Ive heard a lot about which injectors would run best in an N/A quad build...

heres my power train specs from top to bottom

HO Manifold w/ phenolic spacer (changing up from Fontana's to OEMs)
.430 lift .222 duration crane cams
fully ported polished head
HO Springs
HO Lifters
2.3 -> 2.4 retainers
2.4 locks
1mm oversized stainless valves
roughly 11:1 compression
wiseco .20 over race pistons
eagle rods (balanced)
3lbs reduced and balanced GM reground crank
2.3 oil pump swap (incl. removed balance shafts)
OBX underdrive pully
MD lightweight alt pully
rk sport lightened flywheel
spec stage 3 clutch (6 puck)

I also have the RK Sport fuel rail.

So ive heard about ppl running the stock injectors and tune them, and ive heard others on brown tops. I dont want to over do it and dump a @!#$ ton of fuel in, nor do i want to have to severely detune them because they are too big, conversely i dont want to starve the motor, or make a weak/small injector take on too much of a load and burn them out quicker. So what do you all suggest here...

Further, fuel pumps... do i really need to upgrade with my build and if so, is there an intank replacement (i'm not a fan of inline pumps pulling through the stock pump)

When its said and done and tuned, i will only be running 93 octane or better .





Edited 1 time(s). Last edited Thursday, February 11, 2010 9:29 AM

If I were you Id go with either some lsj injectors or some ford greentops, prolly greentops soo you have some breathing room, Im running 440cc greentops on my turbo setup now and will start off my build using them until I upgrade the turbo then my rc 650's will be going in. All said and done my fuel system will be modified walbro 255 intank- walbro 255 inline-8an feed line-rc 650's. For a mild n/a setup some greentops and a racetronix or modified walbro intank will be plenty of fuel for your needs, and keep your idc's safe.

Off topic but anyone whos replaced their fuel lines on their quad/ld9, care to post up some pics? Like from pump up?

My build is going to be similar to yours, Im running the 310cc injectors from the gm supercharger kit. Thats what came stock in the quad 4 HOs. If i bought some again Id probably go with greentops just to make sure I had more than enough.

whatever size the brown tops are seem to be overkill on paul's engine.

i know you cant use brown tops but maybe try and get a tad smaller than them or maybe even the same size.

so green tops are smaller than brown tops??

my buddy ran Cobalt SS Supercharged injectors in his, but he said he's running very rich and he's running the GM Charger

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so were looking at between the green tops and the 310cc GM injectors?

brown tops are 378 cc's green tops are 440

I thought brown tops were 320cc?? I know lsj are 378cc and greentops are 440cc which are what I run now.

Honestly if your looking for plug and play, lsj's would prolly be best and cheapest option. I ran 6-8 psi with the m45 and the idc was around 80% with the lsj's, should be enough for you. Only thing with those is you have to slot the rail bolt holes about 1/4" because they are a bit shorter.

icemike89 wrote:I thought brown tops were 320cc?? I know lsj are 378cc and greentops are 440cc which are what I run now.

Honestly if your looking for plug and play, lsj's would prolly be best and cheapest option. I ran 6-8 psi with the m45 and the idc was around 80% with the lsj's, should be enough for you. Only thing with those is you have to slot the rail bolt holes about 1/4" because they are a bit shorter.

Red Tops are 320cc ( 30lb ). I used them on my Cav with no issues






Jason
99 Z24 Supercharged
157hp/171tq - NA
190hp/170tq @ 6psi

LG0/LD9 for Life

ok so which ones of the fords are high impedance, which ones low?

i know the brown tops are low...

Pretty sure the reds and browns are low imp. Browns being from older fords like the 2.3 turbo motors, not sure about reds. Green are high imp, being from like svt lightnings I beilieve.

Are there ford purple tops too or am I thinking of just some other type of bosch injector? What about other style ford injectors that are high imp, arent there some that are just all black?

Reds and greens are High impedence

My reds are from a Ford motor.






Jason
99 Z24 Supercharged
157hp/171tq - NA
190hp/170tq @ 6psi

LG0/LD9 for Life

what does the stock 2.4 injector put out and is it low or high impediance?



Edited 1 time(s). Last edited Thursday, February 11, 2010 5:03 PM

96-98 its low impedance, 99-02 is high.

pretty sure both are 252cc stock.

252 high. ... ok, so then i'd want something around 310 cc then, because i'm not boosting, the only extra air moving through the intake ports are from the ported head, and the bigger cam... am i right in this thinking?

When I was N/A I first ran LSJ stock injectors (368cc). No issues, but I also tuned the car. I later switched to 310cc, to help a friend out who was supercharged.

The LSJ injectors can be had for aroun d $30-$50 shipped. I might even have a set laying around. You do have to modify the rail slightly for them, but no big deal.



FU Tuning

so i would need to break in the motor on the stockers then switch to the LSJs right before tune? i want to fully break in the motor and clutch before tuning

GME Chat User: Speedline02 wrote:so i would need to break in the motor on the stockers then switch to the LSJs right before tune? i want to fully break in the motor and clutch before tuning

You could do that. You could also install the injectors, and just change the injector constant so it idle right, and then break it in.



FU Tuning

I think i got my injectors for like 40 bucks and they are direct drop in for the high impedence.

so 368 cc vs 310 cc and both are high impediance... what would be the differences i'd notice between the two (i assume 58cc is noticable) ... with a proper tune i'd assume both would get about the same gas milage?

Too Whiney wrote:

GME Chat User: Speedline02 wrote:so i would need to break in the motor on the stockers then switch to the LSJs right before tune? i want to fully break in the motor and clutch before tuning

You could do that. You could also install the injectors, and just change the injector constant so it idle right, and then break it in.

when i first purchased my 97 z24 back in 2002 i bought it not knowing the previous owner had installed a set of rc engineering 270cc injectors (im assuming thats what they are because that is etched into all 4 of them). it wasnt until i nuked the engine that i found them. needless to say a big WHAA?!!?! came over my face when i pulled the rail LOL

anyways, is it because they are so close to the stock size that the car idled/ran ok? it never had any issues with that sort of thing. there was no way in hell it was tuned for them, HPT didnt even come out until 2005 i think.

it wasnt until installed them on my 98 and had shifted tweak the injector constant for them when i sent him my ECM for tuning that they actually got a tune. still ran the same though.

Anyone have a set of LSJ injectors for sale??? the dealership at employee prices wants 40 per injector... and my local part stores don't stock them at all

hit up cobaltss.net ill bet a ton are over there.

god i hate vbulletin sites...

i signed up...... maybe if i get some free time i'll wade through the clutter @!#$ known as the classified system there.

What will happen if I switch from a low to high impedance injector such as a the ford green tops, without gettin a tune right away? I have the gmsc flash so will this really screw with the drivability of the car?

And just to clarify the Green tops use a EV1 connector and stock LD9 injectors use a Delphi 2 connector?

If you switch impedance you can fry your Injector controller in the ecm.