TurboEM1

iTrader: (1)

Hey guys I am building my turbo set up now and have a question.

Car is a 91 CRX Si with a b16a swap. I am converting to OBD1 and getting a full race turbo kit.

I need to buy injectors.

I thought that I would go with 750cc peak and hold since I had a resistor box already and that was the preferred method. Anyway I talked to Andrea at Evans Tuning and she recomended I go with saturated and remove the resistor box.

What do you guys think I should go with? what is the pro/con of each? peak and hold or saturated? 750cc or 1000cc? I dont plan to make more then 350whp.


Thanks


Modified by TurboEM1 at 7:35 PM 12/29/2006

typeoneeg6

1000 cc's will leave room for upgrading for sure... i would think 750's would be plenty though.

LVB18Civic

I thought that saturated only went up to 750cc? If they do go to 1000cc what company and how much?

Deffinetly go with the biggest injectors. I went with 550cc and now I am going to have to upgrade.

TurboEM1

iTrader: (1)

there RC 1000cc saturated and they cost $300 for a set of 4 brand new.

Mr.60trim

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TurboEM1 &raquo;</TD></TR><TR><TD CLASS="quote">what is the pro/con of each? peak and hold or saturated? 750cc or 1000cc? I dont plan to make more then 350whp.</TD></TR></TABLE>
bump because I'm in the same whp area as you and would also like to know.

So I take it that peak and hold is used with a resistor box while saturated isn't?

notoriousB

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TurboEM1 &raquo;</TD></TR><TR><TD CLASS="quote">there RC 1000cc saturated and they cost $300 for a set of 4 brand new.</TD></TR></TABLE>
RC makes 1000cc saturated injectors now?

jared50438

no they dont.. for 350 hp 750s are plenty big...

95dc2teg

Im in the same boat i have peak and hold dsm 450's right now and i want to up grade to 750's. Since i have the resistor box already wired up i was just going to get peak and hold 750's but is this a good idea or should i go with the saturated 750's? and why

TurboEM1

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jared50438 &raquo;</TD></TR><TR><TD CLASS="quote">no they dont.. for 350 hp 750s are plenty big...</TD></TR></TABLE>

yes they do, now back to the original question.

Peak and hold vs. saturated

tony1

Saturated injectors run better than peak and hold injectors do with a resistor, on a computer with high impedance injector drivers (honda ecu)

TurboEM1

iTrader: (1)

it seemed that everyone on this site always says to go with peak and hold and that there better with high hp numbers.

if saturated are better how come they just now have 1000cc when p&h have been out for a while.

Anymore opinions on which to go with?
I may just stay peak and hold since that whats stock now but it would be nice to get rid of the box and clean up the wires. So ill get a couple of more opinions and see whats better.

vtec.dc2

Fuel Injectors - Saturated (High Impediance) vs Peak-n-Hold (Low Impediance)
https://honda-tech.com/zerothread?id=672205
https://honda-tech.com/zerothread?id=579490

jared50438

i have yet to see 1000's on rc or precisions web site... who makes them?

boostedcivicsir

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by notoriousB &raquo;</TD></TR><TR><TD CLASS="quote">
RC makes 1000cc saturated injectors now?</TD></TR></TABLE>

yeah really.......i dont think so....but if we are wrong id like to know.

dmotoguy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TurboEM1 &raquo;</TD></TR><TR><TD CLASS="quote">
Anymore opinions on which to go with?
I may just stay peak and hold since that whats stock now but it would be nice to get rid of the box and clean up the wires. So ill get a couple of more opinions and see whats better.</TD></TR></TABLE>

Very knowledgeable people have already told you to ditch the P&H and go with Saturated.. take their advice.. they know what they are talking about. Peak and Hold did not come stock, stock = saturated.

TurboEM1

iTrader: (1)

Where did I ask which are low impedence and which were high impedence? Where did I say which use a resistor box? I know what you need for which and how both operate but thats not what i was asking.


RC does. There not listed on their website, you have to call for them.

You are wrong They do make them. Give them a call if you dont believe me.You almost convinced me until you said stock are saturated. No their not. My car is a 91 CRX Si like I said in the original post and stock is Peak and Hold.


Thank you for your posts. Someone with information and not crap. This is what I have heard before and am just asking if it is true. My car already has a resistor box wired in so its no trouble to use them since its already there. It does seem like the P&H are better but I have heard to ditch it too.

Anyway the bold part is what I was asking about too. How come saturated were so far behind in sizing? There were a 1000cc peak and hold and only like 750cc saturated last year or so.

tony1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TurboEM1 &raquo;</TD></TR><TR><TD CLASS="quote">
Thank you for your posts. Someone with information and not crap. This is what I have heard before and am just asking if it is true. My car already has a resistor box wired in so its no trouble to use them since its already there. It does seem like the P&H are better but I have heard to ditch it too.

Anyway the bold part is what I was asking about too. How come saturated were so far behind in sizing? There were a 1000cc peak and hold and only like 750cc saturated last year or so.</TD></TR></TABLE>

Maybe information and not crap, but crap information, that's for sure...

Do your own research, don't listen to what anybody tells you. Learn the difference in how a peak and hold injector driver opens an injector compared to a saturated injector driver. Forget about the injector, the driver in the computer is what determines how the injector will operate. A peak and hold injector with a resistor on a saturated driver is crap, it's not the right way to do it. I'm not going to explain any more, but i will tell you this, do the research on how the injector drivers work and you'll see why a peak and hold injector is not as good as a saturated injector, when a saturated injector driver is being used....

HiProfile

Let me say that the info in this thread is suffering from over simplification. Its like saying 'lower rod/stroke ratios make more power'; they usually make more torque, but suck at high rpm, etc.

As far as the OP goes, the guy you called out on stock injector types, you both are right. The majority of Hondas went to saturated after 91, prelude being an exception. If you really want to nit-pick, only the multi-port crx/civic from 88-91 had peak/hold, the dpfi cars had saturated injectors (if you really want to call that POS an injector). BUT because the mpfi cars still used resistor boxes, that means they used an ecu with an injector driver working identical to a saturated driver.

Anyways, the 4th post in that 2nd link above explains it. <u>Peak/hold work best with high pressures because, when run with a driver they were ment for, are sent a HIGH current to open, then a low current is supplied to keep them open. The high current allows for a heavier spring inside, which lets it work at higher fuel pressure. Or looking at it in reverse, the higher current is needed to 'pop' the injector open.

Peak/hold running off a driver meant for saturated injectors (any honda ecu that needs a resistor box) degrades its advantage. The saturated driver sends it a low current to open, and that same low current is used to keep it open. This tends to make them lazy, in terms of being less responsive. Huge peak/hold injectors on a saturated honda ecu/driver don't idle because the tiny duty cycle can sometimes be almost as long as it takes for the injector to open. This slower response is usually 2-6ms</u> extra if I recall, and for reference it takes 200ms on average to blink your eye.

<U>To answer why its taken so long to for saturated injectors to catch up in terms of size</U>, here's one reason. If you call RC (or maybe it was precision) and ask the difference between their 1000cc and 750cc peak/hold injectors, its mainly just a higher flow nozzle; internals are exactly the same, coil, spring, etc. This would say that 750 & up use heavier springs inside (and likewise stronger coils), which need a higher current to open than lighter springs. For a low current saturated injector to flow that much, they need a much larger (heavier) nozzle, which needs a much stronger coil & spring to maintain the same reaction times. It goes w/o saying a coil needs to be much more efficient to work at a lower current put still provide the same power - thats what 1000cc saturated injectors have to do.

In short, they could make 3000cc saturated injectors in the typical honda size, but they will be prone to *terrible* response times, assuming they will even open at all, unless they use EXTREMELY expensive materials in the coils. That large of a saturated injector can be made with today's technology and maintain the required response time, but probably cost $1500 in parts alone - for each injector.

If you could point out any errors tony, that'd be great.

tony1

Only thing i see wrong is the opening time. Typical actual pulsewidth sent to the inj. at idle with 1000's is around 1.5ms or so. I think the opening times or "dead time" is probably closer to .03ms on average. But that's not the important part, the important part is the way the peak and hold injector driver opens the injector. If you run an FJO or AEM injector driver box on your honda then you will get the benefits of a the proper injector driver for the big injectors.

HiProfile

Thanks, I think I mixed it with aprox. MS at idle. I did calulations last year, but my memory has been **** this year

BTW if anyone wants to understand saturated vs peak/hold better, research solenoids & coils for a few minutes. The info here should 'click' after that.

HiProfile

Since when did injectors made from plumbing supplies make 500whp?