Nismo 555 Vs 740 Injectors? For Ecr33

[KiwiRS4T]

Anyone using bosch top feeds? And what other brand, apart from IDs would you say are the best/smoothest etc ?

So far as i know Ids are Bosch injectors. I am a great believer in getting expert advice and one expert on here is Scotty so just ask him for his suggestions (and then go with them).

[SilverECR33]

I stand corrected - I was not thinking clearly when I posted that, let me clarify my meaning..

the stock reg will handle a stock fuel pump, and stock lines, and small - to medium - sized injectors.

when you change flow rates/volume you will need to calibrate.

Edited September 8, 2015 by SilverECR33

[SilverECR33]

yes your right, ID's are EV14's, but ID do modify them.

[GTSBoy]

I stand corrected - I was not thinking clearly when I posted that, let me clarify my meaning..

the stock reg will handle a stock fuel pump, and stock lines, and small - to medium - sized injectors.

when you change flow rates/volume you will need to calibrate.

Even that's not really true.

The stock reg will handle arbitrarily large injectors. It does not really care how large they are. The limitation on whether the engine will run properly with big injectors is the injectors themselves and the ECU.

The stock reg will handle a very large increase in pump capacity. Many people are running pumps with more than double the stock flow through the stock reg.

The size of the lines doesn't really matter either - the reg doesn't care.

The only time you need a bigger capacity regulator is if you are hitting it with more fuel supply than it can flow back to the tank. The only times you EVER need an adjustable regulator are

a) when you have no ability to tune the ECU and need to trim total fuel supply, or

b) you are at the limits of your injectors and need to squeeze a little more flow.

Other than that, there is not really a need to adjust fuel pressure at all, especially these days.

[scotty nm35]

^^ Totally agree, unless you need more pump flow. I usually lower my base pressures as I always go overboard on injector sizing anyway. Can make it easier to tune large injectors also.

Just remember Dale, the fuel pressure raises by one psi for every psi of boost. If you run 45psi base, and add 35psi boost, your WOT fuel pressure is around 80psi, past the limit of what most pumps want to flow efficiently. Hence I drop my fuel pressure to 35psi, as it's wasn't unusual to see 40 psi boost on the soft limit. If you google a few common pumps and what they flow, most don't like anything much over 70psi, the flow drops right off. For most guys it doesn't matter as their boost level is reasonable.

Most injectors get lazy at high pressure too, taking longer to open, sometimes intermittently due to the pressure pushing on the valve shaft. It would get worse the larger the injector I suspect.

Anyway, the stock Skyline fuel system is well sorted and can bypass enough to run a Walbro 460L pump, which could flow near 600kw on 98 I suspect. The same can't be said for the Evo, every car is different, that's why if you are going to muck around with regs and large pumps you should really be monitoring the fuel pressure on the dyno just to be sure. Ditch the stock fuel filter though, they aren't usually up to the task.

If you want a good injector, the new ID1300's or the Bosch 1650's would be the pick, twice the price of a set of modified 1000's though. All are long term ethanol safe, unlike the 2000cc gas injectors.

[Dose Pipe Sutututu]

Stock reg might get silly if you're running twin pumps into it as there's huge amounts of fuel flowing through it.

Even so, I've seen GTRs running the stock reg with twin Bosch pumps going to it without issue

[SilverECR33]

gtsboy your clarification was not correct. flow is important, line size and pumps are also important, ecu and trim cannot fix baseline, the stock reg is not adjustable , and as scotty as rightly also pointed out, boost compensation needs to be taken into account also.

thanks scotty, I remember now. busy life, busy mind.

I was sure the op was doing some upgrades? I didn't realize we were trying to run stock power with large injectors.

but sure GTSboy the stock reg will work great.

[SilverECR33]

maybe I have a little trouble putting my thoughts into text, maybe ill leave the keyboard mechanics to the professionals

Edited September 8, 2015 by SilverECR33

[GTSBoy]

I think my clarification WAS correct. None of the things that I said don't matter require you to replace the reg, nor be able to adjust the fuel pressure as a result of making changes to them.

[Dose Pipe Sutututu]

I'm not sure you understand how a fuel regulator works or that you're having a hard time articulating what you mean lol

[ausdrift]

I ended up going the 740 Nismo to keep it stock looking (which it does very well). Chequered Tuning did the tune and so far Im very happy with it. Drives better than before around town and manages the power well too. No problems

[R31Nismoid]

^^ Totally agree, unless you need more pump flow. I usually lower my base pressures as I always go overboard on injector sizing anyway. Can make it easier to tune large injectors also.

Just remember Dale, the fuel pressure raises by one psi for every psi of boost. If you run 45psi base, and add 35psi boost, your WOT fuel pressure is around 80psi, past the limit of what most pumps want to flow efficiently. Hence I drop my fuel pressure to 35psi, as it's wasn't unusual to see 40 psi boost on the soft limit. If you google a few common pumps and what they flow, most don't like anything much over 70psi, the flow drops right off. For most guys it doesn't matter as their boost level is reasonable.

Most injectors get lazy at high pressure too, taking longer to open, sometimes intermittently due to the pressure pushing on the valve shaft. It would get worse the larger the injector I suspect.

Anyway, the stock Skyline fuel system is well sorted and can bypass enough to run a Walbro 460L pump, which could flow near 600kw on 98 I suspect. The same can't be said for the Evo, every car is different, that's why if you are going to muck around with regs and large pumps you should really be monitoring the fuel pressure on the dyno just to be sure. Ditch the stock fuel filter though, they aren't usually up to the task.

If you want a good injector, the new ID1300's or the Bosch 1650's would be the pick, twice the price of a set of modified 1000's though. All are long term ethanol safe, unlike the 2000cc gas injectors.

Sooooo much this.

When the Walbro's came out (the 260lph ones) everyone was jumping up and down about how good they were vs the Bosch (and cheaper).

Yet once you were running ~16psi+ on a RB you suddenly ran out of fuel because the 260lph flow rate was calculated at 35psi or similar. Where the Bosch was rated at something like 70psi for it's flow. The 260s were only good for low boost/N/A applications as a result (for the most part).

[-S-]

Are top feed more superior than side feed injectors? Reading this thread has made me regret a few purchases. .. especially when reading the word "outdated"

[GTSBoy]

Are top feed more superior than side feed injectors? Reading this thread has made me regret a few purchases. .. especially when reading the word "outdated"

Not inherently. Go back to the early 1990s. RB20s had top feed injectors. The RB25 changed to side feed injectors. The underlying technology in both was approximately the same.

Fast forward to now. Any side feed injector you buy now will be based on the same old (OLD!) designs that were in use in the early 90s. Meanwhile all the new Bosch (and others, like Siemens, etc) injectors are top feed. The newer designs are far superior to the old ones (regardless of whether the old ones were top or side feed). So consequently, yes, top feeds are superior to side feeds, if the top feeds you are comparing are modern.

[4zfed25]

Im run id1000 top feeds on a stock 25 block with all the bolt ons and it starts, idles and drives like a stock 25. And at $640 nz o can't complain and I'll never max them on in this motors life time

[kingtube69]

I have the Nismo 740cc in mine, bought them second had with <2000kms on them had them cleaned and tested. Idles pretty bad when the car is warm (splutters etc). My tuner said it's the injectors. If I were to do it all again, I would go top feed rail and injectors.

[boostn0199]

I have the Nismo 740cc in mine, bought them second had with <2000kms on them had them cleaned and tested. Idles pretty bad when the car is warm (splutters etc). My tuner said it's the injectors. If I were to do it all again, I would go top feed rail and injectors.

Nismos run and idle perfectly, either their not clean or tuner hasn't done a good job if cant get nismos to idle well.

[Dose Pipe Sutututu]

I have the Nismo 740cc in mine, bought them second had with <2000kms on them had them cleaned and tested. Idles pretty bad when the car is warm (splutters etc). My tuner said it's the injectors. If I were to do it all again, I would go top feed rail and injectors.

idle them a little richer, will idle silky smooth OR just go to E85 as you need more fuel on idle so they atomise properly lol

[kingtube69]

idle them a little richer, will idle silky smooth OR just go to E85 as you need more fuel on idle so they atomise properly lol

I'll PM you