Race Report: Cumberland Autocross - 5/15/2010

Chris and Loretta headed down to the Cumberland, Maryland, for the National Road Autosports event called the "Airport Icebreaker Autocross". This was their second trip to Cumberland and were all smiles when they heard that it was going to be great weather. After 3 events in State College with rain and temperatures in the 40's, the sun and 70 degrees was a "warm" welcome.

The events at Cumberland use two taxi-ways, a large paddock, and usually have the same general course configuration. The first half of the course starts with a tight area that leads onto a slalom that is followed by a hairpin and long straight. The overwhelming majority of cars at Cumberland are high horsepower cars thus the courses usually have an straight where they can open up! The difficulty with the Lotus at Cumberland is that the 190hp engine doesn't blast out of the corners like the Cobra's or Corvette's. They have to use the Lotus' handling and braking advantage to the extreme to make up the margin. This is what makes Cumberland such a great venue as they have to push the Lotus and themselves to the limit.

The course initially did not look like it would be a problem, but on their first runs they realized that it was a bit visually confusing. The combination of an abundance of cones and offset gates made picking up pointer cones a difficult exercise. Chris does believe that they could eliminate half of the cones on the course and make it quicker to setup, less cones to reset, and make it easier on the drivers. Regardless, it was a good course and had a lot of different types of corners. The lack of limited slip in the Lotus showed its head a few times on high speed offsets, which actually forced them to drive smoother to keep from losing time.

On Chris' third run, he got a 53.1 and was not able to improve on that time. He kept pushing the braking zones deeper and had three off course calls that eliminated the possibility of getting into the 52's. Loretta kept improving her time and got a 53.3 on her fifth run. She did get a 52.9 on her sixth run, but unfortunately had a cone. The time differences between Chris and Loretta is essentially nill now and who is going to get the fastest time is a 50/50 chance. Loretta has dramatically improved her driving this season and Chris is quickly trying to figure out how to match her pace. Chris and Loretta ended up second and third, respectively, in the Super Stock class.

Below are Chris' and Loretta's fastest runs and a side-by-side comparison of their driving styles.

Chris:



Loretta:



Side-by-side:



The next autocross is May 23rd, at the Mid-State Airport in Philipsburg, PA.

Race Report: Central PA Test and Tune - 4/18/2010

The annual "test and tune" event of the Central PA SCCA is a chance to tune your car and probably more importantly, the driver. After a winter of limited performance driving, this event is usually very helpful to get ready for the upcoming season. The event was held at the CPI facility, which is a great place to learn how to autocross due to lower speeds and technical course designs.

The weather was cold and slightly damp, however we have found that our Lotus Elise still does well in traction limited situations. The cold temperatures must have kept most people away as we had very little attendees, which means a lot of runs for the people that did show up! Drivers ended up with 12 runs and Loretta had me beat by 0.3 seconds at the conclusion of the first 6 runs. If this was a normal 5 run event, she would have surely beat me. I had 6 more runs to come back and I will tell you, it very difficult to get a time quicker than Loretta. On my 12th run, I got a 30.25 compared to Loretta's 30.6. I was temporarily relieved with the time, but I knew it wasn't over as Loretta had her final six runs coming up. In the end, Loretta's fastest time of 30.6 seconds remained, and we ended up first and second in the PAX index.

Below are videos of our fastest runs.

Chris:



Loretta:

Installing a Odyssey PC925 Battery in a Lotus Elise

The stock battery in our Lotus Elise has completely died. After two winters of storage and not using a battery tender, it would no longer hold a charge. I went to the store to see if I could find a replacement, but all of the size 26 batteries were much heavier. On most cars this would not be a problem, but the additional weight would hurt performance while racing.

The stock battery was only available in Europe and due to SCCA Super Stock rules, I could not go with a super lightweight dry cell battery. The battery I chose was the Odyssey PC925, which was the same weight and orientation as the stock unit. The only problem with the Odyssey battery was that it did not have the standard mounts to be held down with the stock brackets. Sector 111, which engineers Lotus performance parts, carries a part called the Xtender to allow a super lightweight battery to be installed in an Elise. The Xtender also has a cut-off switch, but does not work with the Odyssey PC925 due to being a larger battery. With some simple modifications, the Xtender can be used with the PC925 and below I will document the install.

First, remove the stock battery by using an allen wrench to remove the bracket on the side of the battery.

Behind the battery, you will see another metal bracket mounted on the vertical part of the trunk; that also needs to be removed.

Place the PC925 battery in place and push it into the corner where the stock battery was mounted.

Open up the Xtender parts bags and make sure you have all of the pieces pictured below.

Turn the switch over and hook it up to the stock negative battery cable and the additional supplied cable.

Mount the piece of foam rubber on to the aluminum Xtender as pictured below. I had a difficult time trying to bold the switch on the Xtender, so I took a hack saw and shaved the foam piece in half.

Go to a hardware store and purchase a M8-1.25x60mm metric bolt, a package of fender washers, and a large spacer.

Place the Xtender on top of the battery and ensure the battery is pushed into the corner. You will need to drill a new hole in the aluminum bracket as the available slots will not line up. Before you drill the hole, make sure the battery is in the corner and the Xtender is tight around the battery.

After you drill the hole, you can trim off the extra aluminum that will not longer be needed.

Mount the switch to the Xtender bracket and tighten down the 4 bolts and the battery cables.

Place the stock battery bracket into the original location. Test fit the assembly by taking the new bolt and making sure that the Xtender bracket and hole lines up.

Measure the distance from the bottom of the Xtender to the top of the stock battery bracket. Subtract from the distance the thickness of one of the fender washer. Cut the spacer the required distance and use a sander to make sure it is cut square.

Install the newly cut spacer and place a fender washer between the Xtender and the spacer. Take the bolt with a washer and slip it through the drilled hole and tighten it into place.

Push the battery into the corner, hold the Xtender onto the battery and tighten down the bolt with a 13mm wrench.

Install the battery cables and verify all cable bolts are tight.

Verify the battery is mounted snug and the battery cannot move in any direction.

Congratulations! You have successfully performed a custom install of an Odyssey PC925 in a Lotus Elise. You should buy a battery tender to keep the battery charged during storage. Charging an Odyssey battery with a standard automotive charge will cause permanent damage.

Let me know if you have any questions or help with your install.

Audi RS6 - Lightweight Battery Install

The Audi RS6 is a high-performance luxury vehicle and along with that status comes a lot of weight! Even though 500hp+ sounds good, the weight of the car is over 4,000lbs. The car is still quick, but handling, performance, and fuel economy could be improved through weight reduction. The general rule of thumb is that every 10lbs lost, is equivalent to gaining one horse power from the engine. Not only do you get increased performance, but you also get increased fuel economy.

My previous Audi was a S4 and at one point I had an Odyssey PC680 battery installed. The PC680 weighs less than 15lbs., and with mounting brackets, it weights 17lbs. The custom aluminum PC680 bracket for Audi's can be purchase from a person known as Jet Jocket in Canada. When I sold the S4, I kept the lightweight battery so that I could install it in the RS6. The only negative side to a battery this size, is that you could accidentally drain the battery very quickly. You do not want to sit in the car with the radio playing or lights on, for more than a few minutes. It drains as quick as it charges! Don't dispose of your stock battery, as you will probably want to put it back in during the winter.

You will first need to remove the battery cover in the truck by removing the two 1/4 turn fasteners.

Next, with a 13mm wrench, remove the two black brackets on the front and side of the battery.

You will also need to remove the negative battery terminal, as you will have to later relocate it. The negative terminal needs to be relocated, because the PC680 is much shorter and the cable won't reach in the stock location.

Disconnect the terminals from the battery, and you should now be able to remove the battery.

How much does the stock battery weigh compared to the PC680 (with brackets)?

That is almost a 40lbs weight savings!

Next, slide the PC680 battery into the battery tray with the positive terminal closest to the back seat. Slide it all the way up and toward the outside of the car. The custom aluminum bracket I am using is the same width as the stock battery, so it should fit snug.

Take the black side bracket, remove the rubber washer on the bottom, and loop the negative terminal through the bolt. Screw the bolt, negative terminal, and bracket into the threaded hole near the corner of the battery's aluminum platform.

You will want to angle the bracket as seen above and then tighten down. After this bracket is installed, the battery should not be able to move in any direction.

Reconnect the battery terminals, charge the battery, and enjoy a nearly 40lbs weight savings!

Audi RS6 - Replacing Vacuum Lines

Turbocharged cars like the Audi RS6 require many attributes of the engine to be performing perfectly to maintain optimum performance. One of the cheapest fixes and hardest to diagnose, is vacuum and boost leaks. Many of the emissions and accessories on cars are controlled from vacuum generated in the intake system of the engine. Components related to performance and accessories, are all tied together into the same system. One leak in any rubber hose can lead to degraded performance from a turbocharged engine.

I was inspecting the condition of my stock rubber vacuum lines in the RS6, and a few of them fell apart in my hands. I decided that instead of replacing one, I would replace them all with quality silicon hoses. I ordered 15' feet of blue silicon hose from ECS tuning, which is my usual preferred vendor for Audi/VW performance parts. In this blog post, I am only replacing the small braided rubber vacuum hosts on top of the engine.

To replace the hoses, you first must remove the carbon fiber air intake system on top of the engine. This requires removing the silver air intake tubes, two nuts on the bottom of each black air intake tube, and a large center bolt.

After you have the air intake system off, you should located all of the vacuum hoses. I previously replaced the vacuum line to the bypass valves, but I am still going to replace them again with the quality hosts from ECS Tuning.

Before going any further, you should stuff rags down inside the turbo inlet ports on the back of the engine. If anything falls into them, you are going to have serious problems.

The most difficult task of replacing the vacuum lines, is removing the stock metal clamps on the ends. I don't have a special tool for this and if you can find one, I would recommend it! This could have been a thirty minute job, but removing all of those clamps turned into two hours.

While I was installing the vacuum hosts, I also relocated the pickup line for my boost gauge to the fuel pressure regulator. The distance between the fuel pressure regulator and the intake port, was not a far enough distance to connect a boost guage T-fitting. I had to loop the silicon hose around the regulator and back to the intake port to allow for enough distance to install the T-fitting. If you do not have a boost gauge, then you will not have to worry about this problem.

I used small zip ties to tighten the ends of the silicon lines. Pull the zip ties snug and then cut them off with a side cutter. Once you are complete with changing all of the lines, reinspect all of the ends to make sure you didn't miss installing a zip tie.

When complete, you should have something that looks like the following.

Before putting the intake back on, make sure that you remove the rags from the turbo inlet ports. You should also unplug the batter for ten minutes, and reset the ECU codes, to ensure the engine takes advantage of any leaks fixed.

I hope this has been helpful and let me know if you have any question.

Audi RS6 - DIY Boost Leak Tester

During my quest to figure out the boost problem in the RS6, I have had multiple people tell me that there could be a leak somewhere in the system. If you have had a turbo car, you know that a leak could be almost anywhere. It could be as simple as a leak in a turbo hose to a cracked intercooler. I searched online and found plenty of homemade boost leak testers but nothing for the Audi RS6. With the combination of the rarity of the RS6 and knowing that most owners don't do their own work, there was a lack of documentation online to do many tasks.

I decided to take on the task of figuring out how to test for boost leaks and it really wasn't too difficult. I went to Lowes and spent about 30 minutes trying different combinations of fittings and tubes until I finally found something that would work.

Below is what I picked up and they include a 3" PVC cap, 4" x 3" rubber downspout converter, 4" test plug, pressure regulator, air fittings, and some host clamps. I bought J-B weld however I did not need it.



First, you need to cut the lip off of the rubber downspout converter as you only need the outside piece to use as a coupler. 

Take a 3/8" drill bit and drill a hole into the end of the plastic cap. Then use a reamer to open the hole up to something just smaller than the threads in the air regulator. Start out slowly so you do not take off too much plastic. You want to be able to screw the regulator into the cap with enough force that it creates a tight seal.



You will need to put teflon tape on the threads of the air pressure regulator and screw it into the plastic cap. If you aren't sure it is sealed tight, you should use some epoxy or J-B weld on the threads. Screw another air fitting on the other side of the regulator. You will probably not need any teflon tape on the non-cap side of the regulator but your application may vary. Finally, take the rubber coupler created earlier and clamp it on to the end of the cap. Make sure you leave enough of the coupler off of the end of the cap to allow for clamping to the air intake.



Now it is time to mount the leak tester on the intake system but you will first need to remove the silver air intake runners. To remove the runners, loosen the hose clamps and remove the 2 screws (per side) on the black plastic piece above the bumper. Once the runners are removed, pull out the leaf guards and sit them aside.



Take the 4" test plug and tighten it up on the passenger side intake.



Remove the screws on top of the intake system to expose the air filters. Remove the air filters and inside the side intakes is a small hole at the bottom. Use a piece of duct or aluminum tape to cover up the hole but make sure you remove it when you are all done! If you don't cover up this hole you will not build any pressure.



Finally, you are ready to hook up the tester and find your leak! Connect the air pressure regulator, turn the adjustment knob all the way off (clockwise), and turn on your air compressor. You don't need much more than 30psi on the air compressor as you will adjust the final pressure with the boost leak tester regulator.



When I performed this test, I found out that a substantial amount of air was leaking around the MAF sensors. The next step for me to is replace the gaskets on top and bottom of the MAF sensors and test again!

Please let me know if this was helpful or if you have any questions.

Audi RS6 - Transmission logging

I'm still trying to figure out why I am unable to hold more than 10psi of boost in the RS6. It may be a boost leak, but I'm also trying to rule out anything else that could be wrong. Today I logged the transmission values and which include engine RPM, input shaft RPM and output shaft RPM. The reason for this test is to see if the three RPM values move linearly to each other. If they were not linear it would mean the transmission is slipping, which can cause the transmission control unit (TCU) to send a signal to the engine control unit (ECU) to turn down boost.

The logging seems to confirm that there is no transmission slip as seen from the data below. The torque converter locked up around 5100-5400 rpms and from there on the graphs are linear.

I guess I can rule out transmission slip as a cause of my problem! On to the next diagnosis.....

Launch to 3rd gear pull:

3rd gear pull with TC closed: