48 Upgrades Over Last 24 Years on my 996.2 C2

For years, I have been meaning to start a thread on my Seal Grey 2002 996.2 Carrera (68k miles) that I have happily owned for 24 years. So I figured to approach it from the perspective of the 48 upgrades I made over the years to improve the durability, performance and functionality of my 996.2. Importantly, these upgrades did not occur all at once. Instead, it’s been an ongoing process of planning, prioritization and cost containment over the years, as the 996 community identified and developed upgraded parts and procedures that make the car better, faster and stronger. Ownership has been extremely fun and rewarding, and contrary to the many myths on the internet, I have found the m96 powered 996 to be easy to bullet proof, durable as hell and easy to service. Not to mention it is an absolute blast to drive on the street and track. As a PCA driving instructor, I have had the chance to drive just about every Porsche model from the 944 to the 992 on the track and I haven’t found any other Porsche that I would prefer to own other than the 996. IMHO, a well sorted 996 is how a sports car should behave, feel and perform. - The first post on this thread outlines the 48 Upgrades . You can see the list under the pictures of the car. The upgrades are organized by categories: engine, exhaust, intake, software, differential, clutch, suspension, brakes, front-end airflow and cooling, interior, wheels and exterior. For sure, I have plenty more “upgrades” to make which aren’t on the list. Even after 24 years, I haven’t settled on a few big ticket items (aero, wheels, pro-active engine rebuild, etc.). But since the car is a keeper, I have plenty of time to figure it out. - In future posts, I will add more details on the upgrades and reasons for them. This may provide ideas for those looking to do something similar, or at least some good discussion points. Best advice I can give any m96 powered 996 owner is to bullet proof the engine first, and then worry about everything else afterwards. Yep, it’s easy to bullet proof the engine for both street and track driving. No reason to have a pretty paperweight sitting in your garage that you can’t enjoy. Exterior w/ Carrera 2 wheels and Brembo GT Big Brake Kit Interior w/ GT3 seats, Heigo half cage and various other items 48 Upgrades & Procedures by Category Engine (9) Objective : improve engine durability on the street and track. 1. IMSB - LN Retro refreshed when timed out 2. UAOS - Upgraded from Porsche Motorsports AOS to the UAOS w/ Track drain 3. SUMP - 2qt deep sump w/ X51 Baffle. Will upgrade to UIDS in future. 4. Oil Quantity - Run 12.5qts of oil. (factory full 8.5qts + UAOS 2qts + Deep Sump 2qts) 5. Oil Upgrade - Driven DI50 for higher viscosity, moly and greater temp resistance. 6. Oil Filter Housing - LN Billet Oil Filter Housing w/magnet. Mahle OX128/1D ECO oil filter 7. Oil Temp Gauge - Coopduc’s Digital Oil Temp Display 8. Low Temp Thermostat - LN Low Temp Thermostat 9. Procedures - 9 important procedures to follow 1. Water Pump - Refresh OEM water pump every 5-7 years. 2. Oil Changes - Fresh oil and filter before every track event. Min of 2 oil/filter changes a year. 3. Oil Tests - With each oil change. 4. Drop Sump - Every 5 years to see what’s in it. 5. Scope Bores - Every 5 years to see condition. 6. Fuel Injectors - Use Techron 2x a year and replace injectors when needed. 7. Ignition Coils & Spark Plugs - Replace when needed. 8. MAF - Replace when needed. 9. Oxy Sensors - Replace when needed. Exhaust, Intake & Software (5) Objective : improve power output, sound and throttle response. 1. Cats - FVD 200 cell cats 2. Mufflers - FVD Sport Mufflers 3. Plenum - IPD Competition Plenum 4. Throttle Body - 997 GT3 82mm Throttle Body w/ IPD Silicon Hose 5. Software - REVO Stage 2 software for better throttle response and integration of the plenum, throttle body and FVD exhaust. *Use OEM Headers. Differential, Clutch & Shifter (4) Objective : improve ability to get power down to the rear wheels, improve car stability and durability. 1. Differential - Guard LSD 40/60 2. Fluid - Motul Gear 300 75W90 3. Clutch - Spec Stage 1 4. Shifter - 997 GT3 Shifter w/ Function First Shift Right Kit *Use OEM dual mass flywheel to mitigate vibrations. Suspension (5) Objective : improve handling, responsiveness and stability for dual use street & track. 1. Coilovers - Bilstein PSS9s. Full stiff setting in rear, half stiff in front. Continue to use OEM mounts. 2. Sway Bars - Tarret GT3 adjustable sway bars. Full stiff in rear, half stiff in front 3. Drop Links - Tarret Drop Links 4. Control Arms - Demonspeed GT3 Front Adjustable Control Arms. All other arms are OEM. 5. Specs - 996 GT3 height and alignment specs with (1.5) front camber and (2) rear camber. Front-End Air Flow and Cooling (2) Objective : improve front end air flow and stability at speed while improving radiator and brake cooling. 1. Fender Liners - 996 GT3 Front Fender Liners w/cutout behind radiator for more airflow over the radiators, into the wheel wells and over the brakes for more radiator/brake cooling, as well as more front-end stability at high speed 2. Brake Cooling - 996 GT3 Front Upper Brake Ducts and 996 GT3 Front Lower Brake Ducts Brakes (4) Objective : improve braking power and pedal feel. 1. Big Brake Kit - Brembo GT Big Brake Kit (4 piston), (355x32 front, 345x28 rear) 2. Brake Pads - Pagid Yellow R29 3. Master Cylinder - TRW 996 GT3 Master Cylinder 4. Brake Fluid - PFC 650 for higher temps. Fresh brake fluid before each track day. Wheels (2) Objective : continue running lightweight Carrera 2 wheels (8 & 10s w/ 225x40x18, 285x30x18) while improving stance. 1. Wheel Studs - Rennline Competition 60mm steel wheel studs 2. Spacers - H&R 15mm front and rear Exterior (5) Objective : improve headlight and taillight output. Aero and wheel upgrades haven’t been decided yet. 1. Headlight Bulbs - Phillips DS2 Xtreme Vision Gen 2 LED 2. Parking Lights - BAX9S (HGW) 6000k LED 3. High Beams - H9 AvantiLED (pending install) 4. Side Markets - Porsche Clear Side Markers 5. Tail Lights - Adrian LED tail-light kit (pending install) Interior (12) Objective : improve interior look, feel, functionality and driver safety. 1. Seats - 996 GT3 seats 2. Rear Cage - Heigo rear cage 3. Harness - Sabelt Enduro 6-Point harnesses 4. Fire Protection - Halon Fire Extinguisher 5. Center Console - Painted center console 6. Pedals - Rennline black pedals 7. Floor Mats - Rennline black aluminum track mats 8. Radio Horse-Shoe - DB Carbon fiber radio horse-shoe 9. Door Sills - Rennline carbon fiber door sills 10. Radio - Becker Radio refresh w/ Bluetooth 11. Speakers - Audison Prima speakers 12. LED Lighting - Adrian LED interior kit (pending install)

Nice list !

Huge kudos for giving your car above-and-beyond care. Well done! 👏

Nice list. It's a roadmap for those projects. One question: Is there a reason you used the "high temp LN" thermostat instead of the 160F unit? Edit: Looks like you have it corrected now. I agree and also run the 160 thermostat.

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Thanks. Been alot of fun over the years. The LN is also 160�. I see i typed it as high temp, it should read low temp.

How's the Motul 300 gear oil been treating you? Did any undesirable symptoms arise, such as a notchy first gear?

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Up until a few years ago I used Millers Nano for over a decade which was extremely smooth at all temps. I had called Matt Monson at Guard to talk about a couple of things and I asked him what he recomends to run in the Guard LSD I have and he recomended Motul 300. But he mentioned that the gearbox would be "stiffer" until the oil warmed up, but the oil would remove slippage and provide better bite. He was right. In the winter/cold weather months, you have to put up with "notchier" shifting in all gears until the oil warms up. No problems at all in warm weather. Nevertheless, it works well for the Guard LSD and the notchiness in cold weather is a tradeoff for better "bite" on the track. I would not recommend the Motul 300 for a 996 owner who does alot of street driving in the cold weather months. But i would recomend Millers Nano for smoothness.

👑 Great share.

Woohoo! You finally did a build/ownership thread, Glenn! Thanks for sharing your long term experience and approach. You're one of the few folks on here with such a long ownership combined with proper use of your 996. Drive hard & maintain "hard". I also think that there are very few people out there that have driven so many models of the 911, especially on track, and have a proper understanding of the 996 as a sports car.

What tires have you run over the years? I see you are using stock Carrera wheels with OEM tire sizes...

Thanks GC996, that is very helpful!

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Thanks Pete. I originally bought my 996 in 2002 as a 37 year old to learn how to properly drive the car on the track, as well as enjoy it on the street. It was one of those bucket list items. So I immersed myself in everything M96. Spent alot of time at PCA technical events and race events talking to everybody and anybody that drove or supported the M96, so I could to see what they were doing to upgrade parts and procedures to keep the M96 running strong. The conclusion i always came too was to use the best parts on your car that solves for known issues, keep your parts fresh, run great oil with frequent oil changes, and you would not have to worry about enjoying the car thru the rev range on the street and track. A well sorted 996 is a very durable and dependable car.

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I have run alot of different tires over the years. Early on i ran the Michelin PS2. I then picked up a second set of Carrera 2 wheels and ran PS2s on one set for the street and Michelin Pilot Sport Cups for the track, which were awesome tires when they got hot, but scary as hell when cold. Michelin got rid of them because of all of the street accidents that occurred at Cars and Coffee events due to lack of grip when cold. You needed 3 laps around a 2 mile long track to get them sticky. But they were then sticky as hell. When the original Sport cups were discontinued, I went to Hoosiers and Toyo Proxies. Hoosiers are awesome tires. Not a fan of Toyo Proxies. The sidewall was to soft, so i used them on the street in the summer to wear them down. Loud as hell. Now I am running Michelin All Season 4s on the street in the cold weather months and Bridgestone RE71RS on the track. Quite frankly I love the grip and ride on the RE71RS that I just use them on the street for the warm weather months. Incredible durability. Hoping the RE71RZ are just as good or better. Along the way i used continental and bridgestone street tires but can't remember which ones.

Great post!!! I have completed many of the items on your list and have many on my roadmap. This is a great way if organizing your work. My GT3 fender liners are on order! You have been a great help to our community, wish we would have met while I was in Chicago�

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@Bbiela , appreciate the kind words. Let me know if you need any help with the fender liners. Its pretty straight forward. But I can send you any additional pics you may need to line your ducks up. As an FYI, the 996 GT3 upper brake ducts are pretty expensive but worth it for airflow. Many guys use the 997 GT3 upper brake ducts which are cheaper but will require a slight modification. Lower 996 GT3 brake ducts are inexpensive. I plan on posting a bunch of pictures of the mod here on the thread sometime in the near future.

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Thanks Glen, I will happily take any photos you have. I have the lower brake ducts but not the upper�something new for the list 😀. If you are ever in Park City reach out and we can ski or drive depending on the season. Brian

After running the bilsteins for some time, do you have any inclination to change springs? I know that you can go stiffer and still be within Bilstein recommendations.

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For sure, I had thought about it many times over the years as well as every other upgrade that would shave a second here and there off a lap. But in reality, I never really needed it. Even though my car was a dual purpose car and not a full time track car, I could carry alot of speed in the fastest run group and be competitive with lap times over the years. The handling and mechanical grip was and still is incredible. What i am missing is 100 hp to compete against all of the GT4 RSs and new GT3s I run against on the straights. What i will probably do is buy a new set of PSS10s and get my PSS9s rebuilt and recalibrated with a stiffer set of springs to try for a season. But I do like to drive the car around town, so a "race" set-up probably isnt optimal. My set-up now is pretty damn stiff.

Great post, Glenn. That's an impressive list of upgrades. No wonder you are so fast! I've done many of the mechanical upgrades, but since my Targa is not a race car, I do not plan to ruin the ride. I went down that rabbit hole with my orange '69 and it was fast and cornered like it was glued. But it was a miserable street car and my wife refused to ride in it. At fun speeds, it was deafeningly loud and stiff as a board. Now, she likes the Targa because we can talk to each other and it is comfortable. She likes the heated seats, too. So, tell us how your back feels after driving your slot car from Chicago to Philly? My back would be yelling at me by the time I hit Chesterton. And I would need another spine surgery.

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Ed, you had an incredible set-up with your orange "69" 911. You could attack a corner better than anybody. I hear you on track versus street set-up. Its always a compromise. You club raced for decades and your white 996 targa is really a perfect evolution. Believe it or not, the GT3 seats are incredibly comfortable for long drives. The back support is very good. But there is a little secret. All you need to do is get 2 pieces of 1 inch foam and put one under the seat cushion and one under the back cushion and its the most comfortable seat I ever experienced during a long drive. Here are some pictures. Yeah. I know, the interior is a little dirty. Its getting cleaned up this weekend.

Really nice job. it came out great. Can I ask you a question. Do you know the width of the M96. Using a 4 post lift and have 35� clear and wondering if it will fit.

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My 996.2 Narrow body Targa fits on my four-post, drive-on lift without any side to side clearance concerns. Unless your lift is especially narrow for some reason, you should not have a problem. My '54 Cadillac and '74 AMX fit on it too. And they are big cars, much bigger than my 996..

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Very clever. I will have to see if the panels on my OEM buckets are removeable. Anyone know? ​​​​​​​

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sorry I meant engine width to see if I use the four post lift to drop the engine and have it fit between the tracks.

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Sorry JM, i don't know. I would post a specific question in a new thread and someone with the info will see it.

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Dont know. You can have Riggs Brothers take a look at it to see if they can customize something for you. They came highly recomended by a fellow local rennlister and my wife used them for leather seat and convertible top work on her A5 and they did a nice job. They have pretty extensive capabilities.

Great list, nicely organized. I've had my '02 since 2008, aligns with some of my updates, too. I'm not tracking mine now, so I swapped the front sways back to stock (soft) and kept the rear Tarett setup, full stiff. The front links were rattling too much for my taste and I wasn't going to replace them. One difference for me was getting a new engine after IMS failed in 2008... so have the uprated, non-serviceable IMS.

This is great. The only things missing are all the part numbers. Can you share the part numbers for the fender liners and the brake ducts? Did I miss it? Did you replace or upgrade the oil "cooler"? Thanks

Well done. Great write up. You don't have PSM installed? I am interested to know more about the two items in Front-End Air Flow and Cooling. Can you share some more info?

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Thanks! Sorry, haven't had the chance to chase down the part numbers and post yet. Should be able to this evening or tomorrow morning. I didn't yet add the 997S oil cooler but will sometime next year when my indy drops the trans and we take a look at the RMS, LN Retro, clutch and flywheel.

When you say "UAOS 2qts" what is the reason? Should all UAOS users be running more oil?

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Thanks man! Will do later this evening or in the am. No PSM from factory like the GT3. Key is to have a LSD.

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No you are not wide enough. I think the number is 44", could be a little more or less than that. I'm in the same boat.

A number of folks were asking about the GT3 Front Fender Liner upgrade. It�s a very worthwhile upgrade, but it isn�t a cheap mod. To save a couple of dollars you may want to search on Ebay first. Here are the part numbers 996 GT3 Front Fender Liners � (L) 996-504-223-91 � (R) 996-504-224-92 996 GT3 Front Brake Upper Cooling Ducts � (L) 996-575-231-30 � (R) 996-575-232-30 997 GT3 Front Brake Lower Cooling Ducts (Substituted for 996 GT3 Ducts which are no longer available) � (L) 997-341-483-92 � (R) 997-341-484-92 Porsche Plastic Rivets � 999-507-497-40 Explanation I run GT3 front fender liners which helps with both cooling and front end stability because it directs the airflow into the the wheel well by sealing up the Carrera air flow hole that is in front of the tires, as well as removes the shroud that covers the side radiator fans which is what pushes the air down in front of the tires. Many have suggested venting the Carrera fender liners, but its not an effective idea. The problem with the vented Carrera fender liners is that they do not seal up the hole in front of the tires. Sure. You can remove the rear fan shroud, but you still have to find a way to seal up the airflow hole. You will also need to cut a rectangular sized hole on the inner side of the Carrera fender liner for the airflow to more effectively exit into the wheel well. Here is a picture of the GT3 airflow into the wheel well. Here is a picture of the Carrera airflow which is pushed down in front of the front tire. Notice the red circle which outlines the airflow exit of a Carrera fender liner. The GT3 fender liners seal this hole up. This is the Carrera fender liner. Notice the triangular shape hole where the airflow exits under the car. This is the Gt3 fender liner. Notice that there is no triangular hole, instead its sealed. Also notice the rectangular cutout on the inside of the fender liner. You have to remove the rear shroud on the radiator fan. This is what pushes the air down in front of the tires. Here is the Carrera fender liner from the wheel well. Here is the GT3 fender liner. Notice the rectangular cut out circled in red that directs the air to the GT3 upper brake duct which then directs the air to the brakes. Also notice circled in red the GT3 Lower brake duct. An additional mod you can make on the GT3 fender liner is to cut out the "indented" section of the fender liner for more airflow. If you use wire mesh, make sure to secure it well.

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There are many huge advantages to running the UAOS w/ track drain instead of the factory AOS, but one of the biggest is its ability to be able to handle processing more oil than just the factory full level of approx 8.5 qts without the smoking. More oil can not only help to improve oil pressure in the M96, but it can also help to mitigate oil starvation. For the street, you dont necessarily need to run more oil than 8.5 qts, but with the UAOS, you dont have to worry about accidentally over filling the oil by as much as 2 qts. But Skip will tell you to do a blow by test to make sure you can run 2 qts extra. But what if you accidentally overfill it to 9.5 qts and then park your 996 on a hill. If you have the factory AOS you would smoke like a chimney. With the UAOS, you wouldn't have a problem. For sure, if you are going to track, autox or canyon carve, yiu are going to want more oil to help with oil pressure stability and mitigate oil starvation. Which is why I run 12.5 qts of DI50 in mine using a 2 qt deep sump amd the UAOS w/ track drain.

�Michelin got rid of them because of all of the street accidents that occurred at Cars and Coffee events due to lack of grip when cold.� While this is an interesting anecdote, I find it hard to believe that a one of the largest and arguably one of the best tire companies in the world would discontinue a tire line due to a few idiots who crashed their cars after cars & coffee events� Really? C�mon!!!

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Yeah really... They were awesome tires after they were hot. But dangerous as hell when the tires were cold and even worse when the tires were cold in colder weather. It took a few years and they came out with Cup 2s which are excellent high performance street tires.

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Good to see another long term owner! The great thing about the 996 is you can evolve it to how you will be driving it. Sorry to hear about the IMS failure, but glad you got a new engine. How has it been aging for you?

I believe you should also proceed with updating the three aged chain tensioners. It should be an easy & good update.

Awesome thread, Glenn! You were so helpful in talking me through next steps for my suspension upgrades. I'll be putting the Tarett GT3 sways F&R and endlinks next week. Did you ever consider the IMS Solution vs. Retrofit? I'm at 10 years on the retrofit and ~8k miles.

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I used Riggs for my motorhome seat modifications. They did a good job of modifying the foam to make the seat more comfortable than the crappy OEM seat. They also do classic cars and boats. (I did not see your post until now.)

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My pleasure! I have enjoyed the conversations! I have considered the Solution and will ultimately go to it when I get an elective rebuild in the next few years. I originally went with the Retro when it was first released and at that time the Solution wasn't yet out on the market. To me it wasn't a big deal replacing the Retro when it timed out because I frequently had my indy drop my engine or trans to go over service items. So the permanent fix wasn't necessary. But with a rebuild sometime in the future, it would make sense to go to the Solution.

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I have a laundry list of items to check late this fall. I will keep everybody posted. The great news about the 3.6 is the 3 chain system isnt as big of an issue as the 5 chain. But its always good to review.

@GC996 Isn't there a gasket issue as well? the one between the seat and the steering wheel?

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Hah! The person sitting in the drivers seat is always the weakest link!

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ready to blow without warning... steam from the ears...

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thanks, I really don�t want to drop the engine using the process of hanging the back of the car off of the back of the post. Need to figure out a better option. Eventually will figure it out.

Thanks for doing this writeup, it's a nice gift to the community. I've wondered how you were so confident with tracking, but it makes sense. 50% increase in oil quantity, optimize water cooling setup, better AOS, etc. It seems that adding a margin of safety here & there really adds up on these cars. Bravo! p.s. nice work on those seats, not sure I've seen a gray pair before

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Thanks Tony! Margin of safety is a great way to describe it, and its pretty easy to do. I lucked out in the grey GT3 seats. They were special ordered by a fellow PCA member for his car and used them for a couple of months and then decided to sell them. So I jumped at the chance to pick them up. Glad I did. They have been great seats. Comfortable and durable. There is something to be said for keeping your eyes open for various parts in the PCA community. You can not only find the parts you want if you are patient, but you can also save quite a bit if money.