Thoughts on the FAST Ez-EFI system??

[TurboNova]

Originally Posted by camcojb

still don't get the bolded part. There's more than fuel pressure that affects how much fuel the injector sprays. Of course idle needs less fuel than wot or load areas. But you don't HAVE to lower the fuel pressure to accomplish that, you can change the pulse width. I'm not arguing which is "more correct" I'm simply saying it is not a "must" to run the reference line. If it was a "must" then eliminating would not allow the engine to function. That's how absolute a "must" is. Do you get what I'm trying to say? I can take a car you've tuned with the reference line and disconnect the line, re-tune the VE or fuel tables, and make it still run fine. I'm speaking of an end-user tunable system, though I ran Charleys car with EZ EFI both ways and it ran, started, and drove perfectly. The problem with that combo is learning harder throttle areas.

Ok, if you still don't get it then lets look at the straw example.

This is the whole key... think of it as a straw that you blow through.. if you blow normal with no pressure or vac then you blow x amount of air. (WOT sea level 0 vac and 0 pressure)

If you have a suction on the other side and blow the same pressure then you actually get more air through the straw. (engine vac)

If there is someone blowing on the other side of the straw then you need to blow more pressure than they do to get the same amount of air out the other side. (boost)

So the way you are tuning is... there is actually more differential pressure at idle and cruise (more fuel flow)... then you lower the PW more than you should have to since the line is disconnected.... then you chase the fuel injector fuel flow change AND the VE air flow through the table while you are tuning.

This will get you in big trouble when you have say a 4.6 mod engine with 160# injectors that makes decient engine vac at part throttle. You can't lower the PW enough to make up for the extra flow the injectors are flowing....

It is a must and the correct way to do it PERIOD... if you say it isn't then you are just passing bad.. efi info around yet again.

It is the exact same reason you boost reference the regulator... and everyone does that.

[Sieg]

Appreciating the dialog gentlemen, and learning a lot. Keep it up!

[camcojb]

Originally Posted by TurboNova

Ok, if you still don't get it then lets look at the straw example.

This is the whole key... think of it as a straw that you blow through.. if you blow normal with no pressure or vac then you blow x amount of air. (WOT sea level 0 vac and 0 pressure)

If you have a suction on the other side and blow the same pressure then you actually get more air through the straw. (engine vac)

If there is someone blowing on the other side of the straw then you need to blow more pressure than they do to get the same amount of air out the other side. (boost)

So the way you are tuning is... there is actually more differential pressure at idle and cruise (more fuel flow)... then you lower the PW more than you should have to since the line is disconnected.... then you chase the fuel injector fuel flow change AND the VE air flow through the table while you are tuning.

This will get you in big trouble when you have say a 4.6 mod engine with 160# injectors that makes decient engine vac at part throttle. You can't lower the PW enough to make up for the extra flow the injectors are flowing....

It is a must and the correct way to do it PERIOD... if you say it isn't then you are just passing bad.. efi info around yet again.

It is the exact same reason you boost reference the regulator... and everyone does that.

First off, your example of a 4.6 Ford with 160# injectors is not something that's seen every day. Yeah, with that large of an injector idle issues are a concern.

I have not had a single idle issue yet doing it my way. I've never had the pulsewidth go "too low" at idle and cause issues. I've never "chased" the tuning because of this.

You seem to take it personally that I have made it work well in a way different than you think it should be. You've given good advice, I see the purpose of referencing the regulator. But with a rear mounted regulator it's just one more line to run, plus I'm not sure there may not be an issue with the length of the line. Couldn't see an issue with the forced induction builds and the line length, but never tried on N/A.

I don't try to hand out bad info, I simply try to help with things that work for me. I have no problem with your view and would recommend people follow your advice, you're the pro. What I don't agree with is you keep saying that the reference line must be used. That's where you lose credibility. It's obvious that it isn't required or none of my cars or any of the other examples in this thread would run. I mean, they wouldn't even start up according to the "must" claim. That's my point.

[TurboNova]

Originally Posted by camcojb

First off, your example of a 4.6 Ford with 160# injectors is not something that's seen every day. Yeah, with that large of an injector idle issues are a concern.

I have not had a single idle issue yet doing it my way. I've never had the pulsewidth go "too low" at idle and cause issues. I've never "chased" the tuning because of this.

You seem to take it personally that I have made it work well in a way different than you think it should be. You've given good advice, I see the purpose of referencing the regulator. But with a rear mounted regulator it's just one more line to run, plus I'm not sure there may not be an issue with the length of the line. Couldn't see an issue with the forced induction builds and the line length, but never tried on N/A.

I don't try to hand out bad info, I simply try to help with things that work for me. I have no problem with your view and would recommend people follow your advice, you're the pro. What I don't agree with is you keep saying that the reference line must be used. That's where you lose credibility. It's obvious that it isn't required or none of my cars or any of the other examples in this thread would run. I mean, they wouldn't even start up according to the "must" claim. That's my point.

I have tuned 4 ~ 4.6 Fords this week that had that same combo. You are chasing the fuel curve weather you want to believe it or not.. that is fine. Take it personally... no not at all, you just don't seem to get it. One more line to run is no big deal... it's just cheap vac line... line length shouldn't matter.

It's not my credibility... it would be yours to keep arguing that it really does not matter. If you really understood what was happening you would say... I will always do it that way now that I understand. To tell people bad information that is does not matter or everyone here has always done it this way and it worked isn't a good argument.

I never said an engine wouldn't start.. or run... just not "right" most EZ EFI systems wont run very well at all. The real problem is where you try to lean out the idle down around the 1.2-1.4 ms of PW and you keep getting a rich condition you can't get out.

Like I said, you can machine an engine with .008 piston to wall clearance.. would it run.. sure.. but would you do that? No.. So if you now it is better and the proper way to run the regulator with the vac line then why wouldn’t you?

Lets face it the industry is full of people who see one thing and copy everyone else who is doing it that way. If the points leader uses brand X oil then it must be the best stuff out there. If this guy uses these gaskets then everyone should use that gasket. There is more bad info out there than there is good especially in the EFI world. My day usually consists of helping people tune their stuff after 5 other guys just took their money and gave them the tune out of the XFI folder. Part of why I have done well as a EFI tuner is I do a lot of dyno testing trying different stuff and have access to some really cool datalogging stuff most people don't even get to play with ever. I try to help out on a few boards and offer advise on what works and what does not. If I see something people don't get or understand then I try to help them in the right direction at least. This topic is something that I cover in every EFI101 class I teach and usually get blank stares from the students that say... wow everyone else does not do that. When I draw a picture on the board... most get it. There is lots of other stuff like, adding fuel stops detonation.... fuel is power... lots of stuff we debunk on the chassis dyno live at our classes.

Not taking anything personally and not talking down to anyone just trying to educate some bad info.

[camcojb]

Originally Posted by TurboNova

I have tuned 4 ~ 4.6 Fords this week that had that same combo. You are chasing the fuel curve weather you want to believe it or not.. that is fine.

ok, I understand you may tune (4) 4.6 Mod motors with 160# injectors on a regular basis, but come on............ I doubt there's many here that run that size injector. Yes, I already said when you're dealing with something like that you can have idle issues and lowering the fuel pressure with the reference line would be beneficial. I also said that I was mostly talking about EFI in general, the systems that are end-user adjustable. However I tried with and without the reference line on the EZ EFI system and it adjusted for the difference in a few seconds, and after that ran exactly the same. As far as chasing the fuel curve, I start with a base fuel map with BS3, FAST, Accel, etc. that will need everything changed anyway. Even the ones that take engine info to build a base map are off a lot, some so far they won't even start and idle. Simple datalogging shows exactly where and how much you're off, and with some simple math you adjust the VE or fuel map numbers (or maf curve or? depending on the tuning system and EMC) and datalog again.

Originally Posted by TurboNova

I never said an engine wouldn't start.. or run... just not "right" most EZ EFI systems wont run very well at all. [/B]The real problem is where you try to lean out the idle down around the 1.2-1.4 ms of PW and you keep getting a rich condition you can't get out.

not true. You kept saying you "must" run the reference line. Even when I gave you the option to admit that "must" is not correct you clung to it. "Must" means there is no option, it will not work. That's why we've been going in circles here. But then you said if you disconnected the reference on an EZ EFI that it would have to learn the new fuel map which it does; so maybe it's not a "must". As I found out with the one I worked on it ran great at idle with or without that line. You also mentioned many tuners still don't use one; their cars must run I would assume.

I've been doing my own tuning since 1994 when I had a program to burn my own proms. I have done many N/A cars with and without reference lines. Not a single one had an idle issue or tuning issue. I have seen countless other cars in that period of time that didn't use one and ran fine. I am not challenging your knowledge. I can see why you want the reference line there. It makes sense to me and I'll start using them again on the N/A stuff. The only reason I didn't use them is because of the rear mounted regulators I use, and I was told by a tuner that the length of line would cause tuning issues. So thank you for telling me it won't. The only part that we disagreed on was that it is required on all EFI systems. If you would have said it's the best way to go and here's why, it can help with the EZ EFI if you have a fat idle and can't get rid of it, or if you're dealing with a large injector and having idle issues this can help we would have had no disagreement.

My only point was on the "must" part of what you were saying. Hopefully you get what I'm saying, because I really can't explain it any better. Thanks again for your time and info, it is appreciated.

[TurboNova]

I say "Must" because it is the right way to do it for no other reason. I still think even after all the posts you still don't get it. It's not lowering the pressure but more the reason is the pressure differential between the intake and injector remain the same, no matter if you are in boost, vac or no vac.

Do you get that part?

Then the ecu just tunes the actual fuel curve and not the fuel curve and the pressure differential too. This gives the ecu a better ability to tune at the lower PW for any injector size.

If line length was an issue then your rear mounted regulator wouldn't work under boost. The long line will make the change slower but it will still work just the same.

[camcojb]

Originally Posted by TurboNova

I say "Must" because it is the right way to do it for no other reason. I still think even after all the posts you still don't get it. It's not lowering the pressure but more the reason is the pressure differential between the intake and injector remain the same, no matter if you are in boost, vac or no vac.

Do you get that part?

Then the ecu just tunes the actual fuel curve and not the fuel curve and the pressure differential too. This gives the ecu a better ability to tune at the lower PW for any injector size.

If line length was an issue then your rear mounted regulator wouldn't work under boost. The long line will make the change slower but it will still work just the same.

I get it and I give up..............

[ccracin]

Originally Posted by camcojb

I get it and I give up..............

Go Steelers! How's that for agreeable Jody?