996noob

That is what they termed surface-air gap, whereby the carbon or soot buildup on the insulator allows the spark to jump along the conductive deposits and then the the air gap to the electrode, effectively a self-cleaning feature. However, I believe this exists for any spark plug, not just the Bosch ones. As long as there is an electrode, there are two ways it can spark, the air gap, or the surface-air gap. For a single electrode plug - there are two ways, 2 electrode - 4 ways, and the 4 electrode - 8 ways. It's just that with 4 electrodes, the rate of widening of the gap is slower as it is shared by multiple electrodes, and this is the main USP of the Bosch 4 electrode spark plug.

The used 4 mass electrodes plugs act different than the classic 1 mass electrode plug, the spark slides from the central electrode, over the insulator, to the nearest mass electrode, which create that way, a much longer in distance spark, which is able to ignite a leaner fuel/air mix. On classic 1 or 2 mass electrode plugs, the spark jumps from the central to the nearest mass electrode, where the spark length is noticeable smaller.

Back when I worked for Bosch in the South East Asia region, the marketing emphasis for the Super 4 was not so much any added performance, but rather that having 4 electrodes meant that the prescribed gaps would widen 4 times slower than single electrode plugs, and 2 times slower than double electrode plugs, resulting in longer service life than conventional plugs - it was as simple as that. During product training we would also emphasize that only one of the gaps fired at any one time, not all 4, and that it would be random, whichever air gap that would jump easiest at the particular time. I think consumers may have made assumptions about the product that were never intended.

I think it's placebo effect if someone thinks NGK's improve how a vehicle operates but I do agree that +4's are a marketing scam.

I used to work for Bosch (diagnostics sales) but was always told that we couldn't get the Porsche software for our KTS machines to convert them to PIWIS. I guess that's what they told us to keep us from checking further. Anyway, it's been some time since I left the company, but I could get still get a KTS if I contacted them. When I left, the newest model was the 650. What's the model to get now if you wanted to convert it to a PIWIS? And where would you go to get the software to convert to PIWIS?

You could PM me if you don't want to reply on the forum.

Thanks!

Thank you sir

I tracked down another buddy who writes diag software for Snap-On he assured me we could install the Porsche software on the Bosch unit

Thanks for backing it up!

B

Any update on your wireless solution?

Thanks Loren.

The headlight switch has been a problem for others here too.

I would replace the switch.

Recently, my light switch jammed up and could not turn off. I had to force it off by using force, and in the end I lost the "indexing" of my light switch. I think the "indexing" parts internally broke apart. Is the part the same for all 996 model years? Is it expensive?

Make sure you have the bushing for the long bolt pressed back far enough. If its not pushed back fully it can make a huge chore out of getting the alternator back in.

Thanks...I'll check the bushing and see. Sounds like everyone's experience is pretty touch so just might have to lever it in.

Any other tips would be appreciated. I also gave in last night and had it towed to the shop but determined to finish off the job and get her back on the road.

Darron

I am pretty certain that your bushing is not retracted enough. If it took some effort to remove, it will take even more effort to re-install.

I had the same problem, and could not for the life of me get it pressed back far enough with the tools I had at home. You could fashion some sort of "puller" from bolts/nuts/spacers, but I think sending the alternator to machine shop that can press things in and out would be the easiest option.

I have tried that exact combination and can attest 100% that it will fit. Those widths and offsets are very common for aftermarket "Porsche" replica wheels, and are actually a 997 width and offset combination. However, I have found that on the 996, looks-wise, the fronts are a tad too far into the fenders in relation to the rear which are just about right. While the wheels will fit, they are quite far off spec from what Porsche recommends for 996's, just for your information.

Or... replace them with a single air horn (like many of us have).

Did you need to run a relay for the higher current draw of the more powerful horn? Or did the supply of one side of the original horns have enough juice?

Hi

I have discovered that one of my vacuum lines in behind the resonance flap seems to have come out. There is no vacuum coming to the solenoid valve next to the alternator, so I traced the line back and noticed that it joins a three way connector behind the resonance flap pipe. The line from the solenoid valve is plugged in fine. The second connector seems to go to the vacuum cannister. The third connector seems to have plugged nothing in it. Its very difficult to see clearly in there as to whether there is a loose line hanging around there that should be plugged into the connector.

So I have two questions:

1. What impact will having no vacuum coming through this line (and the vacuum cannister being unable to create a vacuum due to the open connector) on the running of the engine?

2. Is there an easy way to get in there to access the connector without removing the throttle and the two pipes? I've done this before to install my PSE (which is probably when I knocked the line out!!) and it was a very hard job to get the two pipes back on.

Its a 1998 Carrera in Irish spec.

Cheers

Greg

Theoretically, the Y connector should be connected to 3 things which are; vacuum reservoir, switchover valve, vacuum source. Since you have traced the connections of the Y connector to the first two mentioned, then what you are probably missing is the vacuum line to the vacuum source at the left or right rubber sleeves which connect the air intake T-piece after the throttle to the left or right intake manifolds.

Somewhere along this vacuum line, you should also have a one-way check valve.

From memory, I believe you need to take out the throttle body and all that stuff to get access to the Y connector behind it.

Your engine will not run well without the vacuum line connected. 1) you will have a vacuum leak. 2) your reserevoir will not get a vacuum accumulated 3) your resonance flap will not move.

Hope this helps.

Just noticed that my mufflers has GEMBALLA stamped on them but I´m unsure about the rest of the exhaust. Can somebody tell? Sorry about the poor pic quality...

Headers, Cats, and Tips look standard to me. Only the Mufflers look to be changed.

if they fit they are not GT3 headers. By your description they are X 51 headers. Your Porsche "specialist" may be not telling you the whole truth

I agree. The bolt pattern on the exhuast gasket and mounting flange is totally different.

If you are talking about the chain tensioner seal, yes you can messing up the timing, the best is to lock the camshafts with a special tool.

HI,

Its looks like I have a leak similar to this. Does anyone have any experience of changing the tensioner seal.

How do you lock the cams?

What tooling is needed

thanks

Jetbox

Me too, I have a leak at the big nut as well. Would be helpful to know what is involved in changing the seal (is it an aluminium crush washer?).

I've just reviewed the pages in the parts catalog associated with the dash & venting and it brought back the memories..... When I was first attempting the dash upgrade, I thought I'd assemble the parts list/numbers (just like you are), buy the parts (used but some new if necessary), and install. Unfortunately, the parts catalogs I have (I have both the PET and pdf versions) do not clearly specify the ducting and bracing part numbers between the older and newer cars. Plus the thought of buying any missing items from porsche at their premium got me thinking. I finally decided to just demand all of the ducting and bracing parts along with the entire dash from the seller (less the electronics). Neither of the two sellers I was negotiating with had any issue with this (who are they going to sell ducting and a brace to?) I got what I asked for and everything bolted right in.

In the event you go the same route I did, I am attempting to list the parts by description that you should look for in the pile that you get from the seller:

In addition to the dash with glove box you'll need:

1. center dash vent/radio console - the whole assembly in the newer car is different. With the early 996 this was pretty much one piece. With the later car it is a number of pieces. There is a sub-frame, the vents are separate and install like a cartridge, there is an outer trim cover and so on. Very different from the earlier car. Try to get the whole thing (less the electronics)

2. Ventilation ducting: the following are different - the center distribution piece and the left duct (that connects the center distro to the duct piece behind the passenger side vent). If memory serves, the rest of the duct pieces are the same.

3. Dash Brace. In the earlier car, this is one big piece of aluminum that goes from one side of the car to the other (behind the dash). In the later car, it is very similar except that they cut out the section where the glove box is. I believe all of the bolt holes/attachments are the same so you could probably cut out the section yourself where the glove box is if you can't get the two newer parts.

Items you won't need: intrument cluster, buttons/switches - your existing ones will snap/install right in and you can't use the new cluster at all.

One last thought about the part numbers, I remember looking over the part numbers of the parts I got from the seller and thinking "wow, where did these numbers come from?" - a number of them were not in the catalogue at all.

Sorry I can't help with the part numbers but it just isn't that easy.

Hope this helps. GA

Was the airbag from the new dash different? Or did the seller not provide the new airbag, and you used the existing one?

Reason that I am asking is that I have the opportunity of getting a Mk2 dash with the glovebox for my Mk1, but on the "new" dash the airbag has been activated. So I was wondering if I need it in the first place, and if I can use my existing one.

I did a search on this topic and found this thread

http://www.renntech...._1entry160676

I'm moving over my discussion to that thread.

I have the opportunity to get a Mk2 dashboard from a C4S, and would like to install this, if possible, into my Mk1 (1999 C2).

The objective really is to get the glove compartment of the Mk2, while getting an overall better condition dashboard in the process.

Here are some technical hurdles I might need some help on:

The C4S airbag has activated. Can I use my Mk1 airbag unit and also the cover?

Are the dashboards interchangeable at all?

Are the electronics, if any specific to the dashboard, interchangeable?

Is the instruments cluster the same?

Have I overlooked anything?

Even if you do find that the headers will fit you car you will only see hp gains if you add "high-flow" mufflers, 100 cel cats and a flash of your ecu.

The headers alone will not give you any noticable improvement..

I've researched this and have determined that the bolt pattern on the GT3 header to engine flange is totally different from the 3.4/3.6 engine of the 996 C2/C4/C4S.

They won't fit.

However, the mufflers MAY fit, but I am still trying to find conclusive evidence whether they do or do not.

Its hard to say without a picture but there are pretty much two of the electrical vacuum switches on the drivers side of the engine. The one thats underneath the intake, buried from plain site is for the secondary air valve. There is also a electrical vacuum switch that is right above the alternator and this is for the resonance flap located in the back of the two intake pipes. If I remember right there is a vacuum "T" right above the alternator that comes from the intake boot that supplies vacuum to both the secondary air and resonance flap switches.

so that vacuum switch activated the resonance flap on the intake?

That looks like the switchover valve for the intake flap. You should have two hard vacuum lines connected to it, one from the vacuum tank buried behind and under the intake, and the other line goes to the flap. The lines are extremely brittle on old cars. I had to change mine as they just desintegrated when I tried to handle them.

I own a 2004 Carmon Red Carrera Cabriolet 6-speed. I have bought 2 Speedster emblems, 1 Roadster emblem, and a 996 emblem that will all fit in place of the Carrera on rear. The emblems are all written in Carrera style cursif, all the size of Carrera...which would look best?

1. Leave the Carrera emblem on to not "cheapen" the car

2. Replace Carrera with Speedster

3. Replace Carrera with Roadster

4. Put 996 and Roadster on rear

4. Or put on just 996 emblem (size of GT3 emblem)

Please give me thoughts, impressions...thanks...Chumly

BTW, whatever I decide after polling true enthusiats, I will sell the rest pretty cheap (30 bucks ea)...Chumly

I was unaware that Porsche made a 996 emblem in the size of the GT3 emblem, for the rear of a 996. Is it Chrome or Black, or come in both colors? What is the part number?

I like the idea of 996 on the back. Never seen it.

They probably forgot to push the separate connectors in, on the rear (sideways) of the headlights.

You were right!

After taking the car back from the paint shop, I realized that the Litronic dipped (main) beams won't angle up when I flash the high beams.

Could this have resulted from starting the car with the lights removed? I would guess that the painters might have moved the car while the lights were not installed.

How do I diagnose and solve this problem?

My car is a 1999 996 3.4L Coupe.

If anyone is interested, I have a complete PSE electrical and vacuum wiring kit available. The only thing you will need to add is the dash switch (left or right side, your choice). This kit is worth over $350 is bought new.

Should've said so earlier! Sending you a PM now.

If you want the PSE always on then don't bother to install anything.

The vacuum and electronics are only used to make the system quiet. The vacuum is used to close the bypass valve in each muffler - so without it the muffler are always louder.

While I agree with you that I'll probably be running them on loud mode most of the time, I need the switch for inspection purposes (inspection is annual) and when our "department of transport" cops come alongside the car (they'll stop you and give you a hefty fine).

I'm lining up a set of used PSE's very soon, without the vacuum or electrical circuits, so this write up is very appropriate for me.

Looks like I will not need to use a dedicated vacuum tank, as I suspected.

I have made up a list of parts based on the relevant TSB's for the install of PSE. However, I can't figure out why there are several different numbers for the harness, or is it that these part numbers are for a set of parts including the harness?

928 573 727 03 Y vacuum connector x2

928 574 717 03 L vacuum connector x4

917 355 021 00 SS Braided teflon vacuum hose (L=380mm) x2

999 512 069 02 Clamps for braided hoses x4

996 605 123 01 Switchover Valve

996 613 987 10 Switch (Right Side of Radio)

996 613 988 10 Switch (Left Side of Radio)

- "Tekalan" Vacuum lines

Harness numbers:

996 612 978 00 PSE electrical Harness, but may include Relay and Switchover valve?

or

996 612 980 03 PSE Harness? or Relay? or Both?

I'm confused by the last two part numbers, and possibly by ordering them I may not need to order some of the above parts as they may come with.

Unknown part numbers:

Bracket for Switchover Valve

Any advice on the part numbers?

Here is a write up of my PSE installation

Orient, thanks for the link to your write up. I'm going to go through it right now. Can I PM you if I have any questions? I'll post a summary of my understanding here so that we have something on Renntech for future reference.

If you want the PSE always on then don't bother to install anything.

The vacuum and electronics are only used to make the system quiet. The vacuum is used to close the bypass valve in each muffler - so without it the muffler are always louder.

While I agree with you that I'll probably be running them on loud mode most of the time, I need the switch for inspection purposes (inspection is annual) and when our "department of transport" cops come alongside the car (they'll stop you and give you a hefty fine).

The valves that control the exhaust are powered to close the bypass ie make the exhaust quiet. If its wired anything like the later 997/ 987 , then the switch on the dash is a momentary pushbutton which sends a signal to the rear ECU (DME) control unit . This unit internally switches the PSE on an off. The DME connects to the solenoid valve on one side of its two terminals (switching to ground when the dash switch is pressed) the other terminal has a power feed +12V . If you want to control the PSE as porsche intended , you will probably need the switch on the dash plus coding of the rear DME , then you would need to add the wiring from the DME to the solenoid control valve for the vacuum. You would also need to pick up a live feed for the other side of the solenoid if the fitting kit wiring loom didnt include this part. I retro fitted a fully operational PSE to my 2005 MY 987S , but needed to add some wiring for the solenoid myself , as there was no kit available. Basically it was a wire from C14 of the DME to the PSE solenoid and a live feed to the other side. Since I already had sport chrono I didnt need to add the wiring from the dash to the DME. After wiring up the car needed to be coded for the PSE option to allow the rear ECU (DME) to activate the terminal C14 to switch the PSE on and off.

I've been reading and re-reading the TSB for the installation of the PSE for 996 so that I can try to fully understand what's going on. I'm learning abit more each time I read it. My understanding is, for the 996, only the speed signal is taken from the DME, to switch the PSE off and on at some speed range, this feature I do not require, otherwise, the switch itself is connected to a relay, and relay connected to the switchover valve, via the harness. At this point, I am inclined to think that I should be able to run the circuit without the additional vacuum tank that comes with the PSE kit. Just wondering if anyone has DIY'ed the full PSE kit with switch on the 996, and perhaps help me understand better how it is wired. I know that quite a few here run the mufflers without the other parts, though.

Anybody been there, done that?

Yes, many have. Do a search here for detailed descriptions.

Does the OEM harness have provisions for the switches? Fishing wires through this car is not a fun task.

No wiring in the harness unless your car was ordered with PSE. Only one wire needs to be run from the engine to the dash. Or, some folks do not use the switch as the PSE default to always open (loud).

Is there a install manual anywhere for this?

Yes, in the TSBs for Carrera 996.

Will it work with my current tips?

Yes, you take the tips off your old mufflers and put them on the new PSE mufflers.

Any extra parts needed for the install?

Not usually. The switch is sold seperately but otherwise everything you need comes in the PSE kit. (again see the TSB for a list of parts)

If I managed to find used PSE mufflers and wanted to install the switch, what parts would I need to get in order to control the switchover valve? I could follow the TSB and parts list to the letter, but is the there a short-cut circuit I could rig up with just the original switch and a relay and some wiring? I don't need all the functions of the speed range switching, etc..

I was wondering if the job could be done by getting the PSE switch, harness + relay (996 618 980 03) and switchover valve (996 605 123 01), some vacuum tubes and accessories, and tap the vacuum from the existing canister line, and control the PSE with that.

Any advice?