qikqbn

Sorry for late reply ;^)    

prices for used porsche engines has gone way up since I did my conversion 10 years ago.  they are now averaging 9-12k for an engine. When I did my conversion I got the engine for closer to 6-7k  with my old engine and a core exchange. ..   The Labor took about 40 hours.  So multiply that by the hourly rate of your favorite mechanic, but figure about 4k for labor...

Now... I would not necessarily do this conversion at today's prices and with the prices of 2007 987 Boxster S /Cayman S  3.4  liter cars selling for 20-25k.... I would just buy a 2007 boxster S  now instead.     10 years ago it was a different story for the 70k price 3.4 liter Boxsters and caymans were going for.   My conversion seemed like a reasonable project at that time.  Not so sure now.  all depends on what you can get the car and engine for now. hope that helps. 

I got a question for you guys. OEM tire sizes for my car 235-35-19 and 305-30-19 . Diameter of these is 25.5 " and 26.3 " respectively. Now given the obvious concern over rolling diameter of the tires on C4S and the impact of too much variation in front-to-back tire diameter on the drive train why not use a 235-40-19 on the front which at 26.4" and nearly identical to the rears 26.3 ? Tires in question are Michelin Pilot Super Sports.

I have an 06 C4S and recently switched to 245/35/19's on the front and I have 305/30/19s on the rear.    the 245  is 25.8" diameter compared to 235 25.5".   The GT3's wear the 245 size too.  adds just a touch more width and looks Great!!  Just my opinion, but going 235-40 route, the tire may look a bit too tall compared to the rears.  Even though my current setup still has the front diameter slightly smaller than the rears, they look almost the same diameter when looking at the car.  the 40 aspect ratio may make it look a bit off balance with the fronts being taller.  just something to think about ;^)

Hey guys, my friend did a short film project on my Carrera 4S. We tried to capture the sights and sounds of driving these awesome cars in a great "Porsche" short film.. Check it out and pass along to your car buddies! Enjoy!

If you are gonna stick with the 997's, then definitely hold out for an "S" with all the options you desire. The regular Carrera has all the goods, but the "S" comes with better power, brakes, suspension and wheels. In the long run I think you will be happier with the upgrades and it will be worth the extra $7-8k difference. Interior options are just as important as the exterior, so I would be picky there too. There are lots of great bargains out there if you are patient and do lots of research.

Phillip and I had very similar experience. Our local dealer salesman and a good mechanic both said you would hate your 997 after driving the 991. Now, if you knew me, then you would know that I LOVE my 997 C4S.

I really admire ALL Porsches and I am a huge fanatic. So I was already excited to see what the 991 would drive like, but when I heard that statement I really had to drive it for myself to see what all the hype was about. I got to test drive the 991. Silver, Pdk, Carrera S. I don't know if its just that expectations were so high, or that I still don't like automatics, but I was not "blown away" like everyone has been saying.

I will say this. It is a great car and a step up in many ways, no doubt about it. The ride was quieter, yet still firm. The interior feels and looks really impressive, , although very busy with buttons, Materials feel and

look high quality. navigation and info in cluster display is a nice gadgety feature. Just not sure if all those gizmos are necessary. in an iconic sports car... I hardly use half the features in my C4s Navigation system! so it seems way overkill.

The 997 is just a great and an amazing car by any standard.. The 991 car looks very modern, as it should, next to a 997 and the 997 is looking a bit dated when parked next to the 991,

but the 997 is still a great looking car. Like the 993, arguably the best looking 911 design, the 997 has a great connection and the spirit of that 993 design. The 997 will always look great,

even 20 years from now. I am also still a stick shift guy. The pdk was really cool to play with, but I wanted full control. Automatics still make me

feel disconnected from the throttle. floor it, wait for downshift, hold on.... I have to say though, no stick shift can upshift that fast... amazing. Low end torque felt the

same to me, and top end pull felt a bit stronger and pulled longer due to higher rev limit, but not that much faster then my 997when pulling hard on full throttle.

Electronic steering felt good. A bit too light at low speeds, but more precise the faster you went. definitely filters out a lot of the bumps which can be good or bad

depending on what kind of roads and driving you are doing.

All in all... i walked away still VERY happy with my 997 C4S. It is a great car and I love it. Would I like a 991 in the future... sure, who wouldn't, but just not sure I would trade my 997 in for one now. I am waiting to see what the next C4S or Turbo has to offer. Or even the next GTS 4. Exciting versions are coming very soon. The 997 will go down in history as the last true 911 with "lively steering feel and rear end 911 characteristic". The last "analog" 911 before it went "digital". The 991 will be the car that takes Porsche into the "electronic control future" and it will accomplish GREAT things and win tons of races. A great first pass and glimpse into whats coming. I just love the way Porsche always strives to pursue excellence..

I am sure they will only get better and better with each iteration.

The staggered wheel idea is an interesting option. But the sport design wheels I have are 20x9 all the way around so I would like to keep all the tires the same size. i have a feeling the 315 would have that "muffin top" look on the rear 9 inch wide wheels. I wonder what 295/40's all around would do for the handling? hmmmm something to think about. thanks for posting all that info.

It would be nice if anyone can post some pics of their larger/taller tires on oem 20's... any takers ;^)

hey dervin1968 and swflhomes,

were you able to figure out how to post those pics. I am contemplating this same idea. I purchased my wife an 04 CS 6 yrs ago with 20 inch sport design wheels and 275/40/20 tires.

It continues to be a great suv and family car, will probably get her a 2011 CS next year, but for now I am about to move on to my 3rd set of tires. 1st I had oem Conti's on it, and now Hankooks Ventus

with about 20k miles on them. Hankooks are not absorbing the bumps very well any more and getting louder. The car still handles great, but just getting tired of the hard tire slaps and bumps

on our crappy freeways out her in los angeles.

I was thinking of going with a taller diameter with 275/45/20, vs the stock 275/40/20, and that it would add a more supple ride. Since my wife drives the car 99% of the time, I don't think she

will notice a loss of canyon driving handling. I also wanted the wheel well fender gap filled a bit better too for better looks.

I noticed swflhomes mentioned he would not do it again... bummer. if either of you could expand on that or supply pics that would be very helpful.

right now, if I stay with original size I hear the hankooks "AS" all season are a lot quieter. any thoughts?

Hey Joe,

Looks to me like you have other factors to consider too.. Manual vs tiptronic? Not sure how much it means to you, but that's a huge decision too, regardless of 2wd vs 4wd.

There is also the 2 inch wider rear end on the C4S, in my opinion stands out more and looks awesome, and wider rear wheels/tires (305 vs 295 tire size).

The better balance with the front axle, psm for awd, preloading brake cylinder feature are different and nice upgrades on C4S.

Also, consider how much time is left on both CPO's and when they expire. New extened warranty's will run ya around $3k

I have experienced greater confidence in handling (especially tight corners) in the dry in a C4S, so in the snow or rain I would only expect that confidence

to grow even greater with AWD. The 2wd Carrera's front end tends to get light and push a lot more then the AWD 4S in tight corners and accellerating

hard through the exit. I found I had to be a lot more restrained in the 2S vs 4S during some spirited canyon driving with my friends 2S and then less

restrained and more confident jumping back into my 4S. This all being in dry weather ! I can not comment on snow conditions, because I will not drive

my C4S in the snow, plus living in Southern Cal, we don't get much snow out here. But rain conditions.... I love hearing and feeling all 4 wheels clawing

for traction ;^)

My advice.... decide what it is you REALLY want... be very patient and search some more. It took me 6 months to find my C4S and it has every option I wanted,

fully loaded, beautiful interior, exterior color, wheels, tires, LOW mileage, and great price. IT was the EXACT car I wanted and dreamed about. I have NO regrets whatsoever.

God was looking out for me because out of frustration I almost purchased a different C4S that I was going to "settle on". I got my cashiers check for the full amount,

drove 2 hours to the dealership and when I got there some one had called 20 minutes before and put a deposit on the car over the phone. I was devastated

because I had spent a lot of time "convincing" myself that one was the car and best I could find, but in my heart I knew I was settling. So my gut never felt right

about it.. 2 months later I found my PERFECT 911 and I knew it the instant I saw her. I could not hand my check over fast enough I was so excited....

I hope you can find one like that.. that you know instantly , "this is the one for me" ;^)

In the mean time take a few more test drives in both automatic vs manual, 2wd vs awd and see if you can get a good feel for how they differ through the canyons.

Dry daily city driving they will feel the same. It is the extremes where the difference will stand out. All the Best on your search.

Bill

C4S in snow :clapping:

Hi all

Recently purchased a used 05 c2S and planning to update the car to the 997.2 look but have some question marks about the parts. I am planning to buy parts seperately (not as a kit) from different websites. My question is does the front led DRL s need any control units to work perfectly as in the rear LED taillights. My car is Euro spec, I know that US spec and EU spec tallights differ in terms of signal bulbs. Is there such difference in the front DRLs in Porsche?

Thanks in advance.

Not sure if you did your project or found your answers... but I was very frustrated at how little information there was out there to do this conversion. People said it could be done and was, but little actual specifics.

Here is what I experienced with my 06 Carrera 4S face lift project. I just turned 40 this year in February and it was a great time to do a little something special for myself, or atleast that's what I told my wife :thumbup:

I wanted to upgrade the look of my C4S and the 2011 Carrera GTS, Speester, and sport classic came out from Porsche and I absolutely love the new Sport Design front bumper.

Since I have the wide body C4S I also added the GT2 side skirts that are also on the GTS,Sport Classic and Speedster.

Like you, I wanted to freshen the look of my C4S with new LED lights as well, which turned out to be quite the nightmare to research. Do you need a computer, what is the wiring diagram, what parts are needed, etc, etc???

Nightmare to find answers and a lot of people wanting to charge you lots of money to give you the answer... but now that I know it is not so bad executing if you have a good indy mechanic or are resourceful and can handle a wiring diagram and splicing.

IF, IF you are ONLY doing the FRONT LED upgrade and bumper... you DO NOT need a new control unit for the lights....

IF... IF you are planning to upgrade the REAR tail Lights to LED and bumper... then you WILL need a updated control unit.

For the FRONT LED upgrade we just had to modify the wiring harness that runs to the front turn signals and fog lights. You must order the 2009 LED "Mini Loom Cables"... 2 qty (L+R)... These mini cables are about 12 inches long and are the new wiring and plug that go into the updated LED turn signals. They will need to be spliced in to your existing turn/signal/fog light wiring harness that runs the entire length of your bumper.

Your existing MAIN cable plugs in just behind your passengar head light. the cable then drops down and runs along the entire bottom of your front bumper all the way to your driver side side marker light.

Along the cable you will see where there are additional wire cable looms that branch off to your turn signal/ fog light. It is those wires to the turn signals that you will have to basically cut and remove and then splice in your 2009 LED mini loom. Your old turn signal has 3 plugs /wires that feed into it for turn signal, fog light, and parking light. The New LED loom is only 1 plug that handles all three function. All the voltage conversion for front LED light is handled inside the new LED turn signal automatically. I have a great indy mechanic and he was able to get the wiring diagrams for the new LED mini cable loom as far as which wire feeds the fog light, turn signal and parking light. There is only 1 ground wire in the new LED cable loom, so your 3 grounds wires of old mini loom will be handled and spliced onto 1 now with the new LED mini loom.

You will need to be resourceful and get your hands on a diagram or have your indy look into to which 3 old "power" wires match up to the 3 power wires of the LED. Once that hurdle is done and the new cables are spliced in

it is just plug in as usual.

NOW... LED's work by turning on your parking light and this turns on the thin LED light. Pull your light knob to activate "fog lights" and now you get thin LED light PLUS Lower line of lights to give that really

nice and bright LED effect. If you have Sport Chrono pkg, then you can go into your settings on the MAIN nav/radio screen and there is a "Memory" section that has the "daytime running lights on/off" check box.

You can check that on, but your headlights will be on as well. I just use the parking light switch and pull for fog light to have that cool LED daylight running, but with no headlights..

OK, so that's all you need know for front LED's wiring only ... NOW all the parts you will need for doing the Front bumper conversion..

-2009 Front Bumper or Sport design bumper

-Lower lip spoiler for design bumper/ or plastic inserts on regular 2009

-Middle air deflector for "center mouth opening". Be sure to check if you have a center radiator for Automatic cars. PDK cars have center

radiator, so the mouth/center shroud is different for Autos vs Manual, but maybe not on 997.1 . 2009 Manual cars have just a center air deflector "wall"

that routes air to the L+R new radiator shroud. PDK cars have an "OPEN" hole that feeds air directly to center radiator.

-Left and Right updated radiator shrouds , much bigger- Old radiator shrouds too small..

-L+R Vent Grills. They also double as the LED mounts and washer nozzle holders Unit.

-Left and Right updated Led turn signal lights-

-2 mini cable looms to run to L+R LED turn signals

-Left and Right updated headlight washer nozzles- If you have head light washer.. old nozzle units will not plug into new LED Grill Unit.

I hope this helps. Price wise... I ordered everything from Luke at Sunset Porsche for a good price. Figure approximately $2500-3000 US for parts and then

whatever you can find for painting. Plus keep some money a side to pay your indy mechanic for saving you a lot of trouble and doing the wiring for you :help:

They are smart and work hard... It will be worth it. Here are a couple of pics of my 2006 Carrera 4S with facelift. ...

Thanks for the reply Number3. I was looking at the yellow tint as I felt it gave it a little more of a European flavor. I talked to the shop that applied my clear bra and they said the film on the headlamp is easily removable if need be.

Tony

Hey Tony,

I realize you are looking for answers for yellow lens tint in particular and if it is legal... Do you have any cop friends? Maybe a good time to just ask them if they

look for that kind of stuff to ticket. I can only tell ya about my experience with the clear bra material

and that it can be easily removed if you get into trouble from your local traffic cops.. If it is just the lens you want material for you can buy the material pre-cut and it is very

easy to apply yourself. It is also not that expensive for just the lens'.

Any thing beyond that I would have a professional install it. A great installer can make all the difference in the world covering the hard to reach spots and making

the bra as "invisible" as possible and getting it to look great .

I highly recommend the clear bra, especially if you are meticulous like most of us and hate to see paint chips from rocks :cursing:

here is a website to look for pre cut material...

http://www.invisiblemask.com/

As far as tinting your lights just for the sake of looking cool... I doubt you would get in much trouble, but if you do, it is easily removed in a few minutes.

Just make sure they are using the right material... Not a window tint material that is thin and easily tears, but a strong protective film good enough to

protect you lens for hwy and racing. Unlike window tint that strips and breaks in pieces when you try to remove it... the clear bra material is very strong and hard to tear.

If you have to, You just pull it off SLOWLY in one piece.

Bill

Great article Bill. Really interesting..

As I go through my life with Porsches I realize that most engine mods are a complete waste of money. There are some...Like your K & N intake that do make a difference. But not many. We men (at least me) are like children.. We fall for the afternarket BS like naive school boys.. Unfortunetly most aftermarket stuff is garbage and should never go on your car. I think that Vivid Racing is probably the biggest culprit.:censored:

I think the next time I want to "bolt something on" I will just "take something off" (that's already there) and put it back on again. Maybe that will quench my thirst for not "leaving well enough alone".

Or maybe I should do what I did when I was a little boy and just get lots of cool "stickers" :clapping:

I LOVE stickers ! :jump: LOL . I hear stickers are good for 10 more hp. Phillip, Turbo's like yours are much easier to squeeze more power out of,

and when i had a turbo (mitsubishi) I was like a kid in a candy store buying every upgrade possible. I did see major gains in power, but I also

inherited major frustration from all the little things that started going wrong too. Seemed like I was always fixing or adjusting boost problems like little

leaks or vacuum lines popping off all the aftermarket stuff. I feel your pain. You still have an awesome beast with or without the upgrades.

bert987 ... interesting info, I did not know 2.7 and 3.4 use same headers on cayman's.. Wow, larger throttle body.... hmmmm Is there programming involved?

One other thing that stood out from the article and also stood out from a gold meister tech I talked to at Porsche is this...

The article and tech confirmed that basically the headers are a part of a system designed by porsche as a unit.

Headers alone will not necessarily give you the results you want. They may shift when and where your peak torque hits,

but the hp may not be what you expect. So basically consider the entire system and not just single upgrades or parts...

now, about that throttle body... ;)

Just wanted to share an article I came across concerning headers and pipe diameters.

I currently have the K&N Cold Air Kit 57-7000 and IPD Plenum.

The K&N kit alone did an amazing job of eliminating most of the dreaded "flat spot" in power

for the 3.8 liter between 4500-6500 rpm. I can not say enough about it, my favorite mod

so far. Pulls significantly harder through 4500-6500 rpm and screams to 7300 rpm. The sound

alone was worth it to me. 5500-7300 rpm shrieks like a GT3 and the performance is noticeable.

The IPD Plenum further eliminated any remaining flat spots and helped a little more on the top end.

All K&N and IPD Plenum dyno's benefit most between 4500-6500 rpm, but the pull to 7000 is

that much more sweeter.

So, since I am happy with my top end pull I was seriously considering adding the x51 headers to my 997 C4S for even better air flow.

The X51 headers have larger diameter primary pipes, so what exactly does that do and how does it benefit or change the power curve delivery?

"The stock 997S headers have ø 42mm tubes. Both the 997S X51 and 996 GT3 headers have ø 48mm tubes."

This article may be old news for most of ya, but still beneficial to those looking into headers now.

I Also realize this article is not Porsche specific, but the science and results should be the same for all cars.

full article is here: http://www.carcraft....sics/index.html

some interesting key points.

"As engine speed increases, so does flow rate. Then, as restrictions increase, velocity slows again, reducing power accordingly. Interestingly, camshaft design, compression ratio, ignition-spark timing, and piston displacement affect all this if an accompanying improvement in the exhaust system isn't included with such changes. In fact, these types of modifications can cause exhaust problems to occur sooner in the rpm range.On the other hand, exhaust systems can be too big for engine packages that don't produce sufficient exhaust-flow volume to necessitate size increase. So we're back to the flow-velocity issue. Sizing of system components, such as headers, can be keyed to engine speed and piston displacement. We'll show you how this is done later in the story.

Graph A illustrates how merely changing pipe diameter affects an engine's output. Note that the smallest diameter creates good midrange torque yet falls off at the top, while the larger primary header pipes add more high-rpm power at the expense of low-speed torque.

Primary pipe length can also skew an engine's power curve based on length changes. Primary-pipe diameter establishes the peak torque point, so changing the pipe length will rock the output curve by pivoting it around that peak torque point. Graph B shows how longer tubes tend to increase power below peak torque while hurting power above peak torque. Shorter tubes tend to affect the engine in exactly the opposite way, hurting midrange torque in favor of increasing top-end power.

Primary pipe diameter plays a big part in determining the torque curve. A pipe that is too small creates peak exhaust-gas velocity too early in the rpm curve and will limit top end horsepower. Pipes too large lose low rpm torque and create peaky output curves.

So, million dollar question???.. Sacrifice low end torque (majority of city driving), for more top end??? which would you perfer? hmmmmm

I have the porsche oem sport shifter on my 997.1 C4S . I love it and and the precision is much better then the stock shifter.

I also have the Porsche/B&M unit on my Boxster 5 speed.. No comparison. the 997 short shifter feels smoother, more precise and less notchy then the B&M.

Stick with the Porsche oem short shifter for the 997 rather than aftermarket. Order it from Sunset imports and get a decent price. Still pricier then B&M, but over the long run you will be very happy.

Just be sure to mark the cables correctly while installing. I would not even think twice about it. You will feel more precise control and

the whole driving experience will feel that much sharper.

all the best,

Bill

I upgraded my 997.1 Carrera 4S to the Sport design front bumper and side skirts that match the 2011 Carrera GTS. I LOVE the new look

of the GTS. Really adds a bit more of an aggressive look. I would also definitely get the "sport shifter". Porsche has come a long way

in the feel and precision with the short shifter kit. WAY better then what they had in the 996. The shorter shifts and precision make

the whole car feel that much more solid and in tune with your inputs.

The GT3 RS front and fender flares are going to look awesome! Nice option. Have you thought about adding spacers to your front wheels,

since the fender flares for the RS were made to work with the 9 inch wide vs 8.5 wheel and 245/35/19 vs 235/35/19 ?

Porsche just announced this week that there is now a 2011 Carrera 4 GTS. Porsche is hitting them out of the ball park lately.

So much awesomeness to chose from. Have you thought about the Carrera 4 GTS ? You can have all wheel drive in your GTS

and possibly skip upgrading your other car... just a thought.

Congratulations! we all envy ya.... in a good way ;^)

Natinupe1,

The 997-1 Turbo is a completely different car than the C4S (or an S.) If had you have spent anytime behind the wheel of the Turbo you would see how different it is than your C4S. My good friend has a 997 C4s and we go driving and swap cars. Totally different car.. My friend agrees as well.

Almost everything about the car feels different. (except it's still a Porsche.) The way you drive the two cars is totally different as well.. 350 normally aspirated HP and 550 turbo are certainly not the same..

Granted my car has been slightly modified but you really can't compare the two. It is certainly not just a "faster C4S"..

Just thought I'd comment...

:cheers:

If you are not careful, and what I think a lot of your Porsche brothers are saying is, decide what you want to use the 911 for and wait and get the car you really want. By the time you finish adding all the modifications

to engine and suspension and getting the car dialed in and spending all that money... you could have just sold your car, and put that extra money down on a used GT3 or Turbo

that is already a lot more car and dialed in the way Porsche meant it to be.. I also have gone down the modification engine swap trail and have a very unique

3.4 liter boxster that drives very much like a Boxster Spyder. I have invested almost 30k in upgrades over the years... Had I been patient and waited I could have

purchased or put down a big chunk of change on a Boxster Spyder which already has all the goodies already on it.... Same goes for your 911. it may seem

to work budget wise now, but when will enough mods, be enough... just something to think about.

As far as the different Porsche models, In a way I can see both sides here. As an owner of a C4S also I can say without a doubt that a 997.1 turbo's power delivery, acceleration,

sounds of intake and exhaust, clutch feel, and driving style are completely different. If you think you need to respect the power of our normally aspirated 355 hp engines,

you better sure as heck respect the turbo's... that sucker hauls butt so you better be ready for the power when it kicks in....

That being said... I can see the point of waiting for something a lot different. The C4S and turbo share the same interior (based on options) and same awd system more or less. The suspension may share a lot

of the same parts, but the driving style completely changes when the Turbo torque kicks in. So it does feel like a very different machine. To drive one at fwy speeds feels about the same until you mash the throttle,

then the similarities fade quickly. There is also the prestige factor that must be considered as well, but that's another topic. The different Porsche 911 models do feel different and you get what

you pay for.... sometimes you pay dearly...

also the next version 911 (991/998) will be different enough that it will be like going from a 996 to a 997... I can't wait to see it and drive it ;^)

Hey Donny,

I know this topic was a few months ago and hopefully it's not like you are in your engine bay all the time to fix something.... But...

I have the GAHH glass rear window convertible top on my 1998 Boxster and I love it... I would never go back to plastic and doing

the Boxster Kung Fu Chop again everytime I wanted to put down the top (using hand to soften plastic window fold when lowering top)

I use to do extensive work on my car as well as all my own maintenace. All you need is a decent tie strap with the ratchet mechanism and

that has the hooks rubber coated.

Put your convertible top in normal engine bay access position, undo cables etc... put one hook of the tie strap along the front edge of the top and

then the other hook right where the cable ball joint snaps into the lower edge of the rear of the top. You will see a metal support brace where

the cable is attached to and there is a small metal lip that the hook of the tie strap can hold on to. It helps to have some tension already in the tie down.

so, just ratchet up the back and while it is pulling together to fold, reach inside the car and push the glass up and over the roll bars, or as far up

as it will go. and just ratchet up some more to a point that seems good but not putting any unnecessary stress on your convertible top seams / glass.

I keep that tie down ratchet in my trunk at all times . I have used it for years like that and I have NO issues with clearence and maintenance access

to the top of the engine. I got the idea because Porsche mechanics use a similar tool to work on the 2003 glass top boxsters.

I hope this helps you .

Bill

Picked up my 3rd Porsche (1st 911) just last week. She was a garage queen and only has 6300 miles on her.

2006 C4S Meteor Gray, fully loaded. Previous owner paid close to $110,000 brand new.

I was making myself sick inside trying to justify buying her, but the moment I saw her all

my anxiety faded away. She is in showroom condition. still smells new. There is such

a joy that you get inside everytime you take a 911 for a drive. It is good for the soul.

if anyone is hesitant and nervous about pulling the trigger like I was, don't be. You will

never regret it. Just make sure to do your homework and pick a good condition one.

She is awesome!

I just saw this post, where was I ??.. Thanks Phillip for the very kind words. you the man.

Many, many thanks to all the Renntech Porsche Nut Guru's who helped me out tremendously

over the years answering all my silly questions and getting me out of many jams. :renntech:

This Forum is the first place I go whenever I need to find out anything Porsche.

Thanks Guys!

Bill Diaz

1998 Boxster @ 29

2004 Cayenne S @ 36

2006 911 C4S @ 39

Bill, do you have any info on how to wire up the Apexi-Select? Which wires to tap into and where?

I think Apexi rolled out AFC-Neo, as a replacement for the SAFC and VAFC. Not sure if "Select" is incorporated into the new Neo.

Sorry for the late response Jinster....

If you are still interested in seeing some wiring diagrams

you can download a few here'

http://www.apexi-usa.com/info/?id=5383

these will give you an idea... they are a bit technical and

the afc-select for german cars can only be found on ebay

or yahoo shopping since it was discontinued and replaced

by newer units...

I have the special diagrams for the boxster if interested

that show the wiring harness and what number ecu terminal

to plug into.

Basically you open up the wiring harness to the ecu and there are 5 wires

to connect. Throttle position, knocking signal, power, rpm, airflow signal.

4 wires are just tapped into the existing wires, know cutting required.

The only wire that is "cut" is the airflow signal. Once the air signal wire

is cut, you splice the incoming signal to go to the AFC-select airflow input.

then attach the AFC-select airflow output wire and splice it onto

the other half of the cut airflow signal wire that goes directly into

the ecu terminal.

The wiring itself seemed very straightforward and simple. The setup of the

actual AFC unit to read the signal properly and adjust to the different rpm ranges

took a little bit of patience and testing. I highly recommend having a air fuel

ratio gauge wideband.

Overall it is a really interesting product and worked

wonders for fine tuning my air fuel ratio. It was the answer to my prayers

at the time. Since then I have installed the cayman s maf housing, so

my tuning with the afc select is still usefull, but not needed quite as much

as before.

send me a message if you need to see the actual diagram and I can scan it for ya.

Bill...

Yeah, well I did a search in the 986 forum for LSD Limited Slip Differential. I couldn't find the exact answer I wanted so I made a new post. I didn't know about the options page, but that still wouldn't have answered my question if Boxsters came with an LSD standard. Anyway, thanks for the help everyone!

I found it hard to believe as well, until i dug a little deeper.

Turns out, theres this option for something LIKE a LSD...

on cars with the stability management option, apparently the computer already has alot of control over the brakes.

so what it can do is take constant measurements of both rear wheels, and apply a tweak of brake to the spinning one.

on a conventional open differential, this makes more torque goto the other wheel.

it does this so fast and so well, if you dump the clutch (with PSM off) it will leave two black marks... if you have one wheel off in the sand and the other on the road, you wont get stuck, etc...

but heres the nicer part.. at higher speeds, (45mph according to Lorens post above) it doesnt do it.. so you can get the excelent high speed cornering of an open diff, while still being able to snap the back around with the throttle when autocrossing... just like a LSD.

add to that, the open diff weighs less..(and its rotating mass) and the system adds no weight, as the hardware already must exist for the ABS... it becomes a software-only upgrade at that point.

its a very cool little feature.

this post was awhile ago, but wanted to add a bit more info incase someone else is looking.

For 986 Boxster 1997-1999 with "Traction Control" (prior to PSM 2000-2004)

What Porsche had done with their traction control option is give you something

that works similar to a "limited slip differential" but is really the "ABD" automatic

braking differential.

According to some of my very early 911/Boxster (1997-1998) Porsche brochures and my own experience with

my 98 Boxsters Traction control "ABD" automatic braking differential .... this is how it works in a nutshell.

Included in "Traction Control" 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.

Even when Traction Control is turned OFF.... ABD will still react up speeds of 45mph or 62 mph with PSM

For the 996 and 2000-2004 boxsters this is how it works with PSM

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 also 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 ;^)

My original 1998 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.

Bill,

Thanks again for the excellent response I think i might be sold on the resistor solution combined with the AEM meter since all the other options seem to be much less cost effective for possibly little advantage. Do you know if anyone has a write up on it ? Again thank you for your help.

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

Right around 340 ohm works well for a stock 996 program using a stock boxster maf housing. I would put in a variable pot resistor, this will allow you to 'tune' the fuel trims right where you want them. 1999 explained this to me a few years ago when I did my first 3.4 conversion. I still think the best solution is to use a properly sized intake tract, as I'm not convinced that the small boxster intake system can flow enough air to feed the 3.4. Look how porsche increase the airbox size when they put the 3.4 into the 987 vs the 986.

-Todd

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

Right around 340 ohm works well for a stock 996 program using a stock boxster maf housing. I would put in a variable pot resistor, this will allow you to 'tune' the fuel trims right where you want them. 1999 explained this to me a few years ago when I did my first 3.4 conversion. I still think the best solution is to use a properly sized intake tract, as I'm not convinced that the small boxster intake system can flow enough air to feed the 3.4. Look how porsche increase the airbox size when they put the 3.4 into the 987 vs the 986.

-Todd

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 ;^)

Bill,

Thanks again for the excellent response I think i might be sold on the resistor solution combined with the AEM meter since all the other options seem to be much less cost effective for possibly little advantage. Do you know if anyone has a write up on it ? Again thank you for your help.

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 ;^)