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out of curiosity.....did you even data log even a short run on the sand in your v-8 rail? the reason i ask is ( based on what the cam guy told you) i would think that would be shown on the data log. i do not doubt it at all, i would really like to see it on the data log as imo that would be very impressive! if that is true ( again i do not doubt it as it makes sense) that would mean you actually built a nascar engine for your rail !! talk about taking it over the top i don't care who or what anyone thinks, to build that and stuff it in a rail ......i have to tip my hat for that one! that just makes fast look normal on the data log i would think that in the midrange at prob 62% and greater tps, one would see something in the range of 95 to 101 kpa?? your ve should be up as well ? if do have the data log save it because i would like to see it just because. i don't know and i bet with the limited run time but say if your inj's were well matched for the build then you were prob say 65% in that mid range? actually interesting to think about when talking about an n/a motor when you think about it!
based on that info your on the threshold of 0 vac.Yes,a very low restriction intake tract. do you know the fuel pressure sensor reads correctly on your data log?Not at this time but is on list of things to check. i have one installed but its not stable at idle. i used the same one enemy uses and it is rock solid for him but not for myself. i have mine mounted in the same place he did as well. also, does your fuel pump see batt voltage? Yes,but will of course double check.have you ever checked the ecu to verify that it is reading the same voltage as the batt?At this time all I can say is battery voltage is steadyacross all rpm ranges. 13.6-13.9 i had to correct my megasquirt, it red 1.5 volts less that what i saw at the batt. if the ecu thinks you have more or less voltage it changes everything.SFAIK the FAST ecu doesn't reference battery voltage but the battery and logged voltage are right on .
so that it impressive and on fuel pressure do you have a vac line connected to the fuel reg? if so disconnect that, it's only used for forced induction.Uh,no,that is incorrect.The regulator is for vac and/or boost referencing. It should be used whether N/A or boosted.See link below. no matter what dripping down to 20 ish psi is an issue This is correct for sure but I don't have enough vac under WOT or mid throttle to pull it anywhere near that low. I believe I need to pull the pumps and do some investigating the supply side.but again that could be vac doing that. just for example....my rising rate fuel reg is rated for up to 100 psi. wasn't easy finding one that actually put a rating on it! mine raises fuel psi 1 lb per 1 psi boost up to 25 psi then it drops to .75 lbs per 1 psi. i run 130 lb inj's also. i tried an actual walbro 450 pump but it began failing quickly or it couldn't move the fuel it was rated for. either way i went to the a1000 which is over kill for myself. the walbro worked correctly for the first several runs but by the 3rd day at st a it started dropping to the point it wasn't supporting 18 psi boost. i did read a post that load/kpa mirror each other up to 100 at sea level and at altitude that changes but seems to part ways by 80 at altitude. so no matter what your motor moves some air n/a!
Quote from: dsrace on October 13, 2019, 07:33:49 AMbased on that info your on the threshold of 0 vac.Yes,a very low restriction intake tract. do you know the fuel pressure sensor reads correctly on your data log?Not at this time but is on list of things to check. i have one installed but its not stable at idle. i used the same one enemy uses and it is rock solid for him but not for myself. i have mine mounted in the same place he did as well. also, does your fuel pump see batt voltage? Yes,but will of course double check.have you ever checked the ecu to verify that it is reading the same voltage as the batt?At this time all I can say is battery voltage is steadyacross all rpm ranges. 13.6-13.9 i had to correct my megasquirt, it red 1.5 volts less that what i saw at the batt. if the ecu thinks you have more or less voltage it changes everything.SFAIK the FAST ecu doesn't reference battery voltage but the battery and logged voltage are right on .
you are correct, they are for vac/boost reference. i know on the passenger vehichles i have worked on the vac reference is usually a 5 psi diff. in my case i set 43.5 psi with vac hose disconnected reconnect and it drops. i have 21" vac at idle. i read that article you posted the link too......very good article! i just would't have thought one would require such a large swing on psi but i can see why now. your right, it must be your pumps or in the fueling system.
Quote from: fabr on October 13, 2019, 09:33:21 AMQuote from: dsrace on October 13, 2019, 07:33:49 AMbased on that info your on the threshold of 0 vac.Yes,a very low restriction intake tract. do you know the fuel pressure sensor reads correctly on your data log?Not at this time but is on list of things to check. i have one installed but its not stable at idle. i used the same one enemy uses and it is rock solid for him but not for myself. i have mine mounted in the same place he did as well. also, does your fuel pump see batt voltage? Yes,but will of course double check.have you ever checked the ecu to verify that it is reading the same voltage as the batt?At this time all I can say is battery voltage is steadyacross all rpm ranges. 13.6-13.9 i had to correct my megasquirt, it red 1.5 volts less that what i saw at the batt. if the ecu thinks you have more or less voltage it changes everything.SFAIK the FAST ecu doesn't reference battery voltage but the battery and logged voltage are right on .what i was getting at on batt volatge it that......inj dead times spec sheets show what they flow at different voltages.True the ecu needs that infor or should need that info to calculated required fuel based on available voltage. this will not cause fuel pressure to dip to 20 psi of course but if its off a bit then it could cause the inj's to flow less fuel than the ecu thinks and in turn you turn the pw up to compensate.I believe FASTs strategy is to use O2 readings to do the compensation instead of flow rates based on voltage. i would assume you needed or there is a place to add the inj deat time/flow info in the faste ecu? i was mistaken earlier, my batt v's were only off .5 v from batt to what the ecu read. my v gauge on my dash was off 1.5 v's.....chickity china gauge that is gone. on another note lol i forgot to reconnect my alt wire back to my batt after working on something before the fall dune trip. i turned the engine on and could not figure out why my afr gauge was reading low 15' to low 16's at idle! my alt keeps my v at 14.1 to 14.8 while running. usually 14.1 to 14.4 but after a few more cold start cranks than normal i will see 14.8v for a bit. so my pump running at 11.5 vs 14.1 reduced fuel flow. not your issue but worth checking if there's a v drop??I don't believe I have the issue but will check.