injector size question

xxninja

Member
Joined
Feb 1, 2002
well i know injector are basically rated by horsepower.

Ive noticed that the hot-airs need alot bigger injectors then the intercools, from reading posts.

right now with my current set up(v-1 intake, t33c, headers)
i am running the delphi #37 injectors.
i have plenty of injector i believe.

But in the coming weeks imma give the Spearco kit a shot and see what happens

So basically i was asking for some input......

If i decide to go with the Spearco kit, though i know i might pick up 80 horse possiblely.
Do you think i would need a larger injector then #37 ???

I have been reading alot of intercooler posts. and they seeem to be running pretty damn quick on 37s.
alot of them are running stockers and down in the low 12s i think

my setup would basically be (T33c, intercooler, v-1 chip and headers)

i always see these posts where people say that 37s are probli good down to high 11s, but is that for intercooled cars or hot-airs?

but i honestly have no idea what kind of HP i have until i can dyno the car.

i really dont wanna pay $360 new injector after i install the intercooler, if i need them, id like to do them both at the same time !

so if ya have some opinions or some advice , id love to hear it
:D

btw does anyone know the formula , to calculate injector size?

ps. i always appreciate the advice :D
 
HP expectations

ok guys im gunna hit the Dyno as soon as it warms up inna few weeks...
Well I am curious as too what kind of HP i may have with my Mods.

i was wondering if any of you had the same mods or similiar and could give me a roundabout figure?

this is what i run currently

* v-1 intake
* t33c
* 37 injectors
*mh cold air kit
*headers
* 2.5 hooker exh , no cat with 2.5 atr downpipe.
*93 octane street chip
*all neccasary fuel mods

i was gonna shot for 2 runs at 15 PSi
and 2 runs at 18 Psi

any ideas?
 
gnttype says they are good to mid 11s, and 480 horses max. I like to be conservative, so lets call it around 410ish and 12 even. Some people have done close to this with stock Ic, turbo and injectors. I would say there is a good chance that you could push the fuel system with that 33. Do you happen to know the flow for those by any chance?
 
Whoa, don't know what I was smoking I meant to say that some guys make it to high 12s on all the stock stuff.
 
I think the 42.5 lb/hr injectors are the most common upgrade. They are a very versitile agent int he fuel system, but for now, as long as you dont wish to run faster than mid 12's, you'll most likely have a good tune with the 37's. As for the 42.5's, i think they are capapble of low 11's or so, but that is a good tune also, and IC and all that. Post your numbers and let us know how you do!

John
 
I would spend a little more myself and go straight to MSD50's, that'll support a TON of power, and has excellent driveability characteristics thanks to the easy of programming. They cost a little more, but I'd rather buy once then have to buy again as I will be doing due to further upgrades. I think with your combo though, the 37's should work pretty good, but you could be as fast as high 11's with an intercooler, and the 42.5s would give a bit more safety margin at that level.
 
if you've got the 37s already just leave em for now.they'll take you pretty far,i'd bet they'll support mid 11s.

as far as hotair fuel requirements i'd say if anything thay need less than the average 86/87.i'm running 42.5#s with about 38# fuel on the leanest maxeffort setting.
 
Originally posted by WFO
if you've got the 37s already just leave em for now.they'll take you pretty far,i'd bet they'll support mid 11s.

as far as hotair fuel requirements i'd say if anything thay need less than the average 86/87.i'm running 42.5#s with about 38# fuel on the leanest maxeffort setting.

I agree. Keep the 37s. If you're only planning on running 18psi you should have a good safety margin with the 33 turbo.

If I were just starting out modding my car from stock, I see no reason to ever go smaller than the 009s. They have excellent street manners and have been pushed to high 10s with a lot of fuel pressure. They're also very cheap.

When I went from a 49 to a 64 on a car that already had a lot of mods, I went from the leanest setting on the Max Effort to the richest to maintain the same 02 readings with 009s. I'm not sure they're going to be up to my new motor but I'm going to experiment with methanol injection before I sell them.
 
I presently run the 42.5 and have plenty of fuel. I was told by a very reliable source you can go low 11's before being worried about what injector to upgrade to next. I'm waiting to see how the high impedience injectors work out.
 
Top