what should i need for a 400 hp fuel system
 

ok i have been searching and all it did was give me more question, ok im lookin at just running ss line in the engine bay and gettign a walboro fuel pump, fpr u know stanard stuff, im still confused thu on what all i need i got 720 and a set of 1600 but can i use the stock rails, which is better parallel or series and how do u tap the stock line from the fuel tank into the y port for the parellel

I have been through this mess and I spent way more money than I needed to. Learn from my mistakes!

If you don't care about the look of stainless lines, the only thing you 100% really need is 1680cc secondary injectors and a legit walbro fuel pump (be careful of ebay knockoff pumps!). J-rat made 550rwhp with stock fuel lines and a walbro pump. Bypass the factory resistor relay completely when you rewire it (search for a thread I made "overkill fuel pump rewire")--it's only useful if you have a stock ECU.

I honestly think you could get away with the factory FPR as well, but I might get flamed for officially recommending it. I have had no issues tuning my friend's FD with 550/1300 and stock FPR, and that car is probably making in the mid 300s to the wheels. All an aftermarket one does is let you increase the base pressure, while eliminating fuel pressure spikes from high fuel flow. When you run an upgraded fuel pump on the factory FPR the fuel pressure is higher at idle, but this can be easily compensated for with proper tuning and I have personally done it.

Buy these injectors: http://www.injector.com/fuelinjector...47e1308196e1be , the last one at the very bottom. I bought the Bosch ones but they don't fit into the stock rail without being modified. I have been told that those "japanese style" ones listed there will drop right in terms of physical fitment and will work as long as you have resistors or a low impedence injector driver for them.

I am living proof that the parallel flow setup is unnecessary. There is nothing wrong with it at all, but it just costs more and takes time to install. I ran 21psi (race fuel) on a T04S 60-1 turbo with fuel rails plumbed in series like stock, making over 400 to the wheels. I had a Supra TT pump. I prefer it over my old walbro, the Supra pump is made by Denso just like the stock pump and is higher quality IMO.

Finally, make sure you've taken care of the pulsation dampener issue, whichever way you choose to do it.

EDIT: I re-read your post and it seems that you already have some 1680's. The top of the injector is too thick/wide to fit in the stock rail, so people tend to get them modified. I'm not sure who does it. I went with an aftermarket rail but I wish I had just bought the ones that drop in. On the bottom of your injector should be an o-ring and a spacer looking thing, along with the pintle cap. Remove those completely and install and s5 pintle cap and OEM injector grommet. Otherwise you will have a vacuum leak.

all you need..[IMG]http://i163.photobucket.com/albums/t...c/pararail.jpg[/IMG]

are the rails pictured in this diagram stock?

you need a pulsation damper...some aftermarket fpr's have them built in but i went with the marren damper for added security.

That diagram refers to S4 TII fuel rails only. S4 NA, and all S5, are different.

^^ thanks for the response... can anyone recommend injectors the will fit nicely in the stock rails? i would like maybe 720cc and 1000cc... would that be over kill on a lite street port with a bnr stage 2 turbo 3 inch turbo back exhaust and a greddy front mount?

greddy 720's (denso) will fit the stock rail. also, witchhunter will modify your larger bosh injectors to work with the stock rail for like 5 bucks a piece.

Sorry in advance for thread jack:

I too am shooting for this HP number. I have a S5 T2... well known source said stock 550 primaries and 1200 (high imp) secondaries should be fine for 350 WHP on pump gas??? :scratch:

Note: I have purchased parallel fuel setup (s4 rails with SS lines and Y splitter and also have Aeromotive A1000 FPR)

What more would I need?

Hope answers help OP :icon_tup:

on an FD you can get the high impedance side feed 850's bored out to 1200 cc. I don't think there are commonly available top feed 1200's (for the FC rail) that are high impedence.

if you want my honest opinion... if you want to buy just what you "need" then you've already bought too much. The parallel fuel mod just doesn't seem as important on a lot of applications as people think (all show aspects aside). I am running my rails in series like stock and my fuel system supported 21psi (T04S 60-1 turbo), with just a rewired Supra TT pump. I honestly think the stock FPR could do the deed too, but I don't want people to go out and just use it because I said so. Lots of FDs are making in the mid 300s on their stock FPR, could the FC FPR be that much different? An undersized FPR usually results in fuel pressure increase (like an undersized wastegate causes boost to be higher).

A lot of V6 engines run the rails in series and seem to be fine. I had a friend who was in the 600awhp range on his VR-4 with the stock rails in series, one rail for each cylinder bank with a factory hardpipe connecting them. Now I know 600awhp isn't the same when it's on a piston engine.

The parallel fuel mod is the safe way to go, it's true. But it's not cheap and I'm not convinced it's that beneficial under say 500whp. Once I get my motor broken in we'll see what a single Supra pump and fuel lines in series can do on my T04R.

parallel fuel rail is not that expensive...

if you have a s4 you are lucky and you can get fittings for the ends of the rail ~15/ each so thats $60. If you have a s5, chop off the ends of your fuel rail and carefully prep the pipe and braze in a -an hose barb. I did this a while ago and have had no issues. Use pushloc hose that is rated upto 120psi (i think) and connectors ~75 and get a fpr ~100 depending on which regulator you get. OR keep an eye on the forums and snag stuff when it gets cheep. I have no problem using a used fuel rail or -an fittings. I would probably buy a new fpr just for peace of mind. You will also need a fuel Y block if you are only running 1 pump ~$25.

Thats $ 260 for a parallel fuel system that you are not going to have to screw with again. Also if you get a nice aftermarket regulator you will not need to worry about the pulsation damper failing.

If you are like me and have no self control when it comes to shinny stainless fittings well you are screwed, it is going to cost quite a bit.

Will stock S4 T2 bolt right up to S5 motor?

I too am a victim of shinny part purchasing but in the end its just peace of mind (being anal) haha

Question: TT supra FP is better than my 6 month old Walbro 255lph? I keep hearing good and bad things about Walbro pumps... :scratch:

if i remeber correctly, the primary s4 rail bolts up to the s5 but the secondary rail does not.

i have not had any problems with my walbro.... but i never get down past 1/4 tank of gas.

the s4 rails bolt up to an s5, you just need to use a couple washers under the secondary rail as spacers.

supra pump > walbro

Not altogether true. The walbro will outflow at certain PSI ranges.

See this is what I'm getting about fuel pumps LOL

My complete setup will be:

Knightsports hybrid turbo w/ ported WG
1200 sec
720 prim
FMIC
walbro or supra FP
Power FC
FCD
14 PSI

Is this good for at least 350 whp???

my friend has the Knightsports hybrid... I think 350 is pushing it on that turbo

everything else is fine, except you dont' want a fuel cut defender if you don't have a stock ECU. The boost fuel cut is adjustable in the Power FC.

but if you have an aftermarket fpr this shouldn't be an issue...correct?

contact bnr. he modified my 1600's

Im shooting for 400+ at the moment and I am banking on my 720/1600 injectors on walbro 255 and stock FPR doing the trick. I see no reason it wouldn't.

You can just trim the plastic on the tops on the American injectors and they will fit into the stock rails or you can buy Japanese 1680's for a little more that drop right in without modification (bottow of the page) http://www.injector.com/fuelinjector...52dd2302dcb60f

We are making over 400whp @ 14.7psi on our vert fuel setup: 630cc/1600cc, Walbro pump, Aeromotive FPR, injector duty cycle in the low 70's, base pressure set at 40psi. Tuned with a Power FC.

Injector dimensions

American 1680

http://www.injector.com/specs/05160.pdf

Japanese 1680

http://www.injector.com/specs/051600PI.pdf

i made 400 at 15psi, i have some 1600 secondary injectors, a walbro, and everything else is stock. so to answer your question, thats all you need, yeah i could have got some safety stuff but i didnt have any more money.

Thanks for all the help.

Sorry again OP for thread jacking LOL :icon_tup:

im assuming that the 750cc and 1000cc japanese marren injectors fit the stock s4 rails without modification... is this correct?