FOXBODY INJECTOR 101: What You Need To Know! *EXPERT ADVICE*

all right guys we've got matt harrison on the line right now and uh you're in what uh oklahoma correct you got it so matt is in oklahoma and uh he does a little bit of tuning on fox bodies i think you've uh tuned a few haven't you yeah something like that maybe more than a few but uh yeah yeah we've been doing this a little while now so uh you've been in the fox bodies for a while yeah actually i got my uh my first one got it's it's been a long time now but uh when i was about 17 picked up a little bone stock fox body and downhill from there man yeah tell me about it right i think everybody's got a story similar to that and that's the thing you know most of our stories you know are probably very very similar i got a couple questions so there's there's been a lot of topics that have been brought up lately you know about injector sizing and things like that and i figured i'd bring an expert on rather than uh you know telling the guys giving them all my opinions anyway but uh you know one of the first things that that i kind of want to touch on is say let's let's say you have a stock um like 302 right and uh maybe you throw a set of heads and a cam on it uh you know what are your thoughts on as far as like injector sizes uh will will a 19 pound injector still be okay for that setup four tried to have a little bit of wiggle room with that 19 pound on you know bone stock engine they don't want to have it at utilization all the time uh but but they also aren't trying to help you build a race car with with the stock components so you know if it's something real real simple like a set of gt40p heads um you know some headers or some stock ported heads cobra intake something like that you might be able to get away with some 19 pounds it's really anything substantial in that you got to start looking uh something a little bit bigger let's say you put a set of heads on a car right let's say we put some uh just some twisted wedge heads and uh a really good camshaft now moving up to like a 24 or 30 pound injector um you know what are the options what's the correct way to uh to get this car to perform right after you do that is it just a mass air meter is what i'm saying can you go buy the mass air meter combo and expect the car to run good or what well not really um you know there's there's going to be a million guys out there that'll say they have used a calibrated map with some 24s or 30s or 42s or whatever and will swear that the car ran fine no problems blah blah blah i mean yeah you can get lucky sometimes but here's what you got to remember about calibrated mass this is where stuff gets sideways not all injectors are made the same in fact really no two manufacturers even if they say it's a you know 24 pound or whatever size it is no two factors injectors behave the same way therefore it is impossible for a mass air manufacturer to make a mass air meter that's suddenly the perfect meter for any 24-pound injector right because there's just always going to be some differences so you know can it work yeah it can work okay but it's it's not going to be ideal now the the big reason though why why i'm so adamant about not going with a calibrated map especially if you go any bigger than 24s is that it it really starts to mess with your ignition timing and your fueling uh without a custom tune and obviously the calibrated math the kind of the whole point of that was to try to get guys by without a tune but uh but you're you know the load measurements in the computer are based on an understanding of what your airflow is your cubic inches and your rpms and it can kind of get a sense of you know how hard you're you're working that particular engine but if it thinks that you're getting less air than you actually are which is what would happen if you you know go to one of those larger calibrated maps then it thinks you're not working the engine hard your timing goes up uh and you know it's it's just not ideal for for pretty much any combo and that's best because that's assuming you you do get lucky this was a decent pair with your injectors which chances are probably it i guess that's one of the things that i really wanted to touch on and i wanted to kind of make make it be aware the the calibrated mass air meter like like what matt's saying you know we've all done it before right and i think you'll kind of agree i mean you can probably get by with like a 24 pound combo and it and it'll probably run pretty good but anything much past that is is really a get by and that's something i don't think that's a that's a way that we that we've thought about it in the past you know used to before dyno tunes were really popular that was the correct thing to do if you didn't have that done then obviously you didn't do it correctly now things have changed we have more access to dinos and tuners and things like that so my personal recommendation and i'm sure matt's going to be the same way is if if you do go to something like that like a 30 36 pound 42 pound injector or something like that you really need to get your car dyno tuned and make sure that everything's correct because essentially i mean what are these mass air meters doing could could we label it as tricking the computer or or how would you how would you word it yeah i mean if your goal is to run it with without it then yeah that's that's what a calibrated mass air meter is for because basically a massive meter is just a 5 volt sensor so the higher the voltage the more airflow but it's not a straight line curve it actually has a kind of more of a you know an exponential looking or logarithmic style curve and what a calibrated mass area is all it's saying is that the shape of the curve should be identical to the shape of the curve of the stock meter it's just at a bigger scale for for more flow for so many years now we've just assumed that that was the correct way to do things and and i i mean i guess we can't say it's the incorrect way but obviously you know if you're going with a with a bigger set of injectors and a mass air meter more than likely you've made some other changes you know you put a cam some heads and maybe a different intake stuff like that so at that point it will really benefit you to to get a custom dyno tune so um one other thing i kind of want to touch on real quick is is tuners right so i run i run a mega squirt in my car a micro squirt and uh that you know back in the day was a was a really good setup it was really popular uh from what i remember but nowadays it's getting really hard to find somebody to tune that with that being said what is your recommendation as far as like a chip or a standalone or anything like that well this is my overarching advice and i don't care what your combo is this is this is step one figure out who's gonna tune your car and ask them because you know i could say i'm an expert at tuning you know this particular car but that's tuning it with certain platforms that i've used and there's a lot of them out there i've never touched you know so just because i know how to tune a forward doesn't mean that i'm going to do a good job tuning it with a system i'm not familiar with so you know that's a key thing you you need to figure out your your reputable tuner whoever you're going to use ask them what they prefer and ask them to explain why they make the recommendation don't just say okay that's what you do so that must be the right way ask them why they recommend that because a lot of tuners will tune in multiple platforms but there's there's a best fit you know if you think about it objectively so that's what you need to do figure out your tuners ask them and ask them to explain their reasoning not that you're you know trying to poke holes in their plan but yeah and and that gives you further assurance that the company you're trying to work with is the right one exactly and and that's something that i found out you know which i planned on tuning you know my own car so i bought the the mega squirt put it in the car and and i actually love the mega squirt i have nothing negative to say except for the fact that there's really nobody to tune that around here uh i don't even know anybody around my area honestly uh short of maybe a outside of 150 mile radius that'll that'll tune that so that's an issue that i have so that's something like it like you said that you need to do first you need to talk to your tuner and find out what it is that they want to do what they want to use and what they're comfortable with let's talk about injector sizing in general so i mean can you go too big on an on an injector for your car for your setup or is that a thing or is that a myth or what is the deal with that that that's a very real thing but you you've got a lot more wiggle room there than uh than you might think so this this is the only reason for the most part you could ever say you went too big you know what you have to realize is that an injector when it first is asked to open and the pulse width starts they don't really behave very normal there there's a rush of fuel coming in it's just starting to open it doesn't really behave as advertised but once it's open and now it's just allowing the flow to go through then it starts to behave normal so what you have to really watch out for minimum pulse width because what they're basically saying is if you know like so let's say you put like i'm just getting crazy here like a 210 pound bosch injector in a stock fibo okay it's like 10 times more than you need yeah to get the amount of fuel out of that injector that that little tiny low horsepower engine needs the pulse width is so short that it doesn't behave well at all and it gets to a point where there's just nothing you can do in the tune to make it suddenly consistent and accurate so basically your idle ends up suffering when you get to that point where you've gone too big now there's also in most tuning platforms you also get to put in what is the minimum allowed pulse width that's something you put in the tune so you know again if you start trying to go that calibrated maf route you put a way bigger set of injectors but you're not able to adjust that minimum pulse width in the tune that could really cause you some issues too or you have an overly rich condition because it's it's forcing it to pulse a lot more and it won't allow it to go any lower even if it's capable of it that's the big one now if you're going to go custom tune as far as you know assuming that that's not going to be an issue for you yeah if it's tuned properly you can just about tune around any other corpse of the injector okay that's something that there's just no way around there's no shortcuts there after talking with you and and honestly kind of looking back at tuning my own car and and the pulse width and stuff like that i get what you're saying so you know like i said before and i always tell guys you don't you don't need these huge injectors and it's true to a point unless you're gonna go get a custom dyno tune so that's that's where the difference is so and this is why i wanted to have you know matt on on here today guys it's for this reason because i knew that there were some gaps that needed feeling for me too so uh you know this is this is beneficial to everyone so you know i would say this i mean and and or you know we'll talk to matt a little bit more about it but uh don't put too big of an injector in a really mild car unless you're going to go get this thing custom dyno tuned you know if you've maybe like you said put a set of gt40 heads intake something like that and you just want to run some 24-pound injectors with a calibrated mass air meter i mean matt you think i mean that would that would be a get by right i mean it shouldn't it shouldn't be that big of an issue yeah you can usually get by with that okay uh but outside of that you know um and i'm not trying to put words in his mouth but i think for for you guys you know trying you know this channel we try to stay budget right i i want you guys to be able to enjoy your car but enjoy it you know as cheaply as possible and like matt said i mean anything much past that i've seen problems i'll give you a good example my buddy ray ian finger had a decently hot little setup had a set of aluminum heads um a comp cam uh cam shaft you know all the stuff right heads cam intake and i think he had 30 30 or 36 pound injectors in the car something like that i can't remember and uh the car ran decent had a calibrated mass air meter it ran decent well ray took the those injectors out and put his 19s back in with that mass air meter and the car actually ran better now what does that tell you that tells you exactly what matt was saying that everything it doesn't work that way sometimes when you get into the bigger injectors and you start throwing them at these cars with just a calibrated mass air meter so i i think you'll agree matt that car with a custom dyno tune and those 30 whatever pound injectors would have probably been night and day difference yeah absolutely night and day so that kind of is helped proving the point that he's trying to make you guys that that calibrated mass air meter uh just thrown on a car on like a mild or hot setup it isn't going to be the the cure-all so you really need to get these cars down in tune and you know matt i've been telling them for for years now you know these cars are pretty forgiving so what's your opinion i mean as far as the the fox body being more forgiving than say some of these new cars i think you could probably agree with that right yeah i i happen to own a 27 gt with a with a blower on it and i can definitely tell you that it doesn't take a whole lot there to make the car absolutely undrivable i mean something as simple as changing a throttle body uh you got a lot of data you have to plug in and it has to be perfect that's right i mean like there's there's math behind it and it has to be right yeah this drive by wire stuff and all the other fancy stuff yeah it's a whole lot harder than it used to be yeah those fox bodies they'll take a beating they'll last a long time i mean you know and even stuff like the you know the 500 horsepower deal and all that i mean truth is if you respect the balance of the engine not over rev it and you have a good tune with safe timing you'd be shocked what you can force through one of these and actually do it not just for a couple passes but do it for a couple seasons exactly so there's one other thing i want to ask you about and that is speed density cars here lately i've had so many people ask can i put heads cam on a speed density car can you tune a speed a speed density car uh without a standalone unit yeah yeah sure i mean the the speed density while it's a totally different computer that you know ford put in those and you know the the settings are a little bit more primitive because just it was an earlier year computer before they switched to mass air slightly less capabilities but in general yeah you still have full control over everything that computer does if you want to tune it okay so yeah you can tune that stock computer effect i mean i've i've even worked with people that have you know turbos on a speed density deal with a stock computer you can still tune that if you you know kind of know the tricks to get around some things wow so it could definitely be done but yeah if no tune on these things um the camshaft is going to be the single biggest effect where it goes from it it would be able to drive to it won't drive because with speed density everything's driven based on vacuum essentially that that plays a huge role in everything whereas with mass air it plays very little role so that's the big thing is when you go to a really big cam with a lot of overlap or whatever it's just going to have probably a whole lot less vacuum and without a tune it just isn't going to respond well and the problem with the vacuum based system also is that if you get in any kind of a situation where maybe things aren't quite right so you get a little bit of that swinging idle or you know kind of some of that surging that sort of deal it'll start to get really out of whack really fast because when you're on the top end of the surge and about to come down you know you're kind of one side of the spectrum of how much vacuum you have and then as the the rpms dip low you're on the other extreme and it's swinging back and forth and having a huge effect on your fuel so it it just kind of it's almost like a turbo it's just out of control and you don't have a way to bleed off the problem yeah tell me about it i have ran into that you know with my car so you know you know mine is speed density as well i have run into situations where i have to box in the timing and the fuel to make it you know act right because it just wants to wander all over the place but um i guess one of the biggest things you know that something new that i learned today was that you could actually tune the speed density computers guys i had no clue of that i had no clue that that could be done so that's why we do these that's that's why we're having this conversation right now so we all learn so hey you guys that are speed density you know and if you don't want to go to mass air you can be tuned absolutely let's see matt is there anything else we want to want to cover well you know on on the whole conversation of just bigger injectors and what are some other things to look out for you know let me give a little bit of other advice you know we talked about one key thing is always figure out who your tuner is going to be first get their advice on some of this stuff here's another really critical thing this is just coming from the perspective of a tuner professional tuners do this for a living okay they have to get paid for their work which is totally reasonable and they're doing it to be profitable it's a business right so nothing wrong with that but what that means is if you hand them a bunch of really weird parts that you don't know what it is and they don't know what it is and you're trying to make them tune around those sorts of things what they're going to do is they're going to give you a a tune that even for their own capabilities is inferior they would be able to give you a better quality outcome with at least a part that you know what it is so and the reason i bring it up with injectors is the two parts that are critical on a fox body or mass air meter and injector if you don't know what you have it's a good nightmare for a tuner to try to get right without just spending lots and lots of time and either charging you a bunch more for it or just charging you what they agreed on but then just giving you kind of a sub cartoon so with injectors not to plug anybody i don't sell any of this stuff so that's not my intent but let me just tell you some manufacturers that publish the data you need ford racing is going to be your your number one go-to because for most of the simple street car applications and i'm going to say all the way up to about an 80 pound injector ford has a whole bunch of size ranges all the way from stock to 80 pounds the price point is very affordable especially as you get into some of those uh you know you get into 47s and 60s and 80s their price points very reasonable and they publish the full data that you need to tune it not just some of it but all of it you need slopes breakpoints offsets whole bunch of numbers i won't bore you with it but it's not just saying it's a 42 pound or a 30 pound or whatever there's a lot more data you need so ford racing is a good one for your kind of you know moderate build type setups and then we start to get into bigger stuff look at fuel injector clinic or injector dynamic injector.net they have absolute complete info for everything about their injectors out there that helps i actually i didn't even know pro m made injectors but i stumbled across in the other day because the customer used them pro-m does the same thing for the ones they sell they have published data just about i won't say everybody but just about everybody else will give you like they'll give you the flow rate and maybe a minimum pulse width and that's about it again not not real good results and then same thing on the mass air meters you know companies like pro-m will give you a calibration sheet that comes with your meter it's actually that exact meter they sold to you on a you know some some test equipment giving you real data that you can plug into the tune it'll always be a little different in the laboratory versus a box body but it's it's very very close makes the tuning process a lot easier you go with some random meter that you don't know anything about you got no calibration sheet for it you don't know what size tube it was supposed to be you know put into man you're just guessing on all this stuff and it's the process of tuning is just harder yeah and you're putting a lot of stress on your tuner i had 80 pound ford racing injectors in my cobra and literally like he's saying guys you can go get injector slope break point everything you need is right there for you it's easy you plug the numbers in and it's cool well i bought this on three turbo kit and i got whatever injectors you know come with theirs guys i unless i'm just looking in the wrong place can't find really anything on these injectors so it was trial and error i mean does it work absolutely but um i could only imagine taking this car to somebody like he said just put a turbo on it you know put some injectors in the car that you don't know anything about you have no information uh you know all this stuff and you just dump it off on a tuner guys you're going to get charged you're definitely going to get charged and and that's probably i guess you could look at it this way that's the difference between taking a car for a retune versus taking something that's not even ran yet and you want to get it all tuned you're going to be charged more for that for their time so like a retune typically doesn't you know cost you as much and that's probably a good example i do have one other thing that's really worth talking about too because it it has a direct effect on knowing what your injector size should be okay so again if you're trying to figure out what should i put in here this is another critical aspect what's your fuel pressure going to be that you're running okay because a fuel injector you know when you when you look at the spec sheets for a set of injectors that's another thing that they give you they'll say all of the this data that you can put in your tune this is based on running this injector at a very specific pressure so like ford they'll do theirs at 39.15 psi a lot of injector manufacturers do it at 43 and a half just three bar some are rated even different than that and of course you could put your fuel pressure wherever you want it if you have an adjustable regulator so so that's another critical thing to bring up because as the pressure increases you can generally get a lot more flow out of an injector if and only if you've got enough fuel pump to support that and that's that's another thing that kind of you got to play a balance between the you know the injector and the fuel pump because as if you start to really turn the fuel pressure up and you've got kind of already a somewhat of an undersized fuel pump it's not going to be able to keep up and you're going to end up going lean up top what we were talking about earlier with pulse width how does that affect it if you go to changing the fuel pressure i mean obviously it's going to richen the car up that pulse width i guess uh that open time is really going to dump a lot more fuel on there correct yeah so if it doesn't understand by being told what's going on hey shorten your pulse width you're going to end up getting more fuel than you did before okay so which i mean i guess that's kind of obvious about turning the fuel pressure up but let's say if this is a workaround then uh you could uh turn your fuel pressure up maybe get a little bit more out of your injector and then come in and adjust the pulse width to uh help with idle is that is that a feasible oh absolutely and i i run into that really commonly with uh you know a decent build headscan intake with a blower on it you know back in the day a lot of guys would go just the absolute go-to was the 42-pound lightning injector they were dime-a-dozen real easy to find it's a quality injector you know cool everybody used it but what you start finding data the 42 pound injector doesn't go particularly far when you start doing a full top end plus a blower with any you know more substantial boost you know 10 12 pounds that 42-pound injector runs out real quick sorry guys we had some technical difficulties so we're going to kind of backtrack if we can so you were you were talking about uh sometimes that's not enough injector with the 42-pound injectors so just kind of go from there if you will yeah yeah so like you know the guys back in the day they'd use uh you know head cam intake with a vortec they'd go ahead and put you know 42-pound injectors on there because they were easy to get a hold of but that 42 pound injure in a boosted application doesn't go nearly as far as it would in a naturally aspirated because you know when you've got a blower on there you got to remember too that's like belt driven so to get that like true rear to the tires horsepower you got to make a whole lot more crank horsepower to get there so so what guys can do though is if you are going to get a custom tune you can take an injector that maybe is just a little bit undersized jack the fuel pressure way way up and you get it to behave like it's a much larger injector and you won't go lean up top and you've got you'll gain back that upper rpm range without uh you know damaging things awesome to be honest there's even arguments sometimes that that you're better at higher pressures you know by coyote car it runs to 60 psi from the factory you know it's not 39 like the old stuff and i think some of these manufacturers actually figured out that as you start to increase the pressure you get uh a little bit of a different flow pattern or a spray pattern coming out of the injector and it has better atomization characteristics i can see that so you know so actually there might even be some benefits to doing that now again if you can't go crazy because that's another thing that injectors are rated on is maximum pressure you're allowed to run them at you can't just say oh let's run 150 psi or something wild you know that's not going to work for you but but within reason though you know sometimes there's actually more benefits to it that's awesome see that now like i said guys this is why we're doing this because i'm learning you guys are learning uh and and look nobody wants to give this type information out you know these days with the internet yeah you're able to you're able to get some of this information but is it right is it good information do you do you know who it came from so that's why we're doing this kind of little series i guess you could say is to really spread the word you so you guys share this video talk about it that's what this is for is to help one another matt brother i appreciate you uh you helping us out with this today i learned a lot i realized that uh there's a lot of this stuff that that i've been talking about that probably wasn't 100 percent true but um you know i do appreciate you taking the time and i'll have all of your information up on the screen and uh you guys look him up if you're in the area mata you are you tuning yet are you are you able to take any cars oh yeah yeah we're doing a lot of remote tune work right now but uh we we try to keep at least one or two cars rotating and uh you know every week also so yeah bring them on let's let's talk and see if we got a good fit for you all right man that sounds good so you guys check him out uh that's matt harrison uh leech motorsports and we're gonna go ahead and wrap this portion up this may end up being a two-part video because we've been going now for about 30 minutes so we may separate this so either way guys as always thanks for watching yeah that's something that i noticed uh really early on uh whenever i was messing with mine i was like you know what man i can go buy a 20 spring and literally just add some more kpa to the car and i'm good i mean it was that simple and i was just blown away at how easy it was but but at the same time i feel like i chase my tail a lot more with speed density versus mass air because it's just it i feel like from a from a you know a diy guy i'm chasing my tail because the car can't compensate for me there's not there's not as much compensation with the speed density car and when the weather changes and pressures change it's like the car just goes nuts it seems to be more aggravating than the mass air cars is that just me or is that is that actually a thing they're just harder to get the drivability out of them and the idle quality and like you said the changing weather conditions they really are more sensitive than that kind of stuff the mass air for drivability and ease of tuning it's a whole lot easier to deal with at least in my opinion you know and like a lot of the the gm crowd those tuners they're just used to doing things with speed density because that's what you know that's just the way that has been for a long time but you know the ford i mean ford has been using mass air for a very long time and they still do so well let me ask you let me ask you something um is what's the deal i've heard that you can have both math mass air meter and speed density and you can run idle off of mass air and then switch over speed density is that a thing yeah yeah and that's actually there's modern computers like the coyote stuff i'm getting into now does that they they have both actually but some of it is is actually not about trying to like okay well in scenario one let's use it do it this way and then in scenario two we'll switch over to mat vice versa but a lot that has to do with failure mode so if the mass air meter fails because back in the day when a mass air meter failed it went into lymph mode and you'd be lucky if truly you could limp at home i mean it was there's not much you can do there to make it drivable without that meter but with the new stuff it just falls back on a speed density as long as that's tuned right you can almost not even notice anything happen okay that's pretty cool other than maybe seeing a check engine light so it's a lot of it's more of that fault tolerance and just a failure mode that works a lot better than the old ones did okay yeah that's cool i had heard you know something about that but to be completely honest with you i didn't really know um but you know the speed density stuff really to me is is awesome i like it it's so freaking easy and uh you don't really have to worry about the whole mass air meter thing but uh at the same time man i just feel like i do not like you said i don't get the drivability it's consistently i'll say as i did with a mass air car um it's like there's always a new hiccup somewhere and and it's like you know i kind of would hate that for somebody who maybe brought you a car that was speed density and expected this thing okay it's now it's custom dyno tuned so it should always just run great i mean i think you run into more problems with that right i mean versus like a mass air car that you've tuned uh you probably have more issues i guess with the speed density car once it left the the dyno yeah yeah so yeah yeah the mass air stuff i mean once you once you get through that tune it's pretty resilient and it'll deal with a lot of changing conditions well i guess that makes sense because i mean uh by i mean well i say back in the day i mean you can throw a cam in these cars and never have to change a mass air or tune it or anything i mean you can do that so i guess that kind of makes sense where you can't do that with a speed density car so that uh you know the part of the system that's giving you your fueling decisions is the mass air meter and that has nothing to do with vacuum so yes the voltage will go up and down is that you know if your rpms start to fluctuate or something but you're you know your fuel is directly impacted in a very major way like a very feature yeah and vacuum and the tour just doesn't work so well with speed density and you really have to jump through hoops to kind of normalize things

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Keywords: FOXBODY, FOX BODY, BREW2L FOXBODY, SMOKE TESTER, FUSION BUILD, 5.0 MUSTANG, OLD SCHOOL MUSTANG, RETRO MUSTANG, TURBO FOXBODY, CALYPSO CLONE, 93 COBRA, FOXBODY INJECTOR, BEST FOX BODY INJECTORS, INJECTOR DATA EXPLAINED, FORD RACING INJECTORS, DO I NEED TO GET A CUSTOM TUNE, 24# INJECTORS VS, 30# INJECTORS, FOXBODY DYNO TUNING, WHAT IS PULSE WIDTH, FOX BODY TIPS AND TRICKS, BREW2L INJECTOR VIDEO, LEECH MOTORSPORTS

Id: 9yVYmUc_8uU

Length: 30min 31sec (1831 seconds)

Published: Thu Oct 29 2020