SAP Simulators anyone?

[mpire]

I am going to build another air pump simulator for the S52 and was going to check to see if anyone wanted one while I was at it.

If we have a dozen takers or so, I can do it all in one batch. The first one takes a while to make, but the second one only takes a little while longer.

Just gauging interest, I haven't bought any parts yet, so let me know.

I have to see if I can find the right connectors to make it a plug and play affair.

Confirmed that mine works on the S52 and the M52TU, probably works on everything else.

Active & Turner sell them for $200, I am shooting for less than half that delivered.

[rf900rkw]

I am quite curious how the same design can work on both active zirconia (m52tu) and passive titania (s52) systems.


Be that as it may and not to rain on the parade, turning off the SAP is a matter of flipping a few bits in the DME, easily done at home now. The only reason to do an emulator is to force the monitor to set for emissions testing.

[mpire]

I don't have anything to reprogram my DME at home.

I'm not sure what difference it makes other than a few different voltages in execution.

I know they all work.

[danomite]

I might be interested. Got any details on how you'll go about it?

[mpire]

You just spoof the ECU with voltage mimicking the O2 simulators running lean for 30 seconds.

[Mr Bingley]

Ok, I'm guessing that it is part of the pollution control system, but what exactly does the secondary air pump do, and why would I want to simulate it?

[rf900rkw]

Emissions control had evolved to the point that they were worried about the few minutes it took for warmup. They developed the heated O2 sensors to the point they were up and online within 10s of seconds of a cold start. The problem then became getting the cats up to temp and working as quickly as possible. The best way to do this is to drive the snot out of the car from the word go. But alas the driving public had been mis-trained to let the engine idle for a long time before gingerly venturing out. That is where the SAI comes in. under the right conditions on a cold start, the DME will jack the fuel mixture way rich, and turn on the air pump. This makes for a very effective blowtorch in the exhaust manifold to heat the cat.

Two take-away points

If there is anything at all not perfect with the engine running. be it a weak coil or fuel trims near max, the massive dose of fuel the SAI injects will show up as a loping idle for the duration of the pump cycle

Letting the car idle on a cold start is not helping in any way. The system forces drive speed fuel into an engine without the RPM to match


And to go back to Brent's comments. Anyone with a KKL INPA system can turn off the SAI with a flip of two bits. The down side of the software disable is the monitor will not set as passed. This is a concern for those like Dan in a smog-nazi district.

[BimmerBreaker]

Im interested

[Blacklane]

I disabled my SAP and installed a simulator because the SAP system is fragile and expensive to repair. If the SAP solenoid fails, hot moist exhaust gas is sent to the SAP pump destroying it. Any valve is going to have a hard time plugging an exhaust leak over and over.

My SAP system looks intact, however there is a steel plate under the SAP solenoid on the manifold and there is a SAP simulator hidden in the DME box. (I think the DME is in there, but it's been a while. In any case, all of the engine control wires go to it).

Another time to install a SAP simulator is when installing headers, since they usually don't have the provision for the SAP solenoid.

Here is a picture of mine, which fits perfectly into a recess in the DME box (shown on the right in the photo).SAP Sim Install.jpg
You need to make all of the connections inside that box anyway.

[mpire]

The SAP only runs for 30 seconds when the car hasn't been driven in a day or so. It doesn't run when the car is already hot or that is the intended design.

Personally, I find this obsession with emissions is downright silly. I am not advocating running a catless car, it smells bad and gets residue on your bumper, but most of the recent emissions crap does more to complicate your car and reduce mileage and reliability than it does to help the environment.

Air pumps run for 30 seconds, then they do nothing but add complexity to a system that didn't need it. It breaks, you get a CEL and then you ignore it because we all know its useless, especially in Florida. Then something actually breaks and you don't know because the stupid CEL has been on for months or years.

Putting cats in the engine compartment is idiotic. Sure it warms them up a second or two faster, but it also deteriorates all the plastic and metal in your engine bay. Too much heat is BAD for EVERYTHING. Especially plastic which gets brittle anyway after 20 years. Put the cats where they belong, as far away from the engine as possible, down in the air stream under the car and lots of heat shielding to keep things cooler. The cats get insanely hot. So hot you can't touch your shift linkage after driving the car for 90 seconds. It will burn you badly, and it is behind the heat shielding.

Then there is the positive crankcase ventilation valve, which clogs up and is way more work to replace than is worth it. Put in a catch can, then dispose of any blow-bye responsibly when you drop off your used oil to be recycled. No one ever changes those on old cars anyway, I have a new one for my old truck and I can't get to the damned thing to change it so I just don't. I made a catch can out of a small aluminum bottle and painted it black.

Lastly, and my personal hatred for this knows no limit, they decided that they needed to eliminate the oil dipstick. BMWs burn oil, they have always burned a little oil. This is normal. So lets replace a $2 strip of metal with a $200 computer sensor that will fail. I get it, stupid people don't use their dipstick, but they won't use the oil sensor either. Most of the recent deletions are only in the US and you can still add the dipstick. The pan still has the hole and it just has a little plug. Why complicate things that don't need complicating?

So yes, some of these things do make sense in the very short term to lower emissions a tiny bit. The reality is that most of this crap is useless long before your warranty runs out. When these cars hit 100k they all all useless and do more harm than good. A properly maintained vehicle with good gaskets and all this unnecessary crap deleted will be in better condition with better gas mileage and put out less pollution than one with all this useless crap clogged up and not working and not replaced because its overly complicated and expensive and no one is going to replace it.

So delete your SAP, your post cat O2s, your PCV, move your cats to the proper location, and install a proper dipstick. May your car run well and last forever.

[LannVouivre]

mpire, where can I get the SAP emulator/removal setup for the M52TUB28? I am quite interested. Also curious about what's involved with replacing the CCV with an oil catch can system, as it seems the forums aren't helping me find either with the search...

[mpire]

Let me add to the list oil filters that aren't up top in the engine bay so they are easy to get to.

Granted, BMW does't have this problem on OUR Z cars, but they do now.

The oil filter should be easy to get to so you can replace it without dripping oil on the ground. That oil gets wiped up and thrown in the trash, or it gets washed into the sewers. Its bad for the environment. Dripping oil is bad for the environment. That should be far more important than some stupid craptastic device to help .001% of emissions.

When they have a gas well just spewing, they set it on fire. Why? Because the burned hydrocarbons are better for the environment than the un-burned ones.



That's probably more dramatic, but when you drive by the land fill and see the burning flame coming out of the vent system its because they want to burn the hydrocarbons instead of letting them into the atmosphere.

That's the whole point of the catalytic converter anyway, to completely burn the hydrocarbons that go through your engine. It is a second combustion chamber.

CxH2x+2 + [(3x+1)/2] O2 → xCO2 + (x+1) H2O

We want complete combustion, that is best for the environment. All those fluid leaks on these older engines, transmissions, power steering systems, valve cover gaskets, and pcv valves are worse for your environment than anything that comes out of your tailpipe.

- - - Updated - - -

mpire, where can I get the SAP emulator/removal setup for the M52TUB28? I am quite interested.

I made one.

[328 Power 04]

I don't see how it can work correctly for both single vanos M52/S52 and then the Dual Vanos engines.... IF you're intercepting the O2 sensor signal and fooling it briefly.

Single vanos M52/S52 has titania O2 sensors that operate at a fixed voltage and change resistance to determine lean/rich status. Great fast sensor, but much more expensive.

Dual vanos engines use the universal style zirconia that change voltage.




If implemented, this solution isn't horrible, because you're actually still kind of doing what the SAP was intending to do: indirectly enrich the fuel mixture to help cat warmup.
Newer BMWs got rid of the secondary air pump completely and have that behavior done by software.


However, you'd be amazed how smooth of an idle and cold start you can have if you just flash out the SAP behavior, and have minor catalyst heating through software.

[mpire]

I don't see how it can work correctly for both single vanos M52/S52 and then the Dual Vanos engines.... IF you're intercepting the O2 sensor signal and fooling it briefly.

Its pretty simple really. The voltages aren't the same on the M52TU and the S52 that I have made them for so far, but the concept and the execution are the same. You just need to set the proper values.

Modules have been installed in my cars for years without any issues, CELs, or codes of any kind for that matter.

I made block off plates from titanium plate. It really is that simple.

Also, if you don't have the fancy software and don't want to screw with your ECU then pulling the ECU and sending it to someone to get flashed is a lot more work than just plugging in a module.

Do whatever you want to do, its your car.

[328 Power 04]

I hope you didn't take it as me debating against these. Because if they work, that's excellent. It was more curiosity than anything.
How does OBD2 readiness respond to these? I know in Florida it doesn't matter, but in other states it does..

[mpire]

I got no idea.

How about you send me your OBD2 programmer and let me try it out and I will give you a better review.

[rf900rkw]

The concept is simple enough, while the pump is on the O2 should peg lean. Abel and I are on the same page. I don't see how you can force feed a voltage to the zirconia, and change the resitance of the circuit for the titania.


Nebbermind, I figured it out.

[danomite]

...so when will these be made and available?

If this is the best/simplest solution to skirting the SAP CEL, then I like it!


Also, Randy nailed it with the "smog-nazi district" comment! This state has too many rules and regulations, and not enough brains behind enacting them! Sooo many redundancies!

[mpire]

I only have one guy interested, so I only ordered enough to make two of them.

So that's it. You can pay someone a couple hundred to delete it in software.

Mine just plugs in and can be unplugged whenever you don't want it anymore. It only does anything for 30 seconds when the car is started cold. If the car is already warm from driving around it doesn't even activate the SAP so this thing rarely gets used and its a major PITA when it breaks.

[danomite]

I only have one guy interested, so I only ordered enough to make two of them.

So that's it. You can pay someone a couple hundred to delete it in software.

Mine just plugs in and can be unplugged whenever you don't want it anymore. It only does anything for 30 seconds when the car is started cold. If the car is already warm from driving around it doesn't even activate the SAP so this thing rarely gets used and its a major PITA when it breaks.

Uhhh....I was the first guy that said he was intereseted...I'm hoping that the "one guy interested" is me.