Quick fuel injector Question

T0rk3d · Jan 21, 2008

Hey all, I might have a good deal on my hands here. Its a maf calibrated for 30#s with the 30# injectors. Its a little bit larger than I need but what would I need to make it work without running to rich or just right?

Right now I have stock fuel system. I am getting ready to do a HCI on my stock block.

Do I need a FPR or a new pump? Will this run right for a couple months until I get a tune?

BlownFiveLiter · Jan 22, 2008

You can run the stock FPR with the 30lb injectors, but you'll want to step up to a bigger pump. Ideally, you'd swap on an adjustable FPR, too, but as we're both aware, parts are expensive, and it adds up quickly. Take a look at the mods in my sig for a moment. I'm still running an entirely stock fuel system. I don't want to put a wideband on it because I'm frightened to see how lean I'm actually running! The 30lb injectors should serve you well. That's going to be my next purchase, along with a LMAF and probably 255lph pump.

T0rk3d · Jan 22, 2008

I can get a brand new aeromotive FPR for 70$ to my door from a guy.

But I need to spend as least amount as possible but safely also. Should I stick with the 19#s, get a 255 and the AFPR?

Im really lost on what to do with the fuel system.

If I plan on getting it tuned in 3-4 months then should I even mess with the AFPR?

BlownFiveLiter · Jan 22, 2008

I'd get the injectors before I spent a dime on the AFPR. They're a must with HCI, I just ran out of money after running into a few snags along the way. My car's honestly being a garage queen at the moment anyway, so it makes it hard to blow up when you don't drive it. You definitely don't want to lean it out and make a paperweight out of a piston though. Doing the fuel pump isn't absolutely essential at this point, but I'd keep it in mind to do in the future.

T0rk3d · Jan 23, 2008

Thanks for the insight. I really dont wanna make scrap metal out of my bottom end haha. I was thinking I can pick up some 24# fairly cheap, buy a calibrated maf, and get a new pump. That should be right at 300$. Im probably buying the maf off a friend. Since it is not going to be tuned for a couple months should I get that AFPR? 70 shipped for a brand new aeromotive isnt too bad of a price. I can squeeze another 70 for it. What do you all think?

final5-0 · Jan 23, 2008

Well

I'm gonna share something with you that might hair lip the King
and
Get all the loyal subjects in Mustang Kingdom a bit upset and bothered

As I see it ..........
The fuel pressure thing is WAY over emphasized by lots of Stangers :Word:

Lets just take your application

30's on a h/c/i combo is not an uncommon kinda thing

Here is the deal with 30's and larger inj's

At low pulsewidth driving conditions like idle and low load cruise ...........

They have tendencies to work a bit sloppy
so
You might be a bit fat when at those conditions

IMHO ... NO afrp of ANY kind is gonna help you all that much
cause
You can't back it down enough

Fuel Pressure ... Fuel Pressure ... Fuel Pressure

I mean ... Lets be honest here
Its like its some kind of .................. Mustang Mantra

I just don't see how afpr's ever got as much credit as they have
for
What little benefits I see that they do

Understand here ... I ain't being critical of those who use them

I've just never seen a use for one ... thats all

Now ... should you get that 30# caled meter and those 30's ???

Depends upon what your plans are for combo parts
and
How you are gonna tune it

Grady

BlownFiveLiter · Jan 24, 2008

I think the fuel pressure regulators got popular before there were any sort of self-tuning devices and the only tuning available was timing and fuel pressure adjustments. IMO, I'd rather tune it based on the stock fuel pressure just to make my life a little easier, if nothing else. Those 30lb injectors are rated that at the stock 39 PSI.

PUNISHER RACING · Jan 24, 2008

I run blowers , I'll take my adjustable regulator !

final5-0 · Jan 24, 2008

StangGT1995 said:
I think the fuel pressure regulators got popular before there were any sort of self-tuning devices and the only tuning available was timing and fuel pressure adjustments. IMO, I'd rather tune it based on the stock fuel pressure just to make my life a little easier, if nothing else. Those 30lb injectors are rated that at the stock 39 PSI.

Yes Matt

I do agree
They got popular when the Fox Stangs came on the scene

I guess its like most things that evolve into a more efficient thing
It just takes a while for the old or outdated methods to die out

A few quick examples of older thinking and how it has slowly changed over
the past few years.

Since 373's operate at too high of a rpm on the highway, you need 355's

Since 94-95 pcm's can't be tuned, you need to retro-fit a Fox pcm

Since 347's burn oil and won't last, you need to go 331

Grady

T0rk3d · Jan 25, 2008

Thanks for all the help guys. I did a bunch of reading on mafs and cant seem to find the answer to this. I know lightning mafs are not calibrated to any # injector and like the cobra/GT at least for the 94-95 years were exactly the same only the computer made the # difference.

Anyway on ebay there is a guy selling a maf and 30# injectors the maf is 80mm and the maf sensor it self is a ford part. He sells maf injector combos all the time and he actually has a great trader rating too. Thing that worries me is its a ford maf and he is claiming it is calibrated for the 30s.

I emailed him and he said the maf and injectors were from a supercharged tbird. Are those mafs calibrated? Can they even be recalibrated if they were not originally for 30(like straight from him)?

Thanks again.

final5-0 · Jan 26, 2008

T0rk3d said:
Thanks for all the help guys. I did a bunch of reading on mafs and cant seem to find the answer to this. I know lightning mafs are not calibrated to any # injector and like the cobra/GT at least for the 94-95 years were exactly the same only the computer made the # difference.

Anyway on ebay there is a guy selling a maf and 30# injectors the maf is 80mm and the maf sensor it self is a ford part. He sells maf injector combos all the time and he actually has a great trader rating too. Thing that worries me is its a ford maf and he is claiming it is calibrated for the 30s.

I emailed him and he said the maf and injectors were from a supercharged tbird. Are those mafs calibrated? Can they even be recalibrated if they were not originally for 30(like straight from him)?

Thanks again.

As far as I know, Ford does not calibrate any of their meters to a certain
size inj.

That kind of thing is mostly done by aftermarket meter maunfacturers.

Greg (blksn955.o) has done a lot of really great work
with the Ford OEM meters so you might wanna search out his findings

Without going into a lot of detail

Ford sets up a meter to be able to handle the amount of airflow they know
a particular motor can draw

So you see ... this means ..........
the meter is all about airflow and NOT inj size

I'd not think you could just bolt on that meter and those inj's on you Stang
without some way to custom tailor the t curve in your 94-95 pcm.

Grady

T0rk3d · Jan 27, 2008

I didnt think that they did. I remember reading, from one of your posts actually, about mafs not being calibrated. The price was a little too good haha.

Im still a little confused on what I should do. I can probably get he 24# setup cheaper and easier than a 30# setup. Woud the 24# be plenty good enough? I will be getting it dyno tuned after about 4 months maybe a little more. I would like to do a tweecer and might very well go that route as I wont be getting it tuned for some time from now. Im running out of money and my living situation is throwing things off. So at this time I want to just get my HCI on and running fairly good before I leave her for a bit.

final5-0 · Jan 27, 2008

T0rk3d said:
I didnt think that they did. I remember reading, from one of your posts actually, about mafs not being calibrated. The price was a little too good haha.

Im still a little confused on what I should do. I can probably get he 24# setup cheaper and easier than a 30# setup. Woud the 24# be plenty good enough? I will be getting it dyno tuned after about 4 months maybe a little more. I would like to do a tweecer and might very well go that route as I wont be getting it tuned for some time from now. Im running out of money and my living situation is throwing things off. So at this time I want to just get my HCI on and running fairly good before I leave her for a bit.

For me to answer intelligently ... if that is even possible

I REALLY need to see what all you have done ... (sig)
and
A bit more info on if h/c/i means oem or aftermarket

Your plans for the future ... that kind of thing

The fact you are considering self tuning makes a REAL BIG difference
in how I would construct a reply for you here

Grady

T0rk3d · Jan 27, 2008

My set up right now is

bbk equal lengths
bassani off road x and catback
underdrives
mac cai
3.73s which will be swapped for 3.55
93 cobra intake

I will be switching the intake for a slightly ported edelbrock performer rpm along with afr 165s emission legal with 1.7 rr. The cam I am 99% going with an FTI cam.

I have a lap top and I like to do things myself. The problem is I dont want to spend 500$ on a tweecer and not really pull any potential out of it until i have messed with it for a year. When I can just drop the 500 and have it running good in a day.

This is gonna be the last bit of money I spend on the car for probably a year at earliest. More like 1 1/2. So I wont be supercharging it or anything like that anytime in the near future. Its going to be my daily driver and be visiting the track 1-2 times a month. I dont really have to drive more than 15 miles a day at the moment.

Not sure what else you wanna know. Thanks for the help though I appreciate it a TON!

final5-0 · Jan 27, 2008

T0rk3d said:
My set up right now is

bbk equal lengths
bassani off road x and catback
underdrives
mac cai
3.73s which will be swapped for 3.55
93 cobra intake

I will be switching the intake for a slightly ported edelbrock performer rpm along with afr 165s emission legal with 1.7 rr. The cam I am 99% going with an FTI cam.

I have a lap top and I like to do things myself. The problem is I dont want to spend 500$ on a tweecer and not really pull any potential out of it until i have messed with it for a year. When I can just drop the 500 and have it running good in a day.

First of all ...
if you wanna be setup to tune for driving around town
AND
wot driving conditions

You need a wide band to go along with that Tweecer interface

This will add another 200 to 300 bux

Now you don't need the wide band to get started tuning for the around
town part

If you are gonna self tune ... you do it at oem fuel pressure
so
You can save the money you would have spent on an afpr

With those plans and using oem fuel pressure ... I'd go with 30's

This is gonna be the last bit of money I spend on the car for probably a year at earliest. More like 1 1/2. So I wont be supercharging it or anything like that anytime in the near future. Its going to be my daily driver and be visiting the track 1-2 times a month. I dont really have to drive more than 15 miles a day at the moment.

Not sure what else you wanna know. Thanks for the help though I appreciate it a TON!

If you do not do the self tuning thing and you are gonna try to get by without
a tune ... I'd do 24's with elevated fuel pressure.

If you were gonna have a chip burnt ... I'd then go 30's

Grady

T0rk3d · Jan 27, 2008

So I should probably go with 30s haha.

Im kinda leaning toward the tweecer now. Would it be ok if I had a maf calibrated to 30s and 30# injectors for a few months (5-6) until I can save up the money for the tweecer.

Here is my deal. I already own a laptop so that makes the choice easier. I am still learning about timing and fuel trims and all that. I know about how you wouldnt want to run 19:1 af ratio that kinda thing.

For a beginner who knows some of the basics, how long or frustrating would it be to tune a HCI with the 30s? Im just looking to get the best out of my money but with the least amount of headaches possible haha.

final5-0 · Jan 27, 2008

T0rk3d said:
So I should probably go with 30s haha.

Im kinda leaning toward the tweecer now. Would it be ok if I had a maf calibrated to 30s and 30# injectors for a few months (5-6) until I can save up the money for the tweecer.

Here is my deal. I already own a laptop so that makes the choice easier. I am still learning about timing and fuel trims and all that. I know about how you wouldnt want to run 19:1 af ratio that kinda thing.

For a beginner who knows some of the basics, how long or frustrating would it be to tune a HCI with the 30s? Im just looking to get the best out of my money but with the least amount of headaches possible haha.

Learning how the pcm does its thing ....

Its easier if you are stock or close to stock :Word:

Different meter and larger inj's can compound the learning experience

I'd do a bit of tuning now ... before you do the other stuff

Grady

T0rk3d · Jan 27, 2008

I would but the problem is I already have everything but the cam, fuel injectors/maf/pump, valve covers and a couple gaskets. And im not gonna be able to afford the tweecer for a little bit.

Do you think it would be safe to run the 30s and maf for a while before the tune though? It wouldnt be too much fuel would it?

final5-0 · Jan 27, 2008

T0rk3d said:
I would but the problem is I already have everything but the cam, fuel injectors/maf/pump, valve covers and a couple gaskets. And im not gonna be able to afford the tweecer for a little bit.

Do you think it would be safe to run the 30s and maf for a while before the tune though? It wouldnt be too much fuel would it?

Safe is not gonna be the thing you will need to focus on IMHO

With the meter caled for those 30's ...........

It will most likely run pretty good once you get the r's up and accelerate

It is at idle and steady cruise you may have issues with being a bit fat

You may have a bit of an issue with starting as well

I can't tell you which way to go here
but
For the long haul ...........
I'd be a bit more patient and do it as we've talked about above

Grady

T0rk3d · Jan 27, 2008

Say I bought the tweecer. Would I be able to just throw the 30s on there on the stock maf as long as its not pegging it voltage wise? If so that would save me at least 100 dollars maybe even more like 130 at least for now. That would be a better step in getting me a tweecer....

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