I will be purchasing injectors very soon for my build. This is the combo I am putting together.


-383
-10.5 CR
-AFR "Eliminator" 195cc *1040 heads
-Miniram
-58 MM TB
-JE Pistons
-Eagle Crank
-Lunati Pro Mods Rods
-Stock ECM for now


I am aiming for 400rwhp. What injectors do you think? I dont want to max out the duty cycle. I am not an expert on injectors by any means, and either are you Sami. I would love to hear from guys who have built stroker's while using the short runner Miniram intake. If you are guessing then I dont really need to read your answers. I hope that doesnt sound mean, but it would be better to read answers from guys who have been there, and done that!!!!

My gut says 36's. Some say 30's, and some say 42's.

 

BTW, I also plan to run prob a 150 shot in the future.

 

http://www.injector.com/injectorselection.php

 

So are they for sale?

 

wet or dry?

 

Since you can adjust injector flow rate in the tune, and you are street driving you would not be using 90% of the injector consistantly(WOT calculations) why would there be a need for anything bigger than 30#'s. Personally for street/some track 24#s would be fine. MO

 

I would say not more than 30, when i contacted jesse for tune on my 383, he says dont upgrade to 30 or more as #24 is enough, but in ur case iam sure u will get 50-75 hp more than my 383 so i would go #30. I had set mine at 42-44 psi installed the nitrous went to track it was sputtering and runing rich, so next track i went with 38 psi no sputtering, the moment i finish line, than it was sputtering. So 38 psi with my #24 served me well. BLM readings are 132-124 which is perfect, i get mostly 124-128 jesse really nailed down this tune, thanks jesse.

 

what's the average duty cycle? if its 80% you're starting to push them and if its 90%+ you're in the red zone and playing with fire (literally).

we know there are certain racer-x weekend-only dedicated 1/4 milers on this board who will tell you all about power down the strip and virtually ignore duty cycle. they like the leaner injectors because they're used to rebuilding their engine every 1-2 years because that is their whole life, and don't really care about medium-term risk to the regular driver guy.

a simple search will reveal those guys.

 

brad: thanks for letting me know this fact, i checked mine is 80%, infact i did not came accross 90% may be i google search on this topic, but i have 3 chips (jesse, tjwong, and alvin), i know u had trouble with jesse's tune but his tune gave me most in 1.4 mile and it passes emmission here in ga too. Tjwong and alvin's chip are nice too but they with jesse's chip the car run cooler as i think he burned fans to kick in at 165 deg. But jesse's chip cost little bit more compare to tjwong and alvin. I bouht jesse's chip long time ago and for 383 he re-burned for free at no extra cost.

 

i had more trouble than that, it wasn't fueled AT ALL in either of tables and with SD engine management, the ring lands on #3 and #5 broke along with a head gasket leak from severe combustion temps due to the ultra-lean condition. fact. another fact is that i've since forgiven the guilty and life is peaches & cream.

if you're at 80% for street duty then you'll be fine.

 

SVO 32's are what I used in my LT1 based 383. They are a pretty easy injector to tune for, and they act a bit more like a 36 lb. injector on a GM application.

Is your nitrous shot going to be dry or wet? Since you brought that up in an injector thread, you must be intending to go dry. A 150 HP shot is quite a bit for a dry shot, but I've heard of guys doing it. In my opinion, if you really are going to stick the bottle on it and shoot a 150 shot, you should plan to use a wet system. There's no need in suffering the tuning problems associated with a big injector on your car, you'll be on motor 99% of the time, installing injectors to support that 1% of the time you'll be spraying and suffering tuning difficulty for the 99% of the time you'll be on motor doesn't make much sense to me.

Let us know what you decide to do.

 

Rick, on one of my old toys, I easily made just over 500rwhp with 42# injectors. At 45psi of fuel pressure, I was at 99% duty cycle midway through a quarter mile run, but NEVER had an issue with fuel delivery, head gaskets, etc.

This was a supercharged car with a strong fuel system, I.E. sumped fuel tank, -10 feed line, Aeromotive A1000 pump, -8 lines to 1/2" I.D. aluminum fuel rails, -6 return line.

Assuming the 400rwhp goal is attainable (and I'd hope it is), and the fact that you plan a "maybe" shot of nitrous, I'd step up to the 42's right from the get go. More importantly, IMHO, I'd also plan a fuel system upgrade. Not saying you need to spend a grand or more like I did, but with stock size lines and just a high volume intank pump to feed 42# injectors, you'd be asking for trouble IMO. Reason I say this is because I went from 30#ers, stock lines/rails and intank pump to 42's with stock lines/rails and intank pump and immediately started seeing a drop in WOT fuel pressure readings. No laptop or scan tool around will tell you that you're getting ready to melt an engine due to fuel pressure loss.

FWIW, as you know I'm a convert from the blower/nitrous Mustang camp, and not long ago I tuned one of my supercharged Mustang buddies' car on a Mustang Dyno. He used 42's and comfortably makes just a hair over 400rwhp, on pump gas, in any weather. I have him setup rather rich, but the car is 100% trouble free and he has no worry of going lean.

One of my own other cars, with a 100hp dry shot (30# injectors) made 372rwhp/434rwtq and stayed plenty safe on the a/f ratio.

Bottom line, although 42's "may" be a little big, you'll have plenty of safety cushion. Much better to have injectors slightly too big, than to have them slightly too small.

edit: I agree w/neat that a wet shot would probably be easier to tune for, although I've personally ran a 175 dry kit on a non GM car without a worry.

 

I havent yet reserched the NOS scene yet. But off the top of my head a 150-200 shot. I would have to go wet for that. I am assuming if I went dry, then a 100 shot would have to do.

Not totally sure to be honest.

 

Yeah. I thought about those SVO's.

 

My MR 406 ran out of injector at about 5200 rpm with 24# SVO's. The HP flattened out at 386 from there on as A/F began to rise. Probably some detonation and misfires in there.


Hard to argue with neat's advice

 

I think u should go for 30-32 as neat said, lot a LTx guys when they installed Cam/head package they went with #30, so with ur combo its pretty much LTx as u doing with mini ram, plus a 383 so #32 may be best bet, ask tjwong.

When u r ready for spray, get NOS brand 05151 kit, its made for Tpi car, and iam sure u will not have problem hooking with miniram too. Its a wet system and NOS brand is quality. Also get 15 lbs bottle instead of 10 lbs, 10 lbs will be "Gone in 60 sec's". It emptied too quick.

Good luck. is ur's is 4+3 or ZF 6 spd, or u planning to replace clutch? how about a short throw shifter too. Hey hotrodding never stops.....

Also do u already have or goin to or not at all considering MSD 6AL box, if u dont have and have plan for than buy crane fireball it comes with reard box separate too for 319 and its quality and cheaper than msd, i saw in pete's car man its awesome piece compare to my MSD funny looking box. Hope to see u soon if everything goes well. sami

 

 

Good place to snoop and see what similar combos are running.

 

have you asked your tuner or are you planning on tuning it yourself ?