I highly recommend bigger injectors. Most HCI combos should be injectored to 30 pounds anyway, IMO.
A lot of guys get away with an adjustable fuel pressure regulator as a band-aid, but that is not the "right" way to do things. The 24 pound level is an easy way out because the stock cobra tune is setup for 24s... loading that cal and working from it is fairly simple.
If you have the patience to hammer out a tune with the TwEECer, then skip the 24s and go to 30 pounders.
Hell, I'm strapping on a 125 shot soon, and even with my grocery-getter stang I think 30s are correct. The propensity to ping, STOCK, in our cars should be considered when you're on the fence. Besides, 30s will also allow some breathing room in case you decide to upgrade to a hotter cam / track heat type combo.
Adam
A lot of guys get away with an adjustable fuel pressure regulator as a band-aid, but that is not the "right" way to do things. The 24 pound level is an easy way out because the stock cobra tune is setup for 24s... loading that cal and working from it is fairly simple.
If you have the patience to hammer out a tune with the TwEECer, then skip the 24s and go to 30 pounders.
Hell, I'm strapping on a 125 shot soon, and even with my grocery-getter stang I think 30s are correct. The propensity to ping, STOCK, in our cars should be considered when you're on the fence. Besides, 30s will also allow some breathing room in case you decide to upgrade to a hotter cam / track heat type combo.
Adam
With aftermarket heads, cam, intake, and all the supporting stuff
and
when talking about a na combo.
I've always believed 24's are right at the limit
or
in some cases, 24's are too small
Keep in mind, I'm talking about using stock fuel pressure here
I base that belief from using many of those inj size formulas you find out there
and
from talking to many other self tuners in the past year or so and hearing some of their experiences when using 24's.
Its the amount of airflow that dictates the size of inj one should choose
I wanna make it clear we are talking about more airflow than a typical bolt on combo. Something around 300rwhp or better.
Sidenote +++ recently Don 95Vert posted Ford uses fuel pressure that is a couple of pounds less than our inj's are rated for. That means you are not getting the all of the inj rating no matter what size inj you run if you use stock pressure
Another thing for Tweecer users
Once upon a time ... the inj duty cycle was known to be off
or
It was a bug in the Tweecer software.
Don't know if V1.30 had the fix or not.
For me ... I don't need no software to tell me what my caculator has told me
and
other peeps have told me about 24's.
See my sig and you'll see I practice what I preach
I'm not telling you to move to 24's as you already have them
Maybe you should run 3 to 4 pounds more pressure as your permanent default fuel pressure setting before you get started on your tune
Thoughts from other members about this as a solution for 95Black50
Grady
and
when talking about a na combo.
I've always believed 24's are right at the limit
or
in some cases, 24's are too small
Keep in mind, I'm talking about using stock fuel pressure here
I base that belief from using many of those inj size formulas you find out there
and
from talking to many other self tuners in the past year or so and hearing some of their experiences when using 24's.
Its the amount of airflow that dictates the size of inj one should choose
I wanna make it clear we are talking about more airflow than a typical bolt on combo. Something around 300rwhp or better.
Sidenote +++ recently Don 95Vert posted Ford uses fuel pressure that is a couple of pounds less than our inj's are rated for. That means you are not getting the all of the inj rating no matter what size inj you run if you use stock pressure
Another thing for Tweecer users
Once upon a time ... the inj duty cycle was known to be off
or
It was a bug in the Tweecer software.
Don't know if V1.30 had the fix or not.
For me ... I don't need no software to tell me what my caculator has told me
and
other peeps have told me about 24's.
See my sig and you'll see I practice what I preach
I'm not telling you to move to 24's as you already have them
Maybe you should run 3 to 4 pounds more pressure as your permanent default fuel pressure setting before you get started on your tune
Thoughts from other members about this as a solution for 95Black50
Grady
95Black50 said:
Thank you for the kind words Chris
Since you be a noob tweec geek, lemme give you a thing or two to think about ... OK
The move to 30's will take you a while to get everything dialed in just right but at your power level... I do think its a wise move
Here are a few things to start your research on that will help you.
Lets talk about your C&L maf
With you being just two days old, (in Tweecer age that is) I'd be willing to bet you are using your maf in cheat mode.
First thing you'll need to do is load in the transfer curve for your C&L ... if no other C&L users fill you in here, you can get the details at the Tweecer site as there are a lot of C&L users there.
Now lets talk about those 30's
Use the following items to load in 30lb values
low slope - scalar
high slope - scalar
inj offset vs batt voltage - function
breakpoint - scalar
EEC Analyzer can help you tremendously with the above items
That should be plenty to get you started when you decide to work with the 30's and your C&L curve
Again ... I'm not all that sure the inj duty cycle you see in your dlogs can be trusted. Search around on the Tweecer site to confirm unless one of the other members can verify my concern here is valid or I'm romin around way out there in left field
You know what Chris? ... It just came to me
You could always juice up the pressure by about say 6 pounds and see if the duty cycle goes down
Then again, if it ain't accurate, how is that gonna help
Sorry for the senior moment
We have gotten quite a few self tuners here so be sure to search around a bit for some excellent research.
I got a little bit of stuff on my site as well that could help I reckon.
Good Luck at the track tomorrow Chris
Since its your first time ... hope you have lots of fun
Grady