Gtr Injectors?

[DRFT 14]

What is the max power (rwkw) capacity of the GTR injectors? They are 440cc. My aim is 250rwkw. Can they flow this? If not, will a fuel pressure regulator help achieve this number? Do I need a FPR if im running a LinkPlus computer, or can aftermarket computers not alter the fuel pressure of injectors?

The next part of my question is regarding fitment to a NEO RB25DET. They are top feed so im guessing there is no problem getting these working? Will my LinkPlus handle the impededence issues?

Many Thanks

[paulr33]

nismo sell direct fit 480cc injectors for the neo rb25det.

the 480cc's are fine for 250rwkw. bass junky is making just over 250 with the nismo 480cc's. what a look what bass junky is runnig, not sure if he has an fpr or not, cant hurt to have one i guess

[N I B]

Stock GTR injectors will handle 250kw.

[DRFT 14]

The Nismo ones are abit out of the question since ive already bought the GTR injectors. Anyhow, i picked up the RB26 injectors for $250. Id have to fork out almost $1000 for a name brand product for an extra 40cc's in the Nismo case. This mkaes the GTR injectors an extra alternative in my opinion. But thanks for the heads up on the Nismo's

And N I B, thanks for the conformation. Can you tell me if a FPR is required to achieve that number or are 440cc injectors all you need for 250rwkw?

[rob82]

You can make about 250 260rwkw on a GTR with standard FPR.

[rob82]

and standard injectors

[DRFT 14]

Excellent Im glad I got that out of the way before getting the car to the dyno, saves having to upgrade later and spend more money tuning the setup twice.

Can anyone add anything in regards to fitment on a NEO RB25DET? Is it streight forward?

[TTT]

how do you go about fitting RB26 injectors to an RB25?

[SLIPPERY]

does the neo still use side feed injectors like the R33 rb25?

if so, good luck putting them in since the GTR injectors are top feed.

[Sydneykid]

If this thread seems a bit harsh, sorry I appologise in advance, but really.............................

If you had done a search you would have found out that RB26DETT injectors are 444 cc's which is enough for 444 bhp. While doing that search you would have also found out that to convert bhp to kw you divide by 1.34 (ie 444 bhp / 1.34 = 331 kw). That same search would have told you that a 2wd R33/34 looses about 60 kw through the drive train (ie; 331 - 60 = 271 rwkw).

A different search would have revealed that RB25DETNeo injectors are top feed but a completely different shape to RB26DETT top feed injectors. In fact that search would have revealed this picture which clearly shows the differences

The injector on the left is top feed for an R34GTT RB25DET Neo

The injector in the middle is side feed for an R33GTST RB25DET

The injector on the right is top feed for an R32GTST RB20DET or R32 GTR RB26DETT.

If you had taken 15 seconds to do a search you would have found out why people have to buy Nismo or other brand name injectors for their R34GTT. Perhaps they were smart enough to do a search before they spent money on something that won't fit.

cheers

PS; did I mention that you should have done search first, rather than start a brand new thread on a subject that has been covered hundreds of time.

Edited February 2, 2006 by Sydneykid

[DRFT 14]

Cheers for the information, much appreciated. But in my defence, I did a search and even asked on someone else's thread in regards to fitment of GTR injectors on the NEO and didnt get a reply. I was under the impression from the information I got from my searches that the fuss with "NEO only" injectors was related to the fact that the NEO is the only top feed 2.5 litre RB, not because they had a unique design. But thanks Sydneykid for the information, you'r always helpful.

I bought the injectors for $250 but they regularly get sold for $350-$400 here in NZ so i havnt really lost anything. I do now realize that im going to have to fork out if I want to ugrade injectors properly.

Im just going to get a FPR and go for 240rwkw. 370 cc = 370 bhp. Increasing pressure to 410cc will give 410hp or 246rwkw. Am I correct in my calculations? And will increasing the injectors to this capacity still be safe?

[PHaT MR30]

i think some people just need to be educated on how to properly use the search function....

and thats no way directed at you DRFT 14

[Sydneykid]

Cheers for the information, much appreciated. But in my defence, I did a search and even asked on someone else's thread in regards to fitment of GTR injectors on the NEO and didnt get a reply. I was under the impression from the information I got from my searches that the fuss with "NEO only" injectors was related to the fact that the NEO is the only top feed 2.5 litre RB, not because they had a unique design. But thanks Sydneykid for the information, you'r always helpful.

I bought the injectors for $250 but they regularly get sold for $350-$400 here in NZ so i havnt really lost anything. I do now realize that im going to have to fork out if I want  to ugrade injectors properly.

Im just going to get a FPR and go for 240rwkw. 370 cc = 370 bhp. Increasing pressure to 410cc will give 410hp or 246rwkw. Am I correct in my calculations? And will increasing the injectors to this capacity still be safe?

<{POST_SNAPBACK}>

I enjoy this forum more than any other, I pick up all sorts of tips and I am happy that I can hand out a few of my own. But the thing that peees me off is people who think they are the FIRST person with a Skyline to have this problem or to find something right or something wrong. There are so many smart people on SAU that there is a 99.99999% chance that someone will have encountered the problem, found a solution and published it. Anyone who wants to know something should do a proper search first, rather than jump in and start a brand new thread on something that has been done to death. The search may well indicate that resurrecting the old thread is the best way, that gives a thread life and makes it an even more valuable source of information.

Starting a new thread means the experienced guys may well pass it over (been there done that), and the only people who respond are new (relatively) inexperienced guys that perpetuate the errors. This thread is a prime example of that, there would be 1,000+ people on this forum who know that upgrading Neo injectors is only accomplished by purchasing aftermarket (relatively expensive) injectors.

Back to the subject at hand…………

Attempting to increase fuel flow by increasing fuel pressure is not all that straight forward. Firstly the laws of fluid dynamics are such that a 10% increase in fuel pressure does not result in a 10% increase in fuel flow. It is much less than that, more like a 35% increase in fuel pressure for a 10% increase in flow. This puts a lot of strain on the fuel pump, which needs to be specified for the base pressure plus boost ie; Bosch fuel pumps are rated at 73.5 psi, so you can run 50 psi fuel pressure and still have 23.5 psi left for boost. Standard fuel pressure is 36-38 psi, so a 35% increase is 50 psi. Based on past experiences that is enough to increase the flow from 370 cc’s to around 400 cc’s (400 bhp or around 235 rwkw).

The second problem is the fuel hoses and clamps, what is a good solution for 36-38 psi may well be overpowered by 50 psi. Particularly as age and wear affect the rubber and clamps. My usual suggestion would be to replace all of the fuel hoses under pressure with nice new hose and upgrade the clamps. I would go so far as to suggest 2 clamps per joint. Under bonnet fuel fires are not pretty.

Hope that helps

Cheers

PS; as search would have found all of that info out as well.