I finally got around to testing the IAT spoof as was discussed in another thread and the results were not good. Refer to the attached Excel sheet for the data of five pulls, the first two with the actual IAT value and the last three with an altered IAT signal:

Excel Data

As it turns out there wasn't too much, if any, change in ignition advance. There might be about 0.5 to 1.0 degree at the most. But that is hard to discern from this data and more tests will be done soon. As you can see I dropped the temperature about 35 degrees F which would be a reasonable amount for a real mod. So there might not be much to gain from this but I will be testing it again on the dyno just in case there is something missing in reading the data with my OBD-2 software.

Of interesting note are the fuel trim changes when I adjusted the IAT value. By dropping the temperature about 30 degree F the short term fuel trim immediately dropped about 2 points. If the number drops the ECU is adjusting to a richer condition. So this worked as expected; an artificial drop in the IAT value would cause the ECU to think the air is denser and add more fuel. This would then be picked up by the O2 sensor as a rich condition and the FT values were adjusted accordingly. The STFT adjusted within 10 seconds and was stable. I went back and forth several times between the actual temp and the altered temp with the FT values going to the respective values every time.

One other thing I will try is altering the MAP signal at WOT to slightly lean out the mixture. This will also be tested on the dyno.

 

Good work Doctor..

Carry on.

 

and the conclusion is that the RES-2 is not as easy as originally Thought...

 

Did you do this while parked in neutral or under load conditions? Also.... what gear were you in. You have to acct. for the knock sensor during those conditions.

Looks like you got a few degrees of advance with the new IAT values. If timing advance is what you want... there must be an easier way here. My NSX had a little screw on the ignition module to change timing. This is not an 'accesible' point... had to drill through a plastic cover and a metal plate to reach it. I am pretty sure there is something similar on the CL-S. What does the service module say about the ignition module? It must be under the dash in this car... can't see anything in the engine-bay.

 

Runs were done in both 2nd and 3rd gears at the same level spot. All logs were done in 2nd gear. Considering I am running 93 octane and provided the engine is fine, Knock Retard is not an issue.

KR and Ignition Advance are two individual values but dependant on one another. Ignition Advance, what I was reading, is the value the ECU determines is the appropriate value based on a table look-up. KR comes into play later after the initial look-up. If knock is present the severity is determined and an appropriate KR value is assigned. This value is then subtracted from the initial Ignition Advance value and a new and final timing value is used.

Ignition Advance - KR = Final Ignition Advance

But again, KR should not have been an issue at these low of speeds, moderate air and 93 octane...

We do not have an independent ignition control module. The ECU controls each coil-on-plug on its own. As mentioned in an a different thread, the only good way we have to get the ideal timing map for performance is by re-programming the ECU. Unfortunately at this time that is not feasible.

 

Steve,

I had done a few mods to the IAT/MAP and gained at best about 5 hp which again is nothing to write home about. Playing with IAT/MAP/TPS in tandom with the V-AFC I was able to lean out the mixture a bit down low and run a bit richer up high which seems to work well for me with my mods .. only problem being the god damned check engine light... damn ecu .. son of a b$#% seems the Acura ECU isnt real happy with ye ole' GM IAT mods/op amps/potentiometers .... live and learn ... hotter plug doesnt hurt though

 

That's what they make zener diodes for...

 

Steve,

I looked over your Excel data sheets and there is some room for hope.

The SLP "timing tricker" seems to show very small gains in advance in lower gears 1st and 2nd. The timing seems to improve with additional load in 3rd gear.

The average gains from 1- to 3-degress of MAX advance are in the 5- to 10-HP range. Considering the price of a few well-chosen parts vs. an intake, it might be a "possible" item of use.

Possible hitch however:

I have a feeling that people with 91-octane would need a switch to turn off the device when using CA pretend premium. IMO, a few gallons of the 100-octane 76 would keep the knock sensor OFF for CA users (if it works with the 93-octane premium you’ve got).

Small and humble favor: would you mind inserting a few voltage values at corresponding temps next time (dyno day/whenever)?

(I have some stuff already ... but ...)

Thanks for the test results...

 

I hope you didn't think it was just a resistor (like that Ebay rip-off charging $2.99 for a 2-cent resistor)

Even Doug mentioned the cold temp issues that relate to "clamping" the voltage to keep any "tricker" from making the ECU think that it is below a certain temp (we're talking a 20-cent part).

 

The drive for the individual spark modules (1 per plug) comes directly from the PCM. Connector C (31P) uses 6 of the pins (drive signals) to send a 5-volt pulses to each one of the 6 ignition coil/modules (sitting on that back of each plug).

There is no separate "ignition" module.

 

In retrospect, a few degrees would be welcome. But still, I only want it at WOT. I have some AD8180 muxs, I just hope they will work on +Vs/gnd instead of the spec'd +Vs/-Vs. But I assume I will need to incorporate an inverter. Once I get the bread board done I'll send ya the diagram and pic.

I am planning on having an A/F monitor hooked up at the dyno so I can trim the MAP signal to get the best ratio and power. It will be interesting how this little circuit works out.

Yes, I'll hook up my Fluke and grab the voltage reading also.

 

If you don't need the buffer amps, you can get a single supply mux from a number of vendors.

If you just want a "pass-through" during non-WOT, you can just use a PI5A124 to allow normal operation (straight through connection to IAT) and you can setup up a derived or constant I, R, and/or V with the other side of the "switch".

Single supply operation.
Mechanical relay replacement.

http://www.pericom.com/specs/PI5A121.pdf

(free samples)

(This unit is like having a single-supply, 8-ohm switch.


IF you want a buffer or amp, look at the Maxim stuff...

http://pdfserv.maxim-ic.com/arpdf/MAX4310-MAX4315.pdf

 

I already have a few of these so I'll just rig up a quick test board hopefully in the next couple of days.

http://www.analog.com/productSelecti...AD8180_2_b.pdf

 

Well, you've got something on your mind...

In pass through the thermistor is being pulled-up by a current source. The buffer amp, in the AD81xx, effectively kills "pass-through", unless you measure the current going into the sensor to "recreate" it and then re-buffer it.

AD81xx data excerpt:

"Each open-loop buffer is implemented as a complementary emitter follower..."

This means it "blocks" the current from the PCM's pin 25 and there is now no pull-up. Time for a replicated current source...

 

After that if you invert the register stack overflkow buffer and cross-reference the neutrino particle dampener to overide the flux capacitor we might have a winner

Guys I love cars and engines but all this e.e. talk sounds like " flied lice to me" Id rather write an assembler routine for a PIC chip to do this ... hahahahahah

 

Ah, screw it then. For the dyno test I'll just use a simple DPDT mechanical momentary switch for the signals. That will be simple to do and easy to rig up. This will show just as well any potential gain.

Actually, this is easier as the base runs and then the switched runs will not require any wiring changes, just a push of a button when it goes WOT.

If it works out then we can worry about the design.

 

THIS is pretty elemental stuff...

I know some guys who could take a couple of Radio Shack parts and make this happen...

The temperature sensor needs "current" from the engine's computer to work. If you block the flow, it just sits there doing nothing.

Simple enough... hey?

This PIC comment reminds me of a student at UCLA who used a one chip processor, with converters and lookup tables to do the work of a couple of 2-cent parts...

Too silly...

BTW, I'm going out right now to buy some vacuum tubes for my project!

 

thank you and now back to our regular scheduled programming...

 

Ladies and gentlemen allow me to present to you Mr. Richard Cranium a.k.a. Eric :P :P Ok Ok jerky I was just saying I dont enjoy e.e. .. not that i dont understand you all..... geeeze.. and dont knock the PIC or I'll send my battle bots after you and your car

 

The you need only a pull up Bipolar PNP transitor to supply the current from VDD...

I know i am an EE Enginer...

 

BNP hey?

 

i have no idea

 

Can we bring welding torches over and start with your chassis for a heavy weight Battle Bot project????

"CL Downshift Hazard" vs. "Biohazard" ???

 

HAHHAHHAHA Now that IS funny ! LOL

 

Bipolar PNP Transistor as a current follower (simple V-I converter)

 

If you give that Bipolar Transistor a constant dose of lithium would it help mood swings, paranoia, mania and depression?

 

I'd love to move this to PM.

I'm geeked-out for the day...

Leave what you think in a PM -- OK?

And let me respond there -- OK?

Thanks