i just want some basic knowledge on injectors. what are the differences in these two types and which is better for turbo charged cars? i just bought a car with 320 peak and hold injectors, i dont feel they are enough and picked up some 550 saturateds. i couldnt find any info on the differences between the injectors so thats why im posting...thanks

 

either type of injectors will work. Peak and Hold need a resistor box where as the saturated injectors don't. It depends on what car you have to determine if they are drop in.

 

the difference between peak and hold injectors and saturated is the resistance they operate at, hence the need for a resistor box. Depends on the ecu's injector driver

 

peak and hold need a resistor box
large injectors anything over 750cc are allways peak and hold

 

The only way you can feel if injectors are too small is if you CRANK the boost beyond what its tuned for (assuming its a Honda), and you FEEL your engine BLOW UP.

Otherwise you use a wideband to check AFR's and your EMS to check duty cycle, or do some rough math after putting it on a dyno. FYI 320's are only good for ~225 on an FI motor, assuming you aren't using an FMU. What CELERITAS said is the basic deal, no need to go beyond that for the OP. Just save yourself time and get peak/hold, or remove the resistor box and put your 550s' in...after you setup the basemap...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nolicense526 &raquo;</TD></TR><TR><TD CLASS="quote">i couldnt find any info on the differences between the injectors</TD></TR></TABLE>

They both work. Make sure you run the correct impedance your injector drivers require, which for a Honduh is ~9.3-12 ohms give or take a little.

 

obd0 civics have resistor boxes...obd1 + have saturated..saturated are not as accurate and peak an hold injectors

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by laocivic &raquo;</TD></TR><TR><TD CLASS="quote">obd0 civics have resistor boxes...obd1 + have saturated..saturated are not as accurate and peak an hold injectors</TD></TR></TABLE>



That's an erroneous statement.

 

are the old dsm blue top peak hold injectors

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Joseph Davis &raquo;</TD></TR><TR><TD CLASS="quote">



That's an erroneous statement.</TD></TR></TABLE>

its true atleast at high rpms

 

Nope.

It's hard to say P&H injectors are more accurate when Honduhs run them across resistor boxes, and never feed them a peaking current to slam them open.

There's a whole lot of injector theory mumbo jumbo that can be, for all practical intents and purposes, completely disregarded. A number of the injector driver boxes on the market that interface with P&H injectors with no resistor box don't even bother to feed a peaking current, they are equipped with a burly IGBT and just saturate the injector and don't worry about it.

Pick your injectors based on size, and run a resistor box if you happen to get P&H/low Z injectors. Don't worry about one style vs the other.

 

How much hp do you think the 550cc saturated are worth. Using the stock fpr.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sr420Det &raquo;</TD></TR><TR><TD CLASS="quote">How much hp do you think the 550cc saturated are worth. Using the stock fpr.</TD></TR></TABLE>

Here is a very basic guide we use when customers ask this question.

Flow Rate vs. HP Level
(Flow Rate for each injector,
in a four cylinder setup.)

310cc 200~220whp
370cc 220~280whp
440cc 280~330whp
550cc 330whp~380whp
660cc 380whp~425whp
720cc 425whp~475whp
880cc 475whp~525whp
980cc 525whp~600whp

Hope that helps.

Craig

 

if you had an injector that was rated for more hp would it hurt you, or would it not matter as long as your injectors could handle it?

 

Sometimes idle quality suffers.

I've gotten nice, smooth idles with the Precision 880 and 1000cc injectors that Tunertoys carries.