24# injectors
- Thread starter Supaman
- Start date
-
Sponsors (?)
88Stang331
New Member
- Mar 30, 2006
- 239
- 0
- 0
bubba-dough
Active Member
I'm not looking for much boost. Just something to have when you need it and maybe for some weekend drags. Right now my engine mods are extrude honed and ported cobra upper and lower intake, edelbrock heads with 1.6 roller rockers, 24# injectors, 70mm throttle body, Pro-m mass air meter and a B-303 cam. I want to purchase a intercooled procharger P1SC in a couple of weeks.
88_GT_5_oh
Sportin' a turbo 5.0 in Canadistan
bryce93lx
Member
24's are good only to a little over 300 horse, with any kind of boost and the head and intake package(a honed cobra flows very well) you have mostlikly 310 or so now and the blower( even at 6 psi) should be a 30% power increase pushing you very close to 400 horse(or more) 30's are the minimum i have a wheel at home that shows the best injectors pm and i will check it for you
Suck it up and buy 42s and a tune. With 24s you'll be needing an FMU to ramp up fuel pressure enough to support the boost. The trouble with doing that is whenever pressure is ramped up then the max volume of fuel the pump is able to produce is reduced.
An FMU must be tuned mechanically whereas sufficient sized fuel injectors can be tune electronically. Many tuning facilities refuse to tune an FMU and that may leave you tuning it yourself.
For that, you'll need a wide band AFR meter. A good one will cost you at least half of what a custom chip will cost. You also may discover that you'll need a helper pump in addition to your in-tank pump because you're trying to provide the necessary fuel volume at elevated pressures. Those also cost money.
Last but not least, fuel injectors become more inefficient, the higher you ramp up the fuel pressure. Atomization is not as complete at 70+ psi as it would be at 40.
In a nut shell... it's better to run properly sized injectors at near stock fuel pressures than forcing smaller ones to do the job.
One other small footnote:
24 lb injectors are usually good to about 300HP as mentioned above. That figure is for normally aspirated applications. More injector is required to make the same power in a boosted app.
Yes... it can be done with 24 lb injectors. There are certainly better ways to do it though. Having the ability to electronically control your AFR will result in an often, much better power band.
Once the custom chip is purchased, it usually only costs about $100 or so for subsequent tunes if you decide to make further modifications down the road.
An FMU must be tuned mechanically whereas sufficient sized fuel injectors can be tune electronically. Many tuning facilities refuse to tune an FMU and that may leave you tuning it yourself.
For that, you'll need a wide band AFR meter. A good one will cost you at least half of what a custom chip will cost. You also may discover that you'll need a helper pump in addition to your in-tank pump because you're trying to provide the necessary fuel volume at elevated pressures. Those also cost money.
Last but not least, fuel injectors become more inefficient, the higher you ramp up the fuel pressure. Atomization is not as complete at 70+ psi as it would be at 40.
In a nut shell... it's better to run properly sized injectors at near stock fuel pressures than forcing smaller ones to do the job.
One other small footnote:
24 lb injectors are usually good to about 300HP as mentioned above. That figure is for normally aspirated applications. More injector is required to make the same power in a boosted app.
Yes... it can be done with 24 lb injectors. There are certainly better ways to do it though. Having the ability to electronically control your AFR will result in an often, much better power band.
Once the custom chip is purchased, it usually only costs about $100 or so for subsequent tunes if you decide to make further modifications down the road.
The only problem I have if I upgrade to larger injectors is the tuning. I live on The Big Island in Hawaii and where I live there is nobodyy that does tuning. We have two dynos on the whole island and none of them does any tuning. If I do upgrade to bigger injectors, is there any way to tune it my self with out putting it on the dyno? I really don't trust those guys.
Yes... there are two options available that are pretty popluar with our cars:
1) TwEECer R/T and a wideband AFR meter.
This option can require quite a learning curve and not what you'd probably consider "user friendly". Still, if you're patient and don't mind the trial and error approach to learning to tune, it'll give the most control. You'll also need to track down the flow data sheet for your meter. You'll need to input that data into the TwEECer but will not need to have it recalibrated.
2) Anderson PMS and wide band AFR meter.
This is considerably easier to learn and operate. You don't have the same control that you would with a TwEECer and you'll need to have your meter recalibrated for 42 lbs injectors. It's also a pretty pricey unit.
Either of these options will allow you to tune for larger injectors.
1) TwEECer R/T and a wideband AFR meter.
This option can require quite a learning curve and not what you'd probably consider "user friendly". Still, if you're patient and don't mind the trial and error approach to learning to tune, it'll give the most control. You'll also need to track down the flow data sheet for your meter. You'll need to input that data into the TwEECer but will not need to have it recalibrated.
2) Anderson PMS and wide band AFR meter.
This is considerably easier to learn and operate. You don't have the same control that you would with a TwEECer and you'll need to have your meter recalibrated for 42 lbs injectors. It's also a pretty pricey unit.
Either of these options will allow you to tune for larger injectors.
88_GT_5_oh
Sportin' a turbo 5.0 in Canadistan
i am running a PMS this year with my turbo car, there is a guy in town that tunes them BUT you can go to www.stangtuning.com and do it yourself with the PMS
Thanks for all the replies. I finally made up my mind. I'm going to get 42# injectors and a anderson PMS. Can't wait to get it all together. Do I need to get a mass air meter calibrated for the PMS? I was reading about it and is said that "Now comes with global fuel adjustments, which means you can offset the mass air for different sized injectors." Thanks again
turbofreek
New Member
Can you provide a link to what you were reading?Supaman said:
I am a tweecer user (atleast for the time being), and the PMS seems pretty different from the tweecer with regard to the MAF setting.
Maybe I misunderstood, but it sounds like the MAF has to be cal'd to the injectors. I thought all the aftermarket tuners allowed the MAF Transfer and Injector settings to be changed independantly.
Just curious,
jason
Similar threads
