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Author Topic: Sufficient fuel system for 500rwhp?  (Read 31734 times)

Offline mattster03

Sufficient fuel system for 500rwhp?
« on: October 26, 2010, 09:30:06 PM »
Looking to get some input on what's required to support 500rwhp via forced induction.  I've been reading a lot of tech and just want to run this by you guys.  I've calculated my injector needs using the following formula:

(rwhp*BSFC)/(# injectors * duty)

and I get

(500*0.6)/(8*0,8)= 46.9 lb/hr

I really like the price and availability of the Ford Motorsports "green tops" which are rated at 42 lb/hr @ 40psi.  I have read that in the higher pressure LS1 fuel system, they flow closer to 50-52psi.  Does anyone on here have actual experience with these to verify HP capacity?  Should green tops be enough for my future system or should I spend the extra hundered or two to get some 60 lb/hr?  I'm also using 80% duty which is pretty generous....

Next is the fuel pump.  I am currently running a denso Supra pump which flows somewhere in the neighborhood of 260-280 L/hr, or some where around 68-75 gal/hr which is around 400-450 lb/hr (assumin 6 lb/gal for fuel). Again I find myself right on the hairy line of "adequate" for my HP needs as my max flow is around 400lb/hr as well.  Any thoughts on this?  SHould I just buck up and the the bosch 044?

Thanks in advance for any input!
« Last Edit: October 26, 2010, 09:49:21 PM by mattster03 »
Current Car: 1993 Mazda RX7 Touring, LS1/T56, Stock Stock Stock

1993 Mazda RX7 R1, LS1/T56, EPS 230/238, TSP Ported heads
10.826 @ 128 , 1.53 60' - SOLD

Feature Article - http://www.importmeet.com/blog/2012/03/29/best-of-both-worlds-v8rx7guys-ls1-swapped-1993-mazda-rx-7/
Swap Info - http://www.cardomain.com/ride/2801662

1986 Mazda RX7 GXL, LT1/T56 "Retired"
Swap Info - http://www.cardomain.com/ride/641869

Offline ablake211

Re: Sufficient fuel system for 500rwhp?
« Reply #1 on: October 26, 2010, 09:56:12 PM »
Get the #60lbs inj for the fact that you have to swap them anyhow and these will give you wiggle room for when you want more power eventually. For your power goal I think you can run that pump(id personally upgrade) but if you run it make sure you have great voltage to it.

Offline Speedfab

Re: Sufficient fuel system for 500rwhp?
« Reply #2 on: October 26, 2010, 10:23:29 PM »
Mototron 60s.  Look hard and you can get a set for 40 each, don't pay more than 400 for the set.  As for the pump, just install another Denso 1020 in parallel with your existing pump and tee them together in the tank.  You'll be done and pretty much set for all you'll ever need.


unless you own a turbo ls9 rx7 you do not know what the fuck you are talking about.

Offline mattster03

Re: Sufficient fuel system for 500rwhp?
« Reply #3 on: October 26, 2010, 10:44:21 PM »
Future HP needs are not part of the question... I'm just wondering about FMS 42lb injectors and a denso pump right now.  Will it be sufficient with a safety margin.
Current Car: 1993 Mazda RX7 Touring, LS1/T56, Stock Stock Stock

1993 Mazda RX7 R1, LS1/T56, EPS 230/238, TSP Ported heads
10.826 @ 128 , 1.53 60' - SOLD

Feature Article - http://www.importmeet.com/blog/2012/03/29/best-of-both-worlds-v8rx7guys-ls1-swapped-1993-mazda-rx-7/
Swap Info - http://www.cardomain.com/ride/2801662

1986 Mazda RX7 GXL, LT1/T56 "Retired"
Swap Info - http://www.cardomain.com/ride/641869

Offline BeasTT

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Re: Sufficient fuel system for 500rwhp?
« Reply #4 on: October 26, 2010, 10:58:26 PM »
I agree with what Tracy said. Check out FIC injectors, and I've been thinking about going twin boschs if you want my double Pumper setup
Nick Shultz

1993 Rx-7
371ci, Twin Billet 6265's, Twin A2W's, ProEFI 128, RacePak IQ3,
McLeod RXT, Speedfab 8.8 solid axle, QA1s, FIC 2150cc, Magnafuel 4303

Offline Jordan Innovations

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Re: Sufficient fuel system for 500rwhp?
« Reply #5 on: October 27, 2010, 03:45:01 AM »
That setup sounds fine to me, but there's a reason everyone's pushing towards a little extra injector and a little extra pump... it's the smart thing to do!  Injectors at your desired size for $40/ea?!?  That's nothing!  And a couple hundred for another Denso pump just to be on the safe side is a drop in the bucket.

Offline Sabre002

Re: Sufficient fuel system for 500rwhp?
« Reply #6 on: October 27, 2010, 08:09:47 AM »
Josh
Manager Business Development, Mazda Motorsports
For info on how to join the Mazda Motorsports Team Support Program Email me.
Jsmit295@mazdausa.com

Offline mattster03

Re: Sufficient fuel system for 500rwhp?
« Reply #7 on: October 27, 2010, 10:21:11 AM »
the only problem is i found someone who is practically giving a way a brand new set of 8 green top 42lb/hr injectors for $100.  I figure these would hold me over for the year, and I could even sell them for a profit when I'm done.  As far as the fuel pump goes, I may want to get a Bosch 044, it's probably a wash price-wise if I would sell my Denso Supra...
Current Car: 1993 Mazda RX7 Touring, LS1/T56, Stock Stock Stock

1993 Mazda RX7 R1, LS1/T56, EPS 230/238, TSP Ported heads
10.826 @ 128 , 1.53 60' - SOLD

Feature Article - http://www.importmeet.com/blog/2012/03/29/best-of-both-worlds-v8rx7guys-ls1-swapped-1993-mazda-rx-7/
Swap Info - http://www.cardomain.com/ride/2801662

1986 Mazda RX7 GXL, LT1/T56 "Retired"
Swap Info - http://www.cardomain.com/ride/641869

Offline digitalsolo

Re: Sufficient fuel system for 500rwhp?
« Reply #8 on: October 27, 2010, 11:05:45 AM »
Green tops really should be fine UP TO 500 HP.    Go much beyond that and you lose the "20% safety margin".   

For 100 bucks, I'd buy them just resell, that's a steal.

Now I'll wait here for someone to post up that stock injectors are fine because their cousin's uncle's son used them in his 1200 HP Camaro.  ;)
Blake MF'ing McBride
1988 Mazda RX7 - Turbo LS1/T56/ProEFI/8.8/Not Slow...   sold.
1965 Mustang Coupe - TT Coyote, TR6060, modern brakes/suspension...
2007 Aston Martin V8 Vantage - Gen V LT4/TR6060, upper/lower pullies, headers, tune.
2021 Tesla Model 3 Performance - Stock...ish.

Offline ablake211

Re: Sufficient fuel system for 500rwhp?
« Reply #9 on: October 27, 2010, 11:12:31 AM »
I never shy away from parts I feel I can use then sell for a few bux at the end of the day.

Also im sure I was pushing it and it wasn't quite the best thing.......but i made 631.7rwhp on a single 044 in my last car.  >:(

Offline mattster03

Re: Sufficient fuel system for 500rwhp?
« Reply #10 on: October 27, 2010, 11:46:14 AM »
are 044's the pumps which are famous for being insanely loud?
Current Car: 1993 Mazda RX7 Touring, LS1/T56, Stock Stock Stock

1993 Mazda RX7 R1, LS1/T56, EPS 230/238, TSP Ported heads
10.826 @ 128 , 1.53 60' - SOLD

Feature Article - http://www.importmeet.com/blog/2012/03/29/best-of-both-worlds-v8rx7guys-ls1-swapped-1993-mazda-rx-7/
Swap Info - http://www.cardomain.com/ride/2801662

1986 Mazda RX7 GXL, LT1/T56 "Retired"
Swap Info - http://www.cardomain.com/ride/641869

Offline Sabre002

Re: Sufficient fuel system for 500rwhp?
« Reply #11 on: October 27, 2010, 12:17:21 PM »
are 044's the pumps which are famous for being insanely loud?

no mine is quieter then the walbro.  Its all in how you mount it.
Josh
Manager Business Development, Mazda Motorsports
For info on how to join the Mazda Motorsports Team Support Program Email me.
Jsmit295@mazdausa.com

Offline MPbdy

Re: Sufficient fuel system for 500rwhp?
« Reply #12 on: October 27, 2010, 12:51:23 PM »
If the green tops are rated 42@40 psi then they will flow 50.5@58 psi.  I echo the sentiments that you should improve your fuel pump situation, but the injectors are plenty for now.  You have headroom on your already generous 80% duty cycle.

HOWEVER

BSFC is calculated using flywheel horsepower.  You basically need to support 580-600 horsepower.

(600*.6)/(8*.8) = 56.25

No dice.  However 600@ 90% duty cycle is 50 lb/hr.  You would be pretty much right there.  With a supercharged car it would not be something I would want to worry about.

Green tops really should be fine UP TO 500 HP.    Go much beyond that and you lose the "20% safety margin".   

For 100 bucks, I'd buy them just resell, that's a steal.

Now I'll wait here for someone to post up that stock injectors are fine because their cousin's uncle's son used them in his 1200 HP Camaro.  ;)

My cousin's uncle's son's car didn't even use injectors.  He just put like 8 walbros on the intake manifold.  It made 1200hp on low boost without a tune!

« Last Edit: October 27, 2010, 12:55:27 PM by Daniel »

Offline spacevomit

Re: Sufficient fuel system for 500rwhp?
« Reply #13 on: October 27, 2010, 12:52:58 PM »
LOL GTFO!?! (Oh wait you're obviously joking hahaha FML).

GregD

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Re: Sufficient fuel system for 500rwhp?
« Reply #14 on: October 27, 2010, 01:01:55 PM »
Of course he was joking.  He used eight 044 pumps on the manifold, not Walbros...