Guest bastaad525 Posted November 10, 2003 Share Posted November 10, 2003 fl327 - awesome! Thank you that's just the info I was looking for I do have a question though... after reading the installation manual online I noted that it specifically says it is NOT compatible with switch type TPS's, now... does that mean that I NEED to upgrade to the 240sx throttle body or otherwise switch over to a potentiometer style TPS to use the HKS? Or can the system function w/o the TPS entirely (this was the impression I got the from the directions)? What type of TPS are you using if any? You mention that you've only been tuning the idle with it so far.... I read that it does have an idle adjustment that is seperate the the regular per-rpm adjustments... does it need the TPS to know when the car is 'officially' idling? Quote Link to comment Share on other sites More sharing options...
fl327 Posted November 10, 2003 Share Posted November 10, 2003 ive been using a stanza/240sx tps forever now, with the extra pins for the variable load. the three pin that goes on that matches the original tps pin is what i use for eccs harness. The black connector off the tps is all you need for eccs, effectively making it a TVS-on off switch. the grey pin connector is what gives signal to variable load. since my ecu knows nothing about that load signal, i connected it directly to the afr, and the box reads load, while eccs gets on and off. i have the wiring for the load sensing written down in the garage somewhere, its pretty easy. now i have two in one tps and tvs. I drove it today around the block a few times, it goes from lean idle to a rich(factory curve) at the drop of a hat, its almost funny. It is kinda fun, I would like to get it on a dyno again to see what I can do for wot, which wont be anything more than I could get on these injectors, but I figure tuning it like this will get me a better understanding of it before I start installing the next round of upgrades. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted February 1, 2005 Share Posted February 1, 2005 =) So after reading this thread.. i understand that the HKS S-AFR will work with our ECU then I will need an MSD ignition and tach adapter to get it to work? I will also need a 60mm TB from a 240SX and use the TPS?? I'm just about to buy this... just making 100% it will work Quote Link to comment Share on other sites More sharing options...
Guest slowrolla Posted February 6, 2005 Share Posted February 6, 2005 X2 I also want to know. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted February 10, 2005 Share Posted February 10, 2005 so um.. anyone? anyone? Quote Link to comment Share on other sites More sharing options...
Sean73 Posted February 10, 2005 Share Posted February 10, 2005 I looked into the HKS S-AFR, and I think the concept is flawed, especially for a turbo car. The way I understand it works, is that it intercepts the MAF voltage, and then sends the ECU a different MAF voltage, at various RPM points that you program in. Here's the problem. It has no idea what boost level you are at. It allows you to program +/- 50% more fuel at each RPM point. Let's say you program 25% more fuel at 3500 RPM. At 3500 RPM, you could be at zero boost (cruising) or full boost (full throttle) and everything in between. So, there's no validity in adding X amount of fuel at Y RPM. Here's another problem. By changing the MAF or AFM voltage, you're fooling the ECU into thinking you're at a different part of the fuel and timing maps. Let's say you program the S-AFR to reduce fuel by 25% across the board, to account for bigger injectors. In addition to the first problem (see above), now your ECU is now going to be in a less-than-optimal region of the timing map. So now your timing is screwed up, and you've defeated the purpose of the bigger injectors and put your engine at risk. You also lose dynamic range of the MAF. Let's say the ECU can interpret a MAF range of 2-4 volts. After making a +/-25% adjustment it will be 2.50-4 volts or 2-3 volts, depending on on which way you adjust. You should be able to use the S-AFR with just about any MAF or AFM injection system. But you would need loads and loads of tuning just to get it to be barely comparable to an OEM setup, and you'd need other aftermarket gizmos to address the timing issue. After all is said and done in parts and tuning costs, you might as well get programmable EFI. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted February 10, 2005 Share Posted February 10, 2005 You can alter the TPS signal with MAP sensor and the AFC can see load. But yes, you can't run 50% larger injectors with AFC and expect the ECU to use the same map. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted March 17, 2005 Share Posted March 17, 2005 Well I just picked up a digital Apexi S-AFC and a DSM BOV today with a flange for only $150 for everything! Not bad! and the guy brought it to me at school.. Anyway.. I will begin swapping everything in, and taking pictures... and documenting everything.. so I will be able to let EVERYONE know how it works out.. and if in fact.. I can USE IT! Anyone have any good recommendations?!?! I will begin next week =) Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted March 17, 2005 Share Posted March 17, 2005 Like you said be sure to keep us updated. Sounds intreasting. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted March 22, 2005 Share Posted March 22, 2005 Alright... ran into a problem... How do I wire the extra wires on the 240sx 60mm TB?? There is a pig-tail with 3 wires.... now.. how exactly do I wire this up to the Apexi SAFC for it to read the TPS? Should I extend a wire all the way across the engine bay, and connect it directly to the Apexi's TPS wire? Quote Link to comment Share on other sites More sharing options...
yo2001 Posted March 22, 2005 Share Posted March 22, 2005 ACF needs the 0v-5vTPS signal. Can't remeber which wire but you need the one that changes the voltage output via throttle position. IF you can't find one, you can get a MAP sensor and get a load signal from that. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted March 22, 2005 Share Posted March 22, 2005 So someting like this?? http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=+MAP+Sensor&N=%2D138779&part=MSD%2D2312&autoview=sku&Ntk=KeywordSearch ------------------------------------------ Map Sensor, Bosch Style, 2 Bar, Each The pressure inside your intake manifold is extremely important input to the ECU. A quality MAP sensor like MSD's is crucial to your engines performance. These sensors will respond to changes in manifold pressures and relay the information to the ECU in the form of a voltage signal ranging from about 1 to 5 volts. They're available in several different versions for naturally aspirated engines as well as engines with forced induction. ------------------------------------------- Ok.. so I can get an MAP sensor.. however.. how would the SAFC tell the difference between the TPS and/or the MAP?? Obviously the SAFC monitors how open or closed the throttle is.. for example the throttle is 38% open, and adds in a certain amount of fuel... But the MAP just monitors the manifold pressure.. soo.. could this tell how open/closed the throttle is? There is a setting on the SAFC which you can monitor the Throttle.. which tells you the percent it is open (38% example) .. would the MAP do the same? Quote Link to comment Share on other sites More sharing options...
yo2001 Posted March 22, 2005 Share Posted March 22, 2005 That's the one. if you do use MAP, the AFC won't know the throttle position (including WOT) but it'll know the load via MAP which can be tuned just like TPS. More accurate too since on a turbo car, the load is not fully dependent on throttle plate but throttle vs gear. You are more likely to need more fuel in higher gear (like 5th gear) 25% throttle than 1st gear with 25% throttle. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted March 23, 2005 Share Posted March 23, 2005 K... the TPS has 3 wires... I THINK this is how it goes.. but then again I just read this post RED - Positive (Power) BLACK - Negative (Ground) WHITE - Sends the signal to the ECU.... ---------------------- quote : tanza/240sx tps forever now, with the extra pins for the variable load. the three pin that goes on that matches the original tps pin is what i use for eccs harness. The black connector off the tps is all you need for eccs, effectively making it a TVS-on off switch. the grey pin connector is what gives signal to variable load. since my ecu knows nothing about that load signal, i connected it directly to the afr, and the box reads load, while eccs gets on and off. ---------------------- or is it ? Black - Turns ECCS on/off Red - to my ignition? Grey/White - Sends load signal to the SAFC ????? So I guess I hook up the black connector? or the Grey/white?? *sigh* Do I need to power the TPS for it to send the signal? Ohh yeh.. guess that's where the 0-5 volts come from correct??! I'll hook it up to the ignition i suppose. OK.. so TPS is figured out.. now for the Tach... Since I am running the stock ignition and electronics... and getting an MSD 6A would be out of my price range right now... could I simply get a TACHOMETER adapter? ------------------------------------- Keep your tachometer honest. Tach Adapter, Magnetic Pickup Ignition Systems, Each If you are using the magnetic pickup input (green and violet wires) to trigger your MSD Ignition, you will need one of these tach adapters. These units will correct the operation of most voltage-triggered tachometers that do not work directly off of the tach output terminal of your MSD unit. -------------------------------------- Now if I get this TACH adapter.. I can still run the stock tachometer without problems right?! Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted March 23, 2005 Share Posted March 23, 2005 OK.. sorry about all these posts... I was reading my FSM.. and I noticed that the stock AFM has 2 wires coming out/in. One is a Air Temperature Sensor One is a POTENTIOMETER ... which is exactly what the 240SX TB has.. a potentiometer so send the signal how open or closed the throttle is. Now if the AFM has a potentiometer.. instead of hooking the SAFC to the throttle and the TPS... why not the potentiometer on the AFM? NOTE : A potentiometer expresses the angle of rotation of the flap, monitored by a potentiometer inside the AFM.... Quote Link to comment Share on other sites More sharing options...
yo2001 Posted March 24, 2005 Share Posted March 24, 2005 out/in should go to the pontentiometer of AFM. TPS or MAP hooks up to throttle signal. Basically, you need 3 things. Airflow signal, rpm signal, and throttle signal. Think of AFC as a complex potentiometer. I say try find a older supra Mark II and III? websites. They been using AFC on AFM for awhile now. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted March 24, 2005 Share Posted March 24, 2005 I scanned the Apexi S-AFC manual's diagram, and wrote next to each connection what ECU PIN and what color the wire should be. I also scanned the 1978 FSM for a diagram of what our car really has, compared to the overly simplified Apexi S-AFC diagram. What I discovered is.. the Throttle Signal or TPS basically connects to 3 PINS on the ECU... IDLE - Pin 2 and Pin 18 (black wire) FULL THROTTLE - Pin 3 and Pin 18 (black wire) and the Air Flow signal or AFM connects to 4 PINS.. *sigh* Pin 6 and Pin 8 (black wire) Pin 7 and Pin 8 (black wire) Pin 8 and Pin 9 (black wire) This is obviously a problem, because the Apexi S-AFC only has the TPS and AFM signal connected to one wire.. not 3 or 4 for each one!!! Anyway.. can anyone give me a good idea on which wires I should connect this to.. to get it running?? Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted March 25, 2005 Share Posted March 25, 2005 Ok guys... blah blah blah I am tryn to figure out this S-AFC thinggy... Anyway... I need the AFM signal wire to the ECU... and I can't figure it out... which "pin" or wire tells the ECU what the air ratio is?? I copied this from BLUE's atlanta Z tech tips page... 6. AFM Measurements taken on a 77 280z referenced to chassis ground. test point 39 36 6 9 8 7 27 Vreg temp rpm 800 13.93 13.93 0.01 11.59 7.48 3.22 5.09 14.04 6 1000 13.92 13.92 0.01 11.64 7.52 4.14 5.14 14.08 6 1200 13.98 13.98 0.01 11.7 7.56 4.68 5.23 14.15 6 1400 14.03 14.03 0.01 11.76 7.59 4.99 5.21 14.18 6 1600 14.35 14.35 0.01 12.06 7.78 5.41 5.25 14.49 6 2300 14.32 14.32 0.01 12.05 7.75 5.82 5.25 14.45 6 Normalized data (to 12V standard) from above table test point 39 36 6 9 8 7 27 Vreg temp rpm 800 11.91 11.91 0.01 9.91 6.39 2.75 4.35 12.00 6 1000 11.86 11.86 0.01 9.92 6.42 3.53 4.38 12.00 6 1200 11.86 11.86 0.01 9.92 6.41 3.97 4.44 12.00 6 1400 11.87 11.87 0.01 9.95 6.42 4.22 4.41 12.00 6 1600 11.88 11.88 0.01 9.99 6.44 4.48 4.35 12.00 6 2300 11.89 11.89 0.01 10.01 6.44 4.83 4.36 12.00 6 The ECU sends a voltage ratio to the ECU. The ratio is U/Ub as per the schematic below. V Ref Resistance (9-8) Vu (8-7) Vub (9-6) Vu/Vub 3.51 3.64 9.90 0.37 3.51 2.88 9.91 0.29 3.51 2.44 9.91 0.25 3.53 2.20 9.94 0.22 3.54 1.96 9.98 0.20 3.57 1.60 10.00 0.16 The following model shows Vu/Vub vs RPM Harris Model: y=1/(a+bx^c) Coefficient Data: a = -62.727835 b = 46.860151 c = 0.049964787 Applying the model to other rpms yields (normalized and assuming Vub=10 and Vpin9=10): RPM Vu/Vub 7 3000 0.139 5.048 4000 0.122 5.220 5000 0.111 5.328 6000 0.104 5.403 7000 0.098 5.460 OK.. so I narrowed everything down to at least PIN 6 which is what I was going to hook the S-AFC (super air flow converter) up to.. But then I noticed that PIN 6 has a 0.01 voltage almost straight across the board.. while PIN 7 flucuates... Is the "main" signal from the AFM to the ECU PIN 6 or PIN 7 ?? Pin 27... is the temp sensor Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted March 25, 2005 Share Posted March 25, 2005 Ok.. after about 2 horus of research LoL.. I have come to the conclusion... This is from the FSM : -------------------------------- "When the flap deflects along with a change in the intake air flow rate, the terminal (PIN 7) mounted to the flap shaft slides on the variable resistor R from R1 to R9, causing the voltage across terminals (PIN 7 and PIN 8 ) to change. A constant voltage Ub (battery volts) is applied across terminals (PIN 6 and PIN 9). Then the air flow rate is converted with the voltage ratio signal U/Ub, which in turn is sent to the control unit for computation." --------------------------------- The applied voltage the AFM sends to the ECU is U/Ub .. basically the voltage ratio signal the ECU needs to control the fuel with the air ratio. HOWEVER.. the FSM fails to state what PIN or what wire the signal is sent out of!!! Pain in the ***.. grr anyway.. after the graph/chart research.. This means.. That PIN 7 is the "output" signal of the U/Ub voltage ratio signal... Hence.. as the RPM's increase.. the "voltage ratio signal" decreases... RPM Vu/Vub 7 3000 0.139 5.048 4000 0.122 5.220 5000 0.111 5.328 6000 0.104 5.403 7000 0.098 5.460 Doesn't this make sense or no??! Anyone care to verify? Quote Link to comment Share on other sites More sharing options...
yo2001 Posted March 25, 2005 Share Posted March 25, 2005 You would need the one that will change the signal from 5v-0v when it's plugged up to the power source if that helps any. I don't have a N/A AFM in front of me to confirm the pin for sure. Is the pin layout same on the turbo AFM? Quote Link to comment Share on other sites More sharing options...
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