Jump to content
SAU Community

Recommended Posts

I know this has been brought up many times and I've read everything at least twice but there's still information missing. I'm looking to run top feed Bosch EV14 injectors in my RB25 using the standard intake manifold. I have various reasons for this, and yes, I have considered just running Nismo side feeds.

I am aware I need 40 or 48mm (seal to seal) length injectors (are 3/4 length 48 or 55mm?) with 7 or 15mm fuel rail spacers respectively to get it to fit under the plenum.

What I need to know is whether I need 11mm or 14mm diameter bodies (which size are most RB25 fuel rails designed for?) and are adapters required on the manifold side if I want to run these top feed injectors in place of the standard ones?

Any input would be greatly appreciated, particularly similar setups with exact specs.

Wouldn't that be determined by the top mount fuel rail you get?

I'm sure you are aware you cant use the side feed rail with top feed injectors.

No adapters are needed for the manifold side. Normally you can use the std injector seal or a standard O ring that normally comes on the injector.

Yeah I'm looking at getting a new rail and pressure regulator as well as the injectors. It would, but very few people (even quality brands) actually specify the size of the rail holes so I'm wondering if it's just assumed to be one size or I have to guess...

For the manifold side I don't understand how both 11 or 14mm could fit?

You'll need 38mm ~ 40mm (o-ring to o-ring) injectors which are commonly known as half height and a 14mm fuel rail. The common half height EV14s I've seen are 2000cc - haven't seen anything less in half height (unless IU can't find them).

On the fuel rail you will need to trim the collars/spacers given to accommodate the injectors.. and in regards to a FPR - you could use the stock one with those EFIHardware adapters OR just go full external FPR.

You'll need 38mm ~ 40mm (o-ring to o-ring) injectors which are commonly known as half height and a 14mm fuel rail. The common half height EV14s I've seen are 2000cc - haven't seen anything less in half height (unless IU can't find them).

On the fuel rail you will need to trim the collars/spacers given to accommodate the injectors.. and in regards to a FPR - you could use the stock one with those EFIHardware adapters OR just go full external FPR.

Thanks. I saw the 40mm ones fit well but they're significantly more expensive as far as I can find and my understanding is standard length EV14s (48mm) will just squeeze under the intake manifold with the right rail. Cheers for the tip on the FPR! That'll save some money as I won't need to run more than the standard pressure anyway.

I have a brand new black r33 proflow rail with 6 alloy length adapters, makes 3/4 length 11mm injectors into full length 14mm to suit the rail. $120 all up if your interested

Cheers. If I can confirm this will fit under the standard plenum with 3/4 length injectors (and obviously shortened spacers) I'll send you a PM.

1/2 length is tits

But then you need to muck around with cutting the spacers down.

Has anyone actually had any issues with the 3/4 length, or is it all hearsay? I have sold quite a few 3/4 sets with rail kits over the last 6 months and have had no complaints as yet. I really need to get an old 33 manifold and do a trial install for myself, I have only done Neo installs so far.

But then you need to muck around with cutting the spacers down.

Has anyone actually had any issues with the 3/4 length, or is it all hearsay? I have sold quite a few 3/4 sets with rail kits over the last 6 months and have had no complaints as yet. I really need to get an old 33 manifold and do a trial install for myself, I have only done Neo installs so far.

AngryRB had 3/4s - fit but loads of dicking around

Yep, one of the sets you sold to my mate in Newcastle had a lot of problems with fitment, was quite the muck around. This was the stainless 1400cc E85 injectors btw.

(This should not be read as blaming Scotty in any way, we had heard that it would be difficult to fit them and they would just fit under there. Turns out just fits is an understatement on an R33 RB25 plenum)

In my case I had a leaking plenum gasket so had to take it off about 5 times, if you didn't have that issue and only had to do this once then its worth it to have some top quality injectors. The vacuum hose underneath between cyl 2 and 3 needs welded up and moved ( brass fitting in pic) and have to shave some material off from under the throttle body, then you have fit the plenum on but its tight still.

The rail I had was a cheap one and I had to shorten the spacers to get the right length but not too hard. Got everything I needed from injectorsonline.com.au , but maybe scotty can do it cheaper for you.

20130907 171442 (640x480)

20130907 171507 (640x480)

Edited by AngryRB

Yep, one of the sets you sold to my mate in Newcastle had a lot of problems with fitment, was quite the muck around. This was the stainless 1400cc E85 injectors btw.

(This should not be read as blaming Scotty in any way, we had heard that it would be difficult to fit them and they would just fit under there. Turns out just fits is an understatement on an R33 RB25 plenum)

All I have been going by is the Proflow and Aeroflow website, they both state 3/4 length injectors are to be used as that is what the kit is to suit. If there are any issues with fitment I need to let them know I guess, but unless someone contacts me I can't help. (without getting a plenum and fitting a kit myself.)

If I can get the length of the standoffs to suit the 1/2 length top feeds I can make them on the lathe and include them in the Aeroflow rail kits. It shouldn't be this hard imo, but everything r33 seems to be that little more difficult. :P

So do Xspurt. There are many sizes available in the half height, that isn't the issue. The problem is no-one has a drop in top feed solution for the 33 gtst, you need to muck around with fittings, spacers etc. If I can work it out I will be able to offer a guaranteed to fit solution for those who aren't willing or unable to modify parts to fit.

So do Xspurt. There are many sizes available in the half height, that isn't the issue. The problem is no-one has a drop in top feed solution for the 33 gtst, you need to muck around with fittings, spacers etc. If I can work it out I will be able to offer a guaranteed to fit solution for those who aren't willing or unable to modify parts to fit.

I already said I would send you all the measurements and parts required :)

Patience Scotty lol

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

    • I had 3 counts over the last couple of weeks once where i got stranded at a jdm paint yard booking in some work. 2nd time was moving the car into the drive way for the inspection and the 3rd was during the inspection for the co2 leak test. Fix: 1st, car off for a hour and half disconnected battery 10mins 4th try car started 2nd, 5th try started 3rd, countless time starting disconnected battery dude was under the hood listening to the starting sequence fuel pump ect.   
    • This. As for your options - I suggest remote mounting the Nissan sensor further away on a length of steel tube. That tube to have a loop in it to handle vibration, etc etc. You will need to either put a tee and a bleed fitting near the sensor, or crack the fitting at the sensor to bleed it full of oil when you first set it up, otherwise you won't get the line filled. But this is a small problem. Just needs enough access to get it done.
    • The time is always correct. Only the date is wrong. It currently thinks it is January 19. Tomorrow it will say it is January 20. The date and time are ( should be ! ) retrieved from the GPS navigation system.
    • Buy yourself a set of easy outs. See if they will get a good bite in and unthread it.   Very very lucky the whole sender didn't let go while on the track and cost you a motor!
    • Well GTSBoy, prepare yourself further. I did a track day with 1/2 a day prep on Friday, inpromptu. The good news is that I got home, and didn't drive the car into a wall. Everything seemed mostly okay. The car was even a little faster than it was last time. I also got to get some good datalog data too. I also noticed a tiny bit of knock which was (luckily?) recorded. All I know is the knock sensors got recalibrated.... and are notorious for false knock. So I don't know if they are too sensitive, not sensitive enough... or some other third option. But I reduced timing anyway. It wasn't every pull through the session either. Think along the lines of -1 degree of timing for say, three instances while at the top of 4th in a 20 minute all-hot-lap session. Unfortunately at the end of session 2... I noticed a little oil. I borrowed some jack stands and a jack and took a look under there, but as is often the case, messing around with it kinda half cleaned it up, it was not conclusive where it was coming from. I decided to give it another go and see how it was. The amount of oil was maybe one/two small drops. I did another 20 minute session and car went well, and I was just starting to get into it and not be terrified of driving on track. I pulled over and checked in the pits and saw this: This is where I called it, packed up and went home as I live ~20 min from the track with a VERY VERY CLOSE EYE on Oil Pressure on the way home. The volume wasn't much but you never know. I checked it today when I had my own space/tools/time to find out what was going on, wanted to clean it up, run the car and see if any of the fittings from around the oil filter were causing it. I have like.. 5 fittings there, so I suspected one was (hopefully?) the culprit. It became immediately apparent as soon as I looked around more closely. 795d266d-a034-4b8c-89c9-d83860f5d00a.mp4       This is the R34 GTT oil sender connected via an adapter to an oil cooler block I have installed which runs AN lines to my cooler (and back). There's also an oil temp sensor on top.  Just after that video, I attempted to unthread the sensor to see if it's loose/worn and it disintegrated in my hand. So yes. I am glad I noticed that oil because it would appear that complete and utter catastrophic engine failure was about 1 second of engine runtime away. I did try to drill the fitting out, and only succeeded in drilling the middle hole much larger and now there's a... smooth hole in there with what looks like a damn sleeve still incredibly tight in there. Not really sure how to proceed from here. My options: 1) Find someone who can remove the stuck fitting, and use a steel adapter so it won't fatigue? (Female BSPT for the R34 sender to 1/8NPT male - HARD to find). IF it isn't possible to remove - Buy a new block ($320) and have someone tap a new 1/8NPT in the top of it ($????) and hope the steel adapter works better. 2) Buy a new block and give up on the OEM pressure sender for the dash entirely, and use the supplied 1/8 NPT for the oil temp sender. Having the oil pressure read 0 in the dash with the warning lamp will give me a lot of anxiety driving around. I do have the actual GM sensor/sender working, but it needs OBD2 as a gauge. If I'm datalogging I don't actually have a readout of what the gauge is currently displaying. 3) Other? Find a new location for the OEM sender? Though I don't know of anywhere that will work. I also don't know if a steel adapter is actually functionally smart here. It's clearly leveraged itself through vibration of the motor and snapped in half. This doesn't seem like a setup a smart person would replicate given the weight of the OEM sender. Still pretty happy being lucky for once and seeing this at the absolute last moment before bye bye motor in a big way, even if an adapter is apparently 6 weeks+ delivery and I have no way to free the current stuck/potentially destroyed threads in the current oil block.
×
×
  • Create New...