Mr.DC2TurBo

Aright before saying NO, please hear me out first. From Boosted-Hybrid's site he posted that if the fuel pressure is around 40psi (sizes were estimated using 90% duty cycle of the injector) with a 12:1 air/fuel ratio that 440cc injectors were capable up to 330whp.

Well, I have an AEM fpr and I was wondering if I turn that up to around 60psi and up will that allow me to compensate for the lack of injector size?

MiraiZ

you should get 550s

Mr.DC2TurBo

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MiraiZ &raquo;</TD></TR><TR><TD CLASS="quote">you should get 550s</TD></TR></TABLE>


I would but I already have the 440cc and I'm short on cash. Just wondering if I can bi pass the 550cc by turning up the fuel pressure.

MikeMAN

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.DC2TurBo &raquo;</TD></TR><TR><TD CLASS="quote">


I would but I already have the 440cc and I'm short on cash. Just wondering if I can bi pass the 550cc by turning up the fuel pressure.</TD></TR></TABLE>

if your injectors are already maxxed out, turning up the fuel pressure isnt going to do anything.

mike

Mr.DC2TurBo

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

if your injectors are already maxxed out, turning up the fuel pressure isnt going to do anything.

mike</TD></TR></TABLE>


I dont think thats true.. If you can raise the fuel pressure then you should be able to allow more flow.

TRE_

i dont know too much about injectors but with 440's and 350 hp i think you'd be pushing it... i'd definantly reccomend upgrading your injectors to 550's if youre planning on going up to 350hp

twkdCD595

from the math standpoint, they should be maxed at just over 300hp, but 350 is a bit of a stretch if you ask my opinion.

just my 2 cents.... upgrade.

Mr.DC2TurBo

I was looking at the RC website about the calculation but when it didn't add up. It says I would need at least 690cc injectors to obtain 350hp. (350*0.6)/(4*.8)=65.625 lbs/hr (689.10 cc/min). So wat am I doing wrong??


Modified by Mr.DC2TurBo at 12:12 AM 2/21/2004

sneakypete

I'm running 440cc injectors on my car and I dynoed 312 whp. The 440's were maxed out from 6000-7000rpm. When I say maxxed out they were wide open and not even pulsing. I'm running a stock intank fuel pump with stock fpr. However, I have an external fuel pump to bump up the fuel pressure. My fuel pressure was 60 psi with the external fuel pump on. So if you get a fpr and turn up the fuel pressure it will help out a little. If your stuck with the 440's then I'd run a walboro intank fuel pump and upgraded fpr. But my advice would be to just save up and get 550's. By the way I'm running hondata.

twkdCD595

note: on the fuel calculator

start upping the fuel pressure @ the rail (at about 100 you should be near the 450's)... not the most desireable way to get more fuel (and I do not suggest it obviously) but all you have left other than pushing the duty cycle past 80% (which I would never do personally just cause).

more pressure seems to lead to problems, but it would work until the pressure finally kills something.

Mr.DC2TurBo

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sneakypete &raquo;</TD></TR><TR><TD CLASS="quote">I'm running 440cc injectors on my car and I dynoed 312 whp. The 440's were maxed out from 6000-7000rpm. When I say maxxed out they were wide open and not even pulsing. I'm running a stock intank fuel pump with stock fpr. However, I have an external fuel pump to bump up the fuel pressure. My fuel pressure was 60 psi with the external fuel pump on. So if you get a fpr and turn up the fuel pressure it will help out a little. If your stuck with the 440's then I'd run a walboro intank fuel pump and upgraded fpr. But my advice would be to just save up and get 550's. By the way I'm running hondata.</TD></TR></TABLE>


Thanks for the info. So you were running stock fpr with external pump and able to push 312whp? So wouldn't a walbaro intank fuel pump, aem fpr and 440cc injectors be able to push more? You couldn't adjust your fuel pressure but I can with the aem. I want to push ~320hp but I am afraid of boost spikes and I might need more fuel. I really dont want to shell out 300 for injectors (rather use that for hondata dyno tunning). My fuel setup right now: s200b, walbaro intank fuel pump, aem fpr and 440cc injectors.

I know I need 550cc but I just wanting to know if this could be an alternative.


Modified by Mr.DC2TurBo at 12:40 AM 2/21/2004

sneakypete

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.DC2TurBo &raquo;</TD></TR><TR><TD CLASS="quote">


You couldn't adjust your fuel pressure but I can with the aem. I want to push ~320hp but I am afraid of boost spikes and I might need more fuel. I really dont want to shell out 300 for injectors (rather use that for hondata dyno tunning). My fuel setup right now: s200b, walbaro intank fuel pump, aem fpr and 440cc injectors.

I know I need 550cc but I just wanting to know if this could be an alternative.


Modified by Mr.DC2TurBo at 12:40 AM 2/21/2004</TD></TR></TABLE>

Even if I was able to up the pressure using a fpr it still wouldn't matter because my injectors were at 100% duty cycle. What I would do is sale your fpr and 440cc injectors, then use that money to buy some 550cc injectors. Go to http://www.kteller.com he has some rc 550's for $260. Or hit up Tom (camp1320) for some off brand injectors.

MikeMAN

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

Even if I was able to up the pressure using a fpr it still wouldn't matter because my injectors were at 100% duty cycle. What I would do is sale your fpr and 440cc injectors, then use that money to buy some 550cc injectors. Go to http://www.kteller.com he has some rc 550's for $260. Or hit up Tom (camp1320) for some off brand injectors.</TD></TR></TABLE>

exactly my point

mike

Mr.DC2TurBo

thats a great deal.

Does anyone know if you can run an fmu with the hondata? Couldn't also having an adjustable fuel pressure regular and fmu allow you to produce a higher fuel pressure, therefore allowing you to run 440cc injectors and maxing them out at a higher hp range?

sneakypete

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.DC2TurBo &raquo;</TD></TR><TR><TD CLASS="quote">thats a great deal.

Does anyone know if you can run an fmu with the hondata? Couldn't also having an adjustable fuel pressure regular and fmu allow you to produce a higher fuel pressure, therefore allowing you to run 440cc injectors and maxing them out at a higher hp range? </TD></TR></TABLE>

Any reputable hondata tuner will tell you to not to use an fmu along with hondata. Its not a good idea to max out your injectors. All you need is for one of your injectors to lock up and you engine will go kabooom. Remember the purpose of running an Engine Management System is to safely tune your car to last and also to make power as safely as possible. Just get the 550's and take your car to the dyno and go from there. You will have no problem with 550's supporting 325 whp at stock fuel pressure.

TheShodan

iTrader: (14)

I Agree. Maxxing out the injectors to be over 90% is asking for serious trouble just to squeeze out a couple of more hp, especially w/ a stock intank fuel pump. I would sell the 440s if that extra hp is that serious to you, and at least get 550s. The turbo calculator can't do it all, that when experience comes in. I know that 450cc injectors from a DSM, can barely get to the 330 mark. Bumping up the fuel pressure too high won't really help, and could wear out what you have prematurely.

Johnyquest

Of COURSE you can turn up your fuel pressure to obtain more flow. I don't know why so many people are telling you otherwise, because it's totally mis-information. If they were correct, than an FMU wouldn't work. Do you think 240's could by ANY means supply enough fuel for a turbo car without an FMU (upping the fuel pressure?)

Saying that if the injectors are 'maxxed out' you can't get more flow by upping the fuel pressure is just plain wrong. It may not be the best way to do it, but if the fuel pressure goes up, the injectors will flow more. Remember, the injectors are rated to flow a certain cc (440 in your case) at a specific pressure. By upping the pressure, you will up the flow. Again, reliability MAY be sacrificed, but I doubt it if the increase isn't too significant.

Good luck.

sneakypete

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Johnyquest &raquo;</TD></TR><TR><TD CLASS="quote">Of COURSE you can turn up your fuel pressure to obtain more flow. I don't know why so many people are telling you otherwise, because it's totally mis-information. If they were correct, than an FMU wouldn't work. Do you think 240's could by ANY means supply enough fuel for a turbo car without an FMU (upping the fuel pressure?)

Saying that if the injectors are 'maxxed out' you can't get more flow by upping the fuel pressure is just plain wrong. It may not be the best way to do it, but if the fuel pressure goes up, the injectors will flow more. Remember, the injectors are rated to flow a certain cc (440 in your case) at a specific pressure. By upping the pressure, you will up the flow. Again, reliability MAY be sacrificed, but I doubt it if the increase isn't too significant.

Good luck.</TD></TR></TABLE>

When an injector is maxxed out this this mean its at 100% duty cycle. 100% duty cycle means that the injector is wide open and that its not even pulsing anymore. Sure you can up the pressure and get flow but all this does is increase the chances of his injectors locking up. You get to a certain poing where increasing pressure has no affect.

99B16Si

i saw a car make 459whp on dsm 450's a couple weeks back. granted it had an fmu and the fuel pressure gauge was maxed out but the injectors still managed to supply enough fuel to keep the a/f below 13:1 at all times. not the best way to do things but it just goes to show u that a little bit extra fuel pressure can help your situation quite a bit...temporarily

Bulldogg83

I had 440's on my old setup and I had them running at 89% duty cycle....they were the only reason that I didn't break 300whp with my greddy kit....should have gone with 550's....

I'd honestly wait until you can scrounge up the remaining difference between the 440's and 550's and then just buy the 550's! but that's my .02

The Tea-father

my 550cc max out at 302whp. this is at 100% duty cycle.

TurboJesse

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fd3st04r &raquo;</TD></TR><TR><TD CLASS="quote">my 550cc max out at 302whp. this is at 100% duty cycle.</TD></TR></TABLE>

are you sure?

The Tea-father

yes this is at 50psi base pressure. right no i'm running 720cc

RAWB

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fd3st04r &raquo;</TD></TR><TR><TD CLASS="quote">yes this is at 50psi base pressure. right no i'm running 720cc</TD></TR></TABLE>

did you have them flow tested? at 50psi, that's not very much hp to be at 100% on 550's.