SAI Delete - what are the real pros and cons?

[f4i-pilot]

'03 1.8T Cab
I'm in the middel of my CVT -5spd swap, what other than getting a bunch of hoses out of the way are the benifits or liabilities of removing the SAI. I live in 757 Virginia and we only have visual inspection on Emissions systems. I am currently replaceing the failed Coolant flange and it would be nice to know before I put all that mess back on.

We only have mild winters here, maybe a few day below freezing, is that really an issue on cold weather startrs?

[old guy]

The SAI system doesn’t have any effect on how the engine starts, hot or cold. The function of the SAI system is to help get the catalytic converter up to temperature faster in order to reduce start up emissions. This was required in order for the 1.8T to obtain a ULEV rating.

There are several down sides to removing the SAI system. Unless you have the SAI written out you will get a CEL. You mentioned that where you are in Virginia they only do a visual inspection for emissions. This is very surprising to me and I wouldn’t count on that for lasting very long. If they go to checking readiness switches you will fail emissions unless you have it written out. Even then you may fail if VA ever goes to forcing a reset.

If you are running a test pipe the SAI isn’t necessary but you will still have to deal with the CEL and possible emissions issues down the road.

[f4i-pilot]

The SAI system doesn’t have any effect on how the engine starts, hot or cold. The function of the SAI system is to help get the catalytic converter up to temperature faster in order to reduce start up emissions. This was required in order for the 1.8T to obtain a ULEV rating.

There are several down sides to removing the SAI system. Unless you have the SAI written out you will get a CEL. You mentioned that where you are in Virginia they only do a visual inspection for emissions. This is very surprising to me and I wouldn’t count on that for lasting very long. If they go to checking readiness switches you will fail emissions unless you have it written out. Even then you may fail if VA ever goes to forcing a reset.

If you are running a test pipe the SAI isn’t necessary but you will still have to deal with the CEL and possible emissions issues down the road.

I am pretty new to Audi so forgive my ignorance, but having them written out, I'm assuming by using VAGCOM, I have a cable do in today, I am going to have to do some coding anyway for the swap and ABS and cluster I believe.

I'm done in the Tidewater Area and we do not even have it up for discussion like they do in Northern VA.
I am not going test pipe just yet, I just wanted to see if I can remove the SAI, since I dame near had to take all the pipes out for the swap and coolant flange replacement.

[old guy]

You cannot write the SAI system out with VCDS (VAGCOM). You will need a tuner or someone well versed with modifying the Motronic ME7 controller.

[redline380]

There in only one negative- you have to pay to get the cel off. A potential negative is not passing emissions, if your state has it.

The positives- removal of a system reminiscent of an appendix, a a vestigial organ so to speak.

Take it out, burn it, and piss on the melting pile of over-engineered pile of shit.

[vjborelli]

The SAI system can be effectively coded out via tuned ME7 software. It can be done for stock tunes, and any other stage of tuning. There are 2 methods of coding it out.

One method will still allow passing inspection, but isn't known by many tuners still. I use this method to pass inspection here in Massachusetts on my own car, and a few of my client vehicles. This method allows the removal of the SAI pump and installation of the block-off plate, but requires that the N112 valve stay installed. This method still allows the SAI diagnostic functions to run, and pass as if the system were still installed.

The other method just disables the DTC, and forces the readiness bits active. This method is the most common, but will fail in states that use newer inspection computers.

Sent from my Nexus 6

[f4i-pilot]

Now that being said that VCDS will not write it out, I was considering an APR tune, and potentially K04, it's only FWD so BT won't be on the table. Would a APR tune do it?


Sent from my iPhone using Audizine mobile app

[vjborelli]

Now that being said that VCDS will not write it out, I was considering an APR tune, and potentially K04, it's only FWD so BT won't be on the table. Would a APR tune do it?


Sent from my iPhone using Audizine mobile app

i believe APR uses the more common method that just disables the DTC, but I could be wrong

Sent from my Nexus 6

[fyremanpat]

Your SAI is one more piece of aging electronics in your car. Its just a matter of time until it fails. If I were in your place, I would hold off on an APR tune. I recommend Motoza tuning with a k04 or whatever other turbo you want. He will be able to write out your SAI and rear O2. As for our inspections here, if you do go with a test pipe you'll want to hang on to the factory cat. You can always install it real quick before getting inspected.

[Gberg888]

I have dealt with SAI with 3 cars, 2 1.8ts and my R32.

SAI sucks, and having SAI in MA sux even more. MA does a pretty in-depth inspection and if you fail for emissions you have to go to a special center where a really grumpy old man (think about the grandpa complaining about 'Nam' and telling you to get off the grass kind of ******) inspects you car and he knows his shit.

Anyways, SAI will throw a code, some states wont catch a code out depending on how sophisticated their systems are and also how it is coded out. Some will. MA catches it all. So at the end of the day, if you are in MA just fix the system or dont drive the car without until its 15 yrs old. At which point they dont care about emissions so you can roll coal or whatever in front of the MAC center as often as you want.

[vjborelli]

I have dealt with SAI with 3 cars, 2 1.8ts and my R32.

SAI sucks, and having SAI in MA sux even more. MA does a pretty in-depth inspection and if you fail for emissions you have to go to a special center where a really grumpy old man (think about the grandpa complaining about 'Nam' and telling you to get off the grass kind of ******) inspects you car and he knows his shit.

Anyways, SAI will throw a code, some states wont catch a code out depending on how sophisticated their systems are and also how it is coded out. Some will. MA catches it all. So at the end of the day, if you are in MA just fix the system or dont drive the car without until its 15 yrs old. At which point they dont care about emissions so you can roll coal or whatever in front of the MAC center as often as you want.

MA doesn't catch it all... I've had my SAI properly coded out for over 2 years, and have never been flagged. I even just removed the SAI from a client vehicle here and just got it inspected last Wednesday.

Sent from my Nexus 6

[amgraham]

I own a shop in Richmond and don't anticipate emissions testing coming here anytime soon. You never know though, all it takes is someone saying "hey, NoVA has to do it, why not the rest of the state?" I wouldn't worry so much about the SAI system being caught if you have it coded out correctly.. As long as the CEL is off and there are no emissions or airbag/safety codes you should pass inspection. If you go the test pipe route that's a different story because if you get a stickler for an inspector and they report it that means a hefty fine for you (but that is nationwide. It's just more of a risk in VA with the yearly inspections).

Also I will give another suggestion for Motoza. I just got their bluetooth tuner and did everything with my phone. I too was looking at APR but didn't want to have to take my car to a dealer. The Motoza 1+ even with the bluetooth was cheaper than the APR tune and I did it all myself in about 10 minutes sitting in my parking lot. Also, when I had a question I called them up and got an actual person (Dave) who talked me through my question and was genuinely willing to help. In addition, if you wanted to tune with the K03 for now then upgrade to the K04 or whatever later you just have to pay them for the upgrade, not an entire new tune. It made a lot more sense to me than APR (plus it's not just a canned tune like APR - they have you send in logs, which I did just using the app on my phone while I drove to work, and they dial it in custom). I'm very impressed so far.

[diagnosticator]

I am continually amazed at how many guys who don't know how the SAI system works, and do not understand why the SAI is necessary on our OE stock B6 1.8Ts, incorrectly believe the system is pure evil from the devil himself. On the the other hand, I believe that "test" pipes are evil and are the work of Satan. Nothing good can result from using them. I know this is true, there are no worthwhile justifications for debate about this. If follows that the irrational fear and hate often expressed here for the SAI system is at the minimum misguided. Therefore, it should be obvious to any informed and reasonable person that the anti SAI/ pro "test" pipe believers are involved in an evil conspiracy focused on devotion to Satan.

(No offense intended. My assertions can't be offensive unless... you believe in Satan.)

[eljay]

I'll just chime in and say that I wish the previous owners of my car left everything alone and I could just replace the cat for a high-flow version and be done.
Instead, I have a test pipe with both O2 sensors, CEL removed, SAI removed, combi valve still left etc. I added a cat in the middle where the Y pipe was. At some point, I will get cash together and put in proper HFC in the factory location and check the tune. It won't get me my SAI system back, but will improve my setup.

All that was to say: if I still has it, I'd keep it.

[diagnosticator]

I'll just chime in and say that I wish the previous owners of my car left everything alone and I could just replace the cat for a high-flow version and be done.
Instead, I have a test pipe with both O2 sensors, CEL removed, SAI removed, combi valve still left etc. I added a cat in the middle where the Y pipe was. At some point, I will get cash together and put in proper HFC in the factory location and check the tune. It won't get me my SAI system back, but will improve my setup.

All that was to say: if I still has it, I'd keep it.

At least there is hope for full redemption for you in the near future.

[old guy]

I too am surprised by the vitriol expressed toward the SAI system. There is really very little to it. It’s basically an air pump and mechanical air valve operated by a vacuum signal from a solenoid. It only runs for up to 90 seconds on a cold start and that’s only when the ambient air temperature is above the frost point.

The much more complicated part of the SAI system is the cam chain adjuster that is used to provide 22° advance when the SAI system is being activated. The early 1.8T CCT’s only provided tension and didn’t have the ability to change the cam timing. A lot simpler. However, one advantage of the cam adjuster is that it can be used to increase the volumetric efficiency in the midrange operation of the engine.

It seems to me that it would be easier to just leave the SAI components alone than having to deal with the consequences of removing them. I am sure that all of the individual States will be going to go to more sophisticated methods of emissions testing in the future.

Especially in the wake of the VW diesel shenanigans.

[userbob0001]

My problem with it is that it does so little, is so prone to failure, and is so expensive to fix. I broke one of the plastic hoses while putting in an intercooler and it's $80 online. I ended up cutting the hose from the ends and using heater hose between them so I got around that, but that's not what was designed.

$100 for hoses, $120 for the pump, and $100 for the combi valve to run for 90 seconds at startup it seems like they could have should have done better. Especially when you add in that the combi valve gets stuck with no indication until the pump fills with water and is also ruined assuming the pump hasn't already blown itself apart.

I'm no fan of test pipes myself and I've got everything together because of that, but I do wish a system that needs to run for less than two minutes per drive took a little less maintenance. That extremely short duration makes me feel like it's pretty superfluous.

Edit: Sorry for the rant, the hose was this past weekend and I was super stressed until I figured out the heater hose thing and the pump, combi, and relay were just a few months ago so I'm still super salty about it.

[f4i-pilot]

Obviously my primary question was based on cleaning up the ridiculous amount of hoses and valves if there was not an operational benefit to them, it was just more of an annoyance to have to deal with them to do the coolant flange.
At this point I will just keep them intact and finish my swap to have an operational car.
I did look into Motoza and looks like pretty stout Tuning system, let me get all my coding done for the swap and that may be the next thing.
I ran into these same American emissions issues when I was working on my '88 Rx7 back in the 90's. The over engineering to meet US guidelines was a special kinda stupid.


Sent from my iPhone using Audizine mobile app

[old guy]

I guess I’m just lucky. 13 years and 220k+ miles and my SAI system still performs as it should. Replaced one hose a few years ago. Probably just jinxed myself and the pump will blow up tomorrow…..

[Kevin C]

I am continually amazed at how many guys who don't know how the SAI system works, and do not understand why the SAI is necessary on our OE stock B6 1.8Ts, incorrectly believe the system is pure evil from the devil himself. On the the other hand, I believe that "test" pipes are evil and are the work of Satan. Nothing good can result from using them. I know this is true, there are no worthwhile justifications for debate about this. If follows that the irrational fear and hate often expressed here for the SAI system is at the minimum misguided. Therefore, it should be obvious to any informed and reasonable person that the anti SAI/ pro "test" pipe believers are involved in an evil conspiracy focused on devotion to Satan.

(No offense intended. My assertions can't be offensive unless... you believe in Satan.)

I guess I’m just lucky. 13 years and 220k+ miles and my SAI system still performs as it should. Replaced one hose a few years ago. Probably just jinxed myself and the pump will blow up tomorrow…..

I'm going to consider myself jinxed... 16 years of SAI and I had one failure. My 2000 Passat had the rivets come loose on the pump and it got pretty loud. The fix was pretty simple, and our B6's have a new pump that doesnt have the same issue. As far as test pipes go, I despise them. In traffic, I can tell almost immediately when the car in front of me has one, I don't like breathing unburned gas and I'm not going to do the same to the person behind me.

Not as sure on the Satan theory, but I agree in concept that it's not a nice thing to do to the guy behind you in traffic, and isn't evil just a concentration of not being nice?

[KHARDa4]

I guess I’m just lucky. 13 years and 220k+ miles and my SAI system still performs as it should. Replaced one hose a few years ago. Probably just jinxed myself and the pump will blow up tomorrow…..

I got all my SAI stuff removed everything is still all good. If you need anything let me know.

[customa4]

I'm going to consider myself jinxed... 16 years of SAI and I had one failure. My 2000 Passat had the rivets come loose on the pump and it got pretty loud. The fix was pretty simple, and our B6's have a new pump that doesnt have the same issue. As far as test pipes go, I despise them. In traffic, I can tell almost immediately when the car in front of me has one, I don't like breathing unburned gas and I'm not going to do the same to the person behind me.

Not as sure on the Satan theory, but I agree in concept that it's not a nice thing to do to the guy behind you in traffic, and isn't evil just a concentration of not being nice?

Agree.

[old guy]

I got all my SAI stuff removed everything is still all good. If you need anything let me know.

Thanks for the offer! I hope I never have to take you up on it…….

[diagnosticator]

Obviously my primary question was based on cleaning up the ridiculous amount of hoses and valves if there was not an operational benefit to them, it was just more of an annoyance to have to deal with them to do the coolant flange.
At this point I will just keep them intact and finish my swap to have an operational car.
I did look into Motoza and looks like pretty stout Tuning system, let me get all my coding done for the swap and that may be the next thing.
I ran into these same American emissions issues when I was working on my '88 Rx7 back in the 90's. The over engineering to meet US guidelines was a special kinda stupid.


Sent from my iPhone using Audizine mobile app

You and many others feel that the emissions equipment is mostly worthless. The factory engineers that are tasked with meeting US emission standards may or may not feel the same way, but the regulations still must be met. The factory did not include the equipment arbitrarily just to piss off a lot of Audi owners. Audi did not need to get the 1.8T certified to the Ultra Low Emissions regulations, but must have believed it would help sales, so ULV emissions certification was worthwhile for that and other reasons. Audi would have enjoyed a little more profit if the SAI and a couple of other systems were not included.
In this case, cold start up emissions are a significant part of the entire test procedure emissions. Minimizing cold start up emissions goes a long way toward reducing the overall emissions during the certification tests. Getting the cat up to operating temp as quickly as possible, serves that purpose and reduces the overall emissions occurring over the test procedures.
Because of the need to include the SAI and other equipment for ULV emissions certification, Audi used other cost cutting methods like specifying the crap brake package the 1.8T A4 had from the factory as one example. Another example of compromise for emissions reasons is the light cast pistons that are used in the AMB are specifically designed to help reduce emissions, compared to the much stronger forged pistons the B5 150 hp and TT225 1.8T engines use.

[diagnosticator]

I too am surprised by the vitriol expressed toward the SAI system. There is really very little to it. It’s basically an air pump and mechanical air valve operated by a vacuum signal from a solenoid. It only runs for up to 90 seconds on a cold start and that’s only when the ambient air temperature is above the frost point.

The much more complicated part of the SAI system is the cam chain adjuster that is used to provide 22° advance when the SAI system is being activated. The early 1.8T CCT’s only provided tension and didn’t have the ability to change the cam timing. A lot simpler. However, one advantage of the cam adjuster is that it can be used to increase the volumetric efficiency in the midrange operation of the engine.

It seems to me that it would be easier to just leave the SAI components alone than having to deal with the consequences of removing them. I am sure that all of the individual States will be going to go to more sophisticated methods of emissions testing in the future.

Especially in the wake of the VW diesel shenanigans.

Besides the cold start emissions reduction SAI provides, variable intake cam timing increases low and mid range torque and is used to regulate the internal EGR. Internal EGR eliminates the need for an add on EGR valve and the plumbing that goes with it. Internal EGR works by using the amount of valve timing overlap implemented at various engine speeds and boost pressures, with controlled reversion of exhaust gas directly from the cylinders into the intake manifold ports.
I wonder if or in what way engine tuners accommodate the internal EGR function when modifying ECU programming, since increasing boost pressure increases internal EGR rates.

[Gberg888]

MA doesn't catch it all... I've had my SAI properly coded out for over 2 years, and have never been flagged. I even just removed the SAI from a client vehicle here and just got it inspected last Wednesday.

Sent from my Nexus 6

Whose tune do you use? Please!!!!

[vjborelli]

Whose tune do you use? Please!!!!

I do my own tuning
I'm currently running an F21L kit with 550 injectors, and just installed a 3" MAF a few months ago.

Need to set some time aside to adjust my tune though... as I just did a bottom end build, and had everything spun balanced as well.



Sent from my Nexus 6

[redline380]

I am continually amazed at how many guys who don't know how the SAI system works, and do not understand why the SAI is necessary on our OE stock B6 1.8Ts, incorrectly believe the system is pure evil from the devil himself.

I am continually amazed at people who think SAI does a lick of good besides help pass emissions. It dead weight 30 seconds after cold start. It does very little during that 30 seconds. It is expensive to fix, easily breakable, and does nothing for the vehicle's performance.

Opinions will differ, but mine is such that it is a completely over-engineered pile of garbage .

[Charles.waite]

Obviously my primary question was based on cleaning up the ridiculous amount of hoses and valves if there was not an operational benefit to them, it was just more of an annoyance to have to deal with them to do the coolant flange.
At this point I will just keep them intact and finish my swap to have an operational car.
I did look into Motoza and looks like pretty stout Tuning system, let me get all my coding done for the swap and that may be the next thing.
I ran into these same American emissions issues when I was working on my '88 Rx7 back in the 90's. The over engineering to meet US guidelines was a special kinda stupid.


Sent from my iPhone using Audizine mobile app

Oh please. The b6 vacuum system is actually pretty simple.

I submit to you, the mid '70s Toyota 2F engine:

[Charles.waite]

Here's another good one of the 2F:



The worst part about all that stuff is that even when it was new from the factory, most of the emissions components were so ineffectual, removing them made very little difference in the pollutant output of the engine anyway.

[diagnosticator]

An '80s Honda Prelude is twice as complex. In that setup, the entire engine management system, instead of being electrical/electronic, was implemented as a complex analog pneumatic vacuum powered engine control system with vacuum circuits instead of electrical circuits.

[diagnosticator]

I am continually amazed at people who think SAI does a lick of good besides help pass emissions. It dead weight 30 seconds after cold start. It does very little during that 30 seconds. It is expensive to fix, easily breakable, and does nothing for the vehicle's performance.

Opinions will differ, but mine is such that it is a completely over-engineered pile of garbage .

The SAI system is required to pass emissions, minimizing the post cold start open loop fuel control time before closed loop control of fuel/air control can begin. The SAI is comprised of only the minimum hardware necessary to perform that function. SAI provides no other function or benefit. Since the SAI system only effects the exhaust gas composition during cold starts downstream after the combustion process, it is not capable of effecting engine performance.

Engine operation also requires a starter motor. Is the starter motor also over engineered and expensive dead weight after the engine is running only worthy of removal?

[eljay]

Can't wait for these this simple concept to come to fruition:
http://www.thestar.com/autos/2015/09...e-changer.html
http://si-cat.com/

[diagnosticator]

Can't wait for these this simple concept to come to fruition:
http://www.thestar.com/autos/2015/09...e-changer.html
http://si-cat.com/

I don't want to rain on anyone parade, but there is nothing really innovative about the described electric cat heater. Cat manufacturers and car makers know the various ways to heat up something. It is likely the method used with our Audis is more powerful than the electric heater method, and does not require high capacity electrical power production. Our Audis inject extra fuel, inject extra oxygen into the exhaust and retard igntion timing to provide the heat needed in the cat to heat the cat core quickly. The extra fuel, mixed with the added oxygen in the exhaust from the SAI, assisted by the increased exhaust gas temp from the retarded ignition timing, causes the extra fuel to burn in the cat core, equivalent to 1000 watts or more of electrical power. A limit to how fast a cat core can be heated up, is determined by the mass of the cat core, and the temp differential in the cat. A certain mass can only absorb heat at a limited maximum heat transfer rate, no matter how much extra heat energy is available in the cat core. Notice the development team does not include a mechanical (or any) engineer.

[Arnie91]

I have a testpipe, and passing emissions is no problem where I am. So if I can make the engine bay a lot cleaner and easier to work in then it seems like a positive. I had just one question. Is it possible to make the SAI System a lot cleaner and compact, has anyone done this?

[diagnosticator]

I have a testpipe, and passing emissions is no problem where I am. So if I can make the engine bay a lot cleaner and easier to work in then it seems like a positive. I had just one question. Is it possible to make the SAI System a lot cleaner and compact, has anyone done this?

"Passing emissions" fraudulently is illegal. Just because the local authorities don't examine your non compliant/removed emissions equipment does not satisfy the legal and practical rules and applicable regulations according to the law.

Minimizing further the hardware included in a functional SAI, would be very difficult and impractical.

[MoparFreak69]

I just removed all that garbage from my A4 and will code it out shortly. To me it's just ugly dead weight. The method I used on my GTI, and what I'll do on my A4 is simple. Under a certain temperature the fuel maps will cause the engine to run leaner (~15:1) with a slightly elevated rpm. I did a couple tests between a fully functional SAI system and my code-out method to monitor how quickly the cats heated up. My method brought the cats up to a typical operating temperature 5-7 seconds faster than the SAI system could on a stock tune. That's enough evidence for me.
Delete all the SAIs!!

[Let it snow]

I just removed all that garbage from my A4 and will code it out shortly. To me it's just ugly dead weight. The method I used on my GTI, and what I'll do on my A4 is simple. Under a certain temperature the fuel maps will cause the engine to run leaner (~15:1) with a slightly elevated rpm. I did a couple tests between a fully functional SAI system and my code-out method to monitor how quickly the cats heated up. My method brought the cats up to a typical operating temperature 5-7 seconds faster than the SAI system could on a stock tune. That's enough evidence for me.
Delete all the SAIs!!

What is your method?

[old guy]

I did a couple tests between a fully functional SAI system and my code-out method to monitor how quickly the cats heated up. My method brought the cats up to a typical operating temperature 5-7 seconds faster than the SAI system could on a stock tune. That's enough evidence for me.
Delete all the SAIs!!

Interesting. Do you get a CEL or have you coded it out? If coded out will it pass the more aggressive emissions reset test or will the SAI readiness bit stay active?

A question for both you and vjborelli: How do you get around the ECU rationality test that occurs approximately 45 seconds after the SAI cycle completes?

[redline380]

Engine operation also requires a starter motor. Is the starter motor also over engineered and expensive dead weight after the engine is running only worthy of removal?

No because it is practical and running without one would unduly burden me

"Passing emissions" fraudulently is illegal.

Who cares? Not me. I am willing to bet over half of members' cars on here are "illegal." I break the law all the time. If I had the opportunity to pass emissions in Minnesota without SAI, I would. Thank God Gov. Jesse Ventura got rid of our emissions. Second best thing he ever did during his tenure.

I have great resentment for many government regulatory agencies, and the EPA is one of them. A bunch of damn crooks that want to impose their agenda. Am I saying factories should be able to spew as much toxic smoke as they desire? No. Am I saying they should loosen regulations on vehicle emissions? No, not even saying that. What I am saying is that I won't let some bureaucrat in D.C. tell me baby seals will die if I take SAI out of my car.