Quote:
Originally Posted by 328FTW
A guy at our club HAD a RB20DE + T skyline and he needed an adjustable FPR but couldn't afford one so he just beat the stock FPR with a hammer to increase spring tension.........it explodered that same day 
For some reason that post reminded me of that incident |
Yeah, I know of a few people that tried to crush the top down to increase pressure and all but one exploded apart... People seem to think cause you can do it to a metal top BOV (like the stock 1g eclipse BOV's) you can do it to any type of valve that operates the same way... It works, but like the guy that you know of and the few that I've seen, it most likely will explode apart... There's a lot of pressure being dealt with in a FPR.......
Something to add here while we are on the subject of FPR's and FMU's (Raising Rate units). I personally would try playing with injector sizes and tuning with a SAFC or something before using a FMU. I have personally seen FMU's not be consistant in pressure control (i.e. might be increasing at say 8:1 one day and the 6:1 another)... It seems to be a hit or miss thing.... IMHO, not worth popping a motor because of a inferior part....
The other problem with drastically increasing the pressure is as pressure rises, its harder to open the injectors thus requiering more currect flow to open it. This can fry the drive transistors in the ECU..... Again, is it worth it??? Oh, let also add the fact that the more pressure you try to run, the hard you are working the pump. The harder you work the pump, the more likelyhood that it will be short lived.
Remember also that as pressure rises, flow decreases (physic's).
You are always safest with changing injector sizes and running a standard pressure and using electronics to alter fueling where you need to alter it.
I personally dont like piggy-back units either,
but they are far safer then a FMU and trying to up the pressure over standard pressure.
You are not limited to the 315 supra injectors, they are just the easiest to use cause they are plug and play basically.... You can use anything (within reasonable size)... Changing to a low imp. (peak and hold) injector will allow you to go bigger and still maintain good idle quality (with some form of electronic tuning device) as long as you dont go more then about 50% larger then the stock size.
The whole reason for using electronics and bigger injectors is cause by adding the turbo to the 5sfe engine, you are changing the VE of the engine quite a bit in certain areas vs. what the ECU VE tables are tuned for. Plus the use of the turbo MAP is causing the ECU to think the engine is in a different opperating range then what its truely in....
I personally think that using the whole stock 3S-GTE turbo and manifold and MAP along with a SAFC or similar and injectors in the 370cc to 470cc range with stock fuel pressure should allow for getting a very good tune from idle to full boost in all RPM range's... I cant say that it will be a perfect setup but mathmatically, it should be very good.
I'll probably be doing something of this nature to my girls car in the near future so I'll have more input once we get to that point (just got her duece
See link for her and have to put a engine in it)....