500 RWHP = fuel pumps ?
 

well im in search of the 500 RWHP ... but my tunner says ill max out the 255 lph before i hit the 500 mark ... question is what should i do ?? should i run 2 in-tank 255 or a biger inline or what ?!?! what other choices are out there.. all of you that have hit the 500 whp point let me know .... curently running 8500 and 1600 cc ...

i know there a few of you out here that have accomplished this and those are the people that i wanna hear about . come on guys .. thanks for the help in advance ! :smiley_12

run two Walboro 255s with a bigger fuel line. Atleast a -6.

I'm going to try this on an rx7.com fuel pump. They are pretty beefy.

dual walbros with a smooth 45 degree Y adaptor to -6 or -8

just do the direct wire and let the fuel pump limit your power... if you want more power you better be doin some drag racing at the track cause theres no point really in making huge power for no reason. if want more run two supras with a 6an line and buy stock in mobile :)

One drop in Skyline pump (BNR32) and be done with it.

2 walbro's,use the hardline for the evap (clean it out) and run 1 line to each rail. make sure you have a good fuel filter ( im running dual SX filters)


I think 500 on one supra pump is pushing the GPM limit.

I think max cooper has a good calculator on his page. and fd3s.net has GPH listings.


You can never have too much avilavable fuel. and always build the car for more than you intend it. If you want 500, build it with a 600hp fuel system

http://ptp.tuningmotorsports.com/pro...cat=420&page=1


and

https://www.rx7club.com/showthread.p...7&page=3&pp=15

i had mine built with dual outlets.


No need to run new hardlines unless your into wasting money

^^^^^^
What he said, same setup I am running, except mine are nippon denso 280 lph pumps.

That's what I run and I'm very happy with it. One supra pump will not support 500 rwhp, esp not on stock wiring. I'm not convinced it will safely support it even getting 13-14 volts.

I've referenced this thread a lot lately, but I think it's good reading on this subject:

https://www.rx7club.com/showthread.p...stem+ramblings

another vote for dual walbro's :)

actually the dual walbros would seem to be best ... and yes im planing on dragging the car ... at 14psi on the t88 already feels like its a lil too much for the streets .... so im sure 500rwhp+ will get some interesting times....

does anyone have this set up now and have a few pics (twin walbros)?!?! and i also tought that having two lines might be a lil too excessive ... so i need more info on that too .... thanks for the info guys ....

I run twin Supra pumps, each with their own 3/8in (-6AN) feed lines to each fuel rail. I will post some pics later when I find them.

I run twin bosch '044's , -10 AN feed and -6 return via a paxton reg. (along with a custom fuel cooler , 4X1600's and 2X550's) no fuel problems WHATSOEVER!!

I stopped running dual pumps, I want the car to stop running if the pump was not operational. With dual pumps, unless you have run some indicator lights that the pumps are getting/using power or working, you might not be aware of the outage until you have the need for the extra pressure. And then what happens?

I run one Bosch '044 pump into AN-08 feed and return with a fuel cooler using dual 1680's and 860's, all top feed injectors. I've seen over 68psi measured from the FPR port (gauge sender is there) when running 22psi of boost.

I used dual walbros and made 600ish. They are for sale if you are interested.

Also, it is smart to use the stock feed and return lines for feed, and the evap line for the return.

just y them together at the regulator.

how much you want for the set up ?? got some pics ?? and does it come with all fittings ?? let me know or pm me ... thanks !!

:icon_tup:

Stock feed and returns both being used as feeds, to a 45 deg Y to -8. And a new -8 braided return :)

I have seen pumps occasionally slow down and cause the fuel pressure to drop without actually stopping altogether and causing the car to stall , what do you think would happen then ? , I am sure that ONE of my ,044's can do the job (at least for a short time) andprevent any failures in the event that the other goes out . I Have my pumps wired with separate relays , so I check them separately ever so often to confirm that they both work .

ps . I have also seen injectors fail under full load and cause motor fdistruction, so what do you suggest to remedy this ? , should we all go to a single injector set up so that the car would stall if its one and only injector fails

Why do you run mutltiple injectors? I run only one! In one big rotor housing!

Seriously, you are comparing the tail to the head and applying the same logic to both. The pump supplies the volume while the injectors release that volume into the runners then into the chamber.

Run two pumps and tune for it and you have a redundant system, yes, but not one that supports failover.

The reason for multiple injectors is not redundancy or failover. It's better distribution of fuel to the needed runner (primary or secondary) and into seperate chambers. The secondaries come on above a certain RPM as needed.

Does your second pump come on when needed and shut when not needed? Did I miss that?

I don't know why your system stalls or chokes down on pressure. One would need to evaluate the whole system taking into consideration how the pumps join their volume, to how your lines handle the volume to the injectors and back to the tank again.

Those pumps could be fighting each other depending on your setup.

Have you personally killed an engine by clogged injector or failure? I have injectors clog or lose power (shoddy wiring) but have not lost an engine over it.

U dont have to school me on how a modern fuel injection system works , I know what the various components are for . The reason for multiple injectors is as you said , but do you know that there are 2250 cc injectors ? if one has an ECU that can control them (like Autronic) then it is very possible to use one big injector in one rotor housing ! , the reason most people use multiple injectors is because of price , availability , tunability/ driverbility and overall practicality since most people are happy with a pair of 1600's and 550's ... , but introducing multiple injectors also introduces multiple failure points into the system, increasing the chance that something can go wrong.
As for my system , it DOES NOT STALL OR CHOKE , I have a pair of identical pumps , each of which IS capable of supplying up to 500 HP worth of fuel , I'm saying that even if my system is tuned for them both , one of them WILL be able to supply the requirement ,since my motors fuel requirement cannot max out the flow , there'd just be less return to the tank . If it was a single pump system , or dual low capacity pumps (using two of them to get enough fuel) , there would be a problem since in either situiation one pump would not be able to keep up , which would cause the motor to be starved for fuel .
Last but not least ......., no I never lost an engine to a faulty injector , but many other people have , because it did not happen to me doesn't mean it cant happen , Did you loose an engine to the failure of one pump in a twin pump setup ?? , the point I'm trying to get across is this , if you do a bit of over engineering and buy QUALITY stuff , then running multiple pumps and injectors will work and would work better than running a single , there is always a possibility that something can go wrong , be it a pump dying , an injector sticking , a fuse blowing , a filter collapsing , if you keep thinking, " what if" you can severly limit what you do , sometimes u just have to put your faith in you "enginering" and hope it all works!

Not following the logic in your post....too tired to follow along the lack of formatting and spelling on top of that. It looks like you took offense to something I said and got emotional. Sorry about that.

Allow me to boil down my point for you:

"You have a redundant fuel pump system. It is not a fail-over or fail safe system. You lose one pump your fuel system behavior to which it was tuned to changes."

Run a test before you put all your faith in your dual pump setup. Stop one of them from working and check your base fuel pressure at idle. Did it change? Care to try in boost and not just at idle without changing your base pressure...on one pump?

Not sure if you had other questions or comments you message. Regards,

Tony

thats what i have

I run one walbro 255lph, and the engine is making an easy 403atw at 12psi on a dyno dynamics roller. Base pressure of 40psi, and no tail off yet.

John

Well if the logic in my post above escapes you , then I think you are the last person who sholld be giving anyone advice on anything rotary or fuel injection related !! , as for my grammar .....I didnt know that this board was a freakin english class !!!! . I went ahead and did the test , I disconnected one pump and guess what , the idle pressure stayed the exact same , I took it for a spin and boosted to 15psi , and guess what ..... no problems at all , my in-car fuel pressure gauge showed the fuel pressure rising with boost as it's supposed to ......... so what do you think 'bout that Mr English man ?