BMW M5

I recently took advantage of an offer to upgrade my Blinder M25 to the latest offering from Blinder, the M27 Extreme. My experience with the M25/J11 model was less than stellar. The M25 unit with J11 heads didn't work very well at all against the LTI Ultralyte gun used here in New York State. After less than two years, my M25 stopped working all together. I was going to replace it with an Laser Interceptor (LI) but then that company seemed to go out of business. A little over a month ago, Blinder sent me an email about their new product, the M27. I responded to the email by describing my experience with the M25. Much to my surprise, I was contacted by Blinder USA's sales rep. After a few emails, some photo's of my installation and describing the history of my install, testing and subsequent issues, Blinder offered to exchange my old M25 for a new M27 for a modest fee. At first I was a bit skeptical but the online reviews seemed to be positive and so I decided to give Blinder another try.

I paid the exchange fee and shipping for a new M27 and within a week, it arrived. The heads and control unit looked similar to the M25 however the new M27 control unit has a USB port on it that allows you to upgrade the firmware yourself. This is a HUGE benefit given the new guns and improvements the mfg can offer post sale. The only thing I will say is that the Manual for the Blinder (both the M25 and M27) is brief and could be a bit more robust in its explanation on installation and updating etc.However, the information online on the Blinder site and at sites like RadarDetector.net  provides a wealth of knowledge.

Removing the old M25 took a while. I had routed all the wires thru the firewall on my BMW M5 and tucked them into a wire harness in the engine compartment. I ended up pulling the old head wires through with a string so that I could pull the new head wires easier. It took me about an hour to uninstall the old heads and install the new ones. This was done without having to remove the front bumper which saved a lot of time.

Since I had previously installed the LED and SPST switch on my dash, I simply wired up the new M27 switch in series with the old M25 switch. I just put the M27 switch on mode II and tucked it up under the dash with the new CPU module. The LED and siren module was the same so I simply hooked up the connector from the old M25 and everything worked like a charm. All in all, it took me about 90 minutes to uninstall the M25 and install the new M27. I parked the car on level ground and adjusted the heads so that they pointed straight ahead and were perfectly level.

Initial Testing (Parked on Level Ground)

My initial test was to park the car on level ground, activate the M27 and shoot it with the LTI Ultralyte from about 75 ft. The car was parked and I had not put the front plate back on so this was the easiest test. The results were promising. No matter where I shot, the LTI ultralyte got an E03 error. It could not get a reading at all using the speed or distance functions.

Next I mounted the front plate. Before mounting the plate, I took some steel wool to it and removed all the shine making it as dull as possible. I also placed a 1/2" piece of weather stripping behind the top lip of the plate so that it is angled downward toward the ground. The idea here is that any light hitting the plate will be directed towards the road and not back towards the gun. (every little bit helps) I then tried shooting the car again while parked from 75 feet. This time I was able to get a reading while shooting the plate after three attempts. Given how close I was, I didn't think this was an issue. It was obvious the M27 was working far better than the M25 and I now needed to test this out on the road.

 

Road Testing

For my road test, I found a long stretch (1 mile) of level open road. It was a clear day, 65 deg, with 45% humidity, light breeze. I found a sign post and used the Ultralyte's survey mode to measure the distance to the sign. I positioned myself about 500 ft from the sign. I then had my wife ( aka Test driver ) drive the M5 up the highway, turn back and drive with traffic toward me at around 50-60 mph. When the car passed the sign (500 ft away) I would try and measure its speed using LTI Ultralyte.

(My LTI Ultralyte was purchased from LTI directly. It has been recently calibrated by LTI and kept in its case. I chose this gun because that's what I've seen used on the roads I drive. I choose a distance of about 500 ft, because that is the distance I was usually targeted at when my M25 went off in the past. )

Open Road Test Results

I made a total of 4 test runs. The first two were taken from the far side of the road to simulate a cruiser parked in the median. The second two were taken on the near side with the LIDAR pointed directly at the car. My aim was for center mass, front plate.

Blinder M27 vs LTI Ultralyte ( 500ft )

RUN 1 far	JTG
RUN 2 far	JTG
RUN 3 near	JTG
RUN 4 near	PT at 48 ft.

JTG: Jam to gun. No speed reading at all.
PT: Punch through. Speed was read by gun.

My initial impression of the Blinder M27 is quite favorable. The unit is far better than its predecessor the M25. It's clear that Blinder has a winner with the M27. Thanks to Blinder USA for building a nice product and for standing behind their products and offering me a easy and cost effective way to upgrade my old defunct M25. I will be testing the unit out for real over the next few months. I post an update again once I've had some road time. 

Last fall I installed an Blinder M25 on the M5.

Here are a few photos from the install. The two M25 heads are spaced a little over 50 cm apart. Blinder recommends between 50 and 60 cm between the heads. The distance from the head to the outside edge of the headlights is not more than 18 inches.

The heads were mounted straight and level per Blinders installation instructions. Here you can see a shot from both the passenger and drivers side.

Another shot....

For added benefit, I took some fine steel wool and did a real number on the front license plate. This made it very dull but completely legible. In other words a poor reflector. I then placed a 1/2" thick length of weather stripping behind the top lip of the plate to tilt it downward toward the road. Any reflected light will be directed downward rather than back towards the source.

I also replaced my shinny front kidney grills with black ones to further reduce the reflectivity of the front area of the car.

Here is a shot of the switch mounted to the dash. The control box is mounted under the dash and routed the wires thru the firewall. This ensures the control box stays dry.

Last but not least, here is a shot of my testing device. This helps me guage changes to my setup and removes any BS regarding the effectiveness of a particular setup on my car. I'll post my test results soon.

The temp warmed up to day. It was actually 50 deg ! I installed my converter circuit for the defi speed pulse and it worked after making a small change See previous post for more detail including schematic.

Here is a shot of the Defi at idle RPM.






Here is another shot of it displaying MPH. I'll take a few more during the day next time.

The ProblemAs mentioned in my previous post, the input to the Defi Control unit to determine speed requires a pulse between 20 and ~270 pulses while the car is traveling 40 mph. The wheel sensor on my 2003 E30 M5 generates 10 pulses / MPH. At 40, the number of pulses sent by the E39 wheel sensor is out of range at ~400. I decided to build a circuit that would divided the pulses generated from the wheel sensor by 2. This would allow me to calibrate the Defi at 40 mph as required.
After calling around town and checking local area shops, I ended up ording the parts I needed from Mouser. I ordered a bunch of cmos parts so I'd have some extras. I used a socket and a small breadboard to wire the thing up.

Here's a shot of the circut after I completed the basic wiring. It's simply a cmos 4013 configured to divide by 2. I added a 47uf/50V cap to decouple and glitches that might be present on the supply line and a small driver to make sure the signal can toggle the flip-flop.

Schematic

R1 - 10K 1/4 watt
R2 - 100K 1/4 watt
Q1 - 2N2222 or equivalent
C1 - 47uf / 50V
4013B CMOS Dual D-Flip Flop
This took me about an hour to do using a socket and some wire wrap. There are two outputs S(out) divides the input signal by 2. S(out-1) divides the input signal by 4. Using this circuit, the Defi should be capable of working with a much wider range of vehicles.



I tested the circuit out by driving it with a simple square wave to make sure I didn't make any wiring mistakes. No sense pulling the car apart and installing this if it won't work on the bench As you can see the inside wave-form is half the frequency.




Now that I'm sure I didn't make any mistakes, I just packaged the thing up in a film canister so I can tuck it away under the dash. The plan is to connect this between the BMW DWS Wheel Speed Sensor and the input to the Defi Control Unit.



Now I just need to wait for it to warm up a bit and I'll install it in the M5. It's only 30 deg here in Ithaca and it's too cold in the garage today to do any work today.

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Here is the Defi Basis unit. The unit goes for about $150.00 online. Below you can see the basics of what you get. As you will see, the install is fairly easy and I did this in a few hours. There is one catch with speed display as the stock unit will not properly display speed. It works pefectly as a tac and I'm working on a simple adapter for the BMW speed signal which should allow the unit to display speed. Right now you can install it and use it as a HUD tach only in about 1.5 hrs. It turns out the frequency of the speed signal off the BMW wheel sensors is too high for the unit to calibrate to at 40 mph. I believe this can be overcome with a simple divide by 2 circuit. I'm working on this now and will post my results. (See section at end of this write up for more information about this issue.)

The unit consists of a display unit that mounts on the dash and a control unit that mounts remotely. There is a simple cable harness that is used to provide power and input signals to the control unit. The cables plug in using simple molex style connectors.












The first task was to remove the dash trim to expose the screws holding the lower dash panel in place. I decided to mount the Defi control unit under the drivers side dash area where I could tap into the OBD-II connector. The OBD-II connector provides switched power ( +12V ) , ground and the crankshaft sensor / engine speed RPM signal.




Since we'll be hooking into the vehicle power and wiring, it's best if you disconnect the battery before doing this.




So first off, remove the trim by gently prying from the bottom, then top.