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posted on May 21st, 2007 at 10:41 AM
wtd: 550cc injectors for my EJ20T
Guys, can anyone help me out with a good set.
Engine is a 1993 which I believe are side feed. Also can anyone confirm what they run standard, are they 375cc or 440cc?
Cheers, Andrew
[ Edited on 21-5-2007 by GTMac ]
1971 Type 3 Fasty - EJ20T
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UPDATE: Cayman S, M3, B4 now added to the list.
seagull
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posted on May 21st, 2007 at 11:06 PM
I have discovered something interesting after I built my own injector cleaner and flow bench.
Basically what the testing revealed is the difference in flow out of your injectors with the std rail set-up, after converting test bench to a
Parallel rail set-up the flows were almost dead identical.
Testing was done using 02 STI rails and 440cc top feed injectors(GT forester). Rail configuration std is very simular to early std RS WRX etc(ie its
series with a reg on end of one rail)....but they are probably more balanced that early rails, so results I expect would be worse with early RS/WRX
rails.
Baseline data ;
Fuel quantity is measured in grams.
Was weighted on digital kitchen scales with a 2g resolution.
Vessel fuel was caught and weighted in was 26g empty.
100ml of solution in vessel weighed 102g
200ml of solution in vessel weighed 176g
300ml of solution in vessel weighed 250g
Base test fuel pressure was 47.5 psi, this is what the std O2 STI reg was tested at, and what parallel after market reg used was set to.
All tests were done with a 60 sec duration.
The Data ;
Testing was done using PWM circuit, going of the adjustable trim pot used 3 test modes were devised...tho they may be far from true DC, they are what
was used for all tests, they are named from the position/range of the trim pot, so its was turned to ~ 25%, 50% and 100%(wide open no audible
pulsing)
Test 1 - part A Std rail config -
DC Inj 1 Inj 2 Inj 3 Inj 4
25% 90 88 86 86
50% 204 202 190 190
100% 334 336 344 340
Test 1 - part B Identical set-up to part A - repeat for accuracy
DC Inj 1 Inj 2 Inj 3 Inj 4
25% 90 90 88 88
50% 204 200 186 184
100% 334 332 340 338
OK so we can see that around the middle duty cycle the flow rate is significantly different, so the position of the injectors in the rails was
swapped...1-4 2-3 because I suspected it was the rails causing the discrepancy not the injectors them selves....
Also note at 100% DC the flow was higher on the rail that scored lower at 50% !
Test 2 - Part A same config as Test 1 except injector positions changed/opposite.
DC Inj 1 Inj 2 Inj 3 Inj 4
25% 88 88 92 90
50% 192 192 208 208
100% 310 310 302 302
Test 2 - part B Identical set-up to part A - repeat for accuracy
DC Inj 1 Inj 2 Inj 3 Inj 4
25% 88 88 92 90
50% 198 198 216 216
100% 314 314 304 304
...So after test 2 we can see thats it definitely the rails not the individual injectors themselves !
OK so now I made an adapter and converted the rails to parallel using 2 T pieces and an aftermarket FPR set the same 47.5 psi base pressure.
Test 3 - part A Parallel rails
DC Inj 1 Inj 2 Inj 3 Inj 4
25% 82 84 84 82
50% 204 204 204 204
100% 344 344 342 342
Test 3 - part B Identical set-up to part A - repeat for accuracy
DC Inj 1 Inj 2 Inj 3 Inj 4
25% 82 82 84 82
50% 206 206 204 204
100% 346 348 346 346
BINGO ! we have a winner, all with-in 2 g of each other !
This is one of the Perth lads * oversteer *
some times I think WES & this guy are bros !
take this in
Looking for that special lady : PM me for coffee & cake
UPDATE: Cayman S, M3, B4 now added to the list.
