S-AFC or Rising Rate Feul Press Riser
July-31st-2003 | 06:24 PM
#1
Guest
Posts: n/a
S-AFC or Rising Rate Feul Press Riser
S-Afc or Rising Rate Feul Press. Riser
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which do you guys prefer ...
The ideal set up would consists of a Turbo (vj20 or 23) with high output injectors ..
car is running on Factory ECU and the engine is a BP-DE ..
Car is also running a High Flow Feul pump
I am just wondering which one you guys would prefer to use ...
Thanks
Bruce
-------------------------
which do you guys prefer ...
The ideal set up would consists of a Turbo (vj20 or 23) with high output injectors ..
car is running on Factory ECU and the engine is a BP-DE ..
Car is also running a High Flow Feul pump
I am just wondering which one you guys would prefer to use ...
Thanks
Bruce
August-1st-2003 | 10:51 AM
#2
Registered User
Joined: Aug 2002
Posts: 118
From: Edmonton, Alberta, Canada
Which factory ECU? LX or GTX?
I have the RRFPR and it works fairly well especially at WOT. Now I have to use the stock LX injectors as the GTX ones run way too rich. Keep in mind I am only producing 7 psi. What I understand is that the RRFPR is really only good for around 8-9 psi. I will be raising my boost at some point and then I'll know for sure if it can keep up.
As for the S-AFC, it does not work at WOT. But instead you can tune your fuel throughout the RPM range which will allow you to run the bigger injectors.
I was thinking of using both.
Probably the best bet is to get the GTX wiring harness and ECU.
just my 2c
I have the RRFPR and it works fairly well especially at WOT. Now I have to use the stock LX injectors as the GTX ones run way too rich. Keep in mind I am only producing 7 psi. What I understand is that the RRFPR is really only good for around 8-9 psi. I will be raising my boost at some point and then I'll know for sure if it can keep up.
As for the S-AFC, it does not work at WOT. But instead you can tune your fuel throughout the RPM range which will allow you to run the bigger injectors.
I was thinking of using both.
Probably the best bet is to get the GTX wiring harness and ECU.
just my 2c
August-1st-2003 | 11:01 AM
#3
Moderator/ Pocket Tuner
Joined: Apr 2002
Posts: 4,150
From: Tampa,Fl
use the FPR..thats what biknman did with his turbo....itll sense the boost and increase fuel pressure...works especially well if your using bigger injectors...most people frown on it with stock injectors but thats what im gonna do with mine..using a vortech FMU
August-1st-2003 | 11:16 AM
#4
Registered User
Joined: Aug 2002
Posts: 118
From: Edmonton, Alberta, Canada
macdaddyslomo
Just curious, but how are you going to control the super rich condition at idle and below WOT with the larger injectors. I'm not questioning the logic, just trying to get other ideas so that I could run the bigger injectors also in a cost efficient manner.
The reason I ask is when I had the GTX injectors installed there was a fair amount of white/black smoke being produced and my spark plugs would turn black just from driving around a bit.
Yes I did check the compression in all four cylinders and its bang on. Oh BTW, its a GTX engine rather then the LX. The compression is lower.
Just curious, but how are you going to control the super rich condition at idle and below WOT with the larger injectors. I'm not questioning the logic, just trying to get other ideas so that I could run the bigger injectors also in a cost efficient manner.
The reason I ask is when I had the GTX injectors installed there was a fair amount of white/black smoke being produced and my spark plugs would turn black just from driving around a bit.
Yes I did check the compression in all four cylinders and its bang on. Oh BTW, its a GTX engine rather then the LX. The compression is lower.
August-1st-2003 | 12:16 PM
#5
Moderator/ Pocket Tuner
Joined: Apr 2002
Posts: 4,150
From: Tampa,Fl
I would say its just a matter of using the right size injectors based on boost you are using...if its a low boost app like 6-8lbs I wouldnt even upgrade the injectors at all, just run the FPR....if its high boost app then the rich conditions at idle will simply have to be tolerated, after all it is an aftermarket turbo on an NA system...not much you can do if you want to avoid detonation...you could go with a cold start injector instead of the fpr and stock injectors....that would avoid a rich mixture as the injector would only spray under boost
August-1st-2003 | 02:43 PM
#6
Guest
Posts: n/a
well I am thinking that I could use a S-afc to control the bigger injectors and then use a Fuel pressure riser or something of the sort that would sense when I am at full throttle and dump more feul in, or a certain amount of extra feul .. I am thinking this may give the best result ..
Or maybe a extra feul pump .. hooked to a relay with a button on the bottom of the gas pedal or somewhere and once the button is depressed it can activate the extra pump, and then flow more feul at WOT..
does that sound crazY?
Or maybe a extra feul pump .. hooked to a relay with a button on the bottom of the gas pedal or somewhere and once the button is depressed it can activate the extra pump, and then flow more feul at WOT..
does that sound crazY?
August-1st-2003 | 02:58 PM
#7
Registered User
Joined: Aug 2002
Posts: 118
From: Edmonton, Alberta, Canada
It sounds reasonable to me. I would love to lower the flow of my GTX injectors at lower RPMs. Its just that my wife will not allow me to put any more money into the car.
As for the second fuel pump, all that will happen is more fuel will be returned to the tank. You need something like the RRFPR to block that return and raise the pressure.
Just as an aside if I was doing the project again I woluld go with a GTX ECU.
Have you priced out and RRFPR and S-AFC?
I bought the RRFPR from Flyin' Miata/Protege for something like $259US and from what I have seen the the S-AFC is in the neighborhood of $300US. Now that comes to a total of $559+shipping and taxes.
I have seen GTX computers on for $500 on this board and in fact received a quote from an auto wrecker in Australia to supply a GTX ECU, complete wiring harness and a knock control unit for $500 Austaralian Dollars. Australian dollars are a little lower then Canadian.
As for the second fuel pump, all that will happen is more fuel will be returned to the tank. You need something like the RRFPR to block that return and raise the pressure.
Just as an aside if I was doing the project again I woluld go with a GTX ECU.
Have you priced out and RRFPR and S-AFC?
I bought the RRFPR from Flyin' Miata/Protege for something like $259US and from what I have seen the the S-AFC is in the neighborhood of $300US. Now that comes to a total of $559+shipping and taxes.
I have seen GTX computers on for $500 on this board and in fact received a quote from an auto wrecker in Australia to supply a GTX ECU, complete wiring harness and a knock control unit for $500 Austaralian Dollars. Australian dollars are a little lower then Canadian.
August-1st-2003 | 03:08 PM
#8
Registered User
Joined: Dec 2001
Posts: 100
From: Charlotte
both will give u the most tuning capability......keep in mind that the FMU (rising rate) works at a FIXED ratio at any given point in the rpm, either ur rich or lean. even with an adj. FMU, u are still only running that ONE ratio under operation. in conjunction with the FMU, the SAFC can help fine tune per rpm range.
August-1st-2003 | 04:42 PM
#9
Guest
Posts: n/a
Originally posted by Mik
It sounds reasonable to me. I would love to lower the flow of my GTX injectors at lower RPMs. Its just that my wife will not allow me to put any more money into the car.
As for the second fuel pump, all that will happen is more fuel will be returned to the tank. You need something like the RRFPR to block that return and raise the pressure.
Just as an aside if I was doing the project again I woluld go with a GTX ECU.
Have you priced out and RRFPR and S-AFC?
I bought the RRFPR from Flyin' Miata/Protege for something like $259US and from what I have seen the the S-AFC is in the neighborhood of $300US. Now that comes to a total of $559+shipping and taxes.
I have seen GTX computers on for $500 on this board and in fact received a quote from an auto wrecker in Australia to supply a GTX ECU, complete wiring harness and a knock control unit for $500 Austaralian Dollars. Australian dollars are a little lower then Canadian.
It sounds reasonable to me. I would love to lower the flow of my GTX injectors at lower RPMs. Its just that my wife will not allow me to put any more money into the car.
As for the second fuel pump, all that will happen is more fuel will be returned to the tank. You need something like the RRFPR to block that return and raise the pressure.
Just as an aside if I was doing the project again I woluld go with a GTX ECU.
Have you priced out and RRFPR and S-AFC?
I bought the RRFPR from Flyin' Miata/Protege for something like $259US and from what I have seen the the S-AFC is in the neighborhood of $300US. Now that comes to a total of $559+shipping and taxes.
I have seen GTX computers on for $500 on this board and in fact received a quote from an auto wrecker in Australia to supply a GTX ECU, complete wiring harness and a knock control unit for $500 Austaralian Dollars. Australian dollars are a little lower then Canadian.
I don't feal like dealing with a harness that is too short. PLus I have a 1995 1.8 BP powered protege ( in my sig) so there are going to be differences .. I really don't think the two are compatible...
August-1st-2003 | 04:49 PM
#10
Guest
Posts: n/a
Originally posted by Rayman
both will give u the most tuning capability......keep in mind that the FMU (rising rate) works at a FIXED ratio at any given point in the rpm, either ur rich or lean. even with an adj. FMU, u are still only running that ONE ratio under operation. in conjunction with the FMU, the SAFC can help fine tune per rpm range.
both will give u the most tuning capability......keep in mind that the FMU (rising rate) works at a FIXED ratio at any given point in the rpm, either ur rich or lean. even with an adj. FMU, u are still only running that ONE ratio under operation. in conjunction with the FMU, the SAFC can help fine tune per rpm range.
what do you think...
A stand alone is really starting to appeal to me right now ... but if I don't need the FMU then I would be ok as I would only be spending about or less than 300 bucks..
Bruce
August-1st-2003 | 11:54 PM
#11
Too Many Cars
Joined: Oct 2001
Posts: 356
From: Danbury, CT
From looking at the other Protege forum, it looks as if the FMUs have overall less then desirable reliability, obviously it is limited to the FMUs included in some of the complete turbo kits as most people aren't starting from scratch building up their own kit with their own choice in components.
Obviously more control over fuel and other variables will ensure you a longer time with your engine, direct control over fuel injectors even at the higher cost I'd say is way better then applying fuel only with a mechanically driven vacuum operated thing-a-majig.
Obviously more control over fuel and other variables will ensure you a longer time with your engine, direct control over fuel injectors even at the higher cost I'd say is way better then applying fuel only with a mechanically driven vacuum operated thing-a-majig.
August-2nd-2003 | 10:52 AM
#13
Registered User
Joined: Dec 2001
Posts: 100
From: Charlotte
Originally posted by tradr
From looking at the other Protege forum, it looks as if the FMUs have overall less then desirable reliability, obviously it is limited to the FMUs included in some of the complete turbo kits as most people aren't starting from scratch building up their own kit with their own choice in components.
Obviously more control over fuel and other variables will ensure you a longer time with your engine, direct control over fuel injectors even at the higher cost I'd say is way better then applying fuel only with a mechanically driven vacuum operated thing-a-majig.
From looking at the other Protege forum, it looks as if the FMUs have overall less then desirable reliability, obviously it is limited to the FMUs included in some of the complete turbo kits as most people aren't starting from scratch building up their own kit with their own choice in components.
Obviously more control over fuel and other variables will ensure you a longer time with your engine, direct control over fuel injectors even at the higher cost I'd say is way better then applying fuel only with a mechanically driven vacuum operated thing-a-majig.
August-3rd-2003 | 02:26 AM
#14
Always Flippin The Game
Joined: Nov 2001
Posts: 558
From: DFW, Texas
Here is what I said on MazdaMP3.com:
Well accually,
OPEN LOOP is where the sensors are ignored (mostly) and predetermined maps are utilized. When this happens (usuallly at WOT around 4500 RPM's) generally the ECU will make the A/F mixture RICH not LEAN. What you speak of above is accually CLOSED LOOP. With closed-loop operations, the A/F mixture is determined mostly by the feeback that various sensors acting together in a "loop." This is where you can run into problems with lean mixtures because the ECU will try to maintain a 14.7:1 A/F ratio for emissions purposes. It will pull back up to 30% of the fuel to achieve this goal EVEN IF you have a RRFPR. That is why most of the turbo kits available for the 3rd gen uses a voltage clamp device on the 1st O2 sensor to keep the ECU from seeing the rich mixture that the RRFPR will provide under partial throttle with boost.
The problem with the s-afc is that in Closed-loop operation, it should work fine, but as soon as you hit WOT/4500 RPM's/OPEN LOOP, it will be useless due to the ECU using its own predetermined maps. I would perfer the s-afc in conjuction if the s-afc would work in OPEN LOOP operation.
Well accually,
OPEN LOOP is where the sensors are ignored (mostly) and predetermined maps are utilized. When this happens (usuallly at WOT around 4500 RPM's) generally the ECU will make the A/F mixture RICH not LEAN. What you speak of above is accually CLOSED LOOP. With closed-loop operations, the A/F mixture is determined mostly by the feeback that various sensors acting together in a "loop." This is where you can run into problems with lean mixtures because the ECU will try to maintain a 14.7:1 A/F ratio for emissions purposes. It will pull back up to 30% of the fuel to achieve this goal EVEN IF you have a RRFPR. That is why most of the turbo kits available for the 3rd gen uses a voltage clamp device on the 1st O2 sensor to keep the ECU from seeing the rich mixture that the RRFPR will provide under partial throttle with boost.
The problem with the s-afc is that in Closed-loop operation, it should work fine, but as soon as you hit WOT/4500 RPM's/OPEN LOOP, it will be useless due to the ECU using its own predetermined maps. I would perfer the s-afc in conjuction if the s-afc would work in OPEN LOOP operation.
August-3rd-2003 | 11:42 AM
#15
Registered User
Joined: Dec 2001
Posts: 100
From: Charlotte
Originally posted by LinuxRacr
Here is what I said on MazdaMP3.com:The problem with the s-afc is that in Closed-loop operation, it should work fine, but as soon as you hit WOT/4500 RPM's/OPEN LOOP, it will be useless due to the ECU using its own predetermined maps. I would perfer the s-afc in conjuction if the s-afc would work in OPEN LOOP operation.
Here is what I said on MazdaMP3.com:The problem with the s-afc is that in Closed-loop operation, it should work fine, but as soon as you hit WOT/4500 RPM's/OPEN LOOP, it will be useless due to the ECU using its own predetermined maps. I would perfer the s-afc in conjuction if the s-afc would work in OPEN LOOP operation.
but yes, thats why i usually tell people that SAFC only works to a certain point before the factory ECU will override its reading and directly go to a predetermined fuel map so the SAFC will become useless after that. that was the case with mine and why i was limited to 7-8psi becuz the FMU/SAFC just couldnt go up anymore, only way to do it is to break into the ECU and remap the fuel