Monday, June 30, 2008

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.

Friday, June 27, 2008

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.

Thursday, June 26, 2008

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.

Wednesday, June 18, 2008

R-Comp Tars

One thing I learned at Miller is that Khumo MX’s are not R-Compound tires. A few years ago they were among the ultimate track tires even though they carry a treadwear rating of 220. But today there are a slew of sticky new track tires available.

I now have 4 track days and about 800 street miles on the Kuhmos and they are almost half gone (4-5mm remaining of the 7.8mm original depth). This seems to be pretty reasonable wear for the performance they provide.

Because my stock suspension doesn’t have enough negative camber, it causes some extra wear on the outer shoulder of the front tires. Rotating fronts and rears only prolongs the inevitable. While at Miller I also experienced a little chunking on the middle of the outside front tire. This is typically caused by overheating. It was warm there and there are a number of corners that really loads the outside front tire.

Scott is running Nitto NT01s on his 3600 Lb, 400+ HP BMW 335i and recently got 9 track days from his first set. That is really good wear -- on par with what I will get from my Kuhmos. Oh, he’s like 17 seconds a lap (at Miller) faster than me too.

Replacing the Kuhmos with Nittos seems a no-brainer, however there is one more twist. Nitto doesn’t make the NT01 in the 245/40-17 size I use, they do however offer it in a 255/40-17. This is a little wider and a little taller than the Kuhmos. Luckily this is a very small amount and it should fit without any mods. Worst case a 5mm spacer up front.

Size....Tire...Size.....Width...Diameter
Nitto...NT01...255/40...10.35....24.92
Kuhmo...MX.....245/40....9.90....24.80

E36 Track Cars

At the Miller event I was lucky enough to pit with a group of local E36 M3 drivers. Two of them, Gabriele “Gabe” Giese and Jeff Blonder both have well setup street/track M3s. Gabe’s Hellrot 1999 has a TC Kline double-adjustable suspension kit with 700F/900R springs. The 200 in/lb difference between front and rear is more than typical for an E36 where the difference is typically 100 in/lbs. She also runs 255/40-17 tires, which required more an a little rear fender rolling. She describes it as having no understeer – ever.

I spent a lot of the weekend chasing Gabe’s car. She is 2-3 seconds a lap faster than I am and was nice enough to give me lot’s of data about the track.

Her car also has a very unique roll bar set up. It ties in the shock towers and all four sub-frame mounts but doesn’t come any farther forward than the “B” pillars. This is a concession to street use. A full cage can be dangerous on the street as the steel cage bars are really close to the driver’s head. On track the driver’s helmet provides the needed protection, but on the street it’s steel vs. skull.

Gabe uses a RaceTech seat with head restraint, which looks really nice but is just a little narrow for me. I think they offer a wider model as well.

Jeff Blonder's M3 is a supercharged Avus blue 1997. He has added a Eurosport twin-screw supercharger and intercooler kit that he claims produces almost 500HP.

Jeff is more my size and uses a Sparco Evo L seat which fit me really well. It’s now on my short list along with the Recaro SP-G. Jeff’s car also has a custom rollbar, although his doesn’t pick up the subframe mounts like Gabe’s car. He does have the stubs welded to the mounts but they aren’t tied to the bar yet.

The final car was Todd Green’s wicked Cosmos Black 1995 M3. This is a pure track car. It is totally gutted (including the dash, wiring harness, doors, Etc.) It has a sunroof delete (using the infamous E-Bay carbon panel (which looks just fine, thanks)) and a carbon hood. Todd says the car is about 2500 Lbs.

Todd runs 295/30-18 Hoosiers on CCW wheels and a full JRZ suspension. These tires are HUGE and stick out from the car even with front and rear flares.

Although pretty close to stock HP (Cams, CAI, Etc) Todd’s car was mixing it up with the fastest Corvettes in the Time Trial group.

NASA Results

Since I had a transponder in my car, results of the NASA event are available on MyLaps

Introduction to Data Acquisition

My new Traqmate GPS data acquisition system arrived the afternoon before I left for Miller. The system is pretty easy to install. I put the main unit on the transmission tunnel just behind the console. It’s mounted using some strong elastic shock cord and a quick-disconnect hook for easy removal. The Display Unit is mounted to a empty cassette tape shell. The tape fits in the OEM radio and makes a convenient location high in the center of the dash.

One nice feature I used on the drive out to Utah is the “Drive” function. It displays speed and time during road trips. It shows that with my miniature 215/45-17 tires the speedo is only 2 Mph off. I had expected 3-4.

The only problem is that in “Drive” mode it is recording way points. I didn’t realize this and was surprised to discover that on the second lap of the first session the memory filled up and it stopped recording laps. I cleaned it out and used it successfully in the second session.
From a driver development perspective here is what I learned.

The track mapping is really good. It clearly shows when the driver moves off-line to pass, or to avoid other cars. This accuracy allowed me to ID which corners are still troublesome because the lines through them are pretty thick (showing a bunch of different lines. In corners that I had nailed, the lines are thin and sharp. This served to confirm that a lot of corners still needed work, but I already know that.

My second focus is on small segments of the track – specifically segments that lead onto the longest straights. At Miller these corners are “Work Out”, “Precision”, “the Attitudes”, “Tooele Turn”, and “Release” with the last the single most important.

Focusing on segment times allows the driver to understand the relationship between entry speed and exit speed and how they impact segment times. At the same time I looked at 2D loads (Accel/Deccel and Left/Right). When combined, this data shows, how braking and turning impact segment times.

This analysis showed many things

1. I was braking too early for turn 1 (Sunset Bend). This was shown by the fact I was threshold braking then coasting for 10-15 feet before the turn in. Remember Sunset bend at the end of the front straight where top speed is 130+ slowing to 76 at turn in. There is significant trail braking as well as. After the analysis I started braking later and carried the braking much deeper into the corner (almost to the apex on the fastest laps).

2. The Black Rock Hairpin is a tricky corner. It’s a increasing radius deal with a little helpful camber around the outer edge. It can be done a number of ways (single-apex, double-apex, no-apex, etc.) Analysis showed that although the camper on the edge was helpful (+1 Mph), the longer distance negated the advantage so early single apex line was the fastest.

3. “Release”, the corner leading onto the longest straight is a 160 degree banked turn. The best line appears to be a late turn-in (using all the the pit-exit lane) and get on the power just after turn-in. The banking makes exit speed easy to find quickly. The trick to “release” is entry speed. On my fastest lap my segment entry speed was 67 Mph resulting in max speed of 131 on the straight. A segment entry speed just 2mph slower results in a max speed of 126 (a loss of 5 Mph). On my fastest laps I was just tickling the rev limiter at the brake zone.

4. Embarrassingly, my fastest time through turns 1,2,3 (a set of Right-Left-Right sweepers) came on a warm-up lap. I went into 1 a little slow and was flat out through 2 and almost flat through 3. This is much different that my original technique of a little right-foot braking for 2 and a little more left-footed for 3. Each time I over-slowed the car with the right foot in 2, which costs time all the way to 3.

GPS Data Acquisition is a really powerful tool and it will require significant work to use effectively. I really want to see throttle position, brake pressure, and RPMs. This additional data will provide more information about both vehicle and driver performance. I’d also like to log Oil Pressure just in case.

Monday, June 16, 2008

Miller, the afterglow

Well, the three-day event at Miller Motorsport Park is over and both the car and driver returned home in one piece.

The track proved to be everything I had hoped – wide, long, complicated and really challenging to learn, even in three days. The facilities are spectacular, even the restrooms smell good. It is truly a world-class facility rivaling Sears, Laguna, Mid-Ohio, and Atlanta for both the track and for the facility.

The NASA event was pretty well run, not the wild-west shootout that I remember NASA group-4 events were in NASA’s early days. For this event Group-4 was combined with the NASA Time Trial (TT) group. The group might also be called the “Old, rich, erectile dysfunction, Corvette group, as that would more accurately capture it’s essence. The combined ego of the group was illustrated by their custom license plates: “FASTEST”, “TRQZILLA”, “WHYLOSE”, “WAY2FAST”, etc. They all had Corvette Jackets (suitably embroidered with all their manly accomplishment, Corvette hats, Corvette T-Shirts, I’m pretty sure I even saw one guy with Corvette socks.

Mixing non-competitive students from the High-Performance Drivers Education program with competitive drivers hoping to record a best lap-time is a little risky but the reality is that Group-4 is really the domain of Driving Instructors and a couple of racers looking for a little more track time. Since there are no instructors, no discussions of driving technique, and no discussion about the track and it's corners, it's pretty hard to call group-4 drivers education.

With a reasonable amount of wheel-to-wheel racing experience I was pretty comfortable with the last second, at-the-apex, dive-bomb style passing the Corvette drivers seem to prefer. A couple of Group-4 students and a couple of instructors were much less comfortable. After a couple of stern warnings from NASA officials (read: threats to send ALL the Corvette drivers home immediately) things got a little better. The issue was finally addressed when the entire Time Trial group was combined with one of the racing groups. This left those of us in Group-4 a little lonely, I mean it’s a 4.5 mile track and with the departure of the Corvettes there were only about 20 cars. I did one entire 30 Min. session without seeing another car. It was actually really nice to be rid of the geriatric penis car group.

Lessons learned at Miller:

The car is going to require significant development to really be fast. In this era of high-horsepower turbo cars (and living and racing at over 5,000 ft., a stock E36 M3 is a bit of a knife in a gun fight – hell, I got passed by a damn Mini in one session.

The upside of the weekend is I got to take a long look at three very well-developed E36 M3s and have a better feel for what it will take. Two were track-day cars and third was a race car. The Track-day cars were exactly with what I want to do in the short term and the race car is what I ultimately get to. I'll detail each car in a future entry.

Monday, June 09, 2008

Addressing body roll

That's sure is a lot of body roll. In this photo, taken just before the apex of turn 10, the car is generating about 1g of lateral acceleration and the body is rolling about 5 degrees. This is described as 5degrees/g.

This is too much roll for the Mac-strut front suspension of the E36 M3.

When the front of a Mac-strut car rolls, the outside (loaded) strut looses camber as it compresses. This reduces grip just when you need it most. Reducing body roll keeps the suspension in the optimum position and maintains the largest amount of negative camber.

Body roll is reduced using a combination of springs and anti-sway bars.


Note how little roll is shown in the photo below of another E36 M3 with large sway bars.

Photos taken by one of the corner workers at the BMWCCA event.

Reducing body roll and preserving negative camber are among the top requirements for selecting the replacement suspension system.

Wednesday, June 04, 2008

BMW Club Driving School

Last weekend was my first driving event in the M3. It was a BMW Club Driving School at Pueblo Motorsports Park. Everything went well. The car was reliable, easy to drive, and fairly fast. It's a little slow to turn in - not surprising since it still as a street alignment.

From a driving perspective, I did pretty well. A little rusty perhaps, but not too bad. I had a great time.

I just signed up for a NASA event at Miller Motorsports Park near Salt Lake City. It's a long haul from Denver but it's a three day event and Miller is a track I have wanted to drive since it opened. It's unusual in that its 4.5 miles long and have 23 corners. (that about twice the typical track).

Thanks to YouTube I've been mentally lapping the track for the last few days. Here is the clip I use most often.



I also hope to have a Traqmate Data Acquisition system in the car in time for the event.