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Porsche Maintenance Tips

What It’s Like When A 996 Turbo Goes Under the Knife for New Coolant Pipes

Yes, removing the Mezger is that daunting.

The one chink in the Mezger’s armor is its flimsy coolant pipes. For such a bulletproof motor, it seems strange that Porsche just glued the coolant pipes on. Though press-fitted, these coolant lines are known to pop off under high RPM load. Hoovie’s lousy luck meant his first trip to Heartland Motorsports Park was interrupted by his own lines popping off. Fortunately, this did not prompt a spin down the front straight, nor did it cook the motor. It was embarrassing though, and as it turned out, quite pricey to mend.

The Mezger motors that see the track will sustain higher temperatures and loads which are prone to make these lines disengage from the coolant console, and ensuring they stay in place during hard cornering and high revs requires a costly fix. While the cheaper band-aid fix would only set him back a few hundred dollars, the sensible approach costs ten times that. After dropping the engine, the hoses need to be pinned or welded in place, and the especially prudent drivers will replace the problematic OEM plastic elbows with stainless steel units.

The process of removing the engine is more labor intensive than dropping an M96. Turbos, intercoolers, head shields, and all the other forced induction ancillaries take a bit more time and effort. The starter and turbo inlets need to come out too, since they won’t clear the CV axles. With a few minor wiring hurdles cleared, the Mezger can be freed from its cramped confines. However, the process takes Hoovie and Wizard nearly two whole days to complete—which is why he was quoted nearly three large.

If there’s one piece of uplifting news here, it’s that BBi Autosport decided to help by offering to fix the busted water pipe situation. BBi, as well as a host of other Porsche-centric shops, can weld the coolant pipes in place for what should be a permanent fix. If you have any Mezger-powered Porsche, be it a Turbo or a GT3, you can preemptively have this work done, so it doesn’t come apart and leave you stranded without coolant. If you can remove your motor to get the « coolant console » out, as Mr. Hoover has, it’ll help save you a ton of labor.

Now you know. Let his misfortune save you a ton of time and money!

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3 Lighting Mods to Clean Up Your Porsche’s Exterior

While a strong enough will and disregard for appearances can stick LED strips to anything, it is not the way to aesthetic harmony for your Porsche. From the factory Porsche’s aesthetics tend toward distinctive, yet understated. While the brand is not immune to following the trends of the moment (I’m looking at you, side strakes on slantnose 911s), typical Porsche styling strives for a cohesive whole over flashy touches. In recent years lighting mods have changed radically over the last several decades. Previously, owners could move from sealed beams to H7 lamps, or add driving lamps. Today owners can pick from numerous types of emitters, consider lamp color temperature, or even use garish clear lenses and chrome housings. But such is not the Porsche way.

Where the lighting changes made to our project 944 were about as subtle as possible (you can’t even see my headlights when they’re off), EatSleepDrive has opted for a slightly more obvious approach. By delving into the Porsche parts bin he has subtly and effectively updated his 997. The video above provides a useful guide to installing a few common parts on 997s, including the front side markers, taillight assemblies, and license plate lights.

Being 997 specific, these tips don’t work for all Porsche owners, but do provide useful pointers. All of the parts used by EatSleepDrive came from the Porsche parts bin. According to the video the tail lamps carry Porsche part numbers, and are Tequipment accessories in Europe. The side markers are also European-market items, and the license plate lights come from the 997.2.

Light Modifications for Other Porsche Models

Because of Porsche’s often lengthy production cycles, this sort of parts-bin picking can be useful for all Porsche owners. US-market 911s were long afflicted with « sugar scoop » headlamp buckets and sealed beam lights, rather than the glazed H7 lamps used elsewhere in the world. That simple change can not only improve the appearance of your 911, but increase useful light output. By the same token, all of the pop-up headlight cars can be easily switched from sealed beams to H7 lamps.

Even More Choices For Transaxle Owners

For 914/924/944 owners, the quest for increased light output is even easier. Drop-in HID conversions can be used without compromising the look of your Porsche when the lights are off.

Owners of early Boxsters and 996s can use headlights from the 2002-up cars for a cleaner look. Porsche omitted the amber front turn signal from the « fried egg » headlamps following the models’ 2002 refresh. Outside of North America post-2002 cars also used clear front side markers, which are especially clean looking on light-colored cars.

From Porsche’s long history, what lighting modifications do you find most handsome, or most useful? Do they come from the Porsche catalog, or from the aftermarket?

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How Tire Pressure and Inflation Affect Your Porsche’s Performance

For those of us who drive on the street, tire pressure probably doesn’t get a lot of consideration. Porsche includes recommendations in the manual, and frankly, why not use them? Of course, when driving deviates from the daily grind, tire pressures become a lot more important. Whether using your Porsche for a track day, autocross, or road rally, more extreme situations than normal may require deviations from « normal » tire pressures.

The video above from Engineering explained does a good job covering the fundamentals of tire pressure and performance in the dry and in the wet. The video also covers important points such as how temperature affects tire pressure, and how tire pressure can affect tire wear.

991 Tire Pressures

The Modern 911 Perspective

The chart above is from the owner’s manual for 2017 911 Carrera 2 models. Let’s dive in to this chart a little. The 911 is rear engined, and runs a staggered wheel and tire setup, and this drives the tire pressure specification. The high percentage of mass over the rear axle requires greater tire pressure than the fronts for two primary reasons. The first is to carry the load of the rear mounted engine, and the second is to mitigate the oversteer inherent in the layout.

991 Carrera S

Lowering rear tire pressure would increase oversteer, and increasing it further would increase understeer. The opposite tire pressure to understeer/oversteer relationship holds true for the front of the car. In a modern 911, the wheel and tire setup is entirely designed around bringing oversteer in line. In addition to the tire pressure differential, the 911 runs a much wider tire at the rear than at the front(this is true in both RWD and AWD models).

944 Tire Pressure

In my case, this is no longer relevant because I am not running stock sized wheels.

Tire Inflation and Older Porsche Models

Porsche specifies a cold tire inflation number for all models. Into the 1990s, this information was generally on a little yellow tag under the fuel filler door, though it is also in your owner’s manual. These tire pressures are designed to tame the cars’ handling somewhat. In a stock, naturally aspirated 944 with the same size tire at all four corners, this was done by reducing the tire pressure slightly at the front end. Tire Rack has a helpful chart which helps to illustrate how several suspension setup changes, including tire pressure, can affect vehicle handling.

Unlike a 911, a 944’s mass is nearly balanced from front to rear. With equal sized tires at both ends, simply dropping tire pressures at the front will induce some understeer. While this will make the car more docile for inexperienced drivers, it is also easy to counteract simply by raising tire pressures on the front axle. To get the same net effect in a 911 requires both a differential in tire pressure and width. This is part of the reason early 911s have a much more well deserved reputation for tricky handling than later cars. Very early 911s use the same width tires front and rear. As time went on, the rear tires became much wider relative to the fronts, while weight distribution remained approximately the same.

Porsche 356 Technical and Restoration Guide

The Classical Perspective

Fortunately, these truths are pretty much universal. If you look back in the 356 Registry magazine archives(which I have a portion of in their Technical and Restoration Guide), you’ll see the same tire pressure advice. In reference to setting a 356 up for autocross, in Volume 8, Issue No. 3, Bob Napier writes:

« … with this setup I usually run 36PSI in the front and 34(PSI) in the rear. The higher front pressure partially offsets the low speed understeer tendency, and, on a real tight course, I might drop to 33 or 32 in the rear in an attempt to get the rear to come around. »

So whether your Porsche is new or old, monitor your tire pressure for optimal handling!

Resources on Tire Pressure and Setup for your Porsche:

 
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Horse Power vs. Torque: Better Known as Horse Power = Horse Poo

Have you ever wondered about the difference between Horsepower and Torque? These two numbers are probably the most well known specifications in the automotive industry. Yet, I didn’t feel like I really had a solid grasp on the differences. I had some idea of each separately, but I was missing just how they interact.

I started doing some searching on the web and then watching a few videos, but they were either too abstract or blew through a few too many important concepts. So, I went back to the math with the most important insight: Torque is measured, but Horsepower is calculated.

In this video, I go through the history of horsepower while calculating its actual value of 33,000 ft-lb/min. Then I go on to derive the equation that equates horsepower to torque and show just where that constant of « 5252 » actually comes from. You’ll be entertained and hopefully, have a little better understanding of these most important specs.

 
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The Joys And Stresses Of An Air-cooled Breakdown

Stranded at the side of the road is never a good feeling, especially when you’re dealing with an unfamiliar and seemingly phantom electrical problem. I’ve driven my 1976 912E about 25,000 miles since I purchased it in August of 2016, and it’s been absolutely faultless in all that time. It’s a little finicky sometimes, but has never left me stranded. That is, until last weekend.

Last weekend, I attended the Driving While Awesome! Coastal Range Rally, which is an awesome point-to-point enthusiast rally with no timing or scoring. It’s been lovingly referred to as ‘Summer Camp for Big Kids’, because it’s three days of driving with about 100 of your favorite car friends. As with last year, I brought my trusty 912E for a weekend of awesome driving on awesome roads. This time, however, it briefly failed me.

Here’s what happened, and how we managed to pull out of it unscathed

Thursday morning I drove over to SFO, from my home base of Reno, Nevada, to pick up my co-driver Adam Hove -who flew in from San Diego for the event. I80 crosses the Sierras at over 8600 feet above sea level, and the snow was coming down inch after inch. The road was closed to all drivers without snow chains. Luckily I had a set in my Porsche’s Mary Poppins-esque front trunk, so I chained up and kept rolling. A few hours later I was parked up at SFO waiting for Adam, arriving just minutes after his plane landed.

That night we checked into our lodging and scooted into town for a relaxing coffee and a chat about what we were looking forward to in the coming three days. Once caffeinated, we climbed back aboard the good ship Porsche. That was when the problems began. No matter how long I would crank the car over, it would not fire to life. My 912 wasn’t particularly low on fuel, but it was on a slope, so we tried to rock the Porsche while cranking to see if the fuel pickup wasn’t working. The fuel pump was certainly running, but it was dark and our capacity for diagnostics was minimal.

Before tromping down the street to pick up a fuel can and a few extra gallons, I remembered that I’d brought a can of starting fluid, so we squirted a few dabs of that good juice into the intake trumpet, and my 912 fired to life. Hmmm, curious. The Porsche has been running finicky at low altitude since I got it, which I think is related to a vacuum leak that I have yet to trace down. It’s usually no more than a minor inconvenience, and had never caused anything like this. Oh well, time to motor on. By the end of the night, the non-start issue had evaporated. The Porsche fired like normal, and didn’t need starting fluid again. I bought a nearby AutoZone out of their stock, just in case.

Friday went off without a hitch, with maybe 10% of our stops for the day requiring a bit of starting fluid to get the little 2-liter rumbling and spitting to life. The roads were great, and the weather was chilly, but dry. We were having a riot giving this car the full beans. We’d started the day in Hollister, California and wound our way down some of the greatest driving roads the state has to offer to get to Paso Robles for our overnight stop. We went to sleep happy and tired that night. The camaraderie between rally attendees was stellar, and I was getting along great with my co-driver (which doesn’t always happen).

Saturday started with another cold but great day ahead

I handed the keys to Adam and had intended to let him drive for much of the day. We hopped across the Carrizo plain out to Soda Lake for a group photo, and then it was a short section up and down the twisty and curvy Highway 58 from Santa Margarita to McKittrick before lunch, so I requested the keys back for this section, one of my favorite driving routes. I was winding my way up the 58, pulling hard in fourth gear at 4500 rpm, hounded by one of the Sharkwerks cars behind, trying to keep up with a friend’s hot Carrera 3.2 ahead, when it happened. As we rounded the final corner of the uphill section and the road flattened out to the plateau before winding down again, the tachometer dropped to zero and the engine conked out. Fear gripped my soul tight as I coasted to the side of the dusty lonely road.

As happens when your Porsche breaks, a million possibilities flood your brain, and it’s impossible to think straight. After a half dozen other rally participants pulled over to help out, we set about attempting to diagnose the issue. There was a fuse burned out, but it was totally unrelated. We tried the starting fluid, and the 912 would stumble to life momentarily, pop, fart, and stumble back to slumber again. It was a curious case. Time for a test light.

We first set about checking that there was power to the coil, which there was. When we tested that the spark plug wires weren’t firing a spark, a pair of extremely kind women offered up the new spare Bosch coil from their 356. The new coil didn’t fix the issue, it would still stumble to life, then pop a bit and die again. Dejected, I began the process of calling AAA to get the 912 towed into town. There was one bystander who could get one bar of signal to his cell phone, and the call was placed.

Most of the folks who had stopped were saddling up again to rejoin the rally, leaving me to my flatbed truck fate. I said my thank yous and goodbyes and some of them helped push the Porsche to a more tow truck-friendly site. A few offered up snacks and bottles of water for our wait, and we settled in for the long roadside wait. One incredibly kind soul, fellow automotive writer Jason Cammisa, offered to stay behind to wait with us for the tow truck and continue diagnostics as long as we had nothing better to do.

Once it was down to just Jason, myself, and co-driver Adam, we set to work. We used a test light to see if the fuel injectors were firing, they were not. We swapped and re-swapped the ignition coil to no avail. We checked and re-checked the distributor cap and rotor, both in great shape. Figuring the worst, that the 912’s EFI computer had fried itself, we got a little down in the dumps for a bit. None of us had really much experience with this primitive mid-1970s mix of mechanical ignition and electronic fuel injection.

« Well, the only spares I brought are an ignition rotor, a set of points, and a set of spark plugs. We could just replace parts to see if it makes a difference, » I offered. We ruled out spark plugs, as all four wouldn’t go bad at once. The rotor seemed in good shape, but we replaced it anyway with no change. Enter the points. None of us had dealt with points before, but we quickly jumped in to figure it out. By putting the Porsche in gear and rocking it forward, we could see the curve of the distributor shaft and where the points follower should be riding. Even at the maximum point, the gap wasn’t separating at all. Problem found, lets get it out of there!

The follower is a little piece of delrin-like plastic that rides on the distributor shaft to push the points open and closed four times per revolution. The follower on the old set of points had bent over to the side, and wasn’t giving enough of a gap to create the spark. The points trigger is also what tells the computer to fire the fuel injectors, which provided us our confounding no-fuel issue. While none of us had any experience of how to set the points gap, the old hot-rodder’s addage of using a business card clamped between the two sides to set for optimal spark was ingrained into our collective brains.

Once the points were replaced and the ignition system was buttoned up again, we held our collective breaths as I climbed into the driver’s seat and hit the starter again. Ruh-ruh-ruh-pop-poppity-pop-brrrrrrrrrmmmmmmm. The Porsche fired right up and settled into its familiar uneven choppy idle. That was the biggest relief I think I’ve ever felt in my entire life. Jason urged me to get the 912 on the road as long as it was running, and we would stop in the next town to see if everything was running okay. I shoved the lever into first, and rumbled onto the pavement with trepidation. After about a mile of motoring, the Porsche felt stronger and more confidence inspiring than it had all week. As the weight eased itself off of my shoulders, I placed it on the accelerator. Jason followed behind in his Mercedes 190E 2.3-16v at a generous pace.

I had intended to call AAA to cancel the truck coming to pick us up, but we actually met the drivers coming down the hill. I waved at them, they waved at me, and we both pulled over to discuss the next steps. They were happy my Porsche was intact, we shook hands, and they went back to the shop with a fun story to tell. It probably cost me one of my AAA tows for the year, but it was worth it to not have to suffer the humiliation of seeing your vintage car sitting backseat on a flatbed.

The three of us, in two low-power German creations, caught up to the tail end of the rally participants as they stopped for lunch in Lebec once we’d found our way to the 5. For the rest of the day, and through Sunday, the Porsche ran flawlessly, giving us another day and a half of incredible roads with some incredible friends. For the second year in a row, CRR has proved to be among the best automotive events on my calendar. I’ll certainly be one of the first to sign up next year.

Once the rally was over, we were about 5-hours south of our starting point, so we still had quite a lot of driving ahead of us. Instead of just succumb to the boredom of the freeway, Adam and I decided we hadn’t had enough fun yet, and detoured down State Route 9 to Skyline Drive for a run up to the famous Alice’s Restaurant, then a sprint down LaHonda back to the highway. We stayed in San Francisco that night at a friend’s house, and I dropped Adam back at SFO. It was a whirlwind weekend, but one that I wouldn’t trade for anything, perhaps even because of the breakdown, rather than in spite of it. We got to experience the highest of highs and the lowest of lows of vintage car ownership, and thankfully we were able to fix it and get back on the road without too much kerfuffle. Here’s to another 25,000 trouble-free miles.

[Some photos provided by Keiron Berndt]

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