Would I benefit fron stepping down to 24 lb injectors?

Discussion in 'Fox 5.0 Mustang Tech' started by mike93lx, Jan 21, 2004.


Thread Status:
Not open for further replies.
  1. Daggar

    Daggar New Member

    Joined:
    Jul 20, 2004
    Messages:
    5,557
    Likes Received:
    111
    Trophy Points:
    0
    I'll use your quote again about how TFS could have a piston to valve clearance problems on 87 and later cars where the AFR heads would not. This is not the case. There are no combo's out there that an AFR 185 can fit onto without P to V problems that the TFS can also not fit onto. The reverse however is true since there is more clearance already built into TFS heads.

    In this particular instance your "information" is incorrect. So are you. It seems that you have many many misconceptions that you believe is gospel truth. Either that, or you don't have the integrity to admit when you are wrong. It seems that you've been shown plenty of reference and documentation by many in an effort to assist you in uderstanding your misconceptions but you still hold the line that everyone must be wrong except for you. This forum offers you the opportunity learn why those misconceptions are incorrect. Michael Yount seems to have taken an extra step even in offering you relevant proof. My suggeston would be to have a discussion with these folks and make the attempt to "understand" those things that are pointed out as false. On the matter of the thermostat well... So far, everything that Mike and Rick have posted on the matter is actually correct. I've verfied it both by research and by trial and error since being here on this forum. A 160* T-stat on a Stang with a stock computer and otherwise correctly functioning cooling system is a problem. I installed one in my own ride at the recommendation of Kenne Bell when I installed the Blowzilla. That never ran right. Drove me nuts trying to discover why. That's when someone suggested that the t-stat might be too low. Like you, I wasn't sure that the t-stat could be the cause of the problem. Then folks like Michael Yount, Rick, TMOSS, and a few others explained the operation of the EEC (where it relates to coolant temp) and referred me to the reference material that allowed me to physically check the mode of the computer. Sure enough... The thing was stuck in open loop mode because the computer did not see the temps necessary to make the change to closed loop. Under those conditions, the computer disregards inputs from other sensors and runs a preset fuel table designed to allow the car to run in what it sees as a "cold engine". It runs very rich and cut daily driving fuel mileage by about 1/3rd. After discarding the 160* stat and installing a 180* stat, the problem went away and the AFR across the RPM range returned to normal. That is not to say that the AFR at WOT was any different (that I noticed) but all other power settings reverted to nominal (WOT settings have their own fuel tables). I'm one of those folks who doesn't want to know just he answer but the method behind that answer. I've certainly gotten that here. So can you.

    On the matter of oil at less than ideal temperatures. I've seen the result of this first hand on an 86 F-150 where not only was a 160* t-stat used but also an oil cooler. Over time, this particular vehicle released less and less oil during oil changes. The owner thought that because of the age of this vehicle, that the oil was being burned and tossed out the exhaust. I was there to help him pull the oil pan and intake off in order to remove all of the sludge left behind due to the oil's inability to get to proper temperature for adequate flow. Once we'd removed all we possibly could by hand and other means, we took it to a facility that was able to flush the parts of that system we could not reach without a full blown tear down. We expended two oil tranfusions and two large filters (the size of K&N conical) on the machine before we felt we'd gotten it clean enough. It's been roughly 5 years since then. The t-stat of course, was replaced at that time due to having to tear apart the top end to get the sludge out. The oil cooler was also removed because it was too clogged to be bothered with. The oil pan was last removed this last summer in August and the engine is clean as a whistle inside. I never understood why until I got here and learned what I've learned from these folks who have all "been there" at one point or another. You can kick and scream and refute it all you like. The facts are the facts and they speak for themselves. Or perhaps... maybe you DO know more than everyone else. In that case, you don't need this forum so.... why are you here?
  2. Michael Yount

    Michael Yount Advanced Member

    Joined:
    Apr 10, 2002
    Messages:
    9,047
    Likes Received:
    0
    Trophy Points:
    77
    raph - come back please!!!! We are having TOO MUCH FUN with you. We NEED you!

    So - let me understand - you're saying the proper way to account for putting larger injectors in a Ford efi engine is to turn down the fuel pressure with an adjustable fuel pressure regulator? Have I got that right?
  3. Daggar

    Daggar New Member

    Joined:
    Jul 20, 2004
    Messages:
    5,557
    Likes Received:
    111
    Trophy Points:
    0
    You've not botheres to take into consideration the adjustable (by the computer) duty cycle of a fuel injector. A larger injector and a correctly calibrated mass air meter will shorten that duty cycle to adjust fro proper AFR. By pumping up the fuel pressure you've accomplished two things.
    1. Caused the computer to (over time) shorten the duty cycle of the injectors to adjust for proper AFR

    2. Caused temporary changes to the AFR at WOT (until the computer has adapted)

    By changing "just" the fuel pressure all you're really doing is "fooling" the fuel injection system into thinking that the injectors are larger than they are (for a prestablished "stock" fuel pressure). It's the same premis as using an FMU on a blown application with one exception. The fuel pressure adjustments made by an FMU are short and temporary and do not allow the computer the time required to adapt to those changes. That's why they work.
  4. Michael Yount

    Michael Yount Advanced Member

    Joined:
    Apr 10, 2002
    Messages:
    9,047
    Likes Received:
    0
    Trophy Points:
    77
    Wait for it.....
  5. Daggar

    Daggar New Member

    Joined:
    Jul 20, 2004
    Messages:
    5,557
    Likes Received:
    111
    Trophy Points:
    0
    NO WAY MIKE!!! You're dead wrong!!! Or haven't you been reading his other posts???? :rlaugh:
  6. Michael Yount

    Michael Yount Advanced Member

    Joined:
    Apr 10, 2002
    Messages:
    9,047
    Likes Received:
    0
    Trophy Points:
    77
    C'mon - don't leave us hangin'....
  7. raph130

    raph130 Founding Member

    Joined:
    Mar 20, 2002
    Messages:
    517
    Likes Received:
    0
    Trophy Points:
    0
    you like sucking on cocks all day?
  8. Daggar

    Daggar New Member

    Joined:
    Jul 20, 2004
    Messages:
    5,557
    Likes Received:
    111
    Trophy Points:
    0
    I guess that means you have nothing relevant to endorse that claim?
  9. Michael Yount

    Michael Yount Advanced Member

    Joined:
    Apr 10, 2002
    Messages:
    9,047
    Likes Received:
    0
    Trophy Points:
    77
    I knew he'd be back - and IT WAS worth the wait.

    So raph, does your witty come-back represent the sum total of your amazing intellectual prowess? We'll wait while you look that word up.

    This is too easy....raph, you're inarticulate AND homophobic.
  10. raph130

    raph130 Founding Member

    Joined:
    Mar 20, 2002
    Messages:
    517
    Likes Received:
    0
    Trophy Points:
    0
    so your trying to tell me that if i stick bigger injectors that flow much more fuel at any given psi compared with stock injectors, i should raise the fuel pressure and make the engine even more pig rich?? is that what your saying genious?
  11. Daggar

    Daggar New Member

    Joined:
    Jul 20, 2004
    Messages:
    5,557
    Likes Received:
    111
    Trophy Points:
    0
    There's an awful lot there you've not accounted for. I've bet Mike one dollar in U.S. currency that if you were able to set aside the personal attacks and actually consider some of the variables that you've left out that you could come up with a list of reasons why what you posted is innacurate. Please try... I HATE having to send him cash through the mail.
  12. Michael Yount

    Michael Yount Advanced Member

    Joined:
    Apr 10, 2002
    Messages:
    9,047
    Likes Received:
    0
    Trophy Points:
    77
    raph - OK, I'll take a stab at it without the name-calling.

    In the stock system, the maf is calibrated to send a voltage signal to the ecu that varies proportionally with the mass of air flowing through the meter. The computer, looking at many other things too, looks at the maf's voltage signal, and determines how much fuel to inject. It's expects to see 38-40 psi of pressure, somewhat less when vacuum is present, and it expects the engine to have 19# injectors. If you were to install an adj. regulator on the motor - completely stock - and turned up the pressure slightly, here's what would happen. The O2 sensors would pick up that the mixture was too rich. The computer would adjust for that by shortening the amount of time it's telling the injectors to stay open. In pretty short order, even with higher fuel pressure, the computer would return the mixture to where it was before. There are limits to it's ability to do that, but it covers more ground than you might think. It's designed to do this because the government has regs (EPA) that require that the oem's build a car that will meet EPA emissions limits for 100K miles, so as bits and pieces wear/tear over time, the system has the ability to adjust. It's called "Adaptive Strategies".

    Now, when you install larger injectors, you're supposed to also install a RE-CALIBRATED maf. The recalibration, among other things, changes the electronic signal that the maf sends to the ecu. If you put 24# injectors in, the recalibration cuts the signal output of the maf by the ratio of 19/24 -- basically telling the engine that only 79% as much air is entering the engine compared to what's ACTUALLY entering the engine. The computer, thinking less air is entering, shortens the pulse width (the amount of time it holds the injector open) on the 24# injector. The result of holding the larger 24# injector open for only 80% of the time is that it injects roughly the same amount of fuel that the 19# injector would. With other mods, and the ability of the engine to flow more air than stock, at some point (bigger throttle openings, higher rpm) air flow exceeds stock levels, but the extra capacity of the 24's allows the ecu to provide more fuel to match more air.

    All the calculations that the ecu does are based on an assumption of 38-40 psi. The system is gonna work best there - assuming you've modded the other parts appropriately. Another way to deal with the larger injectors is with a chip or tweecer. Instead of recalibrating the maf, you can directly tell the ecu what size injector is in the car, and it will make internal adjustments to the pulse width.

    That's why we keep telling you and others to leave the fuel pressure alone. Adjustments for larger injectors should be made electronically, not mechanically; especially when the system is designed to "undo" the pressure changes.
  13. Daggar

    Daggar New Member

    Joined:
    Jul 20, 2004
    Messages:
    5,557
    Likes Received:
    111
    Trophy Points:
    0
    :doh: It's no fair if you post the answer Mike! Sheesh
  14. boldsword

    boldsword New Member

    Joined:
    Oct 6, 2004
    Messages:
    15
    Likes Received:
    0
    Trophy Points:
    0
    Whoah, has this topic gone awry. As for my being a fictittious person or not I am not even gonna bother, what the hell do you people want from me, want me to scan my license for ya? It's a moot point. I run a wide band o2 in my car, currently it indicates slightly rich and that's with 21psi at wot, I would lower it further but my regulator simply doesn't go any lower, the only reason I have 30# injectors is b/c I plan on force feeding 10psi of twin turbocharged boost into my engine in short order. With my fuel pressure set to 40psi at WOT my car ran so rich that my car dynoed around 100rwhp, I had a 190* t-stat in and the computer over several months of driving never adjusted itself to sorrect this situation, turning down the pressure to where it currently is was a night and day difference, of worthy note however is that when my car was running rich it ran silk smooth and never hesitated, I broke in my engine with it like that. If you run a 160 t-stat and the car does indeed stay in open loop with a preset fuel table then that is for the better, that way you can adjust the fuel output with the afpr without the computer trying to intervene right? At WOT the computer uses a different set of tables anyway so this wouldn't effect your power, also at WOT the computer doesn't read of the O2's, it simply reads off the MAF and supplies the correct fuel amount via an algorithm. The pulse width learning curve is for idle and part throttle driveability. I use what works, theories with why the OEM put a certain part in don't get me anywhere and certainly don't help my car run 12's on a stock motor, most original parts were put that way for emmisions,fuel economy, or cost. No way was ford going to give us afpr, you think this country is intelligent enough to be trimming it's own fuel pressure, never mind that the cost would be astronomical. There is much more I could say, but coming in at the butt end of this fiasco is pretty confusing.
  15. Michael Yount

    Michael Yount Advanced Member

    Joined:
    Apr 10, 2002
    Messages:
    9,047
    Likes Received:
    0
    Trophy Points:
    77
    "There is much more I could say,"

    Tell us more - help us understand your tuning secrets. From your post, it would seem you have this all figured out, and we'd like to learn more.
  16. houstonstangguy

    houstonstangguy Founding Member

    Joined:
    Mar 16, 2002
    Messages:
    986
    Likes Received:
    0
    Trophy Points:
    0
    It isn't like I misunderstood what you said because earlier you said:

    you contradicted yourself. my point is that either way even 450 boosted horsepower is too much for 30's. I think most people would agree that at least 36lb'ers are probably what he needs for 10lbs of boost
  17. Michael Yount

    Michael Yount Advanced Member

    Joined:
    Apr 10, 2002
    Messages:
    9,047
    Likes Received:
    0
    Trophy Points:
    77
    boldswold - you say you're running 30# injectors. What type/size maf are you running? What injector size was it calibrated for?
  18. 5spd GT

    5spd GT "the 5.0 owns all" Founding Member

    Joined:
    Aug 7, 2002
    Messages:
    9,557
    Likes Received:
    1
    Trophy Points:
    79
    Dagger: In quote of me where I was talking about clearance issues with the heads...I was being general and I was referring to the AFR 185's...not the TW's...aren't the 185's a 2.02 intake valve...and with that E cam he has planned (without knowing for sure)...I'd be willing to bet there would be p-v clearance problems with those big of valves on the intake side because the valve would basically overlap a non-modified piston in his car...it wouldn't fall in the half-moon relief so to say...that is all I meant by that...I was being general with his "general" statement...I should have been more specific...but anyways...sorry for the explanation but everything else you have said is right on from what I have seen/heard from the "veterans" on here... :nice:

    Raph130 (boldsword) - I don't have much of a doubt (though it appears I'm contridicting myself here...let me explain) that there are indeed two people who have posted with those above names...but it appears (in your unawareness) that you have posted on "boldsword" name because you integrate the same parts on the car though you explained previously that the "A" car has this and the "B" car has that...but you will get on Raph130 (more often than not) and spout that your "friend" has this problem and found out his FP was messed up blah blah blah...but when you go to look at your sig. you find that (again in your unawareness) that you have the EXACT parts in your sig...and your "friend" has explained in the past what he does and does not have...sorry this probably didn't make sense but I know what I mean :shrug: ...like that matters...IN SHORT...LEARN TO BE HONEST...and in the end it will prevail...I promise...If your going to "fool" people on here...it takes some practice and in that case...you need to go back to the gym...You have so far (unless you could prove otherwise) lost all credability as valid IMO...whether that matters to you or not...but your post will be warned of in the future by me...some of the things you are posting could cause some serious damage to the unknowings car and I don't much appreciate that...if I'm not sure of something I will always refer to "make sure this is confirmed" or "wait for a confirmation"...your post literally are dangerous...Literally...

    Michael and others - Quit picking on him with your real knowledge... :rlaugh: :nice: Poor Raph... :(
  19. 5spd GT

    5spd GT "the 5.0 owns all" Founding Member

    Joined:
    Aug 7, 2002
    Messages:
    9,557
    Likes Received:
    1
    Trophy Points:
    79
    I would say that pretty much somes up Raph130's post...his stories are rare to match...
  20. Michael Yount

    Michael Yount Advanced Member

    Joined:
    Apr 10, 2002
    Messages:
    9,047
    Likes Received:
    0
    Trophy Points:
    77
    Near as I can tell, this guy and his "friend" are putting larger injectors on their car without altering the maf or the ecu. And then turning down the fuel pressure to try and cope with the resulting over-rich condition. And they seem to be counseling others in that direction. Near as I can tell.
Thread Status:
Not open for further replies.

Share This Page