Problems with scaling P2s
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MM , do you think the uncapped injectors are actually flowing 880ccs ?
(quoted from another thread)
Well they would have less resistance to flow - which is why they should flow more . Under boost they may flow a little less because of the reduced pressure differential . But same would be true of all the injectors ......... right ?
(quoted from another thread)
I was having serious idle issues with my uncapped P1/P2/Secondaries, overall it ran like poop.
Then in go the Injector Dynamics 1000cc primaries and 2200cc P2/Secondaries and voila! An idle that purrrrrrs... (Mind you, my P1's & P2's fire together, so even with nearly twice the injector size my idle is 10x better)
These ID injectors really do handle very low ms VERY well. Questioning the output/scalability of the uncapped injectors is not dumb at all, especially when the time comes that you're way up there on the revs and on boost...
Then in go the Injector Dynamics 1000cc primaries and 2200cc P2/Secondaries and voila! An idle that purrrrrrs... (Mind you, my P1's & P2's fire together, so even with nearly twice the injector size my idle is 10x better)
These ID injectors really do handle very low ms VERY well. Questioning the output/scalability of the uncapped injectors is not dumb at all, especially when the time comes that you're way up there on the revs and on boost...
Last edited by Brettus; Jan 26, 2011 at 12:49 PM.
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/\OK
A more direct question for you ...
Do the uncapped yellow injectors behave the same way the oem injectors do ?
IE Can they be scaled according to what they flow on a test bench the same way you would scale the stock injectors or are there latency differences enough to upset what happens in operation?
A more direct question for you ...
Do the uncapped yellow injectors behave the same way the oem injectors do ?
IE Can they be scaled according to what they flow on a test bench the same way you would scale the stock injectors or are there latency differences enough to upset what happens in operation?
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/\Apparently gregs was using uncapped yellows at the Socal dyno day yesterday and ran out of capacity at 287whp . If theses injectors truely did flow 800ccs ish there is no way they would max. out at that whp even at 10% reduced output .
Seems to confirm what I've found with trying to scale these . They don't deliver much more than stock capped yellows .
Probably I'm missing something here . Is there anyone out there that has them fitted that has had in car results as per the static flow test?
OD - where did you get your 550ccs figure from ?
Seems to confirm what I've found with trying to scale these . They don't deliver much more than stock capped yellows .
Probably I'm missing something here . Is there anyone out there that has them fitted that has had in car results as per the static flow test?
OD - where did you get your 550ccs figure from ?
Last edited by Brettus; Feb 28, 2011 at 01:22 PM.
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They all bench flow test within a few % of eachother - so it's not any difference between the uncapped yellow injectors themselves .
These other cars you have tuned "way over 300" - same setup Greg had IE stock other than uncapped yellows in P2 ?
Theoretically he had 280/380/800 x 2 = 2920 for 287hp and was running out of fuel
I had 280/380/480 x2 = 2280 for 333hp and was ok at that . 22% less fuel with 14% more hp
See why I can't make sense of this ?
These other cars you have tuned "way over 300" - same setup Greg had IE stock other than uncapped yellows in P2 ?
Theoretically he had 280/380/800 x 2 = 2920 for 287hp and was running out of fuel
I had 280/380/480 x2 = 2280 for 333hp and was ok at that . 22% less fuel with 14% more hp
See why I can't make sense of this ?
Last edited by Brettus; Mar 1, 2011 at 02:14 PM.
Had that configuration on my own car up to 320 HP at the same duty cycle.
I'm pretty sure that MYSQL's setup was also this configuration (316 HP).
I picked his for the comparison, but there are quite a few other setups out there that are identical.
DynamicDookie's setup was on completely stock injectors and he his 270 on a stock GReddy kit over the weekend at the same duty cycle.
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To put it another way , what you appear to be saying is that gregs car was using something like 20% more fuel than it should have for the hp it was making , yet AFRs were showing it was running out of fuel .
Last edited by Brettus; Mar 1, 2011 at 03:55 PM.
No, what I am saying is that the actual amount of fuel supposedly identical injectors actually inject can vary by up to 30%.
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Well - getting back to my original issue . In the case of the uncapped yellows i'm trying to tune it is more like 50% variance from what they bench tested at .......
Last edited by Brettus; Mar 1, 2011 at 08:32 PM.
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I feel you man, been pulling my hair out the last two weeks to get my car to idle right with those 1 piece seals, porting and my intake.
Been through 10 tunes in 2 weeks with nothing changed but various idle stuff - and I finally got it pretty much on time tonight, 2 degrees advance, 13.8 AFR and 1000 RPM, idles like butter.... annoying yes, but when I make 10 PSI at 2200 RPMS it is all worth it.
Been through 10 tunes in 2 weeks with nothing changed but various idle stuff - and I finally got it pretty much on time tonight, 2 degrees advance, 13.8 AFR and 1000 RPM, idles like butter.... annoying yes, but when I make 10 PSI at 2200 RPMS it is all worth it.
They all bench flow test within a few % of eachother - so it's not any difference between the uncapped yellow injectors themselves .
These other cars you have tuned "way over 300" - same setup Greg had IE stock other than uncapped yellows in P2 ?
Theoretically he had 280/380/800 x 2 = 2920 for 287hp and was running out of fuel
I had 280/380/480 x2 = 2280 for 333hp and was ok at that . 22% less fuel with 14% more hp
See why I can't make sense of this ?
These other cars you have tuned "way over 300" - same setup Greg had IE stock other than uncapped yellows in P2 ?
Theoretically he had 280/380/800 x 2 = 2920 for 287hp and was running out of fuel
I had 280/380/480 x2 = 2280 for 333hp and was ok at that . 22% less fuel with 14% more hp
See why I can't make sense of this ?
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I'm gunna go with latency as being the issue and say "**** the uncapped yellows" . 
Using OEM injectors with known latency tables has always worked perfectly for me .
Using OEM injectors with known latency tables has always worked perfectly for me .
Wait ... huh
Brettus I thought you were running uncapped yellows.
Don't know if you recall our brief chat during the SoCal dyno event ...
But I'm planning on using uncapped yellows on my Turbo build, are u saying we shouldn't.
I'm confused. So just run the regular yellows are buy bigger injectors period ... but I guess that means latency .....
Brettus I thought you were running uncapped yellows.
Don't know if you recall our brief chat during the SoCal dyno event ...
But I'm planning on using uncapped yellows on my Turbo build, are u saying we shouldn't.
I'm confused. So just run the regular yellows are buy bigger injectors period ... but I guess that means latency .....
Last edited by wcs; Mar 2, 2011 at 05:27 PM.
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No , I've never had uncapped yellows in my own car . I was trying to tune for someone else with them and struck problems .
According to MM there isn't a problem but I've given up on them .
I know the blues from an AT work fine on the same latency table as the yellows - after that my knowledge is limited on what works.
So yellow yellow blue gives you an extra 400cc overall which is plenty for 325 ish .
According to MM there isn't a problem but I've given up on them .
I know the blues from an AT work fine on the same latency table as the yellows - after that my knowledge is limited on what works.
So yellow yellow blue gives you an extra 400cc overall which is plenty for 325 ish .
Last edited by Brettus; Mar 2, 2011 at 04:39 PM.
I think Brettus is saying that uncapped yellows aren't very consistent and it showed last weekend.
possible alternative = uncapped blues?
possible alternative = uncapped blues?
Last edited by Jedi54; Mar 2, 2011 at 04:41 PM.