Notices

is the rc injector caculator full of donkey poo poo????

Thread Tools
 
Search this Thread
 
Old 08-17-2004, 10:13 PM
  #1  
OG triple OG
Thread Starter
 
ATS*Mark's Avatar
 
Join Date: Mar 2002
Location: Norcal
Posts: 27,633
Likes: 0
Received 2 Likes on 2 Posts
Default is the rc injector caculator full of donkey poo poo????

i was looking at new injectors becausemy current rc 440's for my new setup wont cut it. i come across the rc injector cc calculator , type my stuff in as follows :

desired BHP 450

number of injectors to be used 4

brake specific fuel consumpsion - .65(what rc recomends for turbo)

max duty cycle 50%(i thought that sounded like a nice conservitive number)

fuel pressure i put 45


this thing said i needed 1511 cc injectors , that sounds outragous for 450bhp!!!!

heres the link to the caculator

http://www.rceng.com/technical.htm#WORKSHEET
Old 08-17-2004, 11:08 PM
  #2  
Junior Member
 
RA166E's Avatar
 
Join Date: Oct 2003
Location: WA, USA
Posts: 309
Likes: 0
Received 0 Likes on 0 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (Hella_JDM)

I would try your duty cycle at 80%
When I had RC Engineering flow my injectors, (80% duty cycle) is what was used on their flow sheet.
Old 08-17-2004, 11:13 PM
  #3  
OG triple OG
Thread Starter
 
ATS*Mark's Avatar
 
Join Date: Mar 2002
Location: Norcal
Posts: 27,633
Likes: 0
Received 2 Likes on 2 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (RA166E)

i dont wanna run my injectors that high.....
Old 08-18-2004, 01:24 AM
  #4  
i HAS questions ?
 
.dave's Avatar
 
Join Date: Feb 2003
Location: OH
Posts: 7,850
Likes: 0
Received 0 Likes on 0 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (Hella_JDM)

Then you're going to have to get bigger injectors.

My fuel spreadsheet if you don't like RC's

You could also raise fuel pressure and run smaller injectors, but its up to you.
Old 08-18-2004, 06:30 AM
  #5  
Member
 
norcalcrx's Avatar
 
Join Date: Nov 2001
Location: Albion, Ca, usa
Posts: 1,024
Received 0 Likes on 0 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (Hella_JDM)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hella_JDM &raquo;</TD></TR><TR><TD CLASS="quote">i dont wanna run my injectors that high.....</TD></TR></TABLE>

Why not. That is the norm. If you want your duty cycle to be low, you will have to run really high fuel pressure, or larger injectors. There is no other way around it. Most people run their injectors in the 65-85% range of duty cycle if not more.
Old 08-18-2004, 06:36 AM
  #6  
i my honda
Global Mod
 
White Smoke's Avatar
 
Join Date: May 2003
Location: Maryland
Posts: 9,943
Likes: 0
Received 7 Likes on 6 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (norcalcrx)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by norcalcrx &raquo;</TD></TR><TR><TD CLASS="quote">Why not. That is the norm. If you want your duty cycle to be low, you will have to run really high fuel pressure, or larger injectors. There is no other way around it. Most people run their injectors in the 65-85% range of duty cycle if not more.</TD></TR></TABLE>
Ya if you get larger injectors you will have more problems idling them
Old 08-18-2004, 06:45 AM
  #7  
DaX
Honda-Tech Member
iTrader: (1)
 
DaX's Avatar
 
Join Date: Jul 2003
Posts: 7,114
Received 662 Likes on 524 Posts
Default

General rule of thumb is to not go ABOVE 85% duty cycle...right?
Old 08-18-2004, 06:50 AM
  #8  
Member
 
FOrSfEd's Avatar
 
Join Date: May 2002
Location: TurBlowVille, SC, USA
Posts: 3,719
Likes: 0
Received 0 Likes on 0 Posts
Default Re: (DaX)

Yeah that is correct Dax.
Old 08-18-2004, 07:14 AM
  #9  
Junior Member
 
RA166E's Avatar
 
Join Date: Oct 2003
Location: WA, USA
Posts: 309
Likes: 0
Received 0 Likes on 0 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (Hella_JDM)

Any good injector is designed to run at 80%. High fuel pressure is lots harder on them. Your either going to have too run big injectors or stage them at 50% duty cycle to make 450HP.
Old 08-18-2004, 08:10 AM
  #10  
Member
 
beepy's Avatar
 
Join Date: Feb 2004
Location: Pearl City, HI, USA
Posts: 2,451
Likes: 0
Received 1 Like on 1 Post
Default Re: is the rc injector caculator full of donkey poo poo???? (RA166E)

There is absolutely no reason you should run at 50% duty. The car will idle erratically since the injector won't be able to open for the tiny duration needed for idling.

Also .65 BSFC is way too conservative. This isn't a V-8 we're talking about.
Old 08-18-2004, 11:14 AM
  #11  
OG triple OG
Thread Starter
 
ATS*Mark's Avatar
 
Join Date: Mar 2002
Location: Norcal
Posts: 27,633
Likes: 0
Received 2 Likes on 2 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (beepy)

so you think maybe 75%?
Old 08-18-2004, 11:16 AM
  #12  
OG triple OG
Thread Starter
 
ATS*Mark's Avatar
 
Join Date: Mar 2002
Location: Norcal
Posts: 27,633
Likes: 0
Received 2 Likes on 2 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (Hella_JDM)

ok i tried it with 50 psi fuel pressure and 75% duty cycle and it came up to 956. sounds better but that seems like alot for 400whp....
Old 08-18-2004, 11:54 AM
  #13  
Honda-Tech Member
 
pissedoffsol's Avatar
 
Join Date: Jan 2001
Posts: 2,780
Likes: 0
Received 0 Likes on 0 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (Hella_JDM)

75 is still low...

honda's stock run in the mid 80's
Old 08-18-2004, 12:00 PM
  #14  
OG triple OG
Thread Starter
 
ATS*Mark's Avatar
 
Join Date: Mar 2002
Location: Norcal
Posts: 27,633
Likes: 0
Received 2 Likes on 2 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (pissedoffsol)

rc doesnt recomend going over 80% tho....
Old 08-18-2004, 02:47 PM
  #15  
Honda-Tech Member
 
pissedoffsol's Avatar
 
Join Date: Jan 2001
Posts: 2,780
Likes: 0
Received 0 Likes on 0 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (Hella_JDM)

honda doesn't recommend you put a turbo on their motor either
Old 08-18-2004, 02:54 PM
  #16  
 
mekkis's Avatar
 
Join Date: Apr 2004
Location: I smoke crack rocks
Posts: 151
Likes: 0
Received 0 Likes on 0 Posts
Default

beepy's right, .65 BSFC is a "safe guess" based on traditional V8's with poor VE - not even the more efficient LSx from GM or the Ford mod motors, much less cracked out big bling built Honda engines with lots of aftermarket refinements.

85% duty is the recommended max, Honduh runs the OEM ones at 100% duty as well as stock cars putting out 12:1 AFR WOT, and limiting yourself to 50% duty is completely gay!

Uhm, Ford 1600cc injectors are cheaper than any other... and the price difference allows you to afford an injector driver box that will give good quality idle and part throttle on big cc low Z injectors.
Old 08-18-2004, 02:57 PM
  #17  
Honda-Tech Member
 
EE_Chris's Avatar
 
Join Date: Oct 2001
Location: Severn, MD
Posts: 4,611
Likes: 0
Received 3 Likes on 3 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (Hella_JDM)

Grab some 800cc's, or whatever is just above it and call it a day.

RC doesn't recommend going over 80% - fair enough. So how long do you stay in boost - minutes upon minutes? My point is, you're not living at 80% for any great length of time.
Old 08-18-2004, 03:03 PM
  #18  
Member
 
rioninja's Avatar
 
Join Date: Mar 2001
Location: Philadelphia, PA
Posts: 3,331
Likes: 0
Received 1 Like on 1 Post
Default Re: is the rc injector caculator full of donkey poo poo???? (Hella_JDM)

Your thinking is full of "donkey poo poo."
Do a little more research.
Old 08-18-2004, 03:20 PM
  #19  
Honda-Tech Member
 
DRAGLS's Avatar
 
Join Date: Nov 2001
Location: Orlando,FL
Posts: 1,382
Likes: 0
Received 1 Like on 1 Post
Default Re: is the rc injector caculator full of donkey poo poo???? (rioninja)

The guy doesn't even understand how fuel injection works!
Old 08-18-2004, 06:01 PM
  #20  
Honda-Tech Member
 
Pelican's Avatar
 
Join Date: Apr 2002
Location: Jax/St. Aug, Fl
Posts: 1,019
Likes: 0
Received 0 Likes on 0 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (DRAGLS)

type R

190BHP
4 injectors
.45BSFC assuming the most effecient in the range(go honda)
43psi @ rail w/ 240cc Inj

94% Duty cycle
Old 08-18-2004, 06:11 PM
  #21  
 
mekkis's Avatar
 
Join Date: Apr 2004
Location: I smoke crack rocks
Posts: 151
Likes: 0
Received 0 Likes on 0 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (Pelican)

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

190BHP
4 injectors
.45BSFC assuming the most effecient in the range(go honda)
43psi @ rail w/ 240cc Inj

94% Duty cycle</TD></TR></TABLE>

Not 240cc

Not .45 BSFC under WOT

Not 94% DUTY - 100%
Old 08-18-2004, 07:08 PM
  #22  
OG triple OG
Thread Starter
 
ATS*Mark's Avatar
 
Join Date: Mar 2002
Location: Norcal
Posts: 27,633
Likes: 0
Received 2 Likes on 2 Posts
Default Re: is the rc injector caculator full of donkey poo poo???? (DRAGLS)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DRAGLS &raquo;</TD></TR><TR><TD CLASS="quote">The guy doesn't even understand how fuel injection works! </TD></TR></TABLE>

your an idiot
Old 08-18-2004, 09:16 PM
  #23  
 
Big_Bird's Avatar
 
Join Date: Oct 2003
Location: Vancouver, BC, Canada
Posts: 36
Likes: 0
Received 0 Likes on 0 Posts
Default

There is nothing wrong with 80% duty cycle. anything higher and the injector can't keep up with when it is supposed to be open.

but think about when you will need that 80%, only when you are going wide open throttle and full boost and how long do you do that for like EE_chris said its for small periods of time so unless you want more than your 450whp in the future you don't need an injetor that will put out that much at 50% duty
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
uncledan
Forced Induction
5
08-21-2008 07:46 AM
boost_is_best
Forced Induction
6
02-28-2006 05:02 PM
b20eg6
Honda Civic / Del Sol (1992 - 2000)
19
04-18-2002 03:49 AM
LSturboHB
Acura Integra Type-R
3
01-03-2002 07:28 PM
smoothludey2
Forced Induction
4
09-06-2001 06:48 PM



Quick Reply: is the rc injector caculator full of donkey poo poo????



All times are GMT -8. The time now is 04:44 PM.