As far as I know you are correct, they will not pass a plug in style test with the OBDII stand-a-lone in use, but I think Mike or Chris will have to give us the answer to know for sure.
Dave
Meth Kit with CTSC
- Thread starter RYU
- Start date
As far as I know you are correct, they will not pass a plug in style test with the OBDII stand-a-lone in use, but I think Mike or Chris will have to give us the answer to know for sure.
Dave
They're plug and play. For you, once a year or whenever you have to be tested, just unplug your aftermarket full ECU and plug in your OEM ECU and take it to be tested, rightThat's not too difficult if it works. Maybe even with slightly bigger injectors....
Dave
Really??? I wonder if I can get away with larger injectors and pump and still have the car limp to the inspection station without throwing a cel?
This might be a good start if one wants to look into this. I have to read in more detail tonight.
http://qcwo.com/technicaldomain/iat-resistor-mods-vs-performance-modules-vs-real-chips
Well if its a matter of unplugging the EMS for an hour to get the inspection I can do that... the question is, how will the car run without it? Will it do it and not throw an immedate cell? The factory OBDII system needs to see so many miles on the car without a CEL to allow pass. I unplugged my fuse and took the car in for an inspection lately, the inspector immediately asked if my battery had bee undone. I had to drive several hundred miles without a CEL and then it passed. Mind you, at the time I even was running my cat bypass pipes. All they care about is no CEL's here. That's all. The sniffer is long gone. A few years ago the car had to go on a dyno. After a few years of bitching by stations and expensive gear they revised the law. If I can get an EMS in there with larger injectors and pump, tune with meth, and keep the rest as is, then unplug and get an inspection without having to change injectors and pump that would be ideal.
Read post 100, i think you and I were typing at the same time, but it is not likely to work if you change injectors to larger injectors. Not sure what the OEM ECU limit is for trimming fuel but you will most likely get a code.
Here is an example of a OBDII Drive cycle to get the readiness test to run on a Ford, most of the test follow these same procedures.
http://www.obdii.com/drivecycleford.html
Now you know why I chose the F/IC for my '04, I have the same emmisions testing you have.
Dave
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Unfortunately, trying to keep it smog legal might require you keep your factory ECU with the Comptech. I think there's room to experiment with a F/IC but as DDozier commented it may not be as easy as unplugging/replugging the stock ECU. I had thought the same as Mac_Attack in that, if you're keeping the stock injectors etc, it was in fact easy and easy reswapping.
^^^ EDIT: Nevermind... see what Dave wrote
So this brings us back to the original problem... how to cool AITs with the stock Comptech stuff. I'd like to explore the 100% water spray solution some more. It doesn't have meth so the potential suspected highly unlikely event of it removing the coating on rotors is a non-issue... but how to deal with the AITs the stock AIT sensor is sending to the stock ECU... Dave mentioned an interesting option.
Let's say I try a water spray and have successfully cooled down the AITs incrementally at a time to achieve 190-200 degs during hard driving conditions. What does one monitor? AFRs and AIT only? Does one need to monitor the stock knock sensors? In general, I believe I understand the interdepencies but would like some confirmation :redface:
I've avoided any real "tuning" on my previous cars for many many years but the NSX is the right car to start watching this stuff. Help :biggrin:
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I think as long as you setup the Meth/water injection to come on only in boost and you do not drop the intake air temps below 150*, you should be OK. The fear would be cooling the IAT to NA levels and having the OEM ECU start to add back timing based on the colder reading at the sensor. If you are not woried about the coating issue on the rotors, I think I would still run a 50/50 mix of Meth to get the added cooling effect and octain boost that the meth will allow. You can adjust the amount of spray by changing the nozel size and once you have it adjusted the only other issue will be how much the temps very as the ambient temps change.
Dave
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Thanks Dave! Will report back once I get the setup completed in a few months. Unfortunately, it'll be cooler SoCal winter by then.
I will ask a buddy to build a simple circuit to process the stock AIT sensor voltage signal (as you mentioned on post #99) so at a given signal the voltage will trigger ON the spray system. I would like for it to only come on at around 200 degs to be safe and work my way down from there. I plan on controlling the spray once it's on via some boost dependent mechanism unless someone can think of a better approach. Still have some open questions on exactly what parameters to track (e.g. AIT, AFR?) but hope to figure it out by then.
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The AEM boost-dependent design is nice. You can size meth mixture flow rates with various online calculators and then actually measure it with the optional AEM flowmeter to confirm.
I still think one could get by possibly with larger injectors.
Here's why: You'll have an AEM EMS for 99.9% driving with perhaps an adjustable FPR and conservative 370cc/min fuel injectors (for about 30% more flow than OEM). Add boost-dependent meth injection. Get it tuned to your hearts content with meth and a measured fuel injection pressure downstream of the adjustable FPR.
Now... your inspection is due. A day before, you swap out just the AEM EMS and stick the OEM ECU in place. Lower the FPR some amount (not drastically of course where you'll lean out the engine or not have enough pressure for atomization), but limp around staying out of boost and make sure there are no CEL codes. Run the test, and then go back and swap in your EMS and bump the pressure back up to what you were tuned for.
Wouldn't that work? I appreciate your knowledge of ECU's DDozier, thank you for educating us!
Dave
I still think one could get by possibly with larger injectors.
Here's why: You'll have an AEM EMS for 99.9% driving with perhaps an adjustable FPR and conservative 370cc/min fuel injectors (for about 30% more flow than OEM). Add boost-dependent meth injection. Get it tuned to your hearts content with meth and a measured fuel injection pressure downstream of the adjustable FPR.
Now... your inspection is due. A day before, you swap out just the AEM EMS and stick the OEM ECU in place. Lower the FPR some amount (not drastically of course where you'll lean out the engine or not have enough pressure for atomization), but limp around staying out of boost and make sure there are no CEL codes. Run the test, and then go back and swap in your EMS and bump the pressure back up to what you were tuned for.
Wouldn't that work? I appreciate your knowledge of ECU's DDozier, thank you for educating us!
Dave
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btw... if I had an OBDII I would have downloaded the Torque app for my Android and buy the Bluetooth transmitter that plugs into the OBDII. You can read all sorts of OEM sensor readings and I believe the stock AIT is accessible on the NSX. You can also get the DGauge introduced in the vendor page. http://nsxprime.com/forum/showthread.php?t=150098
I'm thinking of doing this for my supercharged pickup but I want to confirm if the AIT readings is available on that vehicle.
OBDI vs. OBDII has it's pros/cons.
Thanks for taking the time to reply. I was actually afraid it was the other way around (higher temps = higher voltage) as that would not allow a voltage clamp to fulfill the role I envisioned. The way you describe (lower temps = higher voltage) would allow a voltage clamp to serve this need. If you keep the ECU from seeing a voltage higher than 0.78vdc, you keep the ECU from seeing an IAT under 165 (I'm using your example numbers). If you cool the IAT down to 90, and the ECU still thinks it is 165, timing will be retarded. This would solve the single aspect of the problem: It is dangerous for timing to be advanced...which the ECU does when it sees cool air...the ECU will never see cool air.
Now the FIC (or another smarter) option seems far superior because it won't totally screw up the timing when you're not in boost (as I assume a static voltage clamp would) because it can take such into consideration.
Interesting information… thanks Dave! What about if you already have an FIC? Can you essentially run a full stand alone with meth on a daily basis then anytime you need to pass emissions, just swap the EMS with the FIC, pass emissions, and then swap it back? Should be a quick 10 minute procedure without the need for the OEM ECU to relearn everything, right? The only other thing I can think of is that you may have to unplug the dual wideband sensors and plug in the factory O2 sensors if you are using them.
If you get this operational, please let me know. I've been running the generic CTSC (whipple) for a while (12 years, 20k miles if my late night memory and math are right). Went high-boost (CTSC's kit with different RRFPR and larger JDM Prelude injectors) in the early or mid 2000s. I do notice the impact of heat on performance but the kit has been so nice and simple and reliable (save for preventative replacement of the bypass hose with pipe) that I've held off on worrying about the heat because of a nexus of cost and safety/reliability concerns (well discussed in this thread) of solutions.
My dream solution has been an effective intercooler that would be safe without going stand-alone (maybe by managing what IATs the ECU sees). The solution you describe is cheaper and simpler (except for having to refill the water jug - a very small price to pay and optional, really, unless tracking on a hot day)...not to mention realistic (likely achievable).
(Caveat to my experience is that save for a weekend at Hastings and NSXPO 2010 (Vegas) it has all been at high-altitude. The CTSC makes up for living at altitude...plus a little. With lower pressures to start with I'm not getting the same kinds of absolute air pressures (and therefore probably not the same IATs) as lower-land folks.)
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I will and hope it's within my ability and scope. I certainly am not willing to experiment with my C30 so i'll want to be extra sure. With that said, I'm ready to try it. You make an interesting point.. in 12yrs you've done 20k miles. I'll likely do the same. The SC units are scheduled for a rebuild around 100k miles so hopefully, even with meth, that'll give us plenty of useful life for many years of ownership.
I do have one other question and this shows my lack of experience with gauges in general... Sensor heat soak aside, Are the standard AIT gauges able to read accurately from the factory AIT sensor? Are there voltage differences or are they all pretty much standard? Dave laid out some useful voltage output readings but just wondering if the industry is standardized in such. I would assume so...I hope so...
Many years I have prepared in my mind that if I ever went CTSC an aftercooler would be the ideal solution. It may still be if one was to go EMS or F/IC but the "Always On" solution doesn't quite work for us it appears. I suppose one could always turn off the heat exchanger pump but then you've also have some air flow resistance (drop in boost) due to air passing thru the aftercooler. I think for this application i'm convinced to try the meth/water or water solution. The key for me being that my car will not tuned for it from an EMS/FIC perspective, therefore not tuned to depend on it. If you run out of meth/water I'm still fine. The cheapness of it makes it compelling. ...just thinking out loud here.
My first attempt will likely be to try to lower the AITs from ~250 to ~190 as how the factory sensor sees it. I don't want to experiment with a voltage clamp at the first go-around just because if that clamp fails sounds like a Kaboom situation? It's definitely a very very interesting solution.
Another good point. I realize all the tracks I would visit are in socal has some elevation (>2500ft) so in a sense that's also an added buffer albeit at the expense of boost.
Also, I just want to thank some of the key folks who have chimed in on this thread. You gents have helped us moved this forward and hopefully trudge new ground.
You are correct, but there needs to be a delay entered into the clamp process, a simple timing chip ahead of the clamp to delay its actions by 1-2 min after startup should allow the sensor to operate for cold start up then kick in the clamp and lock the minimum timing retard at the desired temp. You would just have to remember to stay out of boost within the first two minutes of startup, something you should be doing anyway.
Dave
The Voltage clamp and setting a minimum timing retard would not matter if you are in boost or not as the OEM ECU takes into account load into its timing calculation and the effect the IAT sensor has on timing at those loads. In other words the OEM ECU does not make a blanket retard of timing based on IAT, it is scaled based on a given load the ECU is seeing, as the load is increased the amount of timing retard is increased. It is a very complex calculation that the ECU is using to determine when and which sensors have an effect on fuel and timing.
The good thing is we know it has an effect, the bad thing is without being able to see the processor code in the OEM ECU we do not know exactly how much and exactly when it happens, that is why you need an OBDII car to do the testing and log a lot of data to have some sort of idea to correlate the effect of the IAT sensor on timing retard and fuel added for a given condition. We understand what they were doing and why, but we do not know exactly when and how much the changes are.
Dave
If you already have the F/IC, then the rest of this does not matter unless you just feel the need to run the stand-a-lone. The F/IC can handle the fuel and ignitions changes needed on a daily bases reguardless of the IAT's you would just need to setup two tunes based on using meth or not using meth. The F/IC supports dual tunes and can be triggered to run either based on the condition of the meth system so all you would need is the F/IC. In theory the F/IC could also be used to control the IAT min temp voltage sent to the OEM ECU and lock the timing at that temp. It can do all of this and retain the OBDII plug in test as long as the tune on the F/IC is good. The stand-a-lone will require a plan such as you have laid out to get around the emmision issues of the plug in OBDII testing, but if the car is setup on the F/IC and tuned correctly then with the power level of a stock CTSC or even a CTSC HiBoost setup can be handled by the F/IC and OEM ECU combination.
I think most of the other questions related to the proposed device to clamp the IAT sensor is geared towards guys that want to cool the charge temps with meth, and retain the CTSC fuel system as designed by CT. Once you decide to go with the F/IC or the standalone ECU I do not think such a device will be needed.
If you go with the F/IC you will have the control needed to deal with the IAT's and the Meth plus you can pass the OBDII testing.
If you go the stand-a-lone route you get complete contol of the engine and you have to come up with a plan to make it pass the emmisions testing as the OEM ECU is not used to manage the fuel and timing any more and the OBDII port is dead. By the way if you did follow your plan you can leave the widebands in place and simply wire the O2 sensor inputs at the ECU to a switch, the switch would be used to change the input at the ECU between the wideband output and the narrow band output of your wideband controller, most if not all wideband controllers have both of these outputs for just this reason, they can output both a narrow band and wideband signal at the same time, you just flip a switch to patch in the output desired.
Dave
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The issue of sensor heat soak in my mind is not much of a factor, and here is why I say that, the engineers at Honda wrote the code in the OEM ECU based on testing the engine with the IAT in the OEM location, that location can heat soak as much as the CTSC location does and I believe they would have taken that into account in there testing and final tune. Everything we do is going to be a compromise as long as the OEM ECU is in the equation. If you go stand-a-lone then you can move the sensor to a better location but if the OEM ECU is in the mix it should stay where it is or as close to the OEM location as possible like CT did.
The IAT sensors follow no standard and every manufacturer is free to choose the sensor that meets their needs for any model they build, I have seen many different sensor styles, mounting method, locations, it is all up to the design/engineer team to pick the parts needed to fit the need.
For us the guys at Honda were nice enough to give us the calibration temps and voltages for the sensor in our car, it can be found in the service manual for the NSX, but those published numbers have been disputed and many people have setup a mini-lab in there kitchen with a pot of water on the stove and a digital thermometer to verify or disprove the published numbers. There is info on their findings at the AEM forums and really is only a factor for the stand-a-lone guys using the stock sensor data.
Dave
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If you are thinking about an OBDII guage or stand-a-lone AEM ECU you should also consider the DashDAQ from DrewTech, it is more expensive but has a few advantages, it can be used in an OBDII aplication or it can also be used with the AEM ECU to read all of its available data stream. So the DashDaq will not become a dead gauge if you move to a stand-a-lone from the F/IC or OBDII standard. Check it out it is worth the look, if you decide to go with it let me know I can set you up with everything you need and make a plug in play harness for all you connections and sensors you add. You can add a host of sensors from widebands, g-meters, analog sensors, GPS.
http://www.dashdaq.com/specs/entirespec.htm
Dave
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Nice gauge setup! I'll look into this more closely. Any place you know of that sells a harness that can plug into the OBD1/ECU so I can make use of the OEM sensors? (Long shot, I know...) Hopefully I can find a good data logging option as well. This is another reason why a standalone would solve all these issues. :redface:
Only tool that can read OBDI for our car is from Honda, and you have to be a dealer to get one, not really a gauge option. "SR5GUY" has been working on a software solution but it requires the ECU to be modified. We are hoping for a data logging solution soon followed by a real time tune of the OEM ECU as a final product. It would be great to have the ability to just change the tune in the OEM ECU, someday soon maybe.
Some pics of my DashDaq install here:
http://nsxprime.com/forum/showpost.php?p=1407351&postcount=7
Dave
Dave, does the DashDaq have the ability to set of audible or visual alerts especially for sensors running in the background?
Damn Dave, can I send my car to you to have everything set up right!? :biggrin::smile:
-Steve
Dave, how is the FIC going to allow the car to pass with larger injectors and pump? Isn't the Honda ECU going to throw a CEL? Or were you saying to use a FIC with two curves (meth and no meth) and stick with the factory pump and injectors?
If you go with the F/IC you can make whatever changes you want to the fuel system and still pass emmisions as long as the end effect is an engine that can be tuned to run very close to OEM design while in closed loop operation. Once the engine goes open loop the ECU stops looking at the O2 sensors and stops monitoring for efficiency, the onboard emmisions test do not run, so there is less to worry about causing a CEL.
The F/IC allows the OEM ECU to think it is in charge of everything, it does this by intercepting the incomming sensors (O2's, MAP) to the ECU altering them to get the ECU to act the way you want, it then looks at the outputs for fuel and ignition from the OEM ECU and modifies the outputs to the fuel injectors and ignition system to alter the way the engine runs. If you add larger injectors the F/IC will intercept the fuel injector pulse sent by the OEM ECU and shorten the pulse to allow less fuel to be injected into the engine. Then when you need more fuel it can also add to the pulse sent by the OEM ECU. There are limitations to the F/IC as far as injector size, I have had good luck with 550cc injectors others have run larger, but the farther you go from the factory injector size the less control you have over the new injector. Since this device was designed to work with OBDII OEM ECU's in most cases the OEM ECU has no idea the F/IC is there and will never throw a code if the tune for closed loop operation is correct.
The other limitation of the F/IC is that it has to modify the OEM ECU's signals and cannot generate its own signals like a stand-a-lone can. It has to react to what the OEM ECU is doing so it cannot be proactive. If you use it in the application it was designed for it is a great option, if you try to do to much like large amounts of boost and really large injectors you will not have an ideal setup to tune and may have issues that can not be worked out.
Dave
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