Chronicles of Sebring
Part 1 ...

Published in the February 2011 issue of “Die Porsche Kassette”

Chronicles of Sebring
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Sebring hates my car!

Well, maybe not just my car, but I haven’t been too lucky there lately.

As they say:  Do you know why there’s just a12 hour race at Sebring?

Because no car can last 13!


A couple of people have asked me to chronicle my recent track days there and I thought I’d also use it to dispel or confirm some popular Porsche Myths.


Last year in May I went to the third DE of the year at my favorite track: Sebring.

Because in the past I had had issues with brake fade (now that I was getting better and faster) I had decided to upgrade the brakes on my Boxster.

I found a nice set of 996  front calipers from a dismantler, rebuilt and painted them and installed them on my car together with new 996 cross-drilled rotors.  I figured that since I had upgraded the fronts, in order to maintain balance I could upgrade the rears by installing my original fronts on the rear.  These calipers had larger pistons and brake pads.  They are a perfect drop in  and I had heard from a couple of people who had already done it.  Unfortunately the early Boxster’s rear rotors are also used for the emergency brake, so there are not as easy to upgrade (upsize) as the fronts.

Chronicles of Sebring: ...                                            by Pedro P. Bonilla (PCA GCR)

The Clutch, the Brakes and the Engine, part 1.

So, I’m now at Sebring and bring my car to Tech Inspection.  The Chief of Tech (who is also a Boxster owner and racer) immediately looks at my brakes and says: “You upgraded your fronts!  Good.  But I see you put your old fronts on the rear.”

Then he looks at me and emphatically says: “It don’t work”

I responded that my eyeballs would almost pop out of my head when I applied the brakes on my way up to the track.  I told him that my car was braking better than ever and that I was sure that I could out brake the 996s because I had a lighter car with their same brakes. 

He again stated: “It don’t work”, and went on to say: “But don’t worry, it takes about a year and a half to get fast enough here at Sebring and then you’ll see it don’t work”.

I passed Tech Inspection and when my group was called to grid, I decided that since I had a new braking system, I’d line up last so no one would be behind me.

MYTH #1 

If you upgrade your Boxster’s front brakes with 996 brakes, put your old front calipers on the rear.

We busted that myth.  The simple reason is that because the Boxster is so well balanced when you trail brake, if the rears lock up even for a fraction of a second before the ABS kicks in, it may be too late to save it.

I have since then replaced my old (smaller) rear calipers and left the 996 fronts and the car is perfect.


On the last session of the day, after having run without any other issues, I lost my clutch just before 16.  Luckily there’s a lot of runoff there and I limped back to the pits without a clutch.


I had towed my little track trailer with my track tires and tools to Sebring, so my question was whether I could make it back home without a clutch and towing a trailer.  I though about it for a while and decided to give it a try.  I live 120 miles due south of the track, just off US 27 and I figured that there were maybe 5 or 6 stop lights and if I timed them right by slowing down when they were red, I could clear them all.


It turns out that there are 17 traffic lights between the track and my house.  I was able to time it right for most of them but on 2 of them I had to come to a complete stop.

So, I shut the engine down, shifted into 1st gear and waited for the light to turn green.  When it did I turned the ignition switch and the car started and lurched forward immediately.  I was then able to up and downshift by rev matching without any issues.

Pedro

Our group got the green flag and we all took to the track.  The first couple of laps were warm up laps so they weren’t that fast.  We were getting reacquainted with the track and it started all coming back.  The tires and the engine were now up to temp and we were now going much faster.

On lap 3, as we’re heading down the front straight everything seems good.  The car is planted and stable. I go wide right at the end of the straight, brake hard at the second marker, turn left and head for the blind apex on turn 1, I drift out to turn 2, which is just a kink and then to 3 pressing hard on the brakes.

Wow! These brakes are great, I think to myself. 

I pick up speed again through 4, 5 and 6 and head for the hairpin (7).  The car still feels good.  I’m into triple digits and again I hit the brakes hard.  The car slows down perfectly I make the right hander and get set for the back part of the track.

No problems with 8, 9, 10, 11, 12 or 13.  I’m going for it!

To me, a good lap at Sebring is going through Bishop’s Bend (14) without lifting.

I hit Bishop’s flat out.  15 is coming up fast!  I stomp on the brakes but I’m still carrying too much speed.  I don’t worry because I can trail brake.  I’ve done it before, no big deal. But, just before the apex I felt the back end of my car break loose and I knew what would happen next.  Both feet in and I went for a spin.

Since I was the last car on that lap I wasn’t in any danger of being hit from behind.  I was able to keep the car on the track, but since I had spun I made my mandatory trip to pit lane to talk to the Marshall.

Lo and behold, it’s our Chief of Tech, now acting as Marshall.  I put my head down as I come up to him, expecting to get a lecture, but he just said: “Holy cow!  That’s the fastest year and a half I ever saw”.  “Were did you spin? on 15?”  “I told you those brakes don’t work”.

MYTH #2

If you have no clutch you have to flatbed your car.

I guess that one’s busted too.  If you’re careful and rev match you can drive safely some distance.  I would not recommend city driving with no clutch, but on a highway it was fine.


It turned out that the clutch slave cylinder was the part that failed.  I decided to fix it but also I wanted to do a few more things to my car because the next track event would be in September, again at Sebring and I wanted to be there as well.

Since my car had just turned 196,000 miles I decided to drop the transmission, take a look at my original clutch and take care of the Rear Main Seal (RMS) that had been leaking for a while.  I also wanted to look at my Intermediate Shaft Bearing (IMS) which is one of the weak points of the M96 engine which most Porsches from 1997 through 2009 share.


So, the tranny comes down, we pull the clutch and flywheel and find the expected RMS leak, and an unexpected IMS Bearing leak.


So, it’s now time to also install the IMS Bearing Retrofit.  Ouch!  The original bearing, once pulled, already showed signs of wear and had substantial play that could be easily felt.


MYTH #3.

Our M96 engines are doomed and they will all explode.

Another one busted.  With close to 200,000 miles on the original IMS bearing, we were able to catch it in time and replace it with LNE’s Retrofit.  It can be done without removing the engine from the car, just the transmission.


With the retrofit in place, we also replaced the RMS and took a look at the clutch, which, with 196K miles, was by now paper thin.  So, a new clutch kit was also in order.  When we went to install the Dual Mass Flywheel, we found a problem.

The elastometer (rubber portion) which dampens excessive vibration had been completely damaged by the many years of oil from the RMS leak.  Time for a new flywheel as well.  Ouch, ouch!


MYTH #4

If you have a rear Main Seal leak, don’t worry, it cant hurt anything but your garage floor.

Left unattended, a RMS leak will damage your Dual Mass Flywheel (which is not inexpensive).


Now the car was perfect again and I was looking forward to the next DE at Sebring in September, which was a two day event ....


On the next issue you can find out ... “the rest of the story”.


For more information on these and other Porsche issues, please visit my website at www.PedrosGarage.com


Happy Porsche-ing,






Track layout image, courtesy of

Sebring International Raceway



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