Not to be rude, your "MECHANIC" sounds like some high school kid...

With the 460's your fine, i would also get on socks site and order his FPR kit, you WILL need some FPR to run those injectors as your fuel pump isnt going to be able to supple enough fuel and it will still go lean on you...

 

May i be struck with lightning were i sit if i am lying, My LC2 accent, stock bottom end, worked head, 380cc injectors, 208hpatw, 22psi & STOCK FUEL PUMP!

You can never overdo a fuel system, it makes me so annoyed when people say oh its to much! there is never too much thats why u have a return line back to your tank, excess fuel goes back. And in the instance, your car runs a blind system, you will still have a reg but it will be built into your tank & pump setup.

After finding out about my fuel system i now always have double the fuel pump capacity for the injectors used.

so for example we use a common question - 300kw from 4 x 550cc injectors in a sr20. Simple answer is no. here's why

Injector size:

Injectors come in two different ratings, they being cubic centimeters per minute (cc's) and pounds per hour (lb). to convert a metric CC injector to lb figure you simply divide by 10. vice versa to go from lb to cc's. So a 550cc injector is a 55lb injector.

So in a perfect world, the figure from lb to hp (horse power) is double. so a 55lb injector will support 110hp. so since the sr20 is a 4 cyl, you add 4 x 110 to get a maximum possible hp potential. So it will be 440hp.

so from there to get hp to kw you have to divide by 1.34 to get kilowats, this gives 328kw - now bare in mind as well this is at the crankshaft and not at the wheels!

now if you are trying to weigh up drivetrain loss, a reasonable figure would be 17% for manuals. so divide your 328kw by 17% to give 272rwkw.

now this is also calculated at 100% duty cycle. If you plan to use e85 fuel, subtract another 25%, so you will be limited to around 195rwkw - scary isn't it!

Fuel pump

to pick your fuel pump, it is alot easier.

So our sr20det is making 258kw on 98 octane unleaded at 100% duty cycle. each injector will be using 550cc/min (or close enough) for each cylinder. so at 100% duty cycle it will be using 2.2L of fuel per minute. in the instance of a walbro gss342 they support support 255 litres p/hour. multiply your 2.2l by 60 (2.2l per min to hours) and you will get 132 litres p/hour. This is just over half its maximum output.

SO:



in the instance of FDOMINISE:



48lb injector is - 96hp @ 100% duty cycle

4 cyl - so 96hp x 4 = 384hp @ 100% duty cycle

so hp to kw - 384hp / 1.34 = 286.56kw at the flywheel

so kw @ flywheel to kw @ wheels - 286.56 - 17% = 237.84kwatw @ 100% duty on 98 octane fuel

98octane to E85 - 237.84 - 25% = 178.34kwatw @100% duty cycle on E85 fuel


so as for the fuel pump:


500cc injectors x 4 = 2.0litres @ 100% duty cycle.

2litres per min x 60 mins (1 hour) is 120litres per hour.


so to be 100% safe with it: 120litres x 2 = 240litres p/hour.



Hope this is a bit informative for all.




Cheers Ryan

 

Wow intresting post very detailed, thanks