what supplies the fuel to the injectors. it is the chrome rail next to your valve covers. I would contact someone at apten or diablo to see if they can program a chip that will let the injectors runs at 25.4 lb/hr all the time. That much fuel is more than enough - any more than that and you will loose throttle response big time. oh, and anytime you upgrade injects, you either have to get a custom chip, or a calibrated MAF. I would go for the chip, it's about the same price, and is reprogrammable if you change them later.

 

[mobiuslogic]

Well, with the FFV engine and PCM, they are actually 24# injectors (it's like 23.7). However, injectors do not have a "half on" position. They are either fully on or fully closed. 24# injectors and needed in the FFV because ethanol does not have as much energy per volume as gasoline (however it can be burned far more efficiently given proper engine design) so more fuel must be shot depending on what percentage of the gasoline is ethanol, which the computer of course figures out for you, which is why larger injectors are needed for when the car is running a full tank of E85 (85% ethanol, 15% gasoline).

In terms of efficiency though, pure ethanol has an octane rating of 113, and E85 has an octane of 105. What that means is that ethanol (pure) can withstand a compression ratio of close to 14:1, compared to 9.5:1 for the vulcan and 10:1 in the duratec. Because of the higher compression ratio possible, more energy can be extracted from the fuel. And the compression ratio can be increased either with new pistons and rods, or as I want, BOOST. But boost that is coupled to the ethanol meter such that depending on the ethanol content in my tank, it will automatically adjust the boost for optimum firing and energy production.

Also, when you upgrade injectors, no, you do not need to get a calibrated MAF. However you do need a chip or a reflashed PCM that takes into account the increased fuel capacity of the injectors. Without doing that, the PCM will be pulsing the injectors LONGER than needed if you leave the programing at 14# but swap up to 24#. Result is wasted gas, running rich, LESS performance, and the possibility of burning up your catalitic converters. With higher capacity injectors, the PCM must fire them for LESS time than the 14# injectors because they flow at a higher rate.

Does that answer your question.....?

-mobiuslogic

 

[FatTortoise]

Originally posted by mobiuslogic@Dec 13 2003, 11:53 PM
Well, with the FFV engine and PCM, they are actually 24# injectors (it's like 23.7). However, injectors do not have a "half on" position. They are either fully on or fully closed. 24# injectors and needed in the FFV because ethanol does not have as much energy per volume as gasoline (however it can be burned far more efficiently given proper engine design) so more fuel must be shot depending on what percentage of the gasoline is ethanol, which the computer of course figures out for you, which is why larger injectors are needed for when the car is running a full tank of E85 (85% ethanol, 15% gasoline).

In terms of efficiency though, pure ethanol has an octane rating of 113, and E85 has an octane of 105. What that means is that ethanol (pure) can withstand a compression ratio of close to 14:1, compared to 9.5:1 for the vulcan and 10:1 in the duratec. Because of the higher compression ratio possible, more energy can be extracted from the fuel. And the compression ratio can be increased either with new pistons and rods, or as I want, BOOST. But boost that is coupled to the ethanol meter such that depending on the ethanol content in my tank, it will automatically adjust the boost for optimum firing and energy production.

Also, when you upgrade injectors, no, you do not need to get a calibrated MAF. However you do need a chip or a reflashed PCM that takes into account the increased fuel capacity of the injectors. Without doing that, the PCM will be pulsing the injectors LONGER than needed if you leave the programing at 14# but swap up to 24#. Result is wasted gas, running rich, LESS performance, and the possibility of burning up your catalitic converters. With higher capacity injectors, the PCM must fire them for LESS time than the 14# injectors because they flow at a higher rate.

Does that answer your question.....?

-mobiuslogic

Wow....

 

[shoz123]

Unless you are using forced induction or nitrous you will see absolutely no performance increase at all. Even with a chip. The effect of adding more fuel and not more O2 will make the mixture rich and the PCM though the O2 senors will pull back on injector ON time.

The only thing you might see is a harder start due to the fact the engine is getting a very rich mixture until the O2s warm up and start sending info back to the PCM.

 

[Guest]

A little side note on the Vulcans. Mike, you already have an FFV, which already has the larger injectors. No need to upgrade unless you move to a forced induction setup, like Paul mentioned.

On the non-FFV Vulcans though, gains should be seen by swapping out to either 17lbs or 19lbs injectors. Through some research, I've found that the 14lbs stock injectors on the Vulcan are good to 157 crank HP at 100% duty cycle. The stock Vulcan is good for 155 crank HP (Gen 3), meaning that any intake/porting mods done will not be realized. Proof of this is my dyno run back in September, with the Apten chip. Even with advanced timing, and modified fuel mapping, the car did not richen up any, and actually ran a little lean. I've read on the Ranger boards that the Vulcan guys are plugging in 19lbs Mustang injectors, and seeing results. The results vary depending on the intake mods done, obviously. People who have installed the 19lbs injectors and have not done any other work did not see any improvement at all. All of the people installed the injectors without any programming, and EEC-V relearned the fuel cirve to compensate.

This leads me to a few conclusions:

Porting and polishing the intakes may indeed offer some benefits.

The Apten chip for the Vulcan may offer some HP gain.

EEC-V will compensate to an extent for larger injectors and increased airflow.

The biggest thing is trial and error. I feel that EEC-V will not make up for a 5 lb change in injector size, but there are 17lbs injectors available also. I think they may be a better choice.

Soon, I'll be trying both, and getting dyno runs it between changes. I'll keep updates going.

 

[silvapain]

From what I have been told, the fuel curves are hard wired into the chip, and the computer cannot adapt to the larger injector sizes. Also, you can use a calibrated MAF INSTEAD of buying a chip. Your'e right mobius, the FFV lengthens the duty cycle when it detects E85.

 

[Guest]

Originally posted by silvapain@Dec 15 2003, 12:41 AM
From what I have been told, the fuel curves are hard wired into the chip, and the computer cannot adapt to the larger injector sizes.

Not arguing, merely pointing out what I've seen--

Kirk's 97 SHO adapted somewhat to larger injectors (threw a o2 code for both banks running rich though). However, the car ran great, no driveability issues whatsoever, and actually got about 28 MPG on the trip to Lapeer in October.

Things of note on this, and the Rangers that I've read up on, is that they all had some sort of intake work done. No, I'm not talking just a cone filter or CAI. I mean manifold porting, head porting, etc. In Kirk's case, he has big bore secondaries installed on the V8, with nitrous, and the injectors were needed.

He's also had his PCM reflashed a few times, and it's managed to relearn some stock settings.

I agree though, to gain full benefits, a chip or MAF is going to be required at some point. In talking to Brian at Apten, larger injectors don't necessarily require a larger MAF. Programming can be done with a chip. The only time a larger MAF is required is when you're pegging the voltage on the current unit, which isn't likely to happen unless you're running some sort of forced induction.

 

[shoz123]

QUOTE

The only time a larger MAF is required is when you're pegging the voltage on the current unit, which isn't likely to happen unless you're running some sort of forced induction.[/b]

When I took my car to Brian for dyno work there was a Muskrat GT that had been S/C. The car ran out of MAF. It only got ~395 hp, he was hoping for ~ 420 hp.

 

[majisto]

Woudn't a higher compression ratio hurt the motor?

 

[mobiuslogic]

Originally posted by Majisto@Dec 15 2003, 10:04 PM
Woudn't a higher compression ratio hurt the motor?

Not if it was built up to withstand the forces and to keep the head gaskets from blowing out. How do you think a diesel keeps running at near to 21:1 compression ratio. Just a matter of how strong the materials that go into it as to how much force (and power) it can handle.

-mobiuslogic

 

[Guest]

Can I some this up in one question for myself?. HOW MUCH POWER DO YOU GET FOR THE 500 BUCKS YOU SPEND?

 

[sable_owner]

You'd be better puting your money into making the engine breathe better,ie better intake t-body and filter. Get the intake ported, get a larger t-body. You will be very happy with that.

 

[silvapain]

Originally posted by 94TaurusGT@Dec 28 2003, 07:05 PM
HOW MUCH POWER DO YOU GET FOR THE 500 BUCKS YOU SPEND?

$500 for what? The injectors? I got mine off of ebay from a mustang GT for $60 for eight. Maybe I'm misunderstanding what you are talking about. The bottom line is, for a vulcan, you will not see any real HP gains at all unless you upgrade the injectors. Allowing the engine to breathe better will not do much good, because the injectors cannot put in any more fuel to compensate. sorry in advance if I'm answering the wrong thing.