After spending 8 months searching I just bought my 08 997tt Cab in August. As I went through a fairly steep learning curve I thought I would put all these things together in a simple package for others who want to go through a similar search. First, let me be clear that everything I say here is my opinion. I also need to acknowledge all of the contributors in the links I included as well as the whole community for their wisdom and advice, I'm really just standing on their shoulders and interpreting their advice. Also, I am not in the car business and I am not a frequent car buyer. I look forward to others adding to this thread as well.

Here are the topics I will cover:
Selecting the car with 4 Questions:
1. Coupe vs Cab
2. Tiptronic or 6 Speed Manual Transmission
3. Model year
4. CPO or not
Then:
The right options
Salt or not/ Geography and Shipping
Pricing
Be ready to pounce
Lease versus buy
High mileage vs low mileage
DME Top data
PPI



Before you get too serious, you need to make some higher-level decisions first. For the 997 there's 4 main choice points to be made, first comes the Coupe vs Cab, 6 speed manual vs Tiptronic automatic the model years or .1 vs .2 and then comes CPO or not.

Coupe vs Cab

This is mostly a personal decision based on beauty, what you will use your car for and the climate you live in. Inherent in the Cab is a higher price($7-10k), less availability and higher weight. You also have less structural rigidity and thus a bit more creaking. As I understand many racetracks require passive rollover protection, a.k.a. fixed rollbars for a cab. I don't think cab cars go to the track as often. This may result in a less abused engine and drivetrain. I feel coupes are a bit better looking with the classic rear quarter panel and window lines. They also are allowed on most tracks as is and are thus preferred by people who like to go to the track more often.

Tiptronic or 6 Speed Manual Transmission

The second choice point is the transmission: 6 speed manual or Tiptronic automatic. This is practically a religious ongoing discussion including multiple issues of Panorama magazine covering the debate. From a purchase and resale perspective I feel the Tip will be outdated technology potentially going down faster in value due to the PDK coming into the used market. This is not to say it's bad technology just that it has been replaced with something newer. I personally have always preferred the connection the 6MT gives between driver and car. So for me the decision was fairly quick. If you're after the ultimate in performance, the tip will outdo the 6MT. Just think about executing a 1-2 shift without losing boost inside of the 3.8 second 0 to 60.
https://www.6speedonline.com/forums/...tiptronic.html

Model year

The third choice point is deciding on the differences between the 07-09(997.1tt) vs 10-11(997.2tt) model year's. In 2009 a few changes were introduced and then in 2010 a more signicifant set, thus the 997.2 designation. At a high-level, in 2009 it was the Radio/Nav PCM replacement and then in 2010 it was the new engine, the PDK transmission, the LED tail lights and the wheel choices. Here's a good thread with more details: https://www.6speedonline.com/forums/...s-997-2-a.html
I focused in on the 08 and 09 model years primarily due to budget, and thus will not be covering beyond 2009 where additional changes occurred such as the S model introduction. Even further I decided to focus on the 08 year unless a really good deal came up on the 09.
https://www.6speedonline.com/forums/...o-07-08-a.html
I bought my car to drive and hear the engine. I haven't had the radio on since I bought the car. In my previous car it was on all the time. In my opinion the 09 PCM swap was not required for me and a good aftermarket add-in like Dension or Mobridge or NAV-TV will get you most of the same features for under $1000. Use board sponsers and you'll get great service. https://www.6speedonline.com/forums/...xperience.html I also don't use Nav as I usually know my route, so I'm ok with the clunky old non-touchscreen interface. On the family weekend cruiser, that’s another story. Bluetooth, ahhh leave a voicemail I'm busy driving. And on Ipod connectivity, I have a 09 Cayenne with the new PCM system and all our Ipods seem to drain their battery down while plugged into the system resulting in nonresponsive Ipod and needing to be charged again at the computer. Perhaps ours is defective.
So in the end for me it boiled down to simply a price difference and you need to decide on your budget to pick .1 or 2009, or .2. I consistently saw a $15k price differential between the 2008 and 2009 model years.

CPO or not

Certified PreOwned (CPO) by PCNA provides two things, first the car is gone over with a checklist and wear components are brought up to 80% or above standards. This can save a bunch of money as I've seen a number of CPO cars where they've replaced tires, brakes (pads and rotors) and battery. We're talking $3-5k worth of work. Don't expect a very thorough inspection here, my checklist came back for signature without everything checked. I also found tons of leaves jammed into the air filter, so how closely are they really checking? Secondly, your getting the peace of mind of a full Porsche warranty. To quote the PCNA site" The Porsche Approved Certified Preowned Program comprises two distinct limited warranty coverages.
1) The limited warranty covers up to 6 years or a cumulative 100,000 miles/160,000 kilometers, whichever comes first if the vehicle is still under the new car limited warranty.
2) The limited warranty covers 2 years from the date of sale, up to a cumulative 100,000 miles/ 160,000 kilometers from the current mileage on the odometer at the time of purchase. "
If anything goes wrong you can take it to the local dealer and go through the usual process which sometimes can result in "that’s normal, not covered". Also, this CPO is transferable to anyone you sell to within the warranty period and you also get Porsche Roadside Assistance. But considering the complexity of these 4wd, twin turbo, electronic stability control cars, I felt it was important.

 

Once you've narrowed down these high-level criteria, you'll be looking at a small subset of the available cars imported that year, 2000 cars for 2008. <production numbers> In my case Cab, CPO and 2008 there were only about 44 cars available at any given time. Narrowing down the colors, I wanted black, I really only had a choice between 10 cars or so. So which one is better?

Finding a car with the right options.

The first task would be to go to the PCNA Preowned search page and browse the listings available for the target car and model year you're interested in. I found other sources such as AutoTrader to have very confusing options lists generated by used car lot software. They listed everything like power windows and airbags.... So it was hard to find the true factory options. Look at the PCNA Preowned listing options that are commonly available and make a list in priority order. And categorize them into must have, highly desirable, and would rather not have. The number of options available is extremely large, but you'll notice that most cars only have about 8 to 12 options installed. When compared with the C2 and C4 cars, there are a number of base included options that traditionally you would be desiring such as Bose stereo and PCM Nav. This thread is also helpful: https://www.6speedonline.com/forums/...ons-997tt.html

You should also spend time at a dealer. Nothing can replace actually seeing and touching these options.

To guide me through sorting cars as they show up on the listings, I created a system to assign points to those options that are highly desirable, and negative points for those I didn't want. Then whenever a car showed up, I would assign points to it and give it a total. You'll quickly see if a car is nicely optioned based on your desires. Each week I would print out the listing of available cars, and see which ones have been added to the list and those that have sold. You'll also notice price changes. Here was my priority order list with point values (+1):

Must have set in concrete:
6 speed transmission
heated seats (+1)
Seats (the fancier the better, like adaptive sport seats(+2))
sport Chrono package Turbo
standard turbo aluminum wheels (after market will be considered on an individual basis)no curb rash!
(2009) must have Bluetooth interface for telephone and Universal audio interface

Highly desirable:
limited slip rear differential lock (+1)
three spoke wheel with multifunction controls (+1)
ventilated seats (pretty rare (+1))
Clear bra on bumper or equivalent (shows that PO cared)

Would not mind:
rocker panel and lip painted in body color
sport shifter
6 disc CD changer
Bi-xenon lights
full leather interior
LoJack

would rather not have these Options, but not a dealbreaker:
PCCB ceramic brakes (high maintenance costs)(-1)
parking assist (ugly rear looks)
aluminum hardtop (who needs it in CA)
XM Radio
extensive interior decoration (carbon fiber etc.) used to jack up the price

 

Salt or not/ Geography and Shipping

Since the PCNA preowned search does not list the state of the dealership selling the car, it's a little tricky to find out where they're located, until you get to know them all . I used telephone area codes in Google search. My preference was for cars from the non-snow regions of the USA. This will result in less or no salt on the roads. Because of modern technology these cars are designed to handle salt, especially in Germany, so this is a debatable criteria as in this link: <anyone find this?>
Shipping for these cars is going to range from $700(in same state, you should really just drive it home) to $2800 (cross country) or so depending on how far away the car is. This will invariably be a price for an enclosed carrier. If you need to find a company for this search the forum, my auto broker took care of this for me.
https://www.6speedonline.com/forums/...d-members.html
https://www.6speedonline.com/forums/...911-turbo.html


Pricing

If you're looking at a Porsche dealer listing on a CPO car, you're going to be seeing the list price established by the used car sales manager. Each dealership has its own personality and approach. But most of them tend to hover around the same price points, thus creating the market. After watching long enough I've sensed certain dealers like to turn over inventory quickly and price aggressively. Their cars usually turn over in less than a month frequently in a week or two. While other dealers stand on their laurels of exclusive neighborhoods and let cars sit for months waiting for the happy-go-lucky deep pockets customer to fall in love with the car and pay their price. Some really enjoy this model sitting in the showroom as a showpiece, frequently this is the top-dog used car in the whole dealership. Most dealerships really only have one or two of these in stock at any given time and there's a whole bunch of dealers that never seem to pop up on the lists, not sure what happens there. And there's a couple dealerships that scour auction houses and other dealers for turbo's, CPO them and resell them. You'll see that these dealers usually have 2-4 cars available. I eventually got my car from one of these dealers, just make sure you examine the Carfax very carefully.

The list price is rarely what you're going to pay, but how far will they come down? I've heard 3 to 5% from the forum, and I have seen a few exceptions in the 8% range. My interpretation is it really depends on what position the dealership is in at the time, along with cars sitting and the end of month bonus that is pending.

Another item to consider is what time of year it is. Summer is Porsche season as my salesman called it and prices follow. Then they drop in Sept when the new model year comes out and all the used inventory ages another year on paper.

Be ready to pounce

I was looking for a BLK/Blk 6MT clean car for 8 months and lost out on three cars before I got mine because it took me more than 4 days to ask all the questions and get all the information such as carfax, service history, DME, etc. mainly because the dealerships had just listed the car and didn't have it all together. All were sold within 1 wk, even the one I bought . The dealership I got mine from did not accept any deposits. Basically the first person with funds sent into their bank account ended up with the deal. So it's best to have the funds ready and wire transfer form in your hand. Ask for wiring instructions at the beginning of the deal (makes you look serious) and be clear on how long it takes your bank to process and get the money to the dealership.
Make sure you have hard and fast criteria set up so you can make your decision quickly and then be ready. Be careful to keep emotion out of it.

Lease versus buy

This boils down to how long you plan to keep the car and whether you will be deducting any part of the car from taxes. Short term (<3 yrs) your better off leasing, long term you should buy to save money. See:
https://www.6speedonline.com/forums/...lease-buy.html

High mileage vs low mileage

As far as mileage goes you're basically trading off against depreciation both short-term and long-term. Short term, you'll probably notice that garage queens with < 10k mi for 08's, get quite a premium. I opted for a 25,000 mi car because I wanted to save a little up front and since I only put 3k mi on the car each year, I should retain the value pretty well. Long-term, a 10 year old car with 30-40k miles will go for much more than one close to 100k mi. This has less to do with the particular model, and more just the way the used-car market works.

 

DME Top data

Ahh yess, the proverbial Digital Motor Electronics (DME) data. Unfortunately as Porsche has recorded and allowed us access to this information, we all look at it and judge purchase decisions on it. In fact we go number crazy because we actually have something to compare and guage by, other than just "oh, that engine sounds good".

First some education on what is an over rev. This is when an engine runs at higher than it's redline RPM's. In other words the whole system is going faster than designed and thus producing engineering stresses above normal operating range. Most engineered components are designed for a certain percentage of overstress and the 997.1 Metzger engine is no exception. In fact, it's probably running in passenger use at far below its true limits. The engine has a rev limiter that is set to cut the engine power at a specified RPM, I believe stock setting is 6800 RPM.

I spoke to my friend who races his dedicated track cars in NASA and he said there is no way to reliably test for all the possible damage due to overrevs. He said that during an over rev, the piston head is traveling away from the crankshaft at a high speed when the crank suddenly pulls it back, so the rod is stressed over engineered limits. Micro cracks form in the hot metal and slowly over time (over many heat cool cycles) expand until full failure, who knows when. Also if the valve comes in contact with the piston arriving faster than expected, the valve will suffer over stress, again cracks or bent out of alignment. I would guess you can probably find some of this damage with pressure testing (leak down test?), but not all.
Lets look at a readout, if you search DME on the forums, you will find plenty of examples, most people paraphrase the information in a short form as follows:

DME:
Range 1 8649 237.6h
Range 2 1546 219.0 h
R3 452 219.0h
R4 107 219.0
R5 17 211.9
R6 8 211.9
operating hours 244.4
Type DME control unit _997TUS00
Etc....


Range 1 is the lowest RPM range that is registered and for the 997.1tt it represents 6800-7000RPM. The other ranges are all listed in this link:
https://www.6speedonline.com/forums/...dme-scans.html
The stock 997.1TT ranges are:
range 1 > 6800 and < 7000
range 2 > 7000 and < 7200
range 3 > 7200 and < 7400
range 4 > 7400 and < 7900
range 5 > 7900 and < 9000
range 6 > 9000
https://www.6speedonline.com/forums/...ev-report.html


So clearly in the example above we have two events about 30 hours (244.4-211.9=32.5 and 244.4-219.0=25.4) or ~1000 mi ago spending less than a quarter second above range 3, but it did register 8 ignitions at 6.
To translate Ignitions to time, I refer to a post from @shadow 2 "I understand how 92 ignitions translated to about 0.25 seconds, ie. 7900rpm * 3 ignitions per rotation = 23700 ignitions per min, 23700ipm / 60 = 395 ignitions per second, so then 92/395 = about .23 seconds."

A good link of over revs and tunes is:
https://www.6speedonline.com/forums/...-counters.html
It contains a great table from Tom@Champion, a dealer and a tuner regarding how concerned you should be about hits in each range:
"Range:
1 -- Don't stress it, the dealer won't.
2 -- Don't stress it, the dealer still won't....but come on, shift when the needle gets close to the red!
3 -- OK...you need to start paying closer attention to those upshifts. The dealer might give you a slap on the wrist, but nothing to worry about.
4 -- Probably need to work on downshifting a little. Not a warranty-breaker, but might raise a few eyebrows at the dealer depending on the circumstances.
5,6 -- Something is wrong. Maybe your shifter linkage is messed up, or maybe someone told you 5th --> 2nd was OK...but you're flirting with disaster. Eventually, something WILL break.
The last 2 cars that came in here with blown motors each showed Range 5 and 6 over-revs. At that level, you're seriously testing the mechanical limitations of the engine. Eventually, it will cause a problem. Some people don't get more than one chance....it could be that one Range 5 or 6 that breaks it. "


As far as I understood the Porsche factory definiton of damage at different ranges is as follows (sorry, couldn't find the thread where I copied this again) Note: this is not a turbo rev range, but the descriptions should stand:

Rev range 1: 6,740 -1 ... to 6,940 -1
⇒ Maximum permitted engine speed exceeded; engine damage possible.
Rev range 2: 6,940 -1 ... to 7,140 -1
⇒ Maximum permitted engine speed exceeded; engine damage possible.
Rev range 3: 7,140 -1 ... to 7,340 -1
⇒ Maximum permitted engine speed exceeded; engine damage probable.
Rev range 4: 7,340 -1 ... to 7,840 -1
⇒ Maximum permitted engine speed clearly exceeded; engine damage probable.
Rev range 5: 7,840 -1 ... to 8,940 -1
⇒ Maximum permitted engine speed very clearly exceeded; engine damage very probable.
Rev range 6: over 8,940 -1
⇒ Engine damage has generally occurred.

Engine hours is also a useful number to see if the miles on the car are truly "highway"
You can take car mileage, divide it by the hours counter and determine average speed for the life of the car. On average it should calculate out to around ~ 35 mph. If you get a very high or low value you should ask some more questions.

As I noted in my thread:
https://www.6speedonline.com/forums/...-purchase.html
After all my research, my limit was no more than 40 ignitions in range 4, I dropped all cars above this.
If you're debating a DME and you are buying, not leasing, consider what will happen when you go to sell it. What will the next owner be thinking. Ha, after they read this post...

PPI

This stands for Pre Purchase Inspection. Many dealers and local Porsche repair facilities will inspect a used car for a minimal price ( I was quoted $200-250 in San Jose area) compared to the problems you may end up with. Most sellers will allow the pick up of the car for this purpose. Everyone recommends this step. I ended up jumping without it and ended up ok, so far. My broker was happy with Porsche CPO. With a private party sale, I would not spend this much money on promises and would require a PPI. Use the forum for reputable PPI shops in the sellers location.

Ahhh finally done, enjoy......

 

Great post. Thanks for putting it together.

 

great summary for 1st time buyers - as you point out in your search, it is surprising how small the universe of cars can get when you really drill down what your want.

i bet your summary of the driving experience will be less clinical.

finally - black turbo cab manual - must say it was a great choice!

 

Nice job - and congrats on the new car. Did you use this website for your searches? It does show the location of the selling dealer (not necessarily where the car was originally purchased though) and does show the options. Unfortunatley, the inventory listed can be dated so you're correct - you have to "pounce" My selling dealer did take a deposit and we signed a purchase agreement and I drove the 200 miles to close the deal within 3 days.

http://www.porsche.com/usa/pre-owned-vehicles/search/

 

thanks for the info, great guideline for many.....

 

Wow - what a fantastic post. I especially appreciate the discussion and summary of over-rev/DME reading. Thanks and enjoy your Turbo baby!

 

Nice work! Rep points for the gentleman.

 

Well done. Excellent and informative summary.

 

The thing about the over revs I don't understand is our cars have rev limiters right? How is the engine over revving into unsafe levels when the limiter is there to keep you out of unsafe levels?

I admit when I first got my turbo and was learning to drive it I bounced off the rev limiter a few times. First gear is way shorter than I realized and the boost and speed ramp up exponentially. Same in 2nd gear, the car just pulls and seems to want to go on forever. New to this kinda of power I was watching the road more than the tach and bumped into the limiter. The reaction I get from the car when I hit the rev limit by mistake is the car seems to have a knee jerk reaction and retards power, in what way I don't know, probably timing, boost etc. Feels like on my mini cooper s when I have traction control on and I spin the wheels a little it over reacts and retards power very obtrusively, which is why I turn it off every time I get in the car I've been too chicken **** to turn off the traction control on the turbo so far >.>

I am guessing my over revs fall into the 1s or 2s? I have never dropped from 5th to 2nd or anything crazy like that.

Every time I see talk about buying a 997tt the over revs are always part of the discussion. If these over revs are such a huge deal, why isn't the Porsche software keeping them in check better? The 911 is said to be over engineered, why allow a customer to push the engine beyond its safety levels?

 

Accelerating to redline will trigger the limiter and cut off fuel. But a misshift say from 5th to 2nd will cause an
overev. The limiter will not prevent this.

 

Can you expand on this a little more? If I am reading your post correctly; taking the car to redline and having the ecu give you the pimp hand is harmless. While down shifting in a negligent manner is a good way to cause one of these codes and is possibly the only way to get them?

Not trying to put words in your mouth. But your answer is kinda brief and I don't know how to read it any other way. If this is the case, that is great news, I will probably never preform an over rev

 

I guess this over rev won't apply to auto trans?