Jump to content
SAU Community

Recommended Posts

there is no logical reason a djetro vs ljetro would make more power or response. if anything the afm should offer better response and load points as its measure air volume and not guessing via pressure

My English is not good enough for you. But there is reason L-jetro is much better than D-jetro. D-jetro is pressure measure that means for exsample same pressure tires, one is big truck tire and another is small car tire. Both of them are same pressure but air capacity of the tire is diffrent quantity. There are many logic which one is better and many people, even engineers told about it much. Some people said "Show me show me how do you prive it?" But all logic is so far and coming new always.

dont forget your limited to 2bar boost and under with the d-jetro with the map sensors they use, if u plan on serious power remember this before u spend your cash :rofl:

i dont know of anyone who has modified a 3 bar map sensor to work with the djetro as yet, i do know one shop who has been trying to do it for a long time and im pretty sure they havent worked it out.

go a full standalone ecu like motec, autronics, etc and u will be very happy with the results and they have internal datalogging, and antilag and all the stuff u could possibly ever want.

thats just my 2c

dont forget your limited to 2bar boost and under with the d-jetro with the map sensors they use, if u plan on serious power remember this before u spend your cash :rofl:

i dont know of anyone who has modified a 3 bar map sensor to work with the djetro as yet, i do know one shop who has been trying to do it for a long time and im pretty sure they havent worked it out.

go a full standalone ecu like motec, autronics, etc and u will be very happy with the results and they have internal datalogging, and antilag and all the stuff u could possibly ever want.

thats just my 2c

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

Just my 2c :P

there is no logical reason a djetro vs ljetro would make more power or response. if anything the afm should offer better response and load points as its measure air volume and not guessing via pressure

Charles' law (sometimes called the Law of Charles and Gay-Lussac) is one of the gas laws. It states that at constant pressure, the volume of a given mass of a gas increases or decreases by the same factor as its temperature (in kelvins) increases or decreases.

That is, you're not 'guessing' an air volume if you know it's pressure (measured by MAP sensor) and its temperature.

Regards,

Saliya

I dont see any reason why a gm 5 bar map sensor or 4 bar could not be adapted to work.

You can program 5 differnt including the stock on it comes with.

Just like as if you were using the l jetro with diff afms.

The sensor is just sending an electronic signal which you can interpret to mean anything really.

But as said before an extra grand wont break the bank but when it comes down to it all i need to ignition and fuel. I just dont want to go spend 6 grand on a full motec setup when a pfc "should" work.

just an update, moving to a higher rated map sensor is easy

the rxr7 guys do it quiet often when they crank the boost up

you need datalogit to edit the map scale and offset

two text boxes and its done

Charles' law (sometimes called the Law of Charles and Gay-Lussac) is one of the gas laws. It states that at constant pressure, the volume of a given mass of a gas increases or decreases by the same factor as its temperature (in kelvins) increases or decreases.

That is, you're not 'guessing' an air volume if you know it's pressure (measured by MAP sensor) and its temperature.

Regards,

Saliya

ok but if i have car tyre with air at 30psi and a truck tyre at 30psi

both have same air temp, clearly they both have different are volumes

i cant see anywhere in the datalogit of powerfc to support that it uses the air temp for "load" calculate, the load axis guesstimation is based on map sensor signal and thats about it. it doesnt use the air temp for placement, but more for correction when its really hot (back off timing). i would the map sensor to be temperature aware, but unsure if it would use this value in showing "air pressure" to the ecu

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Apologies for the long post, but needed somewhere to lay out the entire timeline of events and actions taken:   I've got an 89 GTR with a R34 RB in it. It's been running great all year, driven probably 500KM in the last month. It's not my daily driver, just a weekend fun car.    Build info: R34 RB26 - HKS 2.7 stroker kit, HKS adjustable cam gears, HKS turbo upgrades, Trust intercooler, R34 factory DENSO 440cc injectors, JUN chipped/tuned R32 ECU. All of this work was performed in Japan back in 2019.    Thursday 10/2/25 - It's a nice day and decided I'll drive it to work, I start it up in the garage and I notice it took a few extra cranks and sounded a bit funny. I figure maybe it was just because it was a pretty chilly morning. I pull it out into the driveway to warm up a bit before leaving. As I leave the driveway, it feels very off and sounds like a misfire. I pull it back in the garage to deal with after work and take the daily to work. I was able to diagnose it as a cylinder 5 misfire with the old spark plug test (unplugging each plug until a sound change with the engine running). I take off the whole ignition system, ignitor, plugs, spark. *Important note, it is still on the R32 ignition system with the separate ignitor system. I test each system with a multi-meter and nothing presents as a smoking gun. I put it all back together and it starts up no issue. I go ahead and order the PRP R35 ignition conversion kit. It should arrive today (10/13/25)   Friday 10/3/25 - Another nice day, car starts up great and drives great all day. Very pleased that everything seems to be OK   Sunday 10/5/25 - Decided I'll take it to play some golf, load up and drive to the course about 25 minutes away. Drives wonderful the whole way there, I pull in the parking lot and the engine completely comes to a stop. I do not recall if it sputtered at all, but just remember all of the sudden the engine was off. I roll it into a parking spot, try to crank it back on and nothing.  It'll crank and crank and not even try to start. End up getting it towed back to my house and push it up into the garage.    Items I have checked: Fuel in the tank Fuel Pump relay Fuel pump fuse  Spark Plugs & gap Coil packs Ignitor    I know the cylinders are getting fuel as the plugs smell like fuel after a start attempt. I tried spraying starter fluid into the manifold and cranking and not even a sputter.    I decided to do the live CAS test (removing the the CAS, ignition on and spinning the CAS stalk to see if the injectors pulse and spark is active). All of the injectors were pulsing and I have spark at the plug. The half-moon end of the CAS did seem very loose, I'm not sure how much play is supposed to be there, but it was more than I expected. There was no in/out play of the shaft, just the tip end that is pinned on had quite a bit of play.    CAS Play video   When I put the CAS back in, I stupidly did not re-time the engine. I know I need to do that tonight, however, I do not think it will start given it seemingly was not the issue. My plan is to do the PRP R35 coil kit and retime the engine at the same time.    I plan on ordering the Haltech Nexus Plug-in ECU once they are available again, but ideally would like to get this sorted before firing the parts cannon at it and potentially adding more variables.    Anything glaring that I am missing here, I'm a bit at a loss?          
    • Get it on a dyno. Get something logging Consult. Run it up and find out what is causing it.
    • Looking for a plenum for rb25 de+t neo  Not looking to push much power maybe 300kw at the wheels, is there much difference in flow for Freddy “Greddy style” compared to original Greddy or options like Proflow or Otaku garage?    I won’t be porting the de Neo head for now as I think it’ll be fine 280-300rwkw but appreciate the help and any experiences anyone has between them and any advice. Thanks  Looking at this plenum for now below 
    • engine wise almost no mods: stock ecu Greddy front mount intercooler Greddy forward facing intake w R33 TB stock fuel system, stock injectors, rail etc. Kakimoto racing hyper 3 inch exhaust system Apexi intake filter New NGK –R BCPRES (.8 gap) plugs  
    • Nice one @Pac - looks like a fair few 1600's there! 
×
×
  • Create New...