Rb25det+deceleration=backfire+pop+burble

[**RB2530**]

So like, you've got a RB30det using a standard rb25det ecu and standard rb25det afm?? or have you changed the afm to a z32?

Either way, sounds like you've got either a remapped ecu or an absolutely unheard of freak of nissan nature ecu.

I've never heard of a standard rb25 ecu being able to comfortably handle such mods as a rb30det conversion, bigger turbo, injectors and afm.

If its true that its a standard ecu and its making that kind of power, then your yet to find out the benefits of tuning.

i can disprove his theory my gtr leaned out with bigger turbos and free flowing exhaust and intake , on standard, afms, it was hitting close to 13.3 on boost. pfc all better, no other mods, nissan ecu suck unless they are remmaped, or different eprom is installed,

my 2 cents from my experience first hand,

This is getting so f**king tiring!! It is not a theory...It is fact and a f**king 1st hand experience as well as being based on research and testing I have done. ...My experience is with GTST ECU and not GTR...What you did with your GTR who knows...maybe you had an air leak just after the afms somewhere or one of your afms was buggered...who knows???

I have proven to myself (and a couple of others on this forum who have driven my car) what the stock ECU can do..from now on I will keep it to myself...your loss!!

[Cubes]

Im curious as to how partial boost afr's are. Not just WOT dyno afr's.

For 277rwkw the std afm will be maxing out so from the point of maxing out it may be metering enough air for say 220rwkw yet it has to push in enough fuel for 277rwkw. It will have to go pig rich at some point and then clear up.

Im curious if seat of the pants its noticeable.

[Cubes]

with regards to fuel and shit.

--

With gtr injectors (flowed 480cc at 40psi) and an 044 pump mine were approaching 100% duty over 250rwkw to hold a 12:1afr.

They required a little more fuel pressure to get to 285rwkw at 17psi with a safe duty cycle.

Im not sure about that equation you state.

My own rb30det and another both running stock injectors cracked 180rwkw before afr's crept skywards of 12:1.

Another rb20det running std injectors saw exactly the same inj. duty/afr/power level before fueling became a problem.

A friend on the same dyno with an rb30det with gtr injectors is also saq very similar injector duty cycles/afr's at the same power levels on std rail pressure. Both of us have had to push rail pressure up once over 250rwkw.

And another rb30det gt35r running std exh. manifold, plenum 18psi and making 312rwkw was seeing ~80-85% duty on his 550cc injectors.

Now.. take the above in to consideration.. 312rwkw ~85% duty. 375cc injectors are ~68% of the size.

68% of 312rwkw is 212rwkw with 375cc injectors at ~85% duty. Which is what we also roughly see from stocker rb25's.

The GTST runs around 36psi base.

So.. all that crap said. You are obviously running higher than std fuel pressure and the good old fudge trick of a fuel/ign controller to get around r&r, lack of fueling and too much timing due to bending the airflow volts.

If not Im curious as to how. No doubt youve made a post else where that Ive obviously missed.

[**RB2530**]

Im curious as to how partial boost afr's are. Not just WOT dyno afr's.

For 277rwkw the std afm will be maxing out so from the point of maxing out it may be metering enough air for say 220rwkw yet it has to push in enough fuel for 277rwkw. It will have to go pig rich at some point and then clear up.

Im curious if seat of the pants its noticeable.

AFM is maxing out at 6000rpm... see charts below plus dyno charts. these are reposts.. we only did three WOT runs...note that I had ignition issues due to 1.0mm gap. didn't have time to regap..I have no idea what the partial afrs are...I monitor EGTs full time using a fast acting thermocouple fitted in the exhaust manifold so i am not concerned about lean afrs

I run standard base fuel pressure but use a non stock fp regulator...type and brand is my secret for the moment...

Power_and_AFR.pdf

Power_and_boost.pdf

data_scan_277rwkW_run.pdf

[**RB2530**]

with regards to fuel and shit.

--

So.. all that crap said. You are obviously running higher than std fuel pressure and the good old fudge trick of a fuel/ign controller to get around r&r, lack of fueling and too much timing due to bending the airflow volts.

If not Im curious as to how. No doubt youve made a post else where that Ive obviously missed.

Please have a read of some of my posts..It is all in there...The only fudge iwith the ignition is increasing base timing by a fair bit...very effective CAI and high flowing exhaust allows heaps of ig advance which all rb engines respond very well to...You adjust idle rpm so that stock ECU runs idle at 5deg tdc adn not 15deg...Therefore you can run additional 10deg advance without affecting idle quality...