Can you make INJ act smaller?

[Yobi1Kanobi]

I know that you can adjust fuel pressures to make injectors a little bigger. But here I got a different dilema.

When I first started my build I started out with a 347 and a Powerdyne but I sold the SP and now I am gonna keep it NA but i had already bought 42lbs inj and LMAF. So I dont wanna just ditch it and lose the money.

So whats my options....

My comp ratio is 9.5 to 1

 

[95cobraguy]

u can make an injector stay open longer through a tune. the longer an injector stays open the more fuel it will squirt into the cylinder.

 

[HISSIN50]

I'm not too hot with tuning, but....................

It seems to me that the issue is that when you reduce the pressure, the spray pattern goes to crap. Low DC's and injectors don't go together too well either, though trying to tune (if you have a TwEECer, etc) around it would be the best bet.

The tuning guys will have some much better advice.

Good luck.

 

[final5-0]

Interesting Question

Power adder or not

ALL inj's have an issue when at idle
or possibly
low load cruise conditions
which would mean ... low pulsewidth situations

They are very sloppy with how they go about delivering fuel

Rule of thumb I guess could be stated kind like this ...
The bigger the inj ... the more sloppiness (is that a real word)

With pcm access, you can create a work around for this issue
however
IMHO ... it would be better to have a more suited inj ........
for your combo needs

Dialing back the pressure is not gonna help much ... if at all

I'd talk to your tuner and get his input before doing anything

One Last Thing ... You most likely are gonna now be using a much
smaller portion of your L's transfer curve since you can't put up the
big airflow #'s

Smaller use of its curve ...... for less resolution
and
other geek speak sounding stuff ... don't ya know

Might be better off just moving that stuff to one who needs it

Hopefully someone with more experience will be more help
than
my feeble attempt here

Grady

 

[tjh566]

I could use that stuff.... but no funds right now

 

[mo_dingo]

I am with grady. Sell the maf and injectors and buy some 30's and a pro-m maf cal'ed for it. Or keep stock maf and use a tune to adapt to the injectors.
Scott

 

[Yobi1Kanobi]

well that sucks see becuz i sold 30lbs and a Pro-M and bought this setup up.

If I GOT 30 lbs inj can i make the maf work....

 

[ProKiller]

go turbo and keep the 42#s

 

[Yobi1Kanobi]

not exactly a choice here killer>..but I like the idea

 

[Grn92LX]

Keep the 42's!!!

Since you have a lightning MAF, you will need some sort of tuning device anyway. Keep the 42's

My 30's are near maxed out up top

 

[Yobi1Kanobi]

what is it that you are running with those bolt ons there green92. I am running a 347 TFS heads with an R intake and all the bolt ons that go with it. I was going off a inj calculator that told me that at 400 hp it would require 27 lbs inj. thats why i wanted to go with 30s

 

[Grn92LX]

Don't go by useless internet injector calculators!

I have an 11:1 n/a 347 with TW heads, R manifold, fairly healthy FTI cam, 1 3/4" longtubes, 4.30 gears, anderson PMS, yada yada yada..Shift near 7k rpm.

If money was no object i'd do TEA 205cc twisted wedges, victor 5.0 manifold, 90mm tb, 3" exhaust and a new custom cam and shift at 7,500. And 42lb injectors.

 

[final5-0]

See ... here is the thing about sizing inj's

Most of those help deals are done in fw hp

We almost always ... think and relate in rw hp

Thats the biggie to think about
but
There are several others

Like if you still got the wimpy oem pump ...

Like if stick or auto ...

Like if you got a centri blower drawing away power ...

etc ... etc ... etc ...

You wanna be safe here

This is no place to fart around and not do your homework

Grady

 

[Yobi1Kanobi]

Well i have a 190 in tank now and im doing with a 255 . i have a inline that i cant throw on but dont think it will be necs..And it will be NA....I dont want to under fuel it by anymeans but i dont wanna make it pig rich either one isnt good...

And yes its a TKO 600 back there and Diablo custom tune Revo Chip..