Jump to content
SAU Community

Recommended Posts

heya recently bought a nismo fpr for my rb25det does anyone know about putting it on

1. does the fuel have to be manually primed through it?

2. will my car need to be tuned to the adjusted fuel pressure?

i had a good search around the forums and didnt find anything on topic if there is one set me up with a link ;)

ta simon g

1) no. Turning the key to ACC will prime the system to the desired pressure.

2) yes. any increase in fuel pressure will (respectively) increase or decrease the amount of fuel going in. i.e. more pressure = more fuel.

Why are you installing one anyway? Do you realise the stock one will do fine for up to 25+psi of boost??

1) no. Turning the key to ACC will prime the system to the desired pressure.

2) yes. any increase in fuel pressure will (respectively) increase or decrease the amount of fuel going in. i.e. more pressure = more fuel.

oki doke thanks for the info just another couple Q's..

to get a gauge on it can i just t it onto the fuel outlet? and if i have the pressure right down does that mean better fuel economy? atm strugling to get 250 km a tank -__-

why did i want it.. someone told me i would need one soon and i picked up a good bargin on it too ;)

Why are you installing one anyway? Do you realise the stock one will do fine for up to 25+psi of boost??

Please have a read of this thread from a few days ago.

http://www.skylinesaustralia.com/forums/topic/347078-upgrading-fpr-worth-it/

Then read my post:

The only reason to "upgrade" the factory FPR is really in three instances:

1. When your injectors are starting to max out, but you don't want to upgrade them, so you bump up the rail pressure with the aftermarket adjustable fuel pressure regulator to push them a little but furthur. Obviously this isn't ideal and most people don't recommend it. Just buy the correct injectors to start with.

2. When you are running huge amounts of boost and the factory fuel pressure regulator can not keep up the 1:1 fuel pressure ratio. Therefore you will need an aftermarket fuel pressure regulator that can handle this high amount of boost pressure and keep up the 1:1 ratio.

3. The factory fuel pressure regulator has failed so you may choose to buy an aftermarket one however still run it at factory fuel pressure.

So as you can see, not many people fall into the second category because a lot of people don't run 2+bar of boost through their car. A few do fall into the first category because they may be on a budget and don't want to upgrade the stock injectors so they choose to bump the rail pressure up instead and obviously a few will fall into the third category.

However there is a fourth category that you will find 90% of people with aftermarket fuel pressure regulators fall into:

4. They have no idea what an adjustable fuel pressure regulator does, but they got told to buy one by a mate or read about one somewhere.

For your situation assuming that you are not running E85, your 700cc injectors should be fine for between 400-500HP therefore you do not need an aftermarket fuel pressure regulator.

You are in category 4 just like so many others. Hate to be a barer of bad news, but you just wasted money.

Hi Simon, I reckon better fuel economy will come from everything working properly (especially if your intercooler or pipework has a leak somewhere) and a decent tune, I'd pop it on the dyno before making any adjustments to fuel pressure. And yeah, it's really not necessary to have an aftermarket one, if you've got the right sized injectors and pump you should be right. Feel free to pop over again if you want to test the cooler system for leaks or just chat.

Please have a read of this thread from a few days ago.

http://www.skylinesaustralia.com/forums/topic/347078-upgrading-fpr-worth-it/

Then read my post:

You are in category 4 just like so many others. Hate to be a barer of bad news, but you just wasted money.

at what power level will my fuel system be restictive to power curve/gains? walbro in tank and stock injectors, as im planning for a gt35, im sure i read on here of someones build being restricted by fuel system at 260rwkw...

currently on 230ish

and aparently i dont no how to post w/ quotes haha

hey andrew hows it goin? sounds good mate just have to find the time :P working 2 jobs now, and fulltime girlfriend... haha

If you are planning for a GT35 you will want something like Nismo 740cc injectors.

Stock injectors start running dangerously high duty cycle anything around 220rwkw+ Therefore if you are pushing 230rwkw on stock 15+ year old injectors, you are all ready risking an engine.

wow this ones taking off.. haha i didnt have the intention of lowering pressure just wanted to know if it actually worked like that aswell lol atm i was just guna have it in there running on standard pressure til it needed to be adjusted..

also this was 90$ injectors are not gunna be good for my bank account atm..

thanks for the feedback everyone :|

leave it off. putting it on and know really understanding what you are doing means there is more chance of it doing harm than good. infact it's not going to give you any gain even if you did know what you were doing. seriously it's a waste of time and money. when you get that big turbo you'll need some big injectors and yet you STILL won't need that regulator.....

at what power level will my fuel system be restictive to power curve/gains? walbro in tank and stock injectors, as im planning for a gt35, im sure i read on here of someones build being restricted by fuel system at 260rwkw...

currently on 230ish

and aparently i dont no how to post w/ quotes haha

hey andrew hows it goin? sounds good mate just have to find the time :P working 2 jobs now, and fulltime girlfriend... haha

mate i've got plenty of time... till Feb, just resigned from music. Let me know how you go time wise, can always give you a hand keeping the budget in check

Thanks for the input guys ;) will probs give it the flick then, So does anyone know how to put a gauge on so I can check the pressure of the stock fpr ? Just T it between fuel outlet and the rail? Also I may nit have stock injectors... The guy I got the car off didn't know half of what's on it, I've just been discovering new mods when I get under the car.. Haha so how can I check if the injectors are stock or aftermarket ? Not really wanting to pull off plenum either :D Cheers!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • And finally, the front lower mount. It was doubly weird. Firstly, the lower mount is held in with a bracket that has 3 bolts (it also acts as the steering lock stop), and then a nut on the shock lower mount itself. So, remove the 3x 14mm head bolts , then the 17mm nut that holds the shock in. From there, you can't actually remove the shock from the lower mount bolt (took me a while to work that out....) Sadly I don't have a pic of the other side, but the swaybar mounts to the same bolt that holds the shock in. You need to push that swaybar mount/bolt back so the shock can be pulled out past the lower control arm.  In this pic you can see the bolt partly pushed back, but it had to go further than that to release the shock. Once the shock is out, putting the new one in is "reverse of disassembly". Put the top of the shock through at least one hole and put a nut on loosely to hold it in place. Put the lower end in place and push the swaybar mount / shock bolt back in place, then loosely attach the other 2 top nuts. Bolt the bracket back in place with the 14mm head bolts and finally put the nut onto the lower bolt. Done....you have new suspension on your v37!
    • And now to the front.  No pics of the 3 nuts holding the front struts on, they are easy to spot. Undo 2 and leave the closest one on loosely. Underneath we have to deal with the wiring again, but this time its worse because the plug is behind the guard liner. You'll have to decide how much of the guard liner to remove, I undid the lower liner's top, inside and lower clips, but didn't pull it full off the guard. Same issue undoing the plug as at the rear, you need to firmly push the release clip from below while equally firmly gripping the plug body and pulling it out of  the socket. I used my fancy electrical disconnect pliers to get in there There is also one clip for the wiring, unlike at the rear I could not get behind it so just had to lever it up and out.....not in great condition to re-use in future.
    • Onto the rear lower shock mount. It's worth starting with a decent degrease to remove 10+ years of road grime, and perhaps also spray a penetrating oil on the shock lower nut. Don't forget to include the shock wiring and plug in the clean.... Deal with the wiring first; you need to release 2 clips where the wiring goes into the bracket (use long nose pliers behind the bracket to compress the clip so you can reuse it), and the rubber mount slides out, then release the plug.  I found it very hard to unplug, from underneath you can compress the tab with a screwdriver or similar, and gently but firmly pull the plug out of the socket (regular pliers may help but don't put too much pressure on the plastic. The lower mount is straightforward, 17mm nut and you can pull the shock out. As I wasn't putting a standard shock back in, I gave the car side wiring socket a generous gob of dialectric grease to keep crap out in the future. Putting the new shock in is straightforward, feed it into at least 1 of the bolt holes at the top and reach around to put a nut on it to hold it up. Then put on the other 2 top nuts loosely and put the shock onto the lower mounting bolt (you may need to lift the hub a little if the new shock is shorter). Tighten the lower nut and 3 upper nuts and you are done. In my case the BC Racing shocks came assembled for the fronts, but the rears needed to re-use the factory strut tops. For that you need spring compressors to take the pressure off the top nut (they are compressed enough when the spring can move between the top and bottom spring seats. Then a 17mm ring spanner to undo the nut while using an 8mm open spanner to stop the shaft turning (or, if you are really lucky you might get it off with a rattle gun).
    • You will now be able to lift the parcel shelf trim enough to get to the shock cover bolts; if you need to full remove the parcel shelf trim for some reason you also remove the escutcheons around the rear seat release and you will have to unplug the high stop light wiring from the boot. Next up is removal of the bracket; 6 nuts and a bolt Good news, you've finally got to the strut top! Remove the dust cover and the 3 shock mount nuts (perhaps leave 1 on lightly for now....) Same on the other side, but easier now you've done it all before
    • OK, so a bunch of trim needs to come off to get to the rear shock top mounts. Once the seat is out of the way, the plastic trim needs to come off. Remove 2 clips at the top then slide the trim towards the centre of the car to clear the lower clip Next you need to be able to lift the parcel shelf, which means you need to remove the mid dark trim around the door, and then the upper light trim above the parcel shelf. The mid trim has a clip in the middle to remove first, then lift the lowest trim off the top of the mid trim (unclips). At the top there is a hidden clip on the inner side to release first by pulling inwards, then the main clip releases by pulling the top towards the front of the car. The door seal comes off with the trim, just put them aside. The the lighter upper trim, this is easy to break to top clips so take it carefully. There is a hidden clip towards the bottom and another in the middle to release first by pulling inwards. Once they are out, there are 3 clips along the rear windscreen side of the panel that are hard to get under. This is what the rear of the panel looks like to assist:
×
×
  • Create New...