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-   -   max boost on stock fuel managment? (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/max-boost-stock-fuel-managment-84758/)

violator 06-01-02 11:03 PM

max boost on stock fuel managment?
 
using a pettit unlimited ecu. my boost is creeping to 0.9km/cm2 at 5k all the way to redline on the secondary turbo only. i only get around 0.7bar on the primary turbo. i think 0.9bar is alittle high because i thinks its around 13+psi. is this safe?

one more thing. what is 1.0 kg/cm2 equal too? im seen 1.0=14.7psi, 1.0=14.2psi, 1.0=14.55.
and i dont know which one it is.

luneytune 06-01-02 11:30 PM

1 Bar = 14.7psi or 1 atmosphere.

As far as max boost, without an A/F guage you can't see if your leaning out or your secondary injectors are maxed out. The unlimited ECU can only control what it has to work with. If you have a stock IC your intake temp could reach a high enough temp at 12 psi to induce detonation. With everything stock except the ecu I would limit myself to 12. IMHO:)

neevosh 06-02-02 01:42 AM

1 kg/cm2 is about 14.22. So 0.9 would be about 12.8 psi. I've heard that 12 psi is the most that should be run with the stock IC. Not sure if that's true though.

violator 06-02-02 06:41 AM

im not using stock intercooler. i have apexi gt FMIC, mp/dp, cb, intake, and a streetported motor.

what does "1 Bar = 14.7psi or 1 atmosphere" mean? so does 1.0km/cm2 equal to 14.7psi or 14.22psi?
:confused: :confused:

Mahjik 06-02-02 09:35 AM

1 Bar = 14.5 PSI


Originally posted by Evil Aviator

OK, just for that you get the boring explanation:

The International Standard Atmosphere (ISA) for dry air at sea level is as follows:
Pressure = 29.92 " Hg = 14.7 PSI = 1013.25 millibars
Temperature = 15 C = 59 F
http://www.booty.demon.co.uk/metinfo/isa.htm

This is where the magic 14.7 PSI number comes from. The ambient pressure will vary with elevation, temperature, humidity, and with high and low pressure areas like you see on the news, but 14.7 PSI is the standard reference point.

A "bar" unit of pressure is not derived from ISA pressure, but rather derived from the quantity of 1,000,000 dynes per square centimeter in the CGS system. You may have noticed that ISA pressure is 1013.25 millibars. This equates to 1.01325 bars. If you compare 14.7 psi with 1.01325 bars, you will find a 14.5 : 1 ratio, which is therefore your conversion factor. This conversion factor is a constant.

Now somebody please tell this to Corky Bell so that he can fix the next edition of his otherwise excellent turbocharger book. Oh yeah, and please also let him know that the speed of sound is not a constant.

https://www.rx7club.com/forum/showth...threadid=33293

nmo93 06-02-02 09:35 AM

i hope this will finally help you out. 1 kg/cm^2 = 14.2 psi. 1 bar = 14.5 psi = .987 atmospheres. bar and atmospheres (or atm) is just another unit of pressure. use this link to figure out any pressure conversions you need, it's really good.

http://www.ex.ac.uk/cimt/dictunit/ccpress.htm

nick

violator 06-03-02 01:49 AM

thanks guys i was scaried that i was running too much boost. im running 0.9 kg/cm^2 so its at about 12.8psi; which is ok i think isnt it?

im at sea level does that make a difference?

Street King 06-03-02 02:17 AM

Violator youll be fine. Anything over 14 psi Id be worried about injector duty cycle.

forcefed1 06-03-02 06:38 AM

I don't know about your maps. but with my stock fuel system at 12 PSI using a PFC, I see high duty cycles (96%) and 10.2AFR on the wideband from 6-8K . since I have a good margin to lean things out. I would say your stock fuel system should be safe even up to 13-14 psi. depending on what you call safe. I would make sure you have a new filter in there though.

3rdGen7 06-03-02 07:24 AM

Using a converter

1 kg/cm2 = 14.22334 psi

.7 kg/cm2= 9.95634 psi
.9 kg/cm2= 12.80101 psi

violator 06-04-02 01:40 AM

yea i just changed my fuel filter. seems like at night my boost climbs too 0.9-0.95 km/cm^2. prob cuz its colder at night. not gonna WOT it ne more untill i get my boost controller and see what it does to my boost.


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