why everyone should rewire their fuel pump
12-31-10, 03:08 PM
#151
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Not sure which duty cycle you're asking. Idle is about 4.1-4.3% with mid 13AFR's and max is 70% at 16psi (street port with Aspec 500R).
With (4) 850's at 11 psi (street port with sequential twins) I saw low to mid 80%'s duty cycles in Summer so I upgraded to 1300 secondaries before winter and it droped to low 70%'s at 13 psi.
With (4) 850's at 11 psi (street port with sequential twins) I saw low to mid 80%'s duty cycles in Summer so I upgraded to 1300 secondaries before winter and it droped to low 70%'s at 13 psi.
12-31-10, 03:20 PM
#152
Original Gangster/Rotary!
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^^^ correct. The 1300 are good for twins or small single turbo for low 400s, rich was in the low 400HP range with the 1300s and so is chrispyrx7. I am shooting for 400HP so i will keep my 1300s. If the 1300s become a problem i will jump over to the Injector Dynamics (no resistors) and leave my pockets like Rabbit Ears.
Now running 870/1680 top feed with FJO injector driver and enough fuel for at least 525 rwhp.
01-01-11, 04:15 PM
#154
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so If I have read the posts correctly, Just rewire as the diagrams by adding a relay,
and jump the relay under the hood ? where exactly is this relay that needs to be jumped? photos ? and is jumping this an option or mandatory ?
thanks
and jump the relay under the hood ? where exactly is this relay that needs to be jumped? photos ? and is jumping this an option or mandatory ?
thanks
01-01-11, 06:56 PM
#157
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id rather do it once right the first time, 1300's and injectors that come back from rc have been known to fail, its happened to me with my 850's that have been cleaned from rc took a dump on me, luckily for me it happened out of boost so my 850 primaries were sufficient to run the car in vaccum, but once i entered it was like i hit fuel cut hard
Dave, one factor you forgot to add in those 1300's failing on you was that they were repeatedly brought to 100% duty cycle before you got them...
I personally watched them hit 100% duty cycle on the way to and back from Dgrr 09.
Just saying 1300's aren't as risky as they sound.
01-01-11, 07:00 PM
#158
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Anyone get a good amount of miles on ( 10k +) with their rewired fuel pump setup?
results on wiring condition, pump, etc?
Im wondering if a full pump rewire like i did on a one of the FD's is worth doing on a daily driver FD.
results on wiring condition, pump, etc?
Im wondering if a full pump rewire like i did on a one of the FD's is worth doing on a daily driver FD.
01-01-11, 10:16 PM
#159
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well if my car will ever not break something i would have far more miles on it, but so far nothings given me a problem wiring or fuel pump wise
aslo brian and some people he knows has had the 1300's as well as other cleaned and flow tested injectors by rc fail on him before
aslo brian and some people he knows has had the 1300's as well as other cleaned and flow tested injectors by rc fail on him before
01-14-11, 11:41 PM
#161
Keep in mind if your car is stock it's going to run rich after this mod. Retune your maps unless you like the smell of gas. There are a few ways to do the rewire mod. If using my diagram the relay goes in the back and the relay in the front is just left alone.
06-20-13, 10:12 PM
#168
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1/4 tank due to tank slosh but that's dependant on driving habits and how much HP (forward acceleration) to force the fuel away from the sump. anything below 1/4 in mine and ill pick up air.
06-21-21, 11:23 AM
#170
Wouldn’t the car run rich if you do this?
How many of you have put a volt meter on the fuel pump on a dyno? I saw something scary this past week. Car I was having tuned had 550s/1680s, aeromotive fpr, supra tt pump, new oem fuel filter. Should have been enough fuel for close to 500 rwhp.around 16 psi boost we hit 100% injector duty cycle. Base fuel pressure was 40 psi.Car should have had injector to spare. I watched the fuel pressure gauge and under boost it shot to 60 psi and by 5000 rpm started falling. Fuel pressure fell as low as 40 psi.This explained why we had to add so much fuel at the top of the map. Next I put a volt meter on the fuel pump and was shocked to see just over 11v! Made no differnce if it was at idle ore wot. Car has a new alternator and odyssey 925 battery. Voltage on datalogit was over 12v at all times. This shows how much voltage drop there is in the junk factory wiring, As these cars age and are tampered with it gets worse.The fuel pump should have over 13v. This is another reason motors blow.
06-21-21, 03:21 PM
#173
RX-7 Bad Ass
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Was your car modified at the time?
On a stock FD a Walbro does fine. The Banzai dyno results thread is all done with a Walbro in the car from the get go.
https://www.rx7club.com/3rd-generati...added-1104322/
Good power and good AFR (stock ECU trends more rich), in line with bone stock (stock fuel pump) cars.
Dale
On a stock FD a Walbro does fine. The Banzai dyno results thread is all done with a Walbro in the car from the get go.
https://www.rx7club.com/3rd-generati...added-1104322/
Good power and good AFR (stock ECU trends more rich), in line with bone stock (stock fuel pump) cars.
Dale
06-21-21, 03:25 PM
#174
thewird
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06-21-21, 04:18 PM
#175
If you went to an overkill pump for a stock setup like a walbro 450, you would be overworking the factory regulator in which case you should be getting an aftermarket fuel pressure regulator. Pretty much anything above a walbro 255 will start to overwork the factory regulator to varying degrees which will cause tuning discrepancies. Tuning doesn't fix the fuel pressure swings but can "band-aid" the problem.
thewird
thewird
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estevan62274 (06-21-21)
