Man up, Yo.

After reading about it on my favorite bike-blog, Bike Snob NYC, I decided to test the manliness of my blog with Genderanalyzer .

According to the smart computers over at Genderanalyzer, there is a 89% chance that all this is being written by a man.

My other blog, which I share with my wife gets a "likely female" but produces a 50% score. This thing seems pretty accurate...

Dewalt Impact wrench

This thing rocks. On Saturday I installed snow tires on Kathy's car, rotated the tires on my 3/4 truck and swapped wheels on the M3 so I can sell the LTWs. That's 72 lug nuts including 32 that were torqued to 125 Ft/lbs last fall.

The Dewalt just ate it up and asked for more. It can easily remove lugs bolts when the wheels are off the ground. It's got plenty of power and makes quick work of everything I've thrown at it. When reinstalling wheels, the "rocker" trigger is nicely variable so it's easy to snug-up bolts without over torqing them.

That said I also got to use the 18v Snap-on and talk at length with a guy who owns one. As nice as the Dewalt is, the Snap-on is the best tools available. It produces well over 600 ft/lbs when removing fasteners. In fact the Snap-on is the only wrence designed specifically to remove fasteners. The Dewalt and the Milwaukee are both designed to drive-in fastners with the same power that they are removed. The Snap-on produces twice the torque when removing fasteners than when installing which is perfect for automotive applications.

So If you can part with 5-large for a cordless impact wrench, then grab the Snap-on. If your're thinking more like $300, then the Dewalt is a good choice.

of cordless impact wrenches

This is a must-have tool for any open-tracker. I borrowed one at Miller and was shocked at how quickly I swapped all four wheels -- I'm pretty sure it was less than half the time required using a breaker bar.

I've been looking at them ever since and recently decided to get one -- here is what I learned:

1. The biggest, baddest, cordless impact tools out there (Milwaukee 0779, Snap-on CT4850HO) cost ~$500+ and can generate well over 350+ Ft/Lbs when removing fasteners, more than enough for wheel bolts.

2. For about $300 there are a few wrenches that generate 250-300 Ft/Lbs.

3. Below that are wrenches that generate ~100-200 Ft/Lbs and are probably not suitable for wheel bolts.

4. Some vendors sell wrenches that look alike but have very difference performance -- compare model numbers.

I chose a 18v Dewalt, Model DW059k-2, which generates 300 Ft/Lbs and uses the same battery as my cordless drill-driver. I paid $277 (with a case, charger, and two batteries) from Amazon and received free-shipping. I needed to replace the batteries in my drill driver anyway so it was like spending $100 on the wrench. I'll have it in a couple of days and describe what I learn.

Fall Update

I got one more day in after Hastings, a single NASA day at Pueblo. Work and travel conspired to keep me off-track for at last 3 local track days.

Now, with no events until next year it's time to start thinking rebuild. I'd like to fully rebuild both front and rear suspension with new coil-over springs, bars, shocks, chassis reinforcements, and all new bushings. However in light of the current economic condition, maybe I'll scale back a little bit. Other than that, this winter I'd like to weigh the car, remove the air-bag system, and install a removable steering-wheel.

One thing I had to do was replace the battery. The date indicated that it was 4+ years old so I wasn't surprised it died after the car sat a couple of weeks. I replaced it with an Odyssey PC680 -- which is pretty much a big motorcycle battery -- in a really cool battery-box designed by Russ Wiles and available from BimmerHaus in Boulder.

Learn more about the box and battery here

This removes ~25 Lbs from the trunk and I think it changed the rear ride height a little. 2900 Lbs. here I come.

Hastings After Action

Hastings was great. I wrote something about it on my personal blog here

Not discussed there is one of the highlights of the event, the Saturday night "Bacardi Bus" ride. The bus is a modified School bus used to take Corner Workers to the flag stations during events at Hastings. Most of the original seat have ben removed in favor of used furniture -- couches, love-seats, old car seats. Adding to the fun, they are not attached to the bus.

On Saturday nights, after a couple cold, malted beverages, the bus is loaded with unsuspecting drivers and workers, and sent out on track. The driver goes much faster than you would think a school bus would go on a race track.

As you can see from the in-bus photo, we are tracking to the apex in a full-on deluge.

Motorsport Park Hastings

This weekend is a NASA RM event at Motorsport Park Hastings (MPH)? Get it?

It's supposed to be a really good track. It's a bit of a haul -- 5.5 hours says Google Maps.

I've added fixed camber plates increasing negative camber to 2.5 degrees. This should help reduce some of the tire wear i'm seeing with stock camber settings.

1995 M3 Issues

There are a few important maintenance items that are really must-do on a 1995 M3. They are all actually pretty difficult to do but if you don't, and they fail, you will wish you did.

1. Weak Valve Retainers

Early 1995s (prior to 10/95) have improperly heat-treated valve retainers that can fail causing a catastrophic engine failure.

More details here

2. Loose Oil Pump Nut

The nut attaching the drive pulley to the oil pump can come loose causing a total loss of oil pressure and a few seconds later, catastrophic engine failure.

More details here

3. Loose Rear Diff Bolts

The bolts attaching the LSD cover to the carrier may not have had locktite applied properly at the factory allowing bolts to fall out and be ingested by the ring/pinion gears causing catastrophic differential failure.

More details here

So, go check your nuts, bolts and retainers...

Miller Photos

Better late than never.

I finally connected with the photographer from the Miller NASA event. Here are a couple of really nice shots.

Hard to imagine anything cooler than this

More about roll cages

Ranked by importance, my criteria for optimum cage design is

1. A safer cage is better
2. A stiffer cage is better
3. More driver space is better
4. Easier driver egress is better
5. A lighter cage is better

The following series of charts is from a thread on bimmerforum.com about cage design. One of the members did a series of mathematical simulations of a roll cage designs using ProE to build the model and Mechanica to run the simulations. These simulations estimate what happens to a roll cage when a load is applied to one corner. The goal is to understand the stiffness of each cage design and the trade-offs involved in different designs.

This approach has a few weaknesses, primarily the lack of a similar model of the unibody chassis in order to evaluate how the two structures work in concert.

That said, this is really interesting work and bears thorough review.

This first picture shows a basic 6-point rollcage with “X” style door bars, harness bar, and a rear diagonal.

In this simulation, a 500 Lb. upward force is applied to the driver’s A-pillar leg and the strain on the rest of the cage tubes is represented graphically.

Notice how large the windshield and door openings are in this design – probably not good for stiffness.

Here is a second chart showing what happens if you add an A-pillar down-bar, change the driver’s door-bar to allow easier access, add a bar from driver’s shoulder to rear bulkhead, and small upper windshield gussets. The stiffness of the cage increases by over 60% with the addition of only a couple of strategically placed bars.


Here we have added a bar from the A-pillar straight to the floor and dash bar gussets. This is 76% stiffer and weighs only 23 Lbs more then the original design.

All the models so far have used 1.5” .120 wall DOM tubes. What happens when you go to 1.75 .090 wall DOM? Cage weight goes down 2.5% and stiffness goes up 7%.

This chart shows the difference in stiffness between two different A-pillar configurations. The design on the left is about 10% stiffer than the design on the right. Clearly there are trade offs to be made here, as the new A-pillar bar on the left is pretty close to the driver.

Bryan Watts has this design (with an additional gusset) in his E36 M3 and says it doesn’t interfere with driver’s vision at all.

The door bar configuration shown here – typically called “Porsche style because it is derived from the a Porsche GT-3 Cup car – is about as stiff as the stiffest designs and makes entry/exit easier and because they bow outward they provide more room in the drivers “office”.



This chart shows the stiffest design to date without crazy braces in the windshield area. It has a fairly radical A-pillar bar, small roof and dash bar gussets and a roof diagonal all in1.75x.090 DOM.

At this point I’m planning a cage like the stiffest shown above but with either Porsche-style door-bars or with a standard X. Both of options are pretty close to the ultimate in stiffness. The standard X would allow me to keep the windows in the car. Unless you have an enclosed trailer (not in my plans for a few years) then windows are really practical. The Porsche door bars can be made to just fit while keeping the window glass, but removing the door panels (which are pretty thick on the E36).

I will also extend the cage forward from low on the A-pillar bar to connect to the firewall. This provides some additional protection for the drivers feet.

The final key feature I'll add is a jacking tube integrated into the door bars. This creates a reinforced point from which to lift the car. A short "spike" attaches to a floor jack effectvely preventing the car from slipping off the jack.

Pueblo #2

Saturday it was back to Pueblo for the NASA Summer Beach Party Event. The weather was a little cooler than the 95s we had been seeing last week. It was a nice change. The car ran great, no major problems.

I pitted with a large group of BMW drivers who regularly attend NASA events. I met some of them at the BMWCCA School at Pueblo a couple of months ago. It was nice to feel like part of group for the first time. I think many open-track drivers are reluctant to admit new attendees into the clique until they have show some kind of driving proficiency.

The new HeroCam needs a little debugging. The camera eats batteries at a disturbing rate. The Users Guide recommends buying a couple of sets of rechargeable batteries and now I understand why. The camera seems to get about 90 minutes of recording out of a pair of AAAs. The problem is that the SD card holds 56 minutes of video. As a result, I need to install new batteries for every session. Home Depot sells 16 packs of AAAs for about $10. Rechargables are about $16 for 4 and the charger is about $25. So, for a typical track day with 4 sessions, I'd need 8-10 batteries. Call it 10 for $40 + $25 for the charger = $65.

Non-rechargables cost about $6.20 for the same 10 batteries so it takes 10 track days (or 5 weekends) to recoup the cost of the rechargables. I'll do that many next year for sure so I think I'll get the rechargables.

I also need to upgrade the Traqmate software from TraqView to TraqStudio ($199) so I can integrate video with the Traqmate data on a single screen.

Here are a couple of shots of the camera mounted in the car. For forward looking stuff I used the suction cup mount on the inside of the windscreen with the camer mounted updide down.

I also added a mount to the rear of the car using the supplied plastic mount that attaches to the car with a super adhesive. The camera and case weigh only a few ounces so this is actually a pretty rugged mount.

When I actually mounted the camera, I added a little safety wire between the camera and the license plate frame just in case.

This shows the complete camera mounted on the windscreen. The camera is mounted upside-down here and has a setting to record upside-down so I don't have to flip it in post

The picture quality is acceptable and very usable to YouTube and other web publishing. It even looks OK on a big-screen if you are sitting far enough back.

Because of the battery problems I only captured two sessions. I'll add some video here soon.

Carbon Fiber Roll Cages

Read all about it.

Video

I spent most of a day Sunday trying to mount a video system in the car. Being in the video industry I planned the ultimate in-car video system. I have a Sony HVR Z1 U 4:4:4 1080P HD camera looking forward and a Canon XH-A1 1080i HD camera pointing aft. Using our Red ONE 4k camera seemed like overkill.

The problem is that pro- and pro-sumer cameras are large and heavy, each of the HD cams weighs something over 5 pounds and is large enough to make them all but impossible to mount safely in a car without a cage. They won't fit in the rear window becasue they are too tall. I fabed an arm the attaches between the stock head-rest mounts but found it too flexible for even a single camera. Hard braking dropped the point of aim by 6 inches. After a bunch of trial fitting and fabrication, I have decided on another, very different, path.

I gave up on the HD setup and ordered a GoPro HeroCam. $179 + free shipping. It is solid state, light-weight, comes with lots of mounting options and is designed for just this application. Plus it's in a hard plastic case to allow it to be mounted outside the car. Something quite out of the question with someone elses $5k HD cam.

I'll revisit the full 2-screen HD setup when the cage is in.

...and the Big Brown Truck just dropped off a new Nady PMC-2x Intercom so driver and passenger can chat in comfort.

Counting the days till NASA on Saturday -- lots of new things to try.

Chunking Tire

I finally unwrapped my tires from the Miller event. Here's a photo of my passenger front tire showing significant chunking both on the center band and the edges of inner tread block.

This is suprising because the stock suspension lacks enough negative camber for track work. This is confirmed by some significant wear on the outside shoulder of front tires. The opposite side showed very minor chunking -- 2-3 small chunks total.

I'm not sure when this occured -- I suspect it was saturday afternoon. It was really hot, 98 F, and blazing sun, the track was probably close to 120 F. I was pushing pretty hard as well. There was a little push in a couple of corners but nothing out of hand.

I think the centeral nature of the chunking indicates too much air pressure. Except -- you can clearly see the mold line separating the left and right halves of the tread. If the air pressure is really too high wouldn't you see enough wear on the center rib to obliterate the mold line?

Saturday afternoon I dropped pressures and ended up at 35 Lbs hot in front. I guess I'll drop to 33 but I'm concerned about anything that might increase wear on the outside shoulder.

Oil Cooler Project

This morning I found a deal on about half of an E36 M3 Euro oil cooler. A member of the Spec-E36 list offered the oil cooler and lines for $100 -- a smoking deal. I still need the Euro Housing and some mounting hardware to finish the job. I'm not in a particular hurry so I'll keep looking for a cheap used housing if such a thing exists.

Incredibly cool waste of money

Like fighter pilots of WWII open trackers can now display their "kills"

http://www.trackgraphic.com/store/products.aspx

Traqmate Traqdata Adapter

Traqmate offers an expansion port for logging additional digital and analog signals with the Traqmate system. The product, called Traqdata, provides 4 analog, 2 digital, and RPM inputs.

I primarily want to log RPM and oil pressure. I'll also add oil temp and volts since I already have aftermarket gauges and therefore clean sources for these.

The only problem is the damn thing costs $129+shipping.

As you can see from the picture, it appears to be a terminal board connected to a low-density DB-15 connector. The LD DB-15 is not a very common connector type. It has the same number of pins as high-density DB-15 VGA connector but in two rows instead of three. I think the LD DB-15 was used for PC gaming adapters back in the day.

I'm wondering if buying a 10 ft. LD DB-15 cable and a small terminal board would work instead. It would cost about $10, look a lot cleaner and allow me to run the cable from the transmission tunnel near the rear seat where my Traqmate is mounted to the dash area where everything to be monitored is located.

I think I start playing with the input pins this week to see if I can understand what the pin-out is for this is.

E36 Rollcage Design Considerations

I found this picture on bimmerforum.com. It inspired me to begin to document some roll-cage design considerations.

Lets start with the basics. Note how the main hoop is built on boxed foundation blocks called Plinths – the front legs are on similar blocks. This allows the cage to be tack-welded in place, then lowered from the blocks and fully welded, then raised back to the final location. The footers cannot exceed 100SqIn per SCCA regulations.

The rear upper bars attach at the rear bulkhead. This is an area of contention regarding the E36 chassis. One camp advocates connecting the main hoop to the bulkhead claiming that picking up the chassis as high as possible yields the greatest increase in torsional stiffness. The other camp argues that connecting the main hoop with the shock-mounts and therefore the suspension is best. I fall in the former camp. The cage pictured manages to do both. The main hoop is connected to the rear bulkhead and the rear shock mounts are tied into the rear subframe. Nice.

All 8 rear suspension mounting points (4 sub-frame mounts, 2 trailing arm mounts, and 2 rear shock mounts) are all connected. This increases the stiffness of the rear of the chassis. The smaller size of the tubing connecting the rear suspension shows this is not a full tube-frame car. If it were the tubing would be the same size as the main cage.

This cage also uses the construction method known as “super-nodes”. This is when tube intersections (called Nodes) are designed so the all the tubes intersect precisely and the location of intersections is carefully planned so that the maximum number of tubes joins at each intersection.
In the upper foreground a pair of diagonal windshield can be seen. The windshield opening is one of the larges openings on a roll-cage. These diagonal provide a significant increase in stiffness.

This cage has one a really cool feature. It’s a “jack-tube” welded to the door bars at fore/aft balance point and descending through the chassis. It provides a perfect location to lift the car from below. A short spike-like attachment on a floor-jack goes into the tube providing a totally secure method of lifting the car.

Note also how the entire chassis has been seam-welded. This is a technique to stiffen the chassis by adding additional welds to the body and chassis panels. The factory only welds a chassis at a few locations.

Gen-u-wine Redneck style Traqmate mount

June 27, 2008

PR Newswire

Castle Rock, CO – Today Redneck Engineering is proud to announce the first in a long line of low-cost, marginal quality, handmade, paradigm-shifting parts and accessories for hardcore motorsports enthusiasts and people suffering the debilitating effects of Restless Leg Syndrome (RLS).

This amazing new product is years in the making, requiring dozens of man-minutes of labor and the use of state of the art MacBook Air computing power (and of course Microsoft PowerPoint -- what product would exist without PowerPoint?). No expense was spared in it's construction. Only the finest first-cut endangered rain-forest lumber, Bald Eagle feathers, and freshly harvested baby seal pelts are used in the construction of these modern marvels.

Years of double blind testing have shown the 92% of males 21-40 prefer their Traqmate mounted high on the dash where it’s easy to see and access the controls while on track. Additional research shows that 88% of E36 M3s still have the OEM cassette deck. From these data a revolutionary new idea – sure to be compared with such revolutionary ideas as the Wheel, Internal Combustion and the Hula-hoop, was born. As was our catchy slogan "Stick it in your slot".

The mount is a stylish TDK-SAX cassette shell designed to fit in the OEM M3 tape-deck. To this shell is glued a piece of high-tensile strength steel bent to an attractive 90 degree angle. It may appear to be from a Harbor Freight compressed air filter/regulator/oiler set, but this is only a coincedence. The bond between shell and steel, made with state-of-the-art two-part epoxy is impervious to water, sand, and sweat (I think). This durable piece of imported steel is then screwed to the Traqmate's mounting points with screws made of genuine metal. When inserted into the stock tape-deck, it places the Traqmate DU in a great position. It is also easily to remove between sessions so the driver can download data. It is firmly mounted and doesn't move very much.

No animals were harmed in the testing of this product – well wait a minute, there were a bunch of bugs on the grill after driving back from Utah. OK, a few thousand insects were killed, but I doubt anyone will miss them. So, stick it in your slot!

Redneck Engineering is a fictitious company and this is a fictitious product. This is Humor and was not intended to offend Rednecks or Engineers. For more information about humor, go to your local stand-up comedy club.

Press Pool Photos Only -- Fair Use Rights Apply
Traqmate and Cassette Shell (all tape removed). Note the fine metal work on the mount. After a grueling 10 year apprentice program are the finest artisans selected to assemble your Traqmate mount.











Reverse View -- marvel in the quality of the lima-bean colored finish. Notice the aggressive weight reduction.








Without Traqmate























With Traqmate installed -- DIN Cable is router through center console and up through a small slot slot in the punch-out.

Basic Data Analysis

A little detailed analysis courtesy of Traqmate. This graph is a standard Traqmate graph showing Speed vs. Distance. The area of focus in a series of five interconnected corners at Miller Motorsport Park called Demon, Devil, Diablo and Indecision, Precision.

The first three are typically done as a single, double apex corner – a single arc hitting Demon and Diablo and skipping Devil) then a very short straight, then Indecision, a fast right, then Precision, a very late apex tighter right leading onto a long straight. Since Precision is the most important corner in the section, Indecision is sacrificial. However, It’s too long to just throw it away.

The red and blue colors on the graph represent my first and second sessions on the full track. Since these are my first laps on the full track, there is a lot of learning going on as shown.

At the beginning of the chart (7k ft to 7.3k) you can see my speeds from Demon to Diablo were all over the map – ranging from 51mph on the slowest lap to 64 on the fastest. This is natural given that these were my first laps on this configuration and the apex of Demon is blind.
The section from 8k to 8.5k is the turn-in for Indecision to the apex of Precision. In the early laps my speeds were in the 60s, but by the last session I was approaching 80mph. Comfort builds speed.

Note that at the 9k ft. mark, everything lines up again. I’m not sure if it’s due to masterful driving or fear of the concrete wall along the exit of Precision, but those apex speeds sure are consistent.