19 Lbl injector Limits
09-10-2013, 07:24 AM
#11
3rd Gear Member
Thread Starter
Join Date: Sep 2011
Location: Florida
Posts: 632
You are correct, it is sort of a waste because the heads will limit the hp gain from the manifold, but it will be about 2 years or so before I do the heads, cams, timing chain, pistons, etc. Until then, I'm just wanting a little bit more tb response and fun for cheap. I'm about to go into the masters program at my college, so I cannot afford to put out 2,000 bucks on the things I want just yet (I don't want to buy that stuff used).
09-10-2013, 07:40 AM
#12
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Join Date: Mar 2010
Location: Wisconsin
Posts: 5,061
What gears are you running? If your looking for the best bang for buck / butt-dyno improvement, fun-meter pegged, can't beat a gear swap. That's if you still have stockers. I know that's going a different direction than engine mods, but gears will feel like you have 300 hp. You said moneys tight and your just looking for "fun for cheap",so just a suggestion.
Last edited by 88 orangepeel notch; 09-10-2013 at 07:44 AM.
09-10-2013, 08:47 AM
#15
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Join Date: Mar 2010
Location: Wisconsin
Posts: 5,061
OH CRAP !!! You have to get those gears out of there. Since your alittle above stock power (with more to come)…… I'd do the 3:73's. You WON'T be dissappointed on spending that money. Or if your really cheap like me, keep an eye on Craigslist for a complete rearend with the gears already done. Plug and play then, as long as you know what your buying.
Yeah the intake will help alittle, but nothing compared to a gear swap. You'll be smiling till your face hurts, seriously.
Yeah the intake will help alittle, but nothing compared to a gear swap. You'll be smiling till your face hurts, seriously.
Last edited by 88 orangepeel notch; 09-10-2013 at 08:51 AM.
09-10-2013, 10:52 AM
#18
Join Date: Apr 2010
Location: FL
Posts: 8
Using MAFs that are calibrated for injector size is right up there with leeching to cure ailments. In modern times, we properly calibrate for the injector size by changing the tune. Ford Racing gives us the injector characterization data we need for all Ford Racing injectors. Or if they are OEM Ford injectors, we can pull that data out of a stock tune in a car that came with those injectors.
09-10-2013, 01:01 PM
#19
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Join Date: Sep 2011
Location: Florida
Posts: 632
Well I have a T5 transmission in it with 255/40R17 tires (Nitto 555's), so I guess the 3.55's? As for the injectors, could I put the 24's on and just get the calibration tube (C&L MAF) for the 24lbl injectors? Or would I need an adjustable fuel pressure regulator?
09-10-2013, 01:25 PM
#20
Join Date: Apr 2010
Location: FL
Posts: 8
Using a calibrated MAF to compensate for injector size changes works ok for fox bodies, with 24# injectors. Anything bigger than that, and it gets problematic.
The better way to do it is to tell the computer (via a chip) that you've got 24# injectors. Ford uses a specific set of data tables to describe to the computer how to control the injectors. It's not just "24#". It's low slope, high slope, breakpoint, minimum pulsewidth, and most importantly voltage compensation tables. Each injector is controlled uniquely, and saying 24# (or using a calibrated MAF) only addresses the static flow rate setting (called hi slope).
Since the part throttle timing tables are based on load, and load is based on airflow versus engine size, and airflow is based on MAF readings, and MAF readings are being skewed by a calibrated meter, I don't care to ever use calibrated meters for that purpose.
We still use them for their larger airflow housing and increased electronic range. We just don't use them in the way they were intended, which was to "lie" to the computer about airflow so that the computer will command a lesser pulsewidth the the injectors (which were also changed without the computers knowledge in this case).
What we really want is to use the larger MAF housing, if NECESSARY use the increased electronic range of the larger MAF, and then properly calibrate for both the MAF and the injectors in the tune.
It's like this. We don't tell a calculator to do 12 plus 4 so we can an answer of 16, if the real numbers are 8 + 8 = 16. Sure, you can trick it with limited success... but why would you want to? Let that calculator do the real math with the real numbers. In tuning, there are unintended consequences to using the wrong numbers to come up with the right answer! And spark timing is that consequence.
As we increase the size of the meter electronically (using a calibrated MAF), we are basically making the computer think there is less airflow coming in. The computer then calculates less load, which calls for MORE spark. And the bigger the MAF calibration trick, the bigger the problem. So in effect, a calibrated MAF adds more spark timing at part throttle. This might not be noticeable with a simple 24/19ths MAF calibration (24# injectors where a 19# is supposed to be). But try a 30 or 42# injector, and drivability will quickly suffer.
An adjustable fuel pressure regulator is not necessary, unless you are trying to trim air/fuel ratios on your wideband, without tuning.
The better way to do it is to tell the computer (via a chip) that you've got 24# injectors. Ford uses a specific set of data tables to describe to the computer how to control the injectors. It's not just "24#". It's low slope, high slope, breakpoint, minimum pulsewidth, and most importantly voltage compensation tables. Each injector is controlled uniquely, and saying 24# (or using a calibrated MAF) only addresses the static flow rate setting (called hi slope).
Since the part throttle timing tables are based on load, and load is based on airflow versus engine size, and airflow is based on MAF readings, and MAF readings are being skewed by a calibrated meter, I don't care to ever use calibrated meters for that purpose.
We still use them for their larger airflow housing and increased electronic range. We just don't use them in the way they were intended, which was to "lie" to the computer about airflow so that the computer will command a lesser pulsewidth the the injectors (which were also changed without the computers knowledge in this case).
What we really want is to use the larger MAF housing, if NECESSARY use the increased electronic range of the larger MAF, and then properly calibrate for both the MAF and the injectors in the tune.
It's like this. We don't tell a calculator to do 12 plus 4 so we can an answer of 16, if the real numbers are 8 + 8 = 16. Sure, you can trick it with limited success... but why would you want to? Let that calculator do the real math with the real numbers. In tuning, there are unintended consequences to using the wrong numbers to come up with the right answer! And spark timing is that consequence.
As we increase the size of the meter electronically (using a calibrated MAF), we are basically making the computer think there is less airflow coming in. The computer then calculates less load, which calls for MORE spark. And the bigger the MAF calibration trick, the bigger the problem. So in effect, a calibrated MAF adds more spark timing at part throttle. This might not be noticeable with a simple 24/19ths MAF calibration (24# injectors where a 19# is supposed to be). But try a 30 or 42# injector, and drivability will quickly suffer.
An adjustable fuel pressure regulator is not necessary, unless you are trying to trim air/fuel ratios on your wideband, without tuning.