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-   -   pettit unlimited ecu vs power fc (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/pettit-unlimited-ecu-vs-power-fc-29766/)

Marcus 11-02-01 08:49 AM

pettit unlimited ecu vs power fc
 
I AM DEBATING BETWEEN THE PETTIT UNLIMITED ECU AND THE POWER FC. WHAT COMBO IS THE PETTIT UNLIMITED ECU OPTIMALLY TUNED FOR? I'M THINKING CAT-BACK, DP, HI-FLOW CAT, INTAKE, AND IC. DO I NEED 1300 SECONDARIES AND AN UPGRADED FUEL PUMP TO RUN 14-14.5 PNDS. OF BOOST? CAN THE PETTIT ECU HANDLE THIS? THE REASON FOR THE DEBATE IS THE FACT THAT THERE ARE NO POWER FC TUNERS WITH A DYNO NEAR ME AND GETTING IT PREPROGRAMMED KILLS IT'S ADVANTAGES OVER AN ECU UPGRADE. OR AM I WRONG? THANKS FOR THE INPUT.

KZ1 11-02-01 08:56 AM

I wouldn;t run 15 lbs with Pettit unless you have fuel mods. You don;t need a tuner for a PFC, PFC base maps will run great with those mods too. and for only a few extra hundred you can get teh commander and prohgramme it if you want. don't need any gauges, boost control, etc.

PFC, no contest, nevermind the elimination of the 3k hesitation.

gsxr1000 11-02-01 09:03 AM

if you want to run bigger injectors and 14 psi, get the PFC and find a dyno to get it tuned (you can do it!)

if you want to run a full exhaust, IC, and 13 psi, and don't plan any further mods (aside from perhaps a ported engine), get the Pettit (not the unlimited....the unlimited is just a gimmick imo, moves the fuel cut to from 14.7 to 17 and does not increase fuel....how can it when the injectors are already maxed!!)

the Pettit maps are very good for that set-up with no dyno tuning, never heard any compliants...I think the PFC tends to run pretty rich with the base maps....dyno tune is a must

and I disagree that you don't need boost control with a PFC...that is BS

GoodfellaFD3S 11-02-01 09:44 AM


Originally posted by KZ1
I wouldn;t run 15 lbs with Pettit unless you have fuel mods. You don;t need a tuner for a PFC, PFC base maps will run great with those mods too. and for only a few extra hundred you can get teh commander and prohgramme it if you want. don't need any gauges, boost control, etc.

PFC, no contest, nevermind the elimination of the 3k hesitation.

I agree w/---^

and gsxr1000, why is it BS? The power FC controls boost fine...

gsxr1000 11-02-01 10:54 AM

I've heard from a number of people on here that boost control with a PFC is not very accurate....how does it do it? it doesn't control the pressure signal in the pre-control/wastegate actuator line, right? so what does it do? it probably just increases the pre-set rate the wastegate actuator solenoid is opened and closed to decrease boost

j9fd3s 11-02-01 11:03 AM

the pfc controls boost in the same way as the stock ecu, it bleeds off pressure from the wastegate actuators. the pfc is really the way to go, the car runs soo much better with it, even a stock one

mike

XSeLR8nRX7 11-02-01 11:24 AM


Originally posted by gsxr1000
if you want to run bigger injectors and 14 psi, get the PFC and find a dyno to get it tuned (you can do it!)

if you want to run a full exhaust, IC, and 13 psi, and don't plan any further mods (aside from perhaps a ported engine), get the Pettit (not the unlimited....the unlimited is just a gimmick imo, moves the fuel cut to from 14.7 to 17 and does not increase fuel....how can it when the injectors are already maxed!!)

the Pettit maps are very good for that set-up with no dyno tuning, never heard any compliants...I think the PFC tends to run pretty rich with the base maps....dyno tune is a must

and I disagree that you don't need boost control with a PFC...that is BS


i dont think thats Total BS, im currently running a PFS Purple and even that control's boost real well at the low and medium settings. At the low setting it wont let the boost go over 9.5-10psi and at the medium at stays at about 13psi.

If the PFS controls it well, i cant imagine why the power FC wont.

gsxr1000 11-02-01 11:55 AM

j9fd3s,

my point exactly....the PFS controls boost the same way the stock ECU does....it blindly cycles the wastegate actuator solenoid open and closed (read the R.R. site info on how the RX-7 control boost)....the PFC/PFS just changes that rate

there is no way you can tell me I can go out on a 20 degree morning, fourth gear, with very cold air going through the IC, and not get a big, fat boost spike/increase with either the PFC/PFS....I really doubt they can correct for temperature or humidity like that....I don't think the Apexi AVC-R does either, but at least it physically modulates the pressure signal in the wastegate control line

KZ1 11-02-01 12:46 PM


Originally posted by gsxr1000
j9fd3s,

my point exactly....the PFS controls boost the same way the stock ECU does....it blindly cycles the wastegate actuator solenoid open and closed (read the R.R. site info on how the RX-7 control boost)....the PFC/PFS just changes that rate

there is no way you can tell me I can go out on a 20 degree morning, fourth gear, with very cold air going through the IC, and not get a big, fat boost spike/increase with either the PFC/PFS....I really doubt they can correct for temperature or humidity like that....I don't think the Apexi AVC-R does either, but at least it physically modulates the pressure signal in the wastegate control line

The PFC has a setting where it it reaches that boost it will cut it off. I never get above the limit I set for it. Furthermore, Dyno tune is not a must, most people who have PFC do not Dyno tune. I am not saying PEttit ECU is bad, just not as good, and not nearly as felxible. It isn't even a contest. As for boost control, if you are that anal, just slap on same manual boost controlers, what is the big deal.

gsxr1000 11-02-01 01:03 PM

it's not a big deal, but that's not the point

the issue is, does the PFC accurately control boost?

it doesn't...end of story

DELTA_Rotary 11-02-01 01:18 PM

I've heard stories that the PFC doesnt control boost well either. People got an Apex AVC-R to get the job done.

KZ1 11-02-01 03:05 PM


Originally posted by gsxr1000
it's not a big deal, but that's not the point

the issue is, does the PFC accurately control boost?

it doesn't...end of story

Well for me it does, and I have a midpipe as well.

RX7 RAGE 11-02-01 03:37 PM

So the PFC base map is good enough for my mods below right? I don't wanna blow the motor. :)

gsxr1000 11-02-01 04:53 PM

wow, 4" exhaust....that is a mother....I bet that only makes more power than a 3" at extremely high rpm...less at low rpm

if you get a PFC you need a dyno tune with a good wideband O2 meter...I think anyone would agree with this

better yet....go Haltech...more programmability, esp if you are thinking single at some point...the Haltech is only a couple hundred more, and replaces the heat cycled, POS factory wiring harness and worn out sensors (these ARE seven or eight year old cars, remember)...a new stand alone ECU is ony as good as the worn-out sensors, controls, and wiring will allow it to be

the Power FC is still a compromise, even though most everyone on here seems to to think it's better than sex

Tim Benton 11-02-01 08:35 PM

A far as PFC boost control, you are correct, you do have to tune the PFC for boost control when it does ger extremely cold. I just had to with my PFC. With the commander, I wouldn't worry about boost control....you can control it, it just takes a few clicks of the waste gate duty cycle to bring it back down. SO IT DOES indeed control boost just fine. Better than sex, god I hope not:) but both will put a smile on your face.



Tim Benton

gsxr1000 11-02-01 11:02 PM

sounds good, but you still have to keep an eye on the boost gauge and adjust....the other guys made it sound like you just punch in "12 psi" and you're done, no matter what the ambient conditions

still, all in all, this PFC sex toy is staring to sound pretty good, I have to admit

but I think I'm just going to find a tricked out single turbo car with a Haltech :D

let someone else blow their life savings and 100s of hours working on a car...life is too short


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