This is probably the direction I will take. I'll most likely see if I can get my beloved 997SC's engine replaced, and then eventually when funds allow I'll look into a Spec Miata for the track.
CATTMAN

 

smart move. if you have space where to park trailer - it is the best way to go. 997 is a great DD. it bleeds my heart to see what I do to my car, and when last week it threw up CEL at third lap on my first session of the day it was quite an unpleasant sensation, i thought it was the end of the game. but, well, it seems it will live a bit more.
still, driving $80K car into its death just for sheer fun of it is quite a bit stupid.

discuss all the options and shop around, check if any engines are on ebay now - sometimes you can find an unexpected deal. last year dealers were selling leftover stock of x51 m97 motors for quite a nice price. take your time to find all the options.

 

What's interesting is that the PSDS (Porsche Sport Driving School) beats the pants off their cars every day, and all they ever need to do is change the oil and rubber. However, they face no risk if they destroy a car- PCNA gets them a new one, whereas I face the expensive risk.

I really thought that I could track a 997S hard, for hours on end, and be OK. I was under the impression that they were built for that. But I suppose ANY car that gets beaten hard is at risk of failure, even the CUP cars.
CATTMAN

 

marketing lies. any engine does not have 'life' - it only has certain number of hours it can run from rebuild to rebuild. if you run it at redline for 4 20min sessions a day - it is one number, if you do full racing weekend with up to 12 hours total at redline - it is other number. usually quite close to 100 hours total for street motors, they are not meant to be driven like this. cup car engines are bit better, in fact much better than stock gt3 engines, which are better than m96/m97 engines. you get the idea.
but in the end all motors die.

having spent like $5K or so to re-build stock M97 engine to race specs, balane crankshaft, get lighter rods, stronger studs, etc. helps. you never know how well was everything balanced at factory, some engines are better than others, some are worse. you just never know.

some folks just use metal control and do not ever go much over 6500 rpm on street cars - some say it helps quite a bit. I do not know.
you know content of ln engineering engine articles as well as i do - so, all info is there.

as of PSDS - i bet swaps cars out every 2 years if not more often. they want customers to drive new cars. and i would not want to be an unfortunate soul who will buy one of those 'cpo' cars from any dealer after they were beaten up at PSDS.

PS. sigh up for SCDA or similar 'alternative' events that allow to rent a spec miata for a day, drive it. then try to get somebody with a spec boxster, drive it. properly built spec miata can be found for $10K-$15K budget. spec boxster is probably, well, may be $5K more expensive. maintenance of spec boxster is also more expensive but it got much more power than spec miata. and stay away from supercharged miatas - for same exact reasons you already know.

 

Forgive me for the naive question, but I honestly don't know the answer here ...

OP: Since you've heavily modified your motor using a SC, etc ... and you're producing far more HP then was originally intended, doesn't that alone, reduce the effective life and reliability of the motor?

 

like i said before - there is no 'life'. there are vibrations, compressions, friction on bearings, etc.

adding SC changes some parameters, most critical of them are related to effective temperature of a block and all subsequent issues related to cooling. there is a SC car here in MA that runs 9psi and it has very interesting 'sandwich' front radiator that combines regular primary coolant circle 3rd radiator with additional SC intercooler radiator in front.

issues SC systems get are not unique to Porsche, there are plenty of FI systems on Hondas, Supras, Mustangs, Vettes, some of them run longer, some of them blow. My opinion is all it depends of how well stock engine was assembled and balanced at factory. To take it apart and re-balance takes quie an effort. Probably it would also worth to increase diameter of coolant passages in a stock M97 block for SC system. Who knows.
IMS bearing on '05 engine could still fall apart no matter what. It is damn difficult to predict.

But one way or another when one decides to mess up with stock engine and put any 'improvement' into it - you better have enough money for a new one if anything happens - it is just a fair game, that`s all. no guarantees.

 

Makes sense ... especially this last part.

 

my dad`s older brother was into performance cars and his concept was always same - to get spare engine and while he ran one in the car he had other one in works so he could swap at any time he wanted... if only those M96 ones were cheaper i would do same, it just makes sense.

would be great also to ditch all that MAF electrical crap and put in 100% mechanical throttle intake controls like in older cars. al this modern sh$t just brakes when you need it most... and does not do anything new compared to how engines used to work all the times before.

just to think of it how many m96/m97 engines blew already and how many 993 and 964 cars are still running... Now people say DMEs started to die as chips got older and cause misfire issues on 997 cars. Total bummer. Less electrical parts you got - the better race car it is.

 

Some 997 racecars actually use 993 air-cooled engines.
Those early engines, like the one in my '87 Carrera 3.2 cost much, much more than a new 997 engine.

As for the added stress of adding an SC to my 997, cooling isn't the issue. In fact, my intake temps and oil temps were lower with the SC than without due to the stand-alone radiator and cooling system for the intercooler.

I was running a very conservative 6.1 psi at WOT at redline, and I was hardly ever there. Usually running 0 psi boost, and when on it, about 2-3psi boost.

But an IMS bearing failure isn't related, it's just a crappy bearing.
CATTMAN

 

John, with all respect to what you think - statistics of longivity on m96/m97 supercharged cars that see a lot of track action is not on your side and you are a part of it now, unfortunately.

internal overheat got little to do with what outside sensor shows - it is same issue ln engineering wrote about but you put out more power from block, you get more dissipated heat into block, even as it cools down later it is still in the block. it is just plain laws of physics. bearings die from vibration and lack of lubrication - what was the culprit in your case - who knows. and honestly, it does not really matter. sh$t happens, end of story.

anyway, how is it going with PCNA? did they tell you anything?

 

Or warranties.

 

Since you mention spec miata, I'll just chime in that that you should pick your track car based on the events that you want to do. This is particulrly pertinent for spec miata and that type of car. I can speak from experience with my 944NA, which has similar power to weight. Spec Maita makes a good race car, if you want to race, but for DE, it's just so-so. It can be very frustrating to share a DE track with faster cars and less-experienced drivers.

 

Go find a 996 GT3 and take if for around a track for a few laps, and then compare it to your C2, and ask yourself which one is better. Then step into a 997.1GT3 and do the same thing. The end of the day you will realize that even a used beaten up GT3 is a great car, and a lot more then a 997.1, 997.2, or even the 991 can compare to. As for comparing it to a cup car, no idea where this came from, especially when the OP was looking for a car that was more at home on the track and can still be used as a DD.

 

my car is better as I do own it already.

 

I think you have said that more times then anything else. Must be the GT3 LCA.