Super AFC How to get a s-afc to adjust for boost pressure, info inside.
12-19-04, 01:41 AM
#76
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Originally Posted by gsracer
8 pounds is about the limit of what I would trust the primaries to handle before the secondaries come online as well. If I set the limit to 8 pounds and I boost more than that before the secondaries come online, I can add start adding fuel under 3800 rpm. As it stands, I don't know how much more fuel I can add before I max out the injectors but I'll find that out soon once I can get the car on a dyno.
I've had the car on a dyno running 10.5 pounds on the stock ecu. I have a pair of 720's sitting on my desk at home that should be going in soon. Hopefully over the christmas break I'll get the chance to get those in and take it to the dyno. I'm gonig to shoot for 240 rwhp@12 pounds; I'll probably retard overall timing 2-3 degrees just to play it safe. I'd be scared to push the stock IC too much over 12 pounds as it is. I'll post my safc settings and dyno no matter what goes on once it happens.
this might be a bunch of useless info but...
i don't have a clue as to where they max out at , but when i hit 22psi at around 3500rpms, i get a lean sputter. i know, duh, i was just thinking that information might lead to something. it just so happens that when all the injectors are running, i get the lean sputter at 6500 at 20psi. and i don't want to hear any BS claims, i was just hoping someone could use this information to come up anything relative to when the stock injectors reach 100% DC.
intake and exhaust with streetport, stock turbo, stock TMIC.
and i'm fascinated at the information you all are providing, because i've been in need of an SAFC for quite a while. i've been running 850sec. for a while and i have to run between 17 and 20psi to burn enough of that fuel to run decent. it's good enough for 13.4's but it's not right.
12-19-04, 07:35 PM
#77
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i just switched from tps to boost sensor and went for a test drive. at 10 psi (aftermarket gauge), Thr % read 66%.
seems like if the range is -15psi to +15psi, then 10 psi should be 83% (25/30).
66% at 10psi would make sense if the range was 0-15psi, but i was getting values in vacuum too. I'll have to take someone with me and we'll make a graph of values. then i'll post it up.
in any case, it sure beats 100% with the pedal 1/3 of the way down!
seems like if the range is -15psi to +15psi, then 10 psi should be 83% (25/30).
66% at 10psi would make sense if the range was 0-15psi, but i was getting values in vacuum too. I'll have to take someone with me and we'll make a graph of values. then i'll post it up.
in any case, it sure beats 100% with the pedal 1/3 of the way down!
Last edited by drewl; 12-19-04 at 07:50 PM.
12-20-04, 03:02 AM
#78
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as promised, i made a graph
http://guernsey.globat.com/~mountain...ic/booster.jpg
http://guernsey.globat.com/~mountain...ic/booster.jpg
12-20-04, 01:42 PM
#79
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I just converted mine this weekend.
I put a SPDT switch in the S-AFC's THR input wire so I can toggle from TPS to pressure sensor.
I set it on throttle & initialized the S-AFC, power off/on, did some throttle sweeps, and switched to pressure.
Power on zero pressure shows 43% (THR).
To start off I set low throttle to 45% & high throttle to 75%.
I may go 80-85% on the high THR when the 720 injectors are in.
So far it works great!
At 20% throttle I'm in the low map.
At 30% in today's cold air the boost shoots up & the S-AFC goes right in to the high map.
I put a SPDT switch in the S-AFC's THR input wire so I can toggle from TPS to pressure sensor.
I set it on throttle & initialized the S-AFC, power off/on, did some throttle sweeps, and switched to pressure.
Power on zero pressure shows 43% (THR).
To start off I set low throttle to 45% & high throttle to 75%.
I may go 80-85% on the high THR when the 720 injectors are in.
So far it works great!
At 20% throttle I'm in the low map.
At 30% in today's cold air the boost shoots up & the S-AFC goes right in to the high map.
Last edited by SureShot; 12-20-04 at 01:49 PM.
12-21-04, 12:24 PM
#81
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Originally Posted by fstrnyou
i was thiinking about air temps on the way home from work today, when the safc is doing what it does, is the ECU still adjusting for the air temps?
We're just playing with the air flow.
01-01-05, 07:18 PM
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after reading this thread many times ive decided to tap the S-afc throttle signal to the ECU pressure sensor . since i have the capret out should be easier than runnin another wire thru the dam firewall. will let you all know how it goes .
01-05-05, 07:31 PM
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quick question, when doing this do you need that motorolla thing that they were talking about at the start of this thread(if so how much is it) or can ya just straight wire into it? and if someone could also point out where i have to tap into, and what color wire that would be great, 87TII (racing beat FCD, if it matters).. thx.
03-02-06, 01:43 PM
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I'm ready to wire the TPS wire on the SAFC to my boost sensor.
My car is an S5. (TPS hookup's not that great, even on S5.)
I have a knightsports fuel cut defender, which I'm pretty sure is the same thing as the racing beat one.
Ok, so I'm supposed to hook it directly to the FCD wire, in between the boost sensor and the FCD right? or am I mixed up on this.
There are three wires on that side of the FCD,
Black
Red
White
Which one should I splice into?
I can't find one of the leads to my multi-meter otherwise I'd figure it out for myself..
My car is an S5. (TPS hookup's not that great, even on S5.)
I have a knightsports fuel cut defender, which I'm pretty sure is the same thing as the racing beat one.
Ok, so I'm supposed to hook it directly to the FCD wire, in between the boost sensor and the FCD right? or am I mixed up on this.
There are three wires on that side of the FCD,
Black
Red
White
Which one should I splice into?
I can't find one of the leads to my multi-meter otherwise I'd figure it out for myself..
Last edited by 13angryB's; 03-02-06 at 01:54 PM.
03-03-06, 12:24 AM
#88
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Just a quick plug.....
why not eliminate the FCD entirely with the use of the Rtek7 upgrade? With that, the ECU can see up to 12psi. Then you should be able to tap into the OE boost signal wire from the pressure sensor.
why not eliminate the FCD entirely with the use of the Rtek7 upgrade? With that, the ECU can see up to 12psi. Then you should be able to tap into the OE boost signal wire from the pressure sensor.
03-03-06, 04:03 AM
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It was the white wire, I don't even know why I asked.. 'made perfect sense as soon as I got off the damn computer & looked at it.
This works great.
I don't think they make Rtek7 for S5 yet.
This works great.
I don't think they make Rtek7 for S5 yet.
03-03-06, 01:35 PM
#90
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I actually have taps both before & after the FCD.
Before, for the S-AFC's THR signal, and after for the blue PRS signal.
When you plot the two, you can see the THR (boost) go on up while the PRS signal from the FCD gets clamped at 9PSI (=.63Kg/cm2).
Before, for the S-AFC's THR signal, and after for the blue PRS signal.
When you plot the two, you can see the THR (boost) go on up while the PRS signal from the FCD gets clamped at 9PSI (=.63Kg/cm2).
Last edited by SureShot; 03-03-06 at 01:39 PM.
03-03-06, 02:32 PM
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Originally Posted by SureShot
I actually have taps both before & after the FCD.
Before, for the S-AFC's THR signal, and after for the blue PRS signal.
When you plot the two, you can see the THR (boost) go on up while the PRS signal from the FCD gets clamped at 9PSI (=.63Kg/cm2).
Before, for the S-AFC's THR signal, and after for the blue PRS signal.
When you plot the two, you can see the THR (boost) go on up while the PRS signal from the FCD gets clamped at 9PSI (=.63Kg/cm2).
Would hooking the blue wire up change the way the SAFC reacts,
or is it just so you can monitor both signals?
Last edited by 13angryB's; 03-03-06 at 02:34 PM.
03-06-06, 02:56 PM
#92
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On our 2nd Gens the blue wire just monitors the PRS signal.
I was getting a fuel cut 2 weeks ago, and it helped me rule out a bad boost signal.
The problem turned out to be a problem with the AFM.
I was getting a fuel cut 2 weeks ago, and it helped me rule out a bad boost signal.
The problem turned out to be a problem with the AFM.
04-25-06, 06:11 PM
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Originally Posted by fstrnyou
Just a quick plug.....
why not eliminate the FCD entirely with the use of the Rtek7 upgrade? With that, the ECU can see up to 12psi. Then you should be able to tap into the OE boost signal wire from the pressure sensor.
why not eliminate the FCD entirely with the use of the Rtek7 upgrade? With that, the ECU can see up to 12psi. Then you should be able to tap into the OE boost signal wire from the pressure sensor.
I've been using it for 3 years and the system works great. Just remember the safc will calibrate it's operational range. Some car's TPS are 0V to 12V, some are 0 to 3, some are 0 to 5V.
It takes time for the safc to realize that the pressure sensor for 2nd gen TII rx7s is between 0V to 5V. Once it sets it's operational range to 0 to 5V all is good. Typically I noticed it takes a day of driving.
With this trick, 680cc secondaries, stock fuel pump, RB turbo back and K&N drop in panel I made 196 wrhp and 187 ft-lbs of torque, at about 9 psi. I use Paul Stokes FCD.
Last edited by Cheers!; 04-25-06 at 06:15 PM.
04-27-06, 02:08 PM
#94
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Please Help, Tuning Question!
Recently my motor has been rebuilt and broken in. When it was rebuilt, 750cc secondary injectors were put in, the wastegate was ported and welded open & street port on the intake. After it was broken in we added the Greddy Profec B spec 2 boost controller and the S-AFCII. Now heres the problem. After 3 hours of dyno tuning and $7500 later the car still isnt running right. At cruising with maybe 50% throttle pushed up to 3K RPM daily driving, the car stutters and stumbles. When I hit boost the car jumps around and stumbles bad then pulls through then when you let off the gas the car completely shuts off. Now, its an 88 so it has instant 100% throttle instead of a grid type like the S5. We have cut back the 750's 30% and the low end is as lean as possible. They also tried to tell me that the Boost Sensor was bad. But I think its fine and that the car just isnt tuned right. What do you guys think?
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