Hey all,
TL;DR: Can I run a 350 lph inline fuel pump into the stock Mustang fuel rails and FPR on my 5.0 twin GT35R RX-7 and still expect the FPR to regulate around 40 psi, or do I need an upgraded regulator?
If there's a simple answer, sweet,
/thread.
But this is my first time doing any aftermarket fuel stuff, and I'm here to learn, so here's the long version if anyone wants to throw in their .02.
Disclaimer: I'm not the one that built the motor/swap setup and there are a fair amount of details about it I don't know.
Car: 1988 RX-7 FC, 5.0 swapped. Stock bottom end.
Mods: Twin GT35R turbo setup (dual EWG), built head, Trickflow valve covers, Crower Stage 3 cams, 3" turbo back exhaust.
Power/tune: I was told when I bought the swap it made around 430WHP on 93 octane @ 5psi (wastegate spring pressure). I got a ride in the car before I purchased the swap setup, and my butt dyno would certainly confirm that number. Motor sounded super healthy. It ripped.
Things I'm not sure about: Injector size, tune specifics.
Fuel setup: WAS running stock RX-7 pump (~250lph if my research is correct) into the stock RX-7 fuel filter, into the stock Mustang fuel rails. The builder used a -8AN adapter for the feed and -6AN for the return.
Then, long story short, got it running, but the tank had rusted out, and replacements were stupid expensive ($800+). The rest of the fuel system — hard lines, fill neck, and so on — were also COOKED due to age/rust. And probably clogged with shitty rust debris anyway. A local radiator shop said they would not be able to refurbish the tank because the rust was so cancerous on the seam.
So because of the cost and the sorry state of the current fuel stuff, I made the decision to just bite the bullet and go fuel cell + AN lines + aftermarket pump/filters/etc.
I have an inline pump, a DeatschWerks 9-350. You can see the tech specs for it here.
I don't know much about aftermarket pumps, as this is my first time setting something like this up — the original builder of the car said ~340lph is what he'd do if he were going aftermarket for this setup.
That said, I'm concerned about the PSI of this pump. If I'm reading the spec sheet right, at lower LPH/amperage, (240/~11a) the pump can do up to 100psi.
The spec sheet linked above does say "The pump is rated at 350lph at 40psi and maintains over 300lph at 70psi," so I'm hoping it'll be fine, since I'm near that original ballpark of 250lph/40psi I was at before. But is there a reason I would see higher PSI out of the pump? I don't want to overwhelm the stock fuel pressure regulator.
Anecdotally, I've got a buddy who's a knowledgable race team mechanic. He told me that on numerous builds, they've run a 340lph pump with OEM BMW FPRs with zero issues. (He races E36/E46s primarily.) Not sure how similar those designs are to the Ford ones, but worth mentioning.
For the rest of the fuel setup, I've got a 15-gallon Summit cell, 100 micron pre-pump filter, 10 micron post-pump filter, and -8AN fittings/lines all around (feed and return).
It's still got the -6AN adapter on the stock fuel rail return, so I was just going to run a -6AN to -8AN adapter for the return... Which I'm now realizing is stupid, and I should just get a -8AN adapter for the stock fuel rail return. I do also have a new dedicated wiring kit/relay for the pump.
Anyway, does my fuel setup sound reasonable to you for my build? 350lph, -8AN feed/return, stock fuel rail and FPR?
If I do need a beefier FPR, I found this one from Late Model Restoration. I'm sure adjustability would be nice, but frankly, I'm kind of sick of spending money on this car, and I'd rather not just blow another $150 for fun. If the stock FPR will work, awesome.
Thanks so much for your input.
TL;DR: Can I run a 350 lph inline fuel pump into the stock Mustang fuel rails and FPR on my 5.0 twin GT35R RX-7 and still expect the FPR to regulate around 40 psi, or do I need an upgraded regulator?
Pic for fun:
TL;DR: Can I run a 350 lph inline fuel pump into the stock Mustang fuel rails and FPR on my 5.0 twin GT35R RX-7 and still expect the FPR to regulate around 40 psi, or do I need an upgraded regulator?
If there's a simple answer, sweet,
/thread.
But this is my first time doing any aftermarket fuel stuff, and I'm here to learn, so here's the long version if anyone wants to throw in their .02.
Disclaimer: I'm not the one that built the motor/swap setup and there are a fair amount of details about it I don't know.
Car: 1988 RX-7 FC, 5.0 swapped. Stock bottom end.
Mods: Twin GT35R turbo setup (dual EWG), built head, Trickflow valve covers, Crower Stage 3 cams, 3" turbo back exhaust.
Power/tune: I was told when I bought the swap it made around 430WHP on 93 octane @ 5psi (wastegate spring pressure). I got a ride in the car before I purchased the swap setup, and my butt dyno would certainly confirm that number. Motor sounded super healthy. It ripped.
Things I'm not sure about: Injector size, tune specifics.
Fuel setup: WAS running stock RX-7 pump (~250lph if my research is correct) into the stock RX-7 fuel filter, into the stock Mustang fuel rails. The builder used a -8AN adapter for the feed and -6AN for the return.
Then, long story short, got it running, but the tank had rusted out, and replacements were stupid expensive ($800+). The rest of the fuel system — hard lines, fill neck, and so on — were also COOKED due to age/rust. And probably clogged with shitty rust debris anyway. A local radiator shop said they would not be able to refurbish the tank because the rust was so cancerous on the seam.
So because of the cost and the sorry state of the current fuel stuff, I made the decision to just bite the bullet and go fuel cell + AN lines + aftermarket pump/filters/etc.
I have an inline pump, a DeatschWerks 9-350. You can see the tech specs for it here.
I don't know much about aftermarket pumps, as this is my first time setting something like this up — the original builder of the car said ~340lph is what he'd do if he were going aftermarket for this setup.
That said, I'm concerned about the PSI of this pump. If I'm reading the spec sheet right, at lower LPH/amperage, (240/~11a) the pump can do up to 100psi.
The spec sheet linked above does say "The pump is rated at 350lph at 40psi and maintains over 300lph at 70psi," so I'm hoping it'll be fine, since I'm near that original ballpark of 250lph/40psi I was at before. But is there a reason I would see higher PSI out of the pump? I don't want to overwhelm the stock fuel pressure regulator.
Anecdotally, I've got a buddy who's a knowledgable race team mechanic. He told me that on numerous builds, they've run a 340lph pump with OEM BMW FPRs with zero issues. (He races E36/E46s primarily.) Not sure how similar those designs are to the Ford ones, but worth mentioning.
For the rest of the fuel setup, I've got a 15-gallon Summit cell, 100 micron pre-pump filter, 10 micron post-pump filter, and -8AN fittings/lines all around (feed and return).
It's still got the -6AN adapter on the stock fuel rail return, so I was just going to run a -6AN to -8AN adapter for the return... Which I'm now realizing is stupid, and I should just get a -8AN adapter for the stock fuel rail return. I do also have a new dedicated wiring kit/relay for the pump.
Anyway, does my fuel setup sound reasonable to you for my build? 350lph, -8AN feed/return, stock fuel rail and FPR?
If I do need a beefier FPR, I found this one from Late Model Restoration. I'm sure adjustability would be nice, but frankly, I'm kind of sick of spending money on this car, and I'd rather not just blow another $150 for fun. If the stock FPR will work, awesome.
Thanks so much for your input.
TL;DR: Can I run a 350 lph inline fuel pump into the stock Mustang fuel rails and FPR on my 5.0 twin GT35R RX-7 and still expect the FPR to regulate around 40 psi, or do I need an upgraded regulator?
Pic for fun:
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