My 91 964 Porsche 911 C4 Cab

2009-08-29T11:05:00.003-05:00

We sold our '91 911 C4 Cab this past week and it's already off to its new home in Utah. Gives me an excuse to do some more upgrades to our '99 Boxster track car :-) She'll be missed for sure!

2009-02-01T10:11:00.007-06:00

Time to catch up. It's been almost a year since I installed the new bearings and front brembo replacement rotors. The whole vibration problem ended up being bad calipers. Ouch! New ones nearly broke the bank. The only bright side to this is that it took the dealership almost three weeks to get new ones and I was given a new Porsche Cayman to drive for the time. Nice, but I'll stick to a Boxster or 911. The Cayman is unlivable with the crappy roads we have around here - too stiff.

That brings us to our newest addition to our stable - we added a '99 Boxster 2.5 test mule to our company cars. A very Merry Christmas!

2008-02-01T19:54:00.001-06:00

Well, the new brembo rotors arrived today. Just waiting for the wheel bearings and everything will be off to 300 Below to get cryogenically treated. I'm hoping this will be the last time I have to mess with the bearings and rotors for a while...

2008-01-29T20:32:00.000-06:00

A few updates. The weekend before last, I was invited up to Chicago by the Midwest 356 Club to give a talk on motor oils. Great crowd. Not too bad for my first time speaking to a group of people.

I had decided to drive the 911 up, since it was not too bad out (in the 40s), but in the even the evening, it got very cold, and by the morning, it was below zero without the windchill.

Let me tell you, it's not easy to start the car with 20w50 in it when it's -8F out! It did turn over, and I did get it started, but it probably took a good few minutes for the car to idle on it's own and I let it sit for about 10 minutes before driving off, until the gauge started to move.

Also, when putting my luggage in the car, it slipped and busted the back plastic window on the cab. (more on that later).

The next day, I woke up before sunrise and hit the road to go down to GA, to visit Aircooled Technology to do some more oil testing on their dyno. (just in case you want to know, Brad Penn made the most HP and Swepco made the most torque this time around!) I again, chose to drive the 911. Even with the bitter cold, I did have enough heat and plenty of traction with the winter tires and the fact that the car is a C4, so it's all-wheel drive. Being it was so cold, I didn't get the best mileage, averaging a measly 20mpg on the way down.

Once down there, it was still plenty cold, down in the mid teens, and I'm glad I can report that the Brad Penn starts up nice and smoothly even down to about 15F.

I might try blending in some 10w30 with the 20w50 for next winter, or even go to their 0w30 since I seem to be driving the car more this winter, and the temperatures have been brutal!

In GA, I did happen to find a local apholstery shop that was able to replace the back window and even put in a new headliner for pretty cheap, only $525, so the car is even nicer now that it was when I started.

The only other hiccups I had this drive again were with the brakes, with shimmy, pulsation, and all around vibration when braking, kind of like when you have warped rotors. General concensus looks like I have bad wheel bearings up front. I plan on re-doing the brake job and putting new wheel bearings in the next few weeks.

Happily, I can report that now, with over 4500 mi on the clock with the 20w50 Brad Penn in the engine, that I have only had to add 1/2 a quart, and I think that's mostly because I have a leak somewhere on the right side of the engine, which is accumulating on the heater box and causing the car to mark its territory.

I plan on pulling an oil sample the next time I have the engine warmed up to send out for testing, to see how the oil is holding up to help determine the proper drain intervals.

2007-12-05T09:38:00.001-06:00

So I've now swapped the Pirelli P-Zero Nero tires for my Blizzaks on a set of oe 18' cup wheels that were powdercoated black, which is a great look I might add, especially with how much black there is on a cab! Much better cold traction. I would like to avoid my ice-skating incident from last winter and the associated repairs!

2007-12-05T09:29:00.000-06:00

It's winter again!

Oils: What motor oil should I use? Which oil is best for my Porsche or aircooled engine?

2007-12-05T09:23:00.000-06:00

Oils: What motor oil should I use? Which oil is best for my Porsche or aircooled engine?

Here is some of the research and testing I've been conducting to better inform my customers and the Porsche community as a whole to the dangers of using a CJ-4 or SM rated oil in their older Porsches, which some of the testing has been done in my '91 for purpose of comparing UOAs (used oil analysis).

2007-11-20T00:19:00.001-06:00

Once again, it's been a few months.

I've replaced my clutch slave cylinder since the last batch of "routine" maintainence and I just completed another oil change, this time to Brad Penn Racing 1 20W-50 motor oil. After 2400 miles non-stop highway miles, the UOA looks great! For comparison, here's what the UOA for the Valvoline Racing 20W-50 that came out with 1400 miles on it (granted Valvoline says 800 mi drain for this oil in a 911).

The car averaged about 25 mpg for the trip to and from Daytona Beach for the Rennsport Reunion and didn't use ANY oil over the 2400 mi, which is quite impressive. The car performed flawlessly the whole trip; I'm quite pleased.

On tap for me over the Thanksgiving holiday is Lizzy's b-day and also some time to wax the 911 and put on the winter tires, and hopefully, take the car out for some exercise!

2007-06-09T09:53:00.001-05:00

I haven't had a lot of time for updates lately, but here's what's happened in the last six months. I put the car in a ditch after hitting some black ice, only going about 10-15 miles per hour, but I guess it was enough to tweak the whole front end. The body was absolutely untouched with no damage, but the whole front end had to be redone. Also, the jolt made some small oil leaks really big, leading me to take the car to the local Porsche dealership to be sorted out. Many thousands of dollars later, I have a bone dry resealed engine and a totally new front end on the car. Additionally, I had the front pads and rotors replaced since there was some warping and uneven wear on the pads. The car drives better now than it ever has, and I have purchased since a set of cup wheels and snow tires for next season, so that I don't have a repeat of this painfully expensive ordeal.

Additionally, as I've been using the a/c recently, a funky odor developed of mildew, which at the suggestion of owners on the Pelican Parts forums, I sprayed a bleach solution into the fresh air intake, thoroughly cleaning the ventilation system. Additionally, I located the recirculated intake under the dashboard in the interior and I purchased from Napa a professional product to eliminate the odor causing contamination, and applied it to the system when operating on recirculated. Only advice is that you don't drive the car for at least a week after doing this, since the smell of the professional product is choking to say the least and very strong compared to the bleach solution.

2007-01-22T09:33:00.000-06:00

We finally got our first REAL SNOW here in IL and I have to say, for those who don't care for the early 964 c4's, they sure handle well in the snow. I'd even venture to say that my 91 handles better than my wife's new 4motion passat!

2007-01-22T09:20:00.000-06:00

I got an email from Andrew Doak, a fellow Porsche enthusiast that I thought was funny:

"Hey Charles,

I got an email from a guy in Cali who made me away of your sites. It seems you and I are running parallel lives."

http://www.66912.com
http://www.89c4.com

See the links he sent over. We must have the same taste in cars :-)

2006-11-18T17:25:00.000-06:00

Having just replaced the ECU with a Steve Wong chip, I figured it couldn't hurt to put in a new o2 sensor, since motronic is designed to run in closed loop with exception of WOT. I didn't figure on the sensor literally being welded in.

Lots of heat and a breaker bar, and I got it out, threads and all. A quick trip to napa got me the correct 18M x 1.5 tap, which I ran through the threads with some tap-magic.

Just as good as new.

This is what a new sensor should look like. Make sure to use anti-sieze on the threads. I've been told that milk of magnesia works wonders too!

Done and harness reconnected. Test drive yielded no check engine light, so I must have done it right :-)

2006-11-18T17:17:00.000-06:00

Strut bar. My previous Porshce 912 had one and I very much so could tell the difference. The first time around I had one from Wevo/Smart Racing that was $$$. This time, I just went on eBay and got a billet one from a vendor (Cup-Sport) who makes them in Germany. Looks very good and installed very easily, 5 minutes tops, even with slitting the carpets to get them to fit again. Looks good, doesn't it? And for hundreds less...

2006-11-18T17:14:00.000-06:00

New tires. Pirelli P-Zero Neros. I love them. Rave reviews from fellow Pelicanites for both rain and snow, on top of excellent dry traction. Like I said before, much quieter and feels more planted on bumpy roads over the previous tires.

2006-11-15T06:54:00.000-06:00

Last weekend my wife, daughter, and I took a trip to Chicago in the 911 to visit our friend's new bachelor pad. Luckily, the Rizza Porsche finished the multitude of maintanence I had them do on time the previous Thursday, which gave me time to install my first upgrade - a Steve Wong chip from 911chips.com.

Installation was very straightforward - the hardest part was getting the clamshell (two circuit boards connected with a ribbon cable) apart, to get access to the chip. My word of warning - be careful where you grab, I almost broke off a capacitor! Also, in my haste, I forgot to re-install the plastic retaining clip, so I had to take it apart again.

So far, I have noticed a smoother idle and most definately, faster acceleration. 911chips.com quotes a 1/2 second reduction in zero to 60 times on a stock engine!

I will be also replacing the o2 sensor with a new one from Pelican Parts, as the computer operates in closed loop at 14.7:1 air/fuel ratio, and I want to make sure it's as accurate as possible. I'll know right away if I see an increase in fuel economy from the 19mpg I have observed over the last few tanks of gas.

The front differential was leaking, so I had them put in new axle and pinion seals. Since the car is 15 years old, it's about time to replace all the belts, so the fan, alternator, a/c, and distributor drive belts were all replaced. I also had them change the oil over from the Castrol GTX 20w50 to Mobil 1 0w40. Lastly, I had four new Pirelli P-Zero Neros installed as the car had what I believe were the original tires and they were on their way out. Money well spent in my book.

2006-11-10T11:56:00.000-06:00

With some recent shuffling of my Porsche collection, I have picked up a wonderful low mileage 1991 Porsche 911 C4 Cabriolet, with great plans for the future for this car.

Some background - the car was purchased from Midwest Performance Cars in Chicago - I had enough of eBay and long distance purchases. The car was everything I hoped for and more. I would recommend purchasing a car from Tom Simmons any day.

The car did have a check engine light come on when I picked it up and they did pay to have my local dealer diagnose it and reconnect the loose sensor, which was outstanding.

Here I am at the 914 Club Fall Foliage Classic this October, shortly after picking the car up. We're getting ready for the fun run around Columbus, IN. The Classic is an event organized by various 914club.com members and is held every year. We have a group dinner and awards banquet, fun run and poker run, and prizes.