Question about 19lb Injectors?

[stangzroastrice]

Hey guys, wondering if the stock 19lber's could handle this mild combo I put together N/A wise or will I need some 24's? Eventually I will be going nitrous most likely and thats where 30lber's would probably come in handy...
Anyway here is the motor I put together as follows:

Ported GT40 Cast Iron Heads (Non-P's) w/ 3 angle valve job, etc.
Stock 1.6 Rockers
Comp Cams XE270HR-14 Cam .512" lift
TrickFlow StreetHeat Intake Manifold
BBK 75mm Throttle Body
Underdrive Pulleys
Stock MAF
BBK Ceramic Coated Unequal Shorties
UPR O/R X-pipe
Flowmaster 2 chamber cat-back with dumps

and a Kirban AFPR if upping the fuel pressure is necessary...

what do you guys think?

 

[Stanger007]

I'm a big fan of having larger injectors and fuel pump than you need and using a custom tune to get everything precise.

It looks to me like your 19's will be on the ragged edge. 24's would give you a bit more safety margin but it would still be close. 30's would give you an even larger margin AND allow for future upgrades.

Here's a link to a calculator for calculating proper injector sizing and also a table that shows injector flow rates at various PSI: http://www.mustang-tech.org/wiki/94-95_Mustangs_Tuning_Injectors#Choosing_the_Proper_Sized_Injectors

Wes

 

[final5-0]

Consider all the knowledge at Ford Motor Company

Look at their injector size choice on the 94-95 Cobra

Compare your proposed combo to the Cobra

Does that make you think any differently

Grady

 

[stangzroastrice]

Haha then 24 lber's it is. Now the Cobra and the GT used the same MAF, so does that mean I can just throw in 24lb injectors with no trouble or calibration? Really don't have the money to shell out 100+ bucks for a bigger MAF right now.
thanks!

 

[Stanger007]

No, sadly the injector settings aren't in the MAF but instead in the PCM.

Gotta get a tune or a MAF that tricks the PCM into making the 24s (mostly) work properly.

Wes

 

[Therian]

In which case, you might as well go with 30lbers and a properly calibrated MAF, to save you the trouble of needing to do it all over again once you add the nitrous

 

[stangzroastrice]

ok 30lber's and a cal'd MAF it is haha, thanks for all the help guys

 

[Therian]

I must note though, I believe the 30lbers will be more in need of a proper tune, than 24s. Others should be able to clarify.

Either way, when swapping in a new engine, it's best to have it properly tuned for performance and peace of mind.

 

[stangzroastrice]

yeah, i figured that, hopefully the car will be "driveable" before the tune depending on my money situation at the time

 

[Stanger007]

You may run into hard starts w/ the 30s - the MAF's trickery isn't taken into account when cranking so you get 1.5x more (30/19) fuel than needed during cranking.

Too many things to consider, eh.

Wes