So I know this topic has been covered before in other forums, but I was wonder if anyone has attempted to install an injector resistor box on a fit before to utilize the use of larger peak and hold fuel injectors instead of just upgrading with saturated injectors out of civics or RSXs. And if someone has installed them before, does it affect how I would tune them over tuning our normal saturated injectors? Sharing of past experiences could be helpful, performance wise, tuning etc.

And for those of you who don't know what they are for, the resistor box is just that, a box with resistors in them that basically sit inline between the fuel injectors and power supply( I think). The purpose for using this resistor box is to have the ability to use low impedance/ peak and hold injectors (which run on a lower current) on cars which normally use high impedance/ saturated injectors (which need higher levels of current to operate)

Also does anyone know if dsm injectors from a gs-t will fit our fuel rails? I happen to have them lying around from my previous car (yay 450cc injectors)

 

any reason you wouldnt just use aftermarket saturated injectors?
you can get a set of brand new RC injectors for less than $400 with clips. or find them used for about $200.
theres a few other manufacturers that make injectors that will fit as well.

you can also use acura RDX injectors (410cc). no idea what your plans for your car are, but they would be good up do 300ish+ hp. and they are supposed to have a very good spray pattern.

 

well other than the fact that I have an injector resistor box and 450cc peak and hold injectors, not really. I know these dsm injectors fit other fuel rails on cars such as the integras, but so sure they will fit ours. I know going the OEM route would probably be simpler and probably less problematic, but I would like to exhaust my options before I toss aside the injector resistor box and injectors and opt for the saturated injectors.

 

I've been wondering the same thing as I have several sets of injectors, and when you say resistor box.. you don't by chance have the discontinued FIC EZ-Tune do you?

 

Nope I do not have the FIC easy tune, also to spread the general knowledge and hopefully gain more interest in here, when I say resistor box it can also mean resistor pack which might be a more familiar term. DSM use peak and hold injectors and they have a resistor packs which sit between the 12V power and the injectors (individual 10 ohm 10 watt resistors can be wired inline between each injector as well instead of using a resistor pack)
individual inline resistor install: http://www.d-series.org/forums/archi...r-install.html
resistor pack install: http://www.team-integra.net/forum/di...7&ThreadPage=1
info on preping a resistor pack: http://www.c-speedracing.com/howto/r...box_wiring.php

and i know these are for a different cars/engines it's just info

saturated injectors that operate at a higher impedance of 12 ohms do not require a resistor pack, but if we want to use peak and hold injectors (low impedance injectors) that operate at 2.5 ohms of resistance we would need the resistor pack otherwise we kill our ECU
Info here about killing ECU's by running peak and hold without a resistor pack: http://hondata.com/techlowohminjectors.html

The Fuel Injector Clinic's Easy Tune works with a cars resistor pack (dsms evo's etc) and seems to help with larger injectors (for example: 1500cc) at idle by providing basically a stable signal to the injectors and by increasing the magnetic fields that operate the valves spraying fuel. So in our case I don't think we need those, and as DiamondStarMonsters pointed out they are discontinued, but they can still be found for sale, you just gotta look.
Info: Fuel Injector Clinic's EasyTune gives your fast, big injector ride a smooth idle
http://i4.photobucket.com/albums/y11...specFINAL1.jpg

On another note, would we need peak and hold injector drivers that "accurately reproduces the ECU’s injector pulses in a PEAK & HOLD format and is compatible with full sequential, phase sequential, and batch fired injector pulses" ?
quoted from here: Fjo Racing Products Low Impedance Injector Driver and Siemens DEKA Injectors

 

So after browsing the internet and gathering some more information there are a few general statements I can make to sum up this thread:

The type of injector doesn't really matter as long as we hook them up properly:
- our cars run saturated injectors so those are basically plug and play and our ECU has saturated injector drivers
- but we can also run peak and hold injectors with a resistor box (although this will technically make them operate now as saturated injectors)
- To make use of the advantage of peak and hold injectors we would need peak and hold drivers

So hopefully this has been useful information, although not all encompassing, and hopefully when I do get my wideband in (hopefully sometime before new years), I'll hook up my AEM FIC, resistor box and DSM injectors (hopefully they'll fit) and we'll have a new DIY on the forum

 

I am looking forward to these results! I have a bunch of injectors laying around 450s, 680s, etc and would rather not have to buy more for the fit

 

And since my friend had some injectors laying around which we wasn't using he gave me.

Sure the injectors came off his g35, but that didn't matter to me.

They were one, saturated/high impedance injectors and two, they flowed more than our stock injectors.

These injectors off the G35 are the same injectors as injectors of a 350Z, but they flow at different rates due to the fuel pressure at which they operate.
I believe that the G35 operates at 43.5 PSI of fuel pressure which injectors are normally rated at and flows 290 cc/min. while the 350z operates at 50 psi of fuel pressure essentially making them behave like larger injectors and thus flows at 330 cc/min.

I don't know how these injectors compare to the other injectors everyone uses off the civic si or rsx which are like 310 cc/min; I wonder whether that is what they are rated at for 43.5 psi of fuel pressure, or how they are rated on the cars, since i believe that the RSX also runs a returnless fuel system so maybe it has a similar fuel system psi. So if it's rated at 310 @ 43.5, what might it be rated at say ~50 psi. Anyone Care to take a poke at this inquiry?

Here are some pics of some Ohm measurements that I took while installing the g35 injectors.

DSM 450cc injector


Resistor Box


DSM injector w/ resistor box


Honda Fit Stock Injector


G35 Stock Injector


Anyways, I hopefully someone else can continue my quest to run low impedance injectors with a resistor box on their car so we don't leave this as an unanswered quest for more knowledge.

 

310 @ 43.5psi and 100%IDC becomes 339cc/min @ 52psi (Fit base fuel pressure) and 100%IDC

http://www.rceng.com/technical.aspx

If you are looking to make !200whp without pushing your fuel system to its limits you will need atleast 450cc/min @43.5psi (100% IDC) injectors because even at 52psi and 80% IDCs they only flow 390cc/min.

Now even under say 11psi boost (63psi fuel pressure) they flow 430cc/min @ 80%IDC, which is just enough to be able to run 10.0:1AFRs with a worst case BSFC of (.60).

Which is something you want the ECU to be able to do in case the need arises to richen the mixture in the event of lots of knock, bad fuel or more airflow than expected like if you tuned in the summer, and then go WOT on an 11F air temp day like today.

 

So yeah I got bored again today, an although my 450's aren't totally in yet, hopefully they will be by tomorrow morning.

Like other hondas which use a power distribution plug with a dead end cap such as the one in this link Wiring a Resistor Box for Low-Impedance Injectors - Honda, Acura Tech Website, tutorials, tuning and HOW-TO's. Drag racing, street racing, road racing - C-speedracing.com

our fit uses one as well and the plug looks like this


If you notice the green dead end connector, it connects all the pins on the lower half of the plug together, and the grey dead end connector does the same for the top pics of the plug.

here's me finding the pin for injector 1


and likewise for injector 2


This pretty much sums it up. This is looking at the plug itself so the top is the top row (grey dead end plug), the Xs on the top have no connectors, thus no connections

The bottom row, in the position 4-7, are injectors 4, 1, 3, and 2.


Started on wiring the resistor box in, but there is not much slack to work with


I hope my car starts up tomorrow and i don't fry my ECU

 

Best of luck and keep up the awesome work!

Thank you for sharing all this with us!

 

This morning I woke up to tinker in my engine bay, I HIGHLY suggest getting plugs meant for the injector instead of being like me and filing down the injectors plug and hoping the Fit's stock plugs will plug into them...I got them on...eventually and since they don't click in like stock injectors, Zip-ties will be playing their part in holding the plugs to the injectors...

So after throwing a quick tune at the FIC, I then started up the fit and checked for fuel leaks (the fit started right up on the first try). The first few minutes of driving were worrisome since I didn't know IF my ECU would kill itself while I drove, but after I gassed up and drove from Irvine to Los Angeles and then back again, I can say my project is a success.

The whole dread and worry of frying my ECU is gone, An example can be seen here Tech - Low and high impedance injectors , just look for the video link

Here's to being the first fit with a resistor box and low impedance injectors... CHEERS MATEY

 

Nice F***ing job! I don't think enough people realize how cool this is! You have just opened up a new door in Fit tuning..

Looks like I might not need to get the 8 injector FIC and a dual rail setup after all!

Again thanks for sharing!

This seriously needs to be made a "sticky'd" thread!