To: Parish8
11-04-2002, 04:55 PM
#11
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Re: To: Parish8
Not to get your flame war off topic, but does anybody have a definition for "duty cycle?" From what I've found by searching, it's some sort of standard (80% keeps popping up) that you're not supposed to exceed. If that is correct, what happens when you exceed it? I appreciate any clarification. Any links to "How Fuel Injectors Work" would be good...
11-04-2002, 07:15 PM
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Re: To: Parish8
Parish, I really think RED2GAY is call you a Jackass...Jackass. What Mr.Prix put is true, Horse power divided 2 and then that number divided by the number of injectors....That is at a 80% duty cycle, and i've seen people run 120% duty cycles....But then you run into so much pressure the injector will not open....You know 36 pound injectors are good to 475 at the wheels and could work to 525 at the wheels, I agree with Kevo, you should not have to upgrade your injectors till you build a really bad azz motor
11-04-2002, 08:22 PM
#15
Re: To: Parish8
you guys need to do a little more research. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />
sure your computer can ask for 125% duty cycle but once it reaches 100% it is open all the time and it plan and simple can't be open more than all the time.
your fuel presure is set by the regulator and will not change based on duty cycle
your formula is wrong for hp, it doesn't take into acount BSFC wich varies for NA vs supercharger vx turbo. it is also figured at 100%, not 80%.
here is the right formula
(inj size) x (duty cycle) / (B.S.F.C) x (number of injectors)
in my case
41 x 80% / .60 x 8 = 437hp this seems prety close to me, i am seeing 80% duty cycle and would guess i am around 450hp.
at a 100% duty cycle they are good for 546hp, a good tune and 8psi and i would be real close to that(guessing again). if you guys have any more questions about injectors i would be happy to help. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
oh yea, one last thing alot of people say they have 30lb(at 43.5psi) svo injectors or something like that, they are actualy 35lb(at 58psi) in our cars/trucks. when i say i have 41lb injectors that is the rated flow for my truck(58psi).
sure your computer can ask for 125% duty cycle but once it reaches 100% it is open all the time and it plan and simple can't be open more than all the time.
your fuel presure is set by the regulator and will not change based on duty cycle
your formula is wrong for hp, it doesn't take into acount BSFC wich varies for NA vs supercharger vx turbo. it is also figured at 100%, not 80%.
here is the right formula
(inj size) x (duty cycle) / (B.S.F.C) x (number of injectors)
in my case
41 x 80% / .60 x 8 = 437hp this seems prety close to me, i am seeing 80% duty cycle and would guess i am around 450hp.
at a 100% duty cycle they are good for 546hp, a good tune and 8psi and i would be real close to that(guessing again). if you guys have any more questions about injectors i would be happy to help. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
oh yea, one last thing alot of people say they have 30lb(at 43.5psi) svo injectors or something like that, they are actualy 35lb(at 58psi) in our cars/trucks. when i say i have 41lb injectors that is the rated flow for my truck(58psi).
11-04-2002, 08:46 PM
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Re: To: Parish8
Hyde your right, 36#(@43.5psi fp) injectors could support 525rwhp....on a N/A 6speed, not on a blown 4wd automatic.
Those 41#(same as 35# at 43.5 psi)injectors parish8 has should only support around 550 crank horsepower on his truck since he should be running a slightly higher bsfc with the blower. They will support over 600 crank horsepower on a N/A motor.
parish8 - You can run 100% duty cycle. If you do the injectors will only see that high a dc for a few seconds most of the time. Most companies only recommend 80-90%dc max. because 100% does shorten the life span of the injector and could kill one causing the truck to go lean in that cylinder. <img border="0" alt="[kaboom]" title="" src="graemlins/gr_bomb.gif" />
If your at 80% you could probably add another 90hp and see close ~100% dc.
Get that tranny in and get some ET's so we can get a better idea about the power you're making. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
John
Those 41#(same as 35# at 43.5 psi)injectors parish8 has should only support around 550 crank horsepower on his truck since he should be running a slightly higher bsfc with the blower. They will support over 600 crank horsepower on a N/A motor.
parish8 - You can run 100% duty cycle. If you do the injectors will only see that high a dc for a few seconds most of the time. Most companies only recommend 80-90%dc max. because 100% does shorten the life span of the injector and could kill one causing the truck to go lean in that cylinder. <img border="0" alt="[kaboom]" title="" src="graemlins/gr_bomb.gif" />
If your at 80% you could probably add another 90hp and see close ~100% dc.
Get that tranny in and get some ET's so we can get a better idea about the power you're making. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
John
11-04-2002, 08:49 PM
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Re: To: Parish8
Hahaha...parish8, you got your post in before me. That is a good explanation.
I think people are getting confused about what fuel pressure these injector numbers being thrown around are rated at.
John
I think people are getting confused about what fuel pressure these injector numbers being thrown around are rated at.
John
11-04-2002, 08:52 PM
#18
Re: To: Parish8
these kids just don't know what they don't know <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
at least i hope they are kids, i would hope an adult wouldn't act like these guys. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
at least i hope they are kids, i would hope an adult wouldn't act like these guys. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
11-04-2002, 09:13 PM
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Re: To: Parish8
All I can say is if your an adult,your an idiot.Bring that Super Fuel Injected 4 X Junk down to TEXAS and get cracked by us stupid old kids with stock injectors...One of these days you stuborn old farts are just gonna have to learn...LOL <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" />
11-04-2002, 09:15 PM
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Re: To: Parish8
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by MR.MIX:
<strong>All I can say is if your an adult,your an idiot.Bring that Super Fuel Injected 4 X Junk down to TEXAS and get cracked by us stupid old kids with stock injectors...One of these days you stuborn old farts are just gonna have to learn...LOL <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Isn't it in Texas where you guys have a problem with blowing your motors?
<strong>All I can say is if your an adult,your an idiot.Bring that Super Fuel Injected 4 X Junk down to TEXAS and get cracked by us stupid old kids with stock injectors...One of these days you stuborn old farts are just gonna have to learn...LOL <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Isn't it in Texas where you guys have a problem with blowing your motors?