injector phasing VS. cam timing

[nutz]

oops deleted a post trying to edit

ok, well can anyone shed light on how to do this. I was talking to a tuner and the topic came up, when i search the power forum i find its very important to do (idle and throttle response drivability) i guess when i changed my mb/sec and boost fuel correction i threw it outa wack + my cam is much larger than stock, this is new to me as i was under the impression the EMS di it on it own

if anyone has some insite i would appriciate it

[mole']

newb.....

[nutz]

Quote: Originally Posted by mole'

newb.....

lol, I have seen about 100 srt maps and noone does this, after speaking to an engineer I find it one of the most important and overlooked tables on the EMS, I was under the impression it was done for ya untill today


learning something new every day

[mole']

im always down to learn.

oh ya

no more ems for me

trinity FTW

[nutz]

Quote: Originally Posted by mole'

im always down to learn.

oh ya

no more ems for me

trinity FTW

you'll be back









J/K

[mole']

Quote: Originally Posted by nutz

you'll be back


J/K

well i have it sold, so i hope i dont need to come back.

wish me luck

[nutz]

Quote: Originally Posted by mole'

well i have it sold, so i hope i dont need to come back.

wish me luck

lol, dude you'll be fine I'm pretty sure your in good hands

the EMS is a pita anyways, every time i think I have a hold of stuff POP up comes something new, thank god Chuck has been kind enough to guide along these past couple days I think some very new and exciting things are in the EMS's future

[duster360]

Quote: Originally Posted by nutz

lol, I have seen about 100 srt maps and noone does this, after speaking to an engineer I find it one of the most important and overlooked tables on the EMS, I was under the impression it was done for ya untill today


learning something new every day

man nuts, you're always jacking around with something aren't you?

Its very important to have right for part thottle fueling when using sequential injection. Since the injectors are open nearly the whole time during WOT(+600 crank degrees. note: the intake valve is only open for around 230-250), its not critical when they actually start.

If your not having issues with part throttle drivability, leave it alone.

Note:
older batch fire injection, like on my duster, runs the injectors constantly so there is no such thing as "injector phasing". They never stop firing. The fuel just sits behind the valve until it opens. Works perfectly fine. This was OEM standard for TBI and MPI until tighter emmissions regulation dictated a switch to sequential, because part throttle fuel control was more precise.

[nutz]

lol, just cant seam to be satisfied.

i want it perfect, i mean if my injectors are out of phase or off a bit I should just switch to a batch fire set up. I found a few how to's on the aempower site along with some spread sheets. if i ever figure out how to use em i will post up results

[never2muchboost]

on an srt4 there is no reason to mess with injector phasing. the only reason why you would want to venture in that neighborhood that i can think of is if you are not running an iac motor and you have ginormous cams and you have a bad lean tip in or puddling fuel on the intake valves(cant see that happening though unless you went with a smaller duration cam)
the sled is tuned like that because it doesnt have an iac and it has big cams.

all injector phasing is doing is either retarding or advancing the injector opening in relation to tdc.if you feel the need to mess with it you can force it to idle rpm with no feedback and advance phasing until you peak rpm then drop off.thats about the right spot for advance but keep changes very very small and do yourself a favor and save your map before you screw it up and dont have a turning back point

[NachO_SRT]

I thought this is what the USEC and Deadtimes were for? Once you have that info for your injectors the phasing should fall in line, correct?

Maybe I'm mis-understanding.


Here is an example of what numbers I'm talking about. These are Injector Dynamics 1000CC's for an EVO IX. Mine are the same, just less junk in the packaging cause they were plug and play.




NachO

[nutz]

naa, it has to do with syncing up the intake valve opening to the injector fireing, for some reason if you use the boost correction tables (multiple of base numbers) it screws up this sync pretty bad

IE: if the EMS sees a 4.2us pw but with the boost correction that is only 1.8us it will only sync the number from the map (not the corrected value) so some of your fuel is being shot AFTER the valve is closed and that makes for a delayed reaction and all around shitty performance (from idle to about 3k rpms) it is still syncing to the front of 4.2us

I can change my maps to a hybred boost comp and low load drivability would be much better

so the moral of the story is..... full boost comp while being easier to build/tune will require an advanced understanding of injector phaseing, I had the privladge of looking at an engineers map and their phase tables are very very well done

[NachO_SRT]

Ahhh I get you. This is about the Amount of cycle time VS. The valve event duration.


I see now, carry on.


NachO

[nutz]

if any one wants here are some xls spreadsheets from the AEM forums

[nutz]

Maximum fuel pulsewidth in degrees of crank rotation
343.32 20 33 47 61 70 84 100 108 116 127 141 157 170 182 186 195 205 217 227 238 248
321.11 20 33 47 61 70 84 100 108 116 127 141 157 170 182 186 195 205 217 227 238 248
298.89 20 33 47 61 70 84 100 108 116 127 141 157 170 182 186 195 205 217 227 238 248
276.68 20 33 47 61 70 84 100 108 116 127 141 157 170 182 186 195 205 217 227 238 248
254.46 20 33 47 61 70 84 100 108 116 127 141 157 170 182 186 195 205 217 227 238 248
232.25 20 33 47 61 70 84 100 108 116 127 141 157 170 181 186 195 205 217 227 238 248
212.05 20 33 47 61 70 84 100 108 116 127 140 155 168 179 186 195 205 217 227 236 247
189.84 20 34 47 60 70 84 100 109 116 126 138 153 166 178 186 194 204 216 226 234 244
167.62 20 34 46 59 69 83 101 109 116 126 138 151 164 175 184 193 203 213 223 233 243
145.41 20 34 45 56 68 82 100 109 115 124 135 146 158 171 178 188 199 209 220 229 238
123.19 20 33 44 54 66 80 98 105 111 119 129 141 151 163 171 180 190 199 210 218 227
100.98 19 31 42 52 62 77 95 101 108 111 119 128 136 147 156 165 174 183 194 203 212
84.82 18 29 39 47 56 71 92 97 99 100 107 114 122 131 139 147 155 163 173 181 189
68.66 17 28 37 45 53 64 86 90 87 91 98 104 113 121 129 130 137 142 150 156 163
54.53 17 27 35 43 48 57 79 82 76 83 88 94 101 108 113 115 119 124 131 135 141
38.37 16 25 33 39 44 48 55 59 65 69 73 76 79 83 85 87 89 90 92 93 93
22.21 16 25 30 35 32 36 41 43 48 51 53 55 57 59 60 62 62 63 63 64 63
800 1200 1550 1850 2050 2300 2650 2900 3300 3600 3900 4200 4500 4850 5150 5450 5750 6050 6400 6700 7000