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What part exactly were you looking for a write up on? If it's AEM meter ?'s or AFC Select MAF controller ?'s then I can share my experience... If it has to do with resistors, rheostats, or variable pots... then members Todd or porsche 1999 are the goto guru's... Since I have tried both methods I think overall, this is the way to go. Especially for peace of mind and knowing that you are taking full advantage of the way the 996 3.4 liter ecu was programed originally with the larger maf housing. I Think I will keep it like this for awhile ;^) As I mentioned in your other post: The reason for your difference in A/f at WOT is because your calibrated signal was different than it is now. Running at WOT at a 13:1 air fuel ratio will make your car feel like it has more pep since you are running lean.......maybe too lean. Especially running 91 octane fuel. Had you calibrated the signal with a higher ohm restistor, you would have had the exact same results. All you did was make your engine run leaner than it was. Now you simply "tricked" your engine into thinking it was getting less air than it really is by using a mechanical device rather than an electronic one. I really enjoyed the "calibrated" setup I had before and it worked great for the most part.. It is definitely a great alternative, but now I just feel like I have the best of both worlds. Factory setting air fuel ratios with the ability to fine tune. Thanks for your input 1999, I always learn a lot from you. Bill

Since I have tried both methods I think overall, this is the way to go. Especially for peace of mind and knowing that you are taking full advantage of the way the 996 3.4 liter ecu was programed originally with the larger maf housing. I Think I will keep it like this for awhile ;^) The reason for your difference in A/f at WOT is because your calibrated signal was different than it is now. Running at WOT at a 13:1 air fuel ratio will make your car feel like it has more pep since you are running lean.......maybe too lean. Especially running 91 octane fuel. Had you calibrated the signal with a higher ohm restistor, you would have had the exact same results. Thats what I enjoy about the maf signal controller that I have. I can see an immediate response to air fuel ratio fine tuning from the drivers seat. I am still able to do very fine tuning and adjust the voltage signal if I see any strange spikes or make any intake changes in the future.. but now with the new housing I do not have to make any voltage corrections at the moment. I just did the change last night so I am still feeling out the changes. I may fine tune a little bit later, but for now its nice to have a factory setting starting point, which I felt I was sort of guessing at before. I really enjoyed the "calibrated" setup I had before and it worked great for the most part.. It is definitely a great alternative, but now I just feel like I have the best of both worlds. Factory setting air fuel ratios with the ability to fine tune. Thanks for your input 1999, I always learn a lot from you. Bill

I wanted to give a quick update on my current setup as of last night ... After 7 months of running a "calibrated" maf signal I finally decided to track down the proper MAF housing size and got my hands on Todd's recommended "Cayman/Boxster 987" Maf housing . Brand new from Sunset Porsche parts the discount is still a lot ... $275 because it includes the actuall sensor which I can not use. All I wanted was the housing tube to plug my boxster/996 sensor into. I finally tracked down the proper size maf housing from a dismantler and saved myself over $200...It also has the screen built into it to help with air turbulence. In the process I also discovered a proper sized nice alternative Bosch maf housing for a lot less $$ then Porsche... (pm me if interested) My original 986 boxster maf housing measures inner diameter of 70-72mm. (76mm or 3 inch outer diameter) The 3.4 liter 996/Cayman maf housing measures inner diameter of 83-85 mm (90mm outer or 3.5 inch outer diameter) A difference of close to 20 percent in size. With my "calibrated" maf signal my air fuel ratios were staying a solid 12-12.5 and the car was running very strong. Even so I still felt that "tricking" the ECU with a calibrated signal or resistor may not be taking full advantage of all the fuel maps and how they were designed to work with proper air flow measurement from Porsche. Even though I really enjoyed my setup there was always a question in my mind if I was really allowing the programming to work correctly under those "calibrated" conditions. Since I want my 3.4 Boxster to run it's strongest at all times I decided it was time to switch over to the proper maf housing size. After modifying intake tube lengths for the new housing I got it to fit nicely. My current intake setup is: -Cone filter plugs onto front end of Cayman Maf Housing.. -back end of housing plugs onto 3 inch intake tubing all the way to Throttle body. (996 throttle body is only 3 inches in diameter) I unpluggled the battery, reset my computer, and disabled my "AFC-select" maf voltage controller. After a few runs through the rpm range for the computer to learn the new setup everything seems to be working very nice. I have to say.... I think overall the engine feels stronger and more refined now. My peace of mind feels much better as well since I know for sure that the proper air measurement is working with the fuel maps as designed from Porsche, rather than a "calibrated" signal to trick the computer. Afr readings at wide open throttle are around 13 from low to mid rpms and then drops to around 12.5 for the upper rpm range. My initial impressions are that the car feels more responsive. Hard to say for sure because it was running quite fast before as well. Just seems to be more sorted out all around with partial throttle response being a bit more aggressive and then full throttle applications feeling a bit stronger up top. Since I have tried both methods I think overall, this is the way to go. Especially for peace of mind and knowing that you are taking full advantage of the way the 996 3.4 liter ecu was programed originally with the larger maf housing. I Think I will keep it like this for awhile ;^)

What part exactly were you looking for a write up on? If it's AEM meter ?'s or AFC Select MAF controller ?'s then I can share my experience... If it has to do with resistors, rheostats, or variable pots... then members Todd or porsche 1999 are the goto guru's... I wanted to give a quick update on my current setup as of last night ... After 7 months of running a "calibrated" maf signal I finally decided to track down the proper MAF housing size and got my hands on Todd's recommended "Cayman/Boxster 987" Maf housing . Brand new from Sunset Porsche parts the discount is still a lot ... $275 because it includes the actuall sensor which I can not use. All I wanted was the housing tube to plug my boxster/996 sensor into. I finally tracked down the proper size maf housing from a dismantler and saved myself over $200...It also has the screen built into it to help with air turbulence. In the process I also discovered a proper sized nice alternative Bosch maf housing for a lot less $$ then Porsche... (pm me if interested) My original 986 boxster maf housing measures inner diameter of 70-72mm. (76mm or 3 inch outer diameter) The 3.4 liter 996/Cayman maf housing measures inner diameter of 83-85 mm (90mm outer or 3.5 inch outer diameter) A difference of close to 20 percent in size. With my "calibrated" maf signal my air fuel ratios were staying a solid 12-12.5 and the car was running very strong. Even so I still felt that "tricking" the ECU with a calibrated signal or resistor may not be taking full advantage of all the fuel maps and how they were designed to work with proper air flow measurement from Porsche. Even though I really enjoyed my setup there was always a question in my mind if I was really allowing the programming to work correctly under those "calibrated" conditions. Since I want my 3.4 Boxster to run it's strongest at all times I decided it was time to switch over to the proper maf housing size. After modifying intake tube lengths for the new housing I got it to fit nicely. My current intake setup is: -Cone filter plugs onto front end of Cayman Maf Housing.. -back end of housing plugs onto 3 inch intake tubing all the way to Throttle body. (996 throttle body is only 3 inches in diameter) I unpluggled the battery, reset my computer, and disabled my "AFC-select" maf voltage controller. After a few runs through the rpm range for the computer to learn the new setup everything seems to be working very nice. I have to say.... I think overall the engine feels stronger and more refined now. My peace of mind feels much better as well since I know for sure that the proper air measurement is working with the fuel maps as designed from Porsche, rather than a "calibrated" signal to trick the computer. Afr readings at wide open throttle are around 13 from low to mid rpms and then drops to around 12.5 for the upper rpm range. My initial impressions are that the car feels more responsive. Hard to say for sure because it was running quite fast before as well. Just seems to be more sorted out all around with partial throttle response being a bit more aggressive and then full throttle applications feeling a bit stronger up top. Since I have tried both methods I think overall, this is the way to go. Especially for peace of mind and knowing that you are taking full advantage of the way the 996 3.4 liter ecu was programed originally with the larger maf housing. I Think I will keep it like this for awhile ;^)

Hey Andy, this post was over a year ago, but here is the information I think you are looking for. You may already know this. What you are referring to as LSD "limited slip differential" may also be confused with "ABD" automatic braking differential. According to some of my very early 911/Boxster Porsche brochures and my own experience with Boxsters "ABD" automatic braking differential this is how it works in a nutshell. PSM Porsche stability Management while ON uses ABS, anti-slip regulation, an automatic brake differential and a battery of sensors that monitors direction, pitch, speed, yaw velocity, and lateral acceleration. It will apply the brakes to individual wheels in order to stabilize the vehicle based on what kind of slide/skid the car is in. Included in PSM is the ASR anti slip regulator, and ABD. If one tire slips the automatic brake differential applies the brake to the slipping tire, hence reacting and behaving just like a limited slip differential. If BOTH tires spin, then the ASR slip regulator kicks in and retards the ignition and cuts power so that traction is regained. Turning PSM OFF will disable the ASR, four corner braking montiors, and pitch/yaw sensors...... BUT the Automatic braking differential stays on at ALL times up to 62 mph... That is why you will notice that even with the PSM OFF light showing you will still see a separate flashing warning light letting you know that ABD is still kicking in during certain rear traction sliding situations to try and behave like a limited slip differential.... Hope this makes sense. It is pretty amazing programing that Porsche has developed. But nice to know you can turn it off if you are brave enough ;^)

Bill, From what I have read I think your light may be coming on due to testing your switch without everything else hooked up. On mine I did not have the ignition switch in position 0. When my original piece failed it left my key stuck and I once I forced the key out I neglected to realign it before installing the new switch. So mine was not lined up correctly when I tightened the set screws. Yup, somehow I triggered it while testing the ignition without having everything plugged in. Swung by the dealership and they reset all my fault codes. there were fault codes for the unplugged gauge cluster as well as the seatbelt/airbag sensor... All good now. another lesson learned... take care. Bill

hey spyder I just installed a new ignition switch last night and have a similar issue. car starts fine and everything seems to work , BUT now my airbag light is on. it was never on before so it has to be something with the new part or something was knocked loose. Can you give a few more specifics about what was not working for you and what exactly was not "lining up" ?? maybe we have similar connection issues. did you also notice that it takes a little more effort to turn your key with the new part?.... my boxster is a 1998... I think I know what may have happened. I took the gauge cluster out for much easier access to ignition switch... I tested the car to see if the ignition worked with out having the cluster and a couple other things plugged in... maybe that did it... now i need to get the code cleared... hmmmm... just a thought, but not sure... thanks, Bill

Hmmm... Sometimes our wide performance tires will "wobble" a bit when still cold in the morning. As they warm up, tire pressure increases, and they flex a bit which may help the wobbling go a way a bit.... I have had several tires by now and always experience a little wobble when cold. -balancing would be my first guess. -check tire pressures -maybe "flat spot" from very hard braking or skid... (abs should have prevented that though) -new tires would be my next guess. Be sure to check "inside edge" tread wear.. Porsche sets up the alignment to wear out inside edge faster.. (especially on rears) everything may look fine on outside edge even though tread is very low on inside... -Did the previous owner use "wheel spacers"??? if so, make sure they are flush against the rotor. One time the screw that holds rotor in place was not screwed in tightly and flush. so when the wheel spacer was installed on my car the rotor screw was out just enough to throw things off and cause a horrible wobble. took me several wheel balances to figure that one out... alignment might not be a bad idea, although alignments should not cause major wheel vibrations.. so I was told, but you never know. best of luck, Bill

Cayenne S is the same.... but you should know like gdavison mentioned... According to Porsche the Cayenne's , when cold starting, run in 1st for a few seconds. This is programmed into the transmission computer in order to "warm up" the catalytic converters faster within the first few seconds.... Once Cats are hot, then 2nd gear is the default gear for starting accelleration from stop... No matter how aggressive you drive... 1st gear can only be select with "manual mode" or flicking tip button to downshift at stop... Personally, I really don't like driving our Cayenne S without using "manual mode" stick shift... my wife drives the car fairly easy.. Then when i jump into it the transmission programing is for easy driving where I like to drive aggressively... it never seems to learn fast enough for my driving style, so I automatically drive it like a manual all the time.. Then I can put it into first gear when ever I come to a stop... but that's me... my wife hates my driving .. haha.. Makes for a much funner experience if you ask me... all the best Bill

hey suburban99... hmmm.. could be several things.... don't know how mechanically inclined you are but here are some suggestions to consider... 1. clean MAF sensor.... I use 90% rubbing alcohol... poor into cup, then "dip and swirl" the MAF sensor into it a few times... shake and let dry for a few minutes... after re-installing, unplug battery for a few minutes to reset computer... MAKE SURE YOU HAVE RADIO CODE... 2. While the sensor is drying off.... remove air intake tube and give throttle body a good cleaning with some carburator cleaner or thottle cleaner... watch out for over spay into eyes! 3. New Air Filter?? 4. Check tension on throttle cable... cables can stretch over time... a little trick to increase rpm idle and throttle response is to add a "zip tie" to the very end of the cable where the "hammer anchor" at the very end of the cable slides into throttle control hook.. ... its like adding a little spacer in there to take out some slack.. just enough to take out some tension.... not too much or your idle will be too high... I had to play around with it a bit to get it just right.. ... think of it this way too... if cables are stretched enough then full pedal fully pressed is only opening throttle body 90% versus 100% see here for a little more insight http://www.renntech.org/forums/index.php?showtopic=4446 5.. Fuel or gasoline treatment to clean injectors... 6. New spark plugs 7. better fuel.... are you using cheap gas, low octane?? those a few things I would try first... if all else fails I am sure the dealer would not mind taking your money ;^( Hope these work instead of dealer... all the best. Bill

Hey Pieter, Congratulations on your conversion to 3.4. A few things I would recommend while you have the motor out... Best of luck.... If done properly you will be very happy! Bill Hi Pieter, No problem. I know how stressful and exciting an engine swap can be. Stressful because you want everything to go smoothly, run properly, and last long. Depending on the motor, programming, and your bolt on additions like exhaust and intake a 3.4 motor can make anywhere from 280 horsepower to 325 hp. So getting the right combination of parts together can make a big difference. I am not sure if you have access to discount parts like Sunset Imports (800) 346-0182 that may or may not ship overseas, not sure. but off the top of my head these are some prices I paid approximately... don't quote me though ;^) best thing to do is call Sunset. They are nice guys over there. --As far as RMS. The seal part is only around $10-15 dollars. So it is not expensive, but needs to be installed properly and with care. It will help you sleep better knowing the seal has been updated. --The clutch disc and pressure plate were around $300-350 dollars from Sunset ask the parts guy to cross reference the part number for the 986 2.5 5 speed versus the 987 boxster S.... Maybe the disc part numbers and bolt patterns are the same, ... I changed mine 3 years ago, so the details are a bit hazey. I have had no problems with over 20,000 miles and I drive aggressively. --throw out bearing may be included in clutch kit and the pilot bearing was not that expensive... maybe $20 --the oil baffle was around $30 but needs some Porsche sillicon gasket stuff to reseal the oil case. --AOS was around $90-100 -- dual mass Flywheel... expensive... like $600-700 -- one more note on the air intake... The hi flow air intake is part of the solution. The "size" of your MAF housing makes a bigger difference because it relates a voltage signal to your 996 ecu. Based on the voltage signal the 996 ecu applies certain fuel maps. It is ok to use the stock boxster maf housing, but just be aware that using the smaller housing sends a "higher" signal to the ecu because air has to pass faster through it than a 3.5 inch housing. This higher signal will change your fuel maps and run rich. There are easy solutions to this as you may have read already in the post I gave you earlier. It could be as simple as applying a small resistor to the maf signal wire. But it makes a big difference in performance. all the best. keep us updated on your success... B

Hey Pieter, Congratulations on your conversion to 3.4. A few things I would recommend while you have the motor out... 1. Change the RMS (rear main seal) to the latest offered by porsche for the 3.4... Porsche has upgraded and made this part better several times now. Get the latest and greatest. 2. Depending on how old your plastic Coolant resevoir container is. I would replace it. early boxsters and 996's had problems with these cracking when they get old. I had replaced mine once with the 2.5 motor and then replaced it again just to be safe when I put in the 3.4 since they run a little bit hotter. 3. Change out your flywheel as well. depending on your mileage it may be a good idea. I replaced my clutch with the 987 boxster part number and have had no problems getting 325 hp to the ground. But unless you drag race all the time, then you will want something stronger. get a new pilot and throw out bearing. Flush your clutch fluids.. 4. change your motor mounts if they look tired. you will be dealing with a lot more torque under hard accelleration and engine breaking. 5. Very IMPORTANT. Install a hi flow intake if you want proper performance. The boxster airbox is too small... You also must have a MAF housing tube that is 3.5 inches like the stock 996 or if you use the boxster 3 inch maf housing then you will need to modify or "callibrate" your voltage signal for your 996 ECU to apply the proper fuel maps or else it will run very rich.....see this thread it explains a lot on proper MAF signal: 20-30 hp difference. http://www.renntech.org/forums/index.php?s...mp;#entry125122 6. If you live in a very hot environment then a center radiator may be a good idea, but then you would need an opening in your front bumper for air flow as well. this is optional... 7. replace any coolant hoses that look dried out or brittle. 8. If you plan on tracking the car there is an "oil baffle" made for the 2001 and new engines. This keeps oil from sloshing around so much during hard cornering and causing oil starvation.. If you have a 1999 3.4 engine then it may not have this baffle in it.. 9. make sure to get your key reprogrammed as well to work with the 996 ecu and alarm system. 10. Think about also replacing the Air Oil separator.. much easier to do while engine is out and these do go bad depending on mileage. Best of luck.... If done properly you will be very happy! Bill

Wheels look Great! could you tell us what the width is on those 19's and did you need spacers? How does the ride quality feel? Great choice, they really look great. Bill

Usually the amp has a seperate power lead to the battery. If the battey cable was disconnected, I would assume that this cable may be hanging by itself. Pull the shroud and see if you have a power cable to the amp off! Power amps turn on and off by use of a sense singnal Hence the direct connection to the battery. Thanks Kevin! I'll look at it tomorrow. One question, How is the cable from the amp usually attatched to the battery? Thanks Hey Phillip, So how is it?? What did you notice first about the new motor. is it night and day?? details, details... ;^) what else did you have done, any mods?

What part exactly were you looking for a write up on? If it's AEM meter ?'s or AFC Select MAF controller ?'s then I can share my experience... If it has to do with resistors, rheostats, or variable pots... then members Todd or porsche 1999 are the goto guru's...

Todd mentioned he was not convinced the boxster "airbox intake" could supply enough air. I agree, about the stock "airbox", but I'm on the fence about the 3 inch piping going to throttle body if a cold air "cone" style intake and a straight 3 inch pipe all the way to the throttlbody replace the constrictive airbox.. I definitely saw an increase in performance on the dyno with the cold air intake and new plumbing..so the 3.4 needs to breathe better for sure.. With the less restrive cone filters It may be getting the air it needs, but it just has to travel faster through 3 inches versus 3.5. What surprised me is that I've looked at some RUF photos of their 3400s air intake tube that attaches to the throttle body and it is the same as stock boxster.. but RuF definitely modifies the "airbox" for higher flow. There are some cheaper AFR gauges costing around $50 and they splice into the wires of your existing "narrow band" Oxygen sensors. they read a voltage and give you a read out whether "lean or rich" , but not a very accurate air fuel ratio Number... I am sure they work "ok" if you want to know if you are basically rich or lean ... but if you wanted to know exactly how to dial in 12.5 or a 13 AFR it would be difficult with those gauges. My dyno tuner said the only way to get a very accurate reading is with a "wideband" sensor. These guages which cost around $200 come with their own oxygen sensors and are also able to plug into other types of software for further tuning. This allows pro logging data at the dyno so that you can get a better reading pre-cat than a "sniffer" stuck in the exhaust will give you. On a cosmetic side I chose the AEM also because it came with different color gauge faces and bezels so that it can match perfectly with my silver face gauges or swap for black if you have black faced gauges/bezels.. see quick youtube of overviews ..here are 2 vids to look at.. http://www.youtube.com/watch?v=ivOtfoY8P2Y...feature=related If you can find a proper size Maf housing and intake plumbing then the AFR gauge may not be completely necessary because you still will not be able to "adjust or modify" your signal in any way... You could have it dyno tested once for about $80 to make sure you are good to go with your AFR and never worry about it again. AFR gauges are great for those who have a bit more tweaking to do and have a way of "tuning" so they can dial it in. so if you added a "variable pot resistor", then you could tune or dial in your AFR... that's when the gauge would be very useful... well, hope this helps... all the best Bill

Hey Monkey... If you talked to Todd then you probably already came across this thread: http://www.renntech.org/forums/index.php?s...=21472&st=0 Todd, 1999, and I talked extensively about this exact issue. similar results with a few different ways of getting there. from the cheap to a bit more expensive... It depends on how much flexibilty you want in tuning. I don't know if you are like me, but I wanted to see the results of my tuning/changes. I spent many hours and many dyno runs getting my car dialed in. The one thing that gives me instant feedback without having to go to dyno anymore is the AEM wideband Air fuel ratio gauge: $200 on ebay... website if you wanna see what looks like: http://www.aempower.com/ViewCategory.aspx?CategoryID=67 This requires adding a "bung" and tapping sensor into exhaust. $40-50 bucks for muffler shop to install bung. Then just screw in sensor and easily run wire into car and plug in gauge. Having and Knowing your exact AFR will save you a lot of dyno tuning and money later if you do additional tweaks or add ons. Then it is up to you how to handle the maf signal correction... either increase the size of the maf housing to equal that of the 996, or "calibrate" the voltage signal from the maf to the ecu using a type of resistor .... if you are running rich, then the voltage signal from the maf is too high. best of luck.... Once it is corrected you will feel a very nice difference all around. Like a new car ;^) Bill

No way.... so since I am running a straight 3 inch Maf housing and intake pipe all the way to the throttle body a single resistor or rheostat would have done the trick?? so are you saying all I had to do was add a little resistor inline on my maf signal to the ecu similar to like this photo?? http://www.houseofrage.com/tundra/rrtun33.jpg Or run a single rheostat inline before the ecu and just dial the rheostat down to get the desired 15.5 kg/h reading at idle?? That makes a lot of sense since the smaller 3 inch maf housing piping has globally offset the the voltage. just turning down the voltage globally to the levels that a 3.5 inch housing would produce would be enough to trick the ecu. ****, your good. wow, should have had this dialogue a week ago. I would have loved to try this out, but at this point I have already committed to, installed and dialed in the AFC-SELECT unit... I am still very pleased with the results I have and the fine tuning flexibility the AFC-select +/- 50% correction it gives you makes it a really fine tuning gadget. Plus it has a lot of cool flashing lights... haha... One last question... so is an AFR of 13 flat across the board the most ideal setting or is 12-12.5 a better bet??? Thanks so much for your input. I learned a lot! I am sure this dialogue will help a lot of members. Bill

The easiest and most effective way is to simply get an adjustable vacuum switch similar to the one shown in the link below. The MAF signal #5 wire would be cut with the DME side of the wire going to the common on the switch and the MAF side of the cut wire to BOTH switchable leads on the switch. The switch is activated by vacuum, switching from one lead to the other depending on whether vacuum is present or not. The default lead (vacuum present) would be connected to the MAF side of the cut wire without resistor and the other lead would be connected to the MAF side of the wire with a resistor the size which will give you the A/F ratio you want at WOT. You could also put a rheostat inline to make it easy to test different settings Using the above method, you maintain the current tubing configuration of the intake and it allows an easy way for fine tuning in a matter of seconds. http://images.google.com/imgres?imgurl=htt...l%3Den%26sa%3DN hey 1999.... very clever! So I noticed that on that particular switch you can "preset" a vacuum pressure with a little screw. Is there a certain psi needed before the switch kicks in or do you just have it switch at the slightest vacuum change? I would assume you would figure out the vacuum pressure at a certain throttle position so that it switches close to wot??? I figure there are a lot of different resistor sizes to try out and picking the right one sounds like a lot of trial and error... The rheostat sounds like the way to go and you can just turn the knob down to dial lower the maf signal......aaaahaaaa... very interesting. Gotta know what rheostat resister range to chose though... , but what if you need a "stronger" signal because you are running too lean? hmmm last question... since it is an "on/off" switch method based on vacuum there is not a lot of fine tuning involved, Kind of a one adjustment fixes all and then just leave it....... so how is driveability? can you feel it switching so quickly between the 2 maf signals? Thanks for the info, that was very eye opening...very cool.

Nice job, but it would be alot easier to simply make your MAF have a variable signal. Maf would be calibrated one way in closed loop which would allow the O2 sensors to properly managed the a/f and then would switch to the another calibration in open loop. You then have a fully adjustable MAF signal and full control of your a/f ratio in a matter of seconds. hey 1999-911 and Todd, I have read a lot of your posts on conversions and Thanks for all your input and knowledge...you guys rock! I actually got my hands on a stock 996 air box with the intention of cutting out the MAF housing to use with my cold air intake... well, as you already know... not so easy. I then tried to find some 3.5 inch tubing and create my own MAF housing to mimic this as well, but gave up. The idea of fine tuning won me over in the end. You both have great ideas and options with the similar idea of controlling the MAF signal, but how exactly do you rig it to be able to do that? How do you control when it switches from "closed" to "open" loop calibration? Is it a throttle position or rpm?? Is it a unit you buy and splice into the maf signal wire at the ecu? what's it cost? The AFC-select works a bit like that. 4 wires are connected at the ecu to monitor Throttle position, power, MAF signal, knock sensor. The maf signal wire is the only wire altered so that the signal is sent to the AFC-select unit and then a "new corrected signal wire" is sent back into 996 ecu. What I was impressed with on AFC-select is the ability to designate exactly which rpms to correct voltage % on and at what throttle position I wanted to adjust the signal on. For example: If on the dyno my MAF signal at 70% throttle position (tp) is already giving a rich afr of 10. Below 70% tp the afr is ok. So in this scenario by throttle position 70% I wanted the the voltage corrected by -20%. I can create the parameters for the throttle position like this: at 20% tp = 0% voltage correction...correction would ramp up smoothly so that by 70% throttle position and above = 100% preset voltage correction is reached. (voltage correction being preset at -20%) This allows us to have a nice smooth linear correction on MAF signal output. then we fine tuned every few hundred rpms to smooth out any bumps or dips in the AFR readings.. After all was said and done we made about 15 runs on the dyno as we adjusted the signal correction little by little to make sure of never running too lean. Is there a way to do this type of callibration with a simple resistor to alter the MAF signal? I am all for any solutions or ideas to help. Especially since a lot of us have gone down the bolt on mods and conversion routes only to be disappointed when things are not running properly and as expected. After a couple hundred miles this weekend I am very pleased. Now I have to just keep my fingers off from tinkering with the computer to get that last little .01% correction ;) I also find myself watching my afr reading like crazy whenever I accelerate at wot. It has been great though and holds 12.0 afr pretty solid. Sometimes too many gauges are a distraction! :o What AFR's do you find to be ideal and safe?? Thanks again for your input. it is greatly appreciated. Bill

I realize these posts were awhile ago, but I know there are many of us still dealing with this problem of our MAF sensor causing rich or lean AFR's when we start adding bolt ons. I have had a major break through and wanted to share the solution I came upon. I have a 98 boxster with a 3.4 liter conversion. I have had it over a year this way and have been driving it using very rich AFR's for most of the time. My AFR's have been reading in the 10's for quite awhile. Even this way the car was making decent power, about 310 at the crank, but with all of my modifications I should have been closer to 320-330. ECU Tuning has been a break through, but not how you think. I originally had "powerchip group" reprogram my ecu rom, but after 3 different programs and 3 100 mile round trips to their facility I was still running very rich. I then contacted "Steve", owner of SR Motorsports in Gardena (310-516-1003) for some dyno tuning. He has some amazing experience with tuning import cars and was in the research and development for APEX products for 5 years. I was running very rich for awhile and my Air fuel ratio readings were around 10 under wide open throttle on the dyno. The basic idea we discovered is that the MAF housing diameter for the stock 996 is 3.5 inches. For the Boxster it is 3 inches. When the 3.4 liter motor is drawing in air it is pulling air in "faster" through the smaller boxster 3 inch MAF instead of the stock 996 3.5 inch housing it was oringinally programmed for. This "faster/higher" reading sends a voltage reading to the996 ecu that calls for more fuel and thus richens everything at wide open. The opposite can happen if your MAF housing gets too big. We wanted to be able to fine tune as needed so Steve recommended the "APEX AFC-SELECT" for german cars. http://www.apexi-usa.com/product_electroni...5&pageNum=1 Hard to find these days, but they are out there. I also installed an AEM wideband Air fuel ratio gauge to monitor AFR's from within my car. The APEX AFC-Select allows us to control the voltage reading of the MAF at any designated rpm before it gets to the 996 ecu. By doing so the 996 ecu takes the new voltage reading and adjusts the fuel injectors as required. Thus we were able to fine tune my AFR to read a conservative 12 all across the board. From this tuning alone I gained 20-30 lbs of torque and horsepower across the mid rev range from 3500-7000 rpm. I was stunned and amazed at the difference! The whole process of installation and tuning took about 3 hours. Now I have a system that I can fine tune to my unique modifications. I would highly recommend this procedure over any "ecu rom tuning" in a heart beat because everyone's car mods are different. This eliminates wondering if your "reprogrammed chip" needs to be adjusted if you ever ad anymore bolt ons. Steve's knowledge of the product and ease of use was paramount to making it happen so smoothly..Now granted this is not adjusting timing and other parameters that rom chips do, but for most bolt on mods that deal with faster air flow this is a great solution. We wanted to start out conservative and tuned the air fuel ratio to hold 12 across the entire rev range at wide open throttle. We will later be raising it to an AFR of 13 which should result in a gain of another 10-15 hp and tq. For this test we will keep it conservative and safe at 12 for a few 100 miles to make sure no check engine lights or problems show up.. My before and after dynojet peak dyno readings at the wheels were as follows: base: 255hp @ 6300 and 215tq @ 4600 (wheels) X 1.2 = 306 hp and 258 tq at crank AFR=12 flat :270hp @ 6300 and 235tq @ 4600 (wheels) X 1.2 = 325 hp and 282 tq at crank compare this with a bone stock 300 hp 2001 996 3.4 dynojet: 251hp and 213tq X 1.2 = 300hp and 256tq at crank AFR=13 flat Car has now been dyno'd with close to 325 hp at the crank and weighs only 2750 lbs. Gtech Pro RR g-force meter performance run: *adjusted 0-60 foot launch 1.9 sec 0-60 mph in 4.4 sec 0-100 mph in 10.5 sec 0-130 mph in 17.2 sec 0-150 mph in 27 sec Quarter mile time 12.7 sec @ 110 mph.

I realize these posts were awhile ago, but I know there are many of us still dealing with this problem of our MAF sensor causing rich or lean AFR's when we start adding bolt ons. I have had a major break through and wanted to share the solution I came upon. I have a 98 boxster with a 3.4 liter conversion. I have had it over a year this way and have been driving it using very rich AFR's for most of the time. My AFR's have been reading in the 10's for quite awhile. Even this way the car was making decent power, about 310 at the crank, but with all of my modifications I should have been closer to 320-330. ECU Tuning has been a break through, but not how you think. I originally had "powerchip group" reprogram my ecu rom, but after 3 different programs and 3 100 mile round trips to their facility I was still running very rich. I then contacted "Steve", owner of SR Motorsports in Gardena (310-516-1003) for some dyno tuning. He has some amazing experience with tuning import cars and was in the research and development for APEX products for 5 years. I was running very rich for awhile and my Air fuel ratio readings were around 10 under wide open throttle on the dyno. The basic idea we discovered is that the MAF housing diameter for the stock 996 is 3.5 inches. For the Boxster it is 3 inches. When the 3.4 liter motor is drawing in air it is pulling air in "faster" through the smaller boxster 3 inch MAF instead of the stock 996 3.5 inch housing it was oringinally programmed for. This "faster/higher" reading sends a voltage reading to the996 ecu that calls for more fuel and thus richens everything at wide open. The opposite can happen if your MAF housing gets too big. We wanted to be able to fine tune as needed so Steve recommended the "APEX AFC-SELECT" for german cars. http://www.apexi-usa.com/product_electroni...5&pageNum=1 Hard to find these days, but they are out there. I also installed an AEM wideband Air fuel ratio gauge to monitor AFR's from within my car. The APEX AFC-Select allows us to control the voltage reading of the MAF at any designated rpm before it gets to the 996 ecu. By doing so the 996 ecu takes the new voltage reading and adjusts the fuel injectors as required. Thus we were able to fine tune my AFR to read a conservative 12 all across the board. From this tuning alone I gained 20-30 lbs of torque and horsepower across the mid rev range from 3500-7000 rpm. I was stunned and amazed at the difference! The whole process of installation and tuning took about 3 hours. Now I have a system that I can fine tune to my unique modifications. I would highly recommend this procedure over any "ecu rom tuning" in a heart beat because everyone's car mods are different. This eliminates wondering if your "reprogrammed chip" needs to be adjusted if you ever ad anymore bolt ons. Steve's knowledge of the product and ease of use was paramount to making it happen so smoothly..Now granted this is not adjusting timing and other parameters that rom chips do, but for most bolt on mods that deal with faster air flow this is a great solution. We wanted to start out conservative and tuned the air fuel ratio to hold 12 across the entire rev range at wide open throttle. We will later be raising it to an AFR of 13 which should result in a gain of another 10-15 hp and tq. For this test we will keep it conservative and safe at 12 for a few 100 miles to make sure no check engine lights or problems show up.. My before and after dynojet peak dyno readings at the wheels were as follows: base: 255hp @ 6300 and 215tq @ 4600 (wheels) X 1.2 = 306 hp and 258 tq at crank AFR=12 flat :270hp @ 6300 and 235tq @ 4600 (wheels) X 1.2 = 325 hp and 282 tq at crank compare this with a bone stock 300 hp 2001 996 3.4 dynojet: 251hp and 213tq X 1.2 = 300hp and 256tq at crank AFR=13 flat Car has now been dyno'd with close to 325 hp at the crank and weighs only 2750 lbs. Gtech Pro RR g-force meter performance run: 0-60 foot launch 1.9 sec 0-60 mph in 4.4 sec 0-100 mph in 10.4 sec 0-130 mph in 16.5 sec 0-150 mph in 26 sec Quarter mile time 12.7 sec @ 110 mph.

Hey B I had the exact same "phenom"... started with a weird smell for a few days after parking car in garage. Then cloudy start ups, not too bad and would go away after driving. Then one day the cloudy start up was filling up the garage with smoke, but still seemed to go away... As most of us are guessing right now.. early Air Oil Separator going bad... I caught on soon enough and had it changed right away... No more smokey starts. If you call and ask for the porsche part number you will see that the last couple digits represent how many versions of that part they have changed or improved. I think they are up to 05 or 06... meaning it's a part that has been changed or redesigned by porsche 5 or 6 times... I ordered the part from Sunset Porsche discount parts and then had the dealer do the labor. I hear it is a pain to DIY.... best of luck... Bill