Ping Pinky

boosted

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Pinky give me an educated guess here. If a bikes static fuel pressure is set at 43psi and the bike has secondaries [stage 2] and the fuel pressure is bumped up to 45-46 psi what percentage will it richen the boost map...My bike runs bettor off boost at 45-46 psi and seems to pull just as well on boost. 5000-Redline my AFR on 43 psi was 11.8 to 1. I have no o2 sensor and dyno time is expensive. I know it will richen it a little, but how much.
 
id say no more then half a point
but its been a while since ive even rode a bike (long story)

last time i messed with idle and running FP i ended up dropping mine all the way to 35 psi

why are you wanting to up the FP?
my bikes always seemed to run better at 13.5-14:1 at idle and the boosted AFR i looked at running 11.8:1




from my experience our bikes (my turbo builders and mine) would run pig rich at 46+ psi at idle and would try and cut out so id say 5 psi range would raise the afr .5-1 afr point?? (this is a guess as i dont have proof of the rise)

sorry i cant be more accurate as i dont have a dyno to test on yet
also sorry to ramble
 
I just looked at my dyno sheet and the afr is high at 14.5-15:1 till I hit apx 5000 rpms. then you can lay a platter on the AFR line 11.8:1 to redline. I value your oppinion thanks for the quick response.
 
That gets interesting.. your secondary system + primary are probably about 890cc total at 43psi , and 920cc at 46 psi (on line injector calculator) or around 3-4% richer in total
but if you wanted to change your fuel maps to reflect this its probably more like 5-6% on the secondarys only ....but still 3-4 % if you were working on a PC3 pre boost to fix the lean area
Pinky is probably fairly close with the effect on the A/F
 
i had another member of my site do some testing and this is the results he came up with
LoFP.jpg

MidFP.jpg

HiFP.jpg


and here is what he also responded with about the last a/f (this is all done strictly at idle, no boosted runs)

"The last A/F was more like 13.1-45psi. They bounce around, give or take .3.

Idling @ 1500

It "sounds" the best between 13.5 and 14.0 A/F, 38-40psi. Though sometimes it's harder to start at a lower psi.
Any more or less than 13.1 or 14.3, 35psi or 45 psi and the motor sounds like it's about to die."

(thank you cory for the help)
 
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