Hi guys.......i am running .9 bar of boost on my fd3s on stock twins with stock intercooler and intakes and N1 exhaust and Power FC.......i was wondering what are the maximum safest limit of the boost that i could go to.......a friend of mine told me that the rx-7 on stock motor should not be boosted past .9 bar is that true and if not how much more boost can i run and shall i install a downpipe and midpipe? https://www.nopistons.com/forums/pub...1047683358.gif

i would keep it around 12-13psi. I guess 14 would be "safe" but your really pushing it. If you keep it at 12 and you spike you SHOULD be ok. If you run 14 and you spike your motor will def be done.

You shouldnot really exceed 12 psi on the stock fuel. If you add enough fuel via the dataloggit and don't max the pump or injectors you could maybe run up to 15 psi off the stock fuel system. Even then you should at least upgrade the fuel pump. I would not install a mid pipe unless you get it tuned or your asking for a broken engine.

i wouldn't push more than 13 psi on the stock setup even with an aftermarket ECU... the stock fuel system just can't handle it.

thanks guys for your replies. i was planning on installing a walbro 255 fuel pump... and front mount intercooler do u think that will help...and buy stock fuel system u mean the stock fuel pump or even the injectors and do u think after upgrading the fuel pump i can run more boost with the front mount intercooler on the stock twins i actually want to run around 15 psi of boost...at 12.5 psi of boost my a/r remains at 14.1 on the fuel ratio gauge....ur replies in this matter would be highly appriciated.....

[quote name='Stryk3r' date='Apr 23 2005, 03:46 AM']thanks guys for your replies. i was planning on installing a walbro 255 fuel pump... and front mount intercooler do u think that will help...and buy stock fuel system u mean the stock fuel pump or even the injectors and do u think after upgrading the fuel pump i can run more boost with the front mount intercooler on the stock twins i actually want to run around 15 psi of boost...at 12.5 psi of boost my a/r remains at 14.1 on the fuel ratio gauge....ur replies in this matter would be highly appriciated.....


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I ran 15 psi on stock injectors, walbro, purple box. I had it tuned by PFS. It ran that way for a little over a year with no problems whatsoever.

[quote name='Stryk3r' date='Apr 23 2005, 03:46 AM']thanks guys for your replies. i was planning on installing a walbro 255 fuel pump... and front mount intercooler do u think that will help...and buy stock fuel system u mean the stock fuel pump or even the injectors and do u think after upgrading the fuel pump i can run more boost with the front mount intercooler on the stock twins i actually want to run around 15 psi of boost...at 12.5 psi of boost my a/r remains at 14.1 on the fuel ratio gauge....ur replies in this matter would be highly appriciated.....


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14:1 is way too lean under load, it should be more like 11.5-11:1

some one told me that 14:1 is perfect air fuel mixture........is this not true cause i tried runnign my car at 13:1 mixture and the car seemed slow......

[quote name='Stryk3r' date='Apr 23 2005, 11:08 AM']some one told me that 14:1 is perfect air fuel mixture........is this not true cause i tried runnign my car at 13:1 mixture and the car seemed slow......


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perfect for what? 14.7:1 is perfect for emissions, but its way wrong for full load.

14:1 is perfect excuse to buy a new engine soon