Best fuel pump and injector size?

[2000xp8]

Let's just say dyno's have now been the norm for 15 years.
Fuel injected fox bodies were around 10 years sooner.
If these cars don't run right without a chip, how exactly did everyone get by before the dyno, you are saying it was by luck?
I've seen plenty of these cars on the dyno first hand, i've also seen plenty of these so called chipped cars, and almost every time the car runs better with the chip pulled.

I've read a fair amount of your posts, normally i find them to be pretty intellligent, but your one size fits all injector solution for basically an A trim it senseless and misleading.
If the heads cam intake for this guy is right around the corner, then he should hold off on the sc install and do it all at once time.
Would you tell a guy that had h/c/i to use 42's because in the future he was going to get a supercharger? Or would you tell him to use 24's until said supercharger was installed?

How exactly would he be doing it once and doing it right if he's using the wrong size injector for his setup?

While we are on the subject of laughable, that's exactly what the guys dyno'ing the car are going to think when they realize a 300rwhp car has 42lb injectors, their first thought, just another jackass who gets all their info from the internet.

 

[millhouse]

Let's just say dyno's have now been the norm for 15 years.
Fuel injected fox bodies were around 10 years sooner.
If these cars don't run right without a chip, how exactly did everyone get by before the dyno, you are saying it was by luck?
I've seen plenty of these cars on the dyno first hand, i've also seen plenty of these so called chipped cars, and almost every time the car runs better with the chip pulled.

I've read a fair amount of your posts, normally i find them to be pretty intellligent, but your one size fits all injector solution for basically an A trim it senseless and misleading.
If the heads cam intake for this guy is right around the corner, then he should hold off on the sc install and do it all at once time.
Would you tell a guy that had h/c/i to use 42's because in the future he was going to get a supercharger? Or would you tell him to use 24's until said supercharger was installed?

How exactly would he be doing it once and doing it right if he's using the wrong size injector for his setup?

While we are on the subject of laughable, that's exactly what the guys dyno'ing the car are going to think when they realize a 300rwhp car has 42lb injectors, their first thought, just another jackass who gets all their info from the internet.

In the past they were either tuned with fuel pressure and disabled closed loop operation or used an FMU. Both are hacks to say the least...but if I had to pick one, I'd go FMU.

As for waiting for future upgrades...you should know by now that they typically come in spurts. If/when he installs a supercharger...I wouldn't expect him to upgrade for atleast several years.

As for those so called "chip" cars...you have no idea what chip they were running nor where they were from. A true dyno tuned vehicle by a reputable/knowledgeable shop would unequivocally have a safer tune and produce more power to boot. This applies at virtually all mod levels from your basic intake swap up past forced induction setups. Obviously at lower mod levels the costs are not justified, but once you start getting into the 300rwhp range untuned it certainly does.

Something to remember is that you can have a awesome tune with 42lb injectors, adequate maf meter on a simple h/c/i combo. Paying for the tune certainly does hurt the wallet...but a good portion of the costs are tied up in the chip. A re-tune for a supercharger should only cost ~ $150, as most everything else should already be in order.

 

[sfcadams]

Hey guys, thanks for all of the input so far. I am not sure if I made things clear or not.

Here is my current setup: Totally stock non-mass air 5.0

Definately will be converting to mass-air (1st priority)

No plan on cam or head swap.

Might (read:might) swap to cobra upper and lower.

Installing Paxton 1220SL after conversion to mass-air.

Given what I have said above, let me ask these questions.

1) Any problem running a larger in-tank fuel pump while still NA? Recommendation on size with regards to installing a supercharger down the road?
2) Stock mass-air cars run 19lb injectors so should I stay at 19lb injectors until I introduce the supercharger?
3) Once I introduce the supercharger what size injectors should I run since it will be all stock with the exception of maybe a cobra upper/lower at some point?
4) Adjustable fuel pressure regulator... Yes or no?

 

[millhouse]

Hey guys, thanks for all of the input so far. I am not sure if I made things clear or not.

Here is my current setup: Totally stock non-mass air 5.0

Definately will be converting to mass-air (1st priority)

No plan on cam or head swap.

Might (read:might) swap to cobra upper and lower.

Installing Paxton 1220SL after conversion to mass-air.

Given what I have said above, let me ask these questions.

1) Any problem running a larger in-tank fuel pump while still NA? Recommendation on size with regards to installing a supercharger down the road?
2) Stock mass-air cars run 19lb injectors so should I stay at 19lb injectors until I introduce the supercharger?
3) Once I introduce the supercharger what size injectors should I run since it will be all stock with the exception of maybe a cobra upper/lower at some point?
4) Adjustable fuel pressure regulator... Yes or no?

1) No, no problems
2) Yes
3) 36lb-ers will do
4) No

Unless you have a wideband and can verify that your setup will be safe, you'll need a tune as well. If you want to extract the most horsepower out of the charger...you'll need a tune also.

 

[sfcadams]

Ok got it. I am just curious as to what point an adjustable fuel pressure regulator would come into play then? People use them for a reason and I am just curious as to what that reason is?

 

[BYRDPE]

Ok got it. I am just curious as to what point an adjustable fuel pressure regulator would come into play then? People use them for a reason and I am just curious as to what that reason is?

you'll get conflicting information on this. i have one and my fp is set higher than the stock setting. your tuner will be mapping your fp in your ecu.
if you have decided on who is going to tune your car...ask them if you need one for them to tune.
good luck!

 

[can95droptop]

This was in the 94-95 forum

Quote:
Fuel Injector Selection:

Injector HP Ratings: divide flow rating by .5 and multiply the result by the number of injectors. The following examples use a 100% duty cycle. These ratings are for N/A engines at the flywheel.

Example:

19 lb injectors/.5 = 38 - 38 x 8 = 304 HP
24 lb injectors/.5 = 48 - 48 x 8 = 384 HP
30 lb injectors/.5 = 60 - 60 x 8 = 480 HP
36 lb injectors/.5 = 72 - 72 x 8 = 576 HP
42 lb injectors/.5 = 84 - 84 x 8 = 672 HP

The preferred duty cycle is about 85% maximum, so for a safety factor multiply the final figure times .85.

304 HP x .85 = 258 HP for 19lb injectors
385 HP x .85 = 326 HP for 24lb injectors
480 HP x .85 = 408 HP for 30lb injectors
576 HP x .85 = 490 HP for 36lb injectors
672 HP x .85 = 571 HP for 42lb injectors

Remember that the above ratings are at 39 PSI. Increasing the pressure will effectively increase the flow rating. Example: a 19 lb injector will flow 24 lbs at 63 PSI, and a 24 lb injector will flow 30 lbs at 63 PSI.

See Automotive Performance Software / Interactive JavaScripts Calculators to get the calculators used in these examples.

The above information is courtesy of jrichker!

 

[Cobra912]

Unless your current FPR is broken…keep the stocker. You do not tune with fuel pressure…but with the computer itself. Any reputable shop is going to see that you have an adjustable FPR and have you set it to the stock 39lbs before the tune anyways.

Again, keep the stocker and save the cash for some of the other upgrades needed.

As for installing the fuel pump…I’d wait until your closer to installing the supercharger. You have no need for it now…so you’re better off saving it’s life for when you’ll need it.

YEP.

 

[vristang]

Before you touch anything, i'd convert the car to Mass air, people screw up the maf conversion often enough by itself, make the car run right as a maf car, then add the SC setup because trouble shooting with the SC on there will be twice as hard.

This I agree with... if you take the projects one step at a time, it will be easier to track any problems that come up.

I'm going to disagree with the 42's, i'm of the opinion that you use the injectors for the setup you have now, not just stuff in the biggest set.
When you use the right injector and meter for the job, other than timing, the car pretty much tunes itself. If you need a dyno tune for it to run right, that means you screwed up somewhere.

This is straight BS
A so called "calibrated" MAF meter is just a bandaid... no better way to put it.

If the system is seeing boost from a turbo or SC, then get a custom J3 chip/tune burned.
With the money already spent on the boost system, there is no reason to cheap out with a 'calibrated' MAF.

Let's just say dyno's have now been the norm for 15 years.
Fuel injected fox bodies were around 10 years sooner.
If these cars don't run right without a chip, how exactly did everyone get by before the dyno, you are saying it was by luck?
I've seen plenty of these cars on the dyno first hand, i've also seen plenty of these so called chipped cars, and almost every time the car runs better with the chip pulled.

Then either the cars were STOCK, or the guy doing the tuning was a POS and didn't know what he was doing.
You gonna throw the guy under the bus? Who was this mythical tuner of which you speak?

I've read a fair amount of your posts, normally i find them to be pretty intellligent, but your one size fits all injector solution for basically an A trim it senseless and misleading.
If the heads cam intake for this guy is right around the corner, then he should hold off on the sc install and do it all at once time.
Would you tell a guy that had h/c/i to use 42's because in the future he was going to get a supercharger? Or would you tell him to use 24's until said supercharger was installed?

This is where your retardation shows...
With a chip, runnig 42's is a no brainer...
Now you have advised a guy to buy 24's now... knowing that he will need 42's later.
The better advice is to buy the injector which will be needed in the final setup, and use the tuning capabilities in the mean time to correct for it.
Cheaper in the long run... by approximately the cost of a set of injectors....

How exactly would he be doing it once and doing it right if he's using the wrong size injector for his setup?

See directly above retard..

While we are on the subject of laughable, that's exactly what the guys dyno'ing the car are going to think when they realize a 300rwhp car has 42lb injectors, their first thought, just another jackass who gets all their info from the internet.

Sounds like you have 'witnessed' many dyno sessions.... when reality is you should have been reading up on what really matters in tuning....

1) No, no problems
2) Yes
3) 36lb-ers will do
4) No

+1 on all counts... but I would err on the larger side of the injector range....
You can tune for an injector that is a little too big... there's nothing you can do with an injector that is a little too small...

Ok got it. I am just curious as to what point an adjustable fuel pressure regulator would come into play then? People use them for a reason and I am just curious as to what that reason is?

If you are getting a custom ECU tune via a J3 chip, then a FPR is absolutely worthless. If a 'tuning' shop tells you that you need an FPR for a tune, then walk away and find another shop
It really is that simple.

Tuning via fuel pressure is old school. It was done because that was the best option available. Today there are better options, and they should be utilized.



jason

 

[2000xp8]

This I agree with... if you take the projects one step at a time, it will be easier to track any problems that come up.


This is straight BS
A so called "calibrated" MAF meter is just a bandaid... no better way to put it.

If the system is seeing boost from a turbo or SC, then get a custom J3 chip/tune burned.
With the money already spent on the boost system, there is no reason to cheap out with a 'calibrated' MAF.






Then either the cars were STOCK, or the guy doing the tuning was a POS and didn't know what he was doing.
You gonna throw the guy under the bus? Who was this mythical tuner of which you speak?



This is where your retardation shows...
With a chip, runnig 42's is a no brainer...
Now you have advised a guy to buy 24's now... knowing that he will need 42's later.
The better advice is to buy the injector which will be needed in the final setup, and use the tuning capabilities in the mean time to correct for it.
Cheaper in the long run... by approximately the cost of a set of injectors....

See directly above retard..


Sounds like you have 'witnessed' many dyno sessions.... when reality is you should have been reading up on what really matters in tuning....




+1 on all counts... but I would err on the larger side of the injector range....
You can tune for an injector that is a little too big... there's nothing you can do with an injector that is a little too small...






If you are getting a custom ECU tune via a J3 chip, then a FPR is absolutely worthless. If a 'tuning' shop tells you that you need an FPR for a tune, then walk away and find another shop
It really is that simple.

Tuning via fuel pressure is old school. It was done because that was the best option available. Today there are better options, and they should be utilized.



jason

Seriously,
You are the guy that costs other guys hundreds of dollars on tuners, chips and dyno runs that they don't need.
I'm the retard, but you'll have the guy spend a freaken grand on a chip or a tuner just so you can run 42 lb injectors in the far off or possibly nonexistant future.
Oh yeah, and the hp benefit from the tuner? What about 3rwhp?
Not exactly cost effective.
If your car doesn't run right before a tuning device, then the tuner is just a bandaid. The stock computer can handle over 600rwhp.

I guess no big deal, you are just helping spend other peoples money.

Some of you guys must of gotten your cars after 1996 when all this tuner stuff became available based on modular cars demanding their use.
Because if you had your car before that time, you'd realize none of this crap does anything for a fox but burn a hole in your pocket.

I'm thinking maybe you have stock in 42lb injectors, because according to your information, they can be used for every combo out there. I guess they should stop making 24's, 30's and 36's, because 42's will work just fine.

As far as the name calling, it's just unecessary, but if you think it makes you sound right or smarter, i guess run with it.

 

[sfcadams]

Ok, I think I am really confused since there seem to be so many different opinions on this....

 

[sfcadams]

Anyone else care to put in their .02?

 

[2000xp8]

Anyone else care to put in their .02?

Not many are going to respond anymore, probably out of fear that other members will berate for their opinion.

How many pounds of boost do you plan on running, or how many pounds is the base kit?
Right now, i'll assume 6.
And take my word on this, this is no freaken way you need 42lb injectors for that. Especially since you have no plans for heads as you stated on page 1.