Factory ECU limitations
#1
Full Member
Thread Starter
Factory ECU limitations
I have spent hours searching and reading through the forum as well as other sites and it seems there is so much back and forth on many subjects. I just got my first FD and am wanting to update some components. It is a 1992 Japanese imported FD.
so far the parts I have gotten are
Koyo Nflo radiator
Pettit racing silicone radiator hoses
New thermostat
new fuel filter
new plugs and wires
vinny fab swirl pot thermostat housing / ast delete
ARC race spec SMIC
fc thermo switch
banzai light weight pulley kit.
Im also wanting to do an intake probably auto exe (if I can find one for a decent price)
I have a boost controller and gauges on the way as well.
I have read on some post that even a larger SMIC can causing lean running engine issues especially mixed with an intake. I am a career automotive technician and am not new to modifying cars. I do understand that opening any intake system to allow better flow and more air will change air fuel ratios, but most cars its not enough of a change to matter. I am however knew to rotaries and from what Im reading they seem much more susceptible to these changes and I am just wanting to make sure I dont cause pre detonation as Id like to enjoy the car for as long as possible.
So Im just trying to figure out what all I can install without problems or if I should just save up and pick up a power FC and then install everything.
.
so far the parts I have gotten are
Koyo Nflo radiator
Pettit racing silicone radiator hoses
New thermostat
new fuel filter
new plugs and wires
vinny fab swirl pot thermostat housing / ast delete
ARC race spec SMIC
fc thermo switch
banzai light weight pulley kit.
Im also wanting to do an intake probably auto exe (if I can find one for a decent price)
I have a boost controller and gauges on the way as well.
I have read on some post that even a larger SMIC can causing lean running engine issues especially mixed with an intake. I am a career automotive technician and am not new to modifying cars. I do understand that opening any intake system to allow better flow and more air will change air fuel ratios, but most cars its not enough of a change to matter. I am however knew to rotaries and from what Im reading they seem much more susceptible to these changes and I am just wanting to make sure I dont cause pre detonation as Id like to enjoy the car for as long as possible.
So Im just trying to figure out what all I can install without problems or if I should just save up and pick up a power FC and then install everything.
.
Last edited by Kaizenru3; 03-09-23 at 07:01 AM.
The following 2 users liked this post by Banzai-Racing:
DaleClark (03-09-23),
Molotovman (03-09-23)
#3
Full Member
Thread Starter
great read and definitely answered my questions! Thank you so much. Ive actually been needing to call yall to get scheduled for some work. Youre just a couple hours north of me.
#4
RX-7 Bad Ass
iTrader: (55)
^That thread is a gold standard for modding an FD for sure.
That intercooler is pretty conservative really, I don't see that causing any problems.
With the stock ECU if you can keep boost at 10psi you can do most anything you want. Having a boost controller to bypass the factory boost control is key here.
An upgraded fuel pump like the Walbro 255 is an excellent and easy/cheap thing to add fuel, the stock pump just isn't adequate.
Dale
That intercooler is pretty conservative really, I don't see that causing any problems.
With the stock ECU if you can keep boost at 10psi you can do most anything you want. Having a boost controller to bypass the factory boost control is key here.
An upgraded fuel pump like the Walbro 255 is an excellent and easy/cheap thing to add fuel, the stock pump just isn't adequate.
Dale
#5
Full Member
Thread Starter
^That thread is a gold standard for modding an FD for sure.
That intercooler is pretty conservative really, I don't see that causing any problems.
With the stock ECU if you can keep boost at 10psi you can do most anything you want. Having a boost controller to bypass the factory boost control is key here.
An upgraded fuel pump like the Walbro 255 is an excellent and easy/cheap thing to add fuel, the stock pump just isn't adequate.
Dale
That intercooler is pretty conservative really, I don't see that causing any problems.
With the stock ECU if you can keep boost at 10psi you can do most anything you want. Having a boost controller to bypass the factory boost control is key here.
An upgraded fuel pump like the Walbro 255 is an excellent and easy/cheap thing to add fuel, the stock pump just isn't adequate.
Dale
#6
Rotary Enthusiast
iTrader: (32)
I have run many A/F measurements on my FD with the original ECU, JDM OE downpipe, Blitz SMIC, catback + OE main cat, and with and without a modified intake and the A/F's were never leaner than 10.4-10.6 when in boost at any level (using the OE boost control system). So your mods should be fine.
One caveat, you should verify that you have good voltage at the fuel pump and possibly consider the Walbro 255 upgrade. I totally went through the electrical supply to the fuel pump on my car and also replaced the fuel pump with a new OE pump (which is a Denso) just to make sure that fuel delivery would be reliable. I'm not sure if this changed the A/F's at all however, it was more of a reliability exercise. https://www.rx7club.com/3rd-generati...-pump-1119325/
Since you have a JDM FD, probably you need 93 octane fuel as I think these were calibrated for Japanese premium which is 100 RON. I just installed a JDM ROM-tune in my car and now I'm using octane booster since what they call premium in California is only 91 AKI.
One caveat, you should verify that you have good voltage at the fuel pump and possibly consider the Walbro 255 upgrade. I totally went through the electrical supply to the fuel pump on my car and also replaced the fuel pump with a new OE pump (which is a Denso) just to make sure that fuel delivery would be reliable. I'm not sure if this changed the A/F's at all however, it was more of a reliability exercise. https://www.rx7club.com/3rd-generati...-pump-1119325/
Since you have a JDM FD, probably you need 93 octane fuel as I think these were calibrated for Japanese premium which is 100 RON. I just installed a JDM ROM-tune in my car and now I'm using octane booster since what they call premium in California is only 91 AKI.
Last edited by jza80; 03-09-23 at 12:18 PM.
The following users liked this post:
c0rbin9 (03-09-23)
#7
Full Member
Thread Starter
I have run many A/F measurements on my FD with the original ECU, JDM OE downpipe, Blitz SMIC, catback + OE main cat, and with and without a modified intake and the A/F's were never leaner than 10.4-10.6 when in boost at any level (using the OE boost control system). So your mods should be fine.
One caveat, you should verify that you have good voltage at the fuel pump and possibly consider the Walbro 255 upgrade. I totally went through the electrical supply to the fuel pump on my car and also replaced the fuel pump with a new OE pump (which is a Denso) just to make sure that fuel delivery would be reliable. I'm not sure if this changed the A/F's at all however, it was more of a reliability exercise. https://www.rx7club.com/3rd-generati...-pump-1119325/
Since you have a JDM FD, probably you need 93 octane fuel as I think these were calibrated for Japanese premium which is 100 RON. I just installed a JDM ROM-tune in my car and now I'm using octane booster since what they call premium in California is only 91 AKI.
One caveat, you should verify that you have good voltage at the fuel pump and possibly consider the Walbro 255 upgrade. I totally went through the electrical supply to the fuel pump on my car and also replaced the fuel pump with a new OE pump (which is a Denso) just to make sure that fuel delivery would be reliable. I'm not sure if this changed the A/F's at all however, it was more of a reliability exercise. https://www.rx7club.com/3rd-generati...-pump-1119325/
Since you have a JDM FD, probably you need 93 octane fuel as I think these were calibrated for Japanese premium which is 100 RON. I just installed a JDM ROM-tune in my car and now I'm using octane booster since what they call premium in California is only 91 AKI.
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#8
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here is a typical tuning menu from Japan, RX-7,RX-8ΘΗREΤπSΙ[X©ηtB[hobN΅½mEnEπΰΖΙ΅½`
[jOvVbv ²‘€ο
pretty close to Banzai's recipe.
pretty close to Banzai's recipe.
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