2000 4.3 procharged with cam tuning issue

orih_cz_kay

Member
After looking at your data log, it looks like you are running out of fuel past 4500 rpm or you need to have the tune checked. your a/f is in the 14s and that is not good. The a/f should be around 11.3-11.7 during WOT. Your 39lb injectors are real close to max assuming your hp is close to your torque. As some other members suggested try and get a data log. If you own an sct tuner and a laptop your all set. the log software can be downloaded for free from sct's web site.

just a heads up, the dyno graph you were looking at was vsixxer24's. mine is around 11.3 at WOT.
 

6 Shooter

Well-Known Member
I have run both returnless, and the return style in the Mustang. There are pluses and minuses for both types. With a return style, you will have to buy an adjustable regulator, a pump or pumps which can be installed inside or outside the fuel tank, plus add a return line from the fuel rails to our fuel tank. The other issues with return style is that the pumps may cavitate when the fuel level gets to 1/4 full due to all the bubbles and splashing going on inside the fuel tank. Further, those types of systems do not like a completely full fuel tank as the returned fuel has no where to go back into a full tank, thus creating extra fuel vapors which need to go somewhere.

The returnless system solves all of those issues, but the tricky part is tuning the system for the pumps. Tuning requires changes in the pump voltage table plus about 4-5 other tables. Not hard, but takes a little time and some data logging at various throttle settings. Am back to returnless and am going through the returnless pump tuning process now. Am near the end and am just finding about fuel flow numbers for WOT. With a blown V-6, the motor needs a hell of a lot of fuel delivery to keep the motor somewhat cool to avoid detonation (motor/pistons from melting).
 

vsixxer24

Active Member
After looking at your data log, it looks like you are running out of fuel past 4500 rpm or you need to have the tune checked. your a/f is in the 14s and that is not good. The a/f should be around 11.3-11.7 during WOT. Your 39lb injectors are real close to max assuming your hp is close to your torque. As some other members suggested try and get a data log. If you own an sct tuner and a laptop your all set. the log software can be downloaded for free from sct's web site.
That is my dyno sheet showing a/f LOL...and yes, I know I was maxxing out the injectors around 4500. Threw a rod before I can change out the injectors.
 

vsixxer24

Active Member
are you running a return or return less fuel system?

which do you guys recommend for my set up?

I was running returnless.. However, I am looking at an aeromotive hat that accepts a return line. Thinking of switching over.

Tuner- most guys on here use SCT.. seems that is the way to go. I like my tweecer RT tho, seems like you can a bit more with it. The SCT software logs only OBDII systems and the RT gives the same information (PID Registers) on both EEC-IV and EEC-V PCM modules.
 

douglass

Active Member
just a heads up, the dyno graph you were looking at was vsixxer24's. mine is around 11.3 at WOT.

Sure is, my bad. Jumping to a 60lb injector could lead to other issues, but may be the only option if you plan on making more power that you are now. The 60lb SD injectors have a huge min. PW, and that could cause over fueling at idle or low speed rpms on decel. I experienced some of this with the Ford Racing 42lb injectors when I had them installed. if your holding an 11.3 fuel curve to the rev limiter then at least you know you have enough injector for your current set up.

6 Shooter is 100% correct, the v6 engine will require a bigger injector than a V8 to make the same hp.

Anyway Start with a data log if possible. That way we can see what the car is doing when you are have having your issues. Could simply be a MAF value correction. Also depending on how aggressive the cam is would depend on if the computer would need to be reprogrammed which it sounds like that is the case with your situation.

As long as you have the SCT handheld in your possession, then you should be able to data log the car. Unfortunately with the issue you are having I don't see how we will be able to help much more with out it if it is a tune related problem. Assuming everything mechanical is good, then the next step is to see what the computer is doing.

Throwing parts at the car gets expensive, and in some cases will require the car to be re-tuned again.
 
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orih_cz_kay

Member
I have run both returnless, and the return style in the Mustang. There are pluses and minuses for both types. With a return style, you will have to buy an adjustable regulator, a pump or pumps which can be installed inside or outside the fuel tank, plus add a return line from the fuel rails to our fuel tank. The other issues with return style is that the pumps may cavitate when the fuel level gets to 1/4 full due to all the bubbles and splashing going on inside the fuel tank. Further, those types of systems do not like a completely full fuel tank as the returned fuel has no where to go back into a full tank, thus creating extra fuel vapors which need to go somewhere.

The returnless system solves all of those issues, but the tricky part is tuning the system for the pumps. Tuning requires changes in the pump voltage table plus about 4-5 other tables. Not hard, but takes a little time and some data logging at various throttle settings. Am back to returnless and am going through the returnless pump tuning process now. Am near the end and am just finding about fuel flow numbers for WOT. With a blown V-6, the motor needs a hell of a lot of fuel delivery to keep the motor somewhat cool to avoid detonation (motor/pistons from melting).

ok i think i'll stay with the returnless. at least for now.

and do you know at what power/RPM the 39# injectors would max out? "douglass" mentioned some problems with bigger injectors. experience any of these?
 

orih_cz_kay

Member
Sure is, my bad. Jumping to a 60lb injector could lead to other issues, but may be the only option if you plan on making more power that you are now. The 60lb SD injectors have a huge min. PW, and that could cause over fueling at idle or low speed rpms on decel. I experienced some of this with the Ford Racing 42lb injectors when I had them installed. if your holding an 11.3 fuel curve to the rev limiter then at least you know you have enough injector for your current set up.

6 Shooter is 100% correct, the v6 engine will require a bigger injector than a V8 to make the same hp.

Anyway Start with a data log if possible. That way we can see what the car is doing when you are have having your issues. Could simply be a MAF value correction. Also depending on how aggressive the cam is would depend on if the computer would need to be reprogrammed which it sounds like that is the case with your situation.

As long as you have the SCT handheld in your possession, then you should be able to data log the car. Unfortunately with the issue you are having I don't see how we will be able to help much more with out it if it is a tune related problem. Assuming everything mechanical is good, then the next step is to see what the computer is doing.

Throwing parts at the car gets expensive, and in some cases will require the car to be re-tuned again.

i'll try and do a datalog.
 

6 Shooter

Well-Known Member
Think the 39s are good for maybe 350 or a little more HP. That is a guess however. Only a data log will tell the truth. With a high performance blown motor, you have NO chance to find out what the hell the motor is doing or how safe It is without data logging. Period. If you can't data log, you are fooling yourself and trusting most likely flawed tunes that will fry your motor. Been doing the data logging for years now and the data logs in almost 100% have shown flawed mechanical issues or flawed portions of the tune. Both issues will torch your motor. Tuning has to be done methodically and slowly to be safe. Drivability issues always surface along the way with changes to pumps, injectors, wiring, etc.
 

orih_cz_kay

Member
Think the 39s are good for maybe 350 or a little more HP. That is a guess however. Only a data log will tell the truth. With a high performance blown motor, you have NO chance to find out what the hell the motor is doing or how safe It is without data logging. Period. If you can't data log, you are fooling yourself and trusting most likely flawed tunes that will fry your motor. Been doing the data logging for years now and the data logs in almost 100% have shown flawed mechanical issues or flawed portions of the tune. Both issues will torch your motor. Tuning has to be done methodically and slowly to be safe. Drivability issues always surface along the way with changes to pumps, injectors, wiring, etc.

oh ok. 60# injectors should be way more than enough with what im going for.

i just tried to datalog and i got a pop up that said on the computer side, "no part number found in SCT device. please contact SCT for support for help." then the second pop up said, "part number does not match any supported device!"...... looks like imma have to call SCT tomorrow when they're open...
 

douglass

Active Member
and do you know at what power/RPM the 39# injectors would max out? "douglass" mentioned some problems with bigger injectors. experience any of these?

(330hp @ crank) x (bsfc .57lbs/hr)= 188.1 lbs/hr

(188.1lbs/hr) / 6 injectors = 31.25 lbs/hr

(31.25 lbs/hr) / (0.8)= 39.065 lbs/hr min injector to operate safely

the bsfc can be .55-.60 for supercharged engines, i averaged them out

the 0.8 is 20% safety margin so the injectors operate at 80% duty cycle. in a lot of cases injectors will max around 80%.

all you have to do is change the desired crank hp and you can find the suggested injector

a 60lb injector should be good to around 500hp at the crank
 

orih_cz_kay

Member
(330hp @ crank) x (bsfc .57lbs/hr)= 188.1 lbs/hr

(188.1lbs/hr) / 6 injectors = 31.25 lbs/hr

(31.25 lbs/hr) / (0.8)= 39.065 lbs/hr min injector to operate safely

the bsfc can be .55-.60 for supercharged engines, i averaged them out

the 0.8 is 20% safety margin so the injectors operate at 80% duty cycle. in a lot of cases injectors will max around 80%.

all you have to do is change the desired crank hp and you can find the suggested injector

a 60lb injector should be good to around 500hp at the crank

wow thanks!

im at 323 rwhp right now at 5400 rpm. soo at 6500 rpm maybe 390 rwhp - 400 rwhp is what im thinking. soo 450 hp at the crank?

does that sound right at 6500 rpm? is that what others with the same setup as me have?
 

douglass

Active Member
just because you can rev the engine higher does not mean you will make more hp. On my SC set up, I used the m90 super charger. when I dyno'd the car my peak hp was at 4600 rpm then slowly fell off. I set the rev limit at 5400 just to give me room at the higher end of the gears. You will want to plan on some wot tuning on a dyno to see where you are with hp. just be mindful that you are close to maxing out your injectors.
 

orih_cz_kay

Member
just because you can rev the engine higher does not mean you will make more hp. On my SC set up, I used the m90 super charger. when I dyno'd the car my peak hp was at 4600 rpm then slowly fell off. I set the rev limit at 5400 just to give me room at the higher end of the gears. You will want to plan on some wot tuning on a dyno to see where you are with hp. just be mindful that you are close to maxing out your injectors.

what set up do you have?
 

douglass

Active Member
I had a 99 mustang block with sc heads and a 93 m90 blower. i maxed out the 30lb injectors with bolt on upgrades. Upgraded to a 42lb injector (green top), then sold them. I then bought the Ford Racing 39lb Injectors (03-04 cobra). I had some mechanical problems with the block, and swapped my stock engine back in. I also have the Advantage III software which allows me to do all my own tuning. Once learned it is a great freedom to do what ever you want to the car without having to depend on someone else.
 

JTsStang

Boosted V6
2n6w4yq.jpeg
and do you know at what power/RPM the 39# injectors would max out? "douglass" mentioned some problems with bigger injectors. experience any of these?
Depends on rail pressure. I made 370rwhp with a procharger on 39's. The fuel system was holding me back. The returnless fuel system is flawed for boost. Usually the pressure stays static at 35-42psi while in full boost. Nothing wrong with this for your setup though. BUT one thing I'd recommend is having your tuner load the 55psi fuel pressure file onto your tune just for safety. I know you wont know what I'm talking about without owning pro racer software but your tuner will know if you mention it to him. Basicly what this does is increases rail pressure to 55psi when you go wot.
 

orih_cz_kay

Member
I had a 99 mustang block with sc heads and a 93 m90 blower. i maxed out the 30lb injectors with bolt on upgrades. Upgraded to a 42lb injector (green top), then sold them. I then bought the Ford Racing 39lb Injectors (03-04 cobra). I had some mechanical problems with the block, and swapped my stock engine back in. I also have the Advantage III software which allows me to do all my own tuning. Once learned it is a great freedom to do what ever you want to the car without having to depend on someone else.

wow. and yea it would be great to know how to tune. i'd open a business!
 

orih_cz_kay

Member
View attachment 158815
Depends on rail pressure. I made 370rwhp with a procharger on 39's. The fuel system was holding me back. The returnless fuel system is flawed for boost. Usually the pressure stays static at 35-42psi while in full boost. Nothing wrong with this for your setup though. BUT one thing I'd recommend is having your tuner load the 55psi fuel pressure file onto your tune just for safety. I know you wont know what I'm talking about without owning pro racer software but your tuner will know if you mention it to him. Basicly what this does is increases rail pressure to 55psi when you go wot.

ahh thank you. i'll bring it up!
 
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