Category Archives: Electrical


TR6 Front LED Bulbs

img_4070The missing Triumph TR6 front LED bulbs came in this week.  I say missing because the “kit” I bought included the wrong front LED bulbs:  for the 1972 TR6, the bulb must have two “filaments”.  In other words, these bulbs double as parking lights and turn signals.

Today’s featured image shows the bulbs installed and in their “park light” mode.  I left the lenses off to show off the amber color and just how bright hey are!

And one more picture, this time a closeup showing all the little light emitting diodes and why the coverage is so great.


Multiple rows of LED’s providing full coverage


LED Lights for a Triumph TR6

img_4055Today, I installed a long overdue improvement on bowtie6: a set of LED lights for a Triumph TR6.  The “kit” consists of all new 360 degree replacement LED bulbs.  This means, the new bulbs have diodes on all sides and give a much brighter beam compared to the traditional bulbs.

The advantage is obvious:  a much brighter indicator with little or no heat dissipation.  I’ve seen the effects of traditional bulbs on the TR6 tail light clusters:  damage can occur and this replacements are expensive.  The downside is this improvement is a little on the pricey side.  I’ll explain shortly…

img_4057This picture shows on the right, a traditional front side-marker light bulb as fitted to a 1971 Triumph TR6.  The bulb on the left is the LED replacement, with amber light emitting diodes.  Yes, the replacement bulbs are available in different colors depending upon their intended use.  As you can see, there are four diodes around each side and one on the tip.  This provides the 360 degree coverage.

All bulbs in the kit came individually and carefully packaged in a box.  Shipping was not too bad, however the kit was $125.00.  Yes, rather pricey but worth it.

img_4053By now you are asking for proof.  Well, take a look at the following pictures.  The first picture shows the “stock” front-side marker light:

img_4058Followed by this picture, showing the replacement LED bulb in action:

img_4059The difference is noticeable and I must say, the picture does no justice.  In person, the LED replacements are much brighter.

Moving along to the back of the car, this picture shows the new LED bulbs on the left and the traditional bulbs on the right:

img_4064The picture shows the red “running” lights and the white back-up lights in the “on” setting.  Each LED replacement is much brighter with a richer light beam and full coverage.  The amber turn signals are not “on” unfortunately, but believe me they are very bright now!

Here is a close-up of the rear running lights with the LED bulb on the left and the traditional bulb on the right:

Finally, if you decide on getting one of these LED kits let me save you some aggravation.  The manufacturer’s website has a mistake on the bulbs required.  The front turn signal bulbs need two “filaments”.  The website has the replacements are only one “filament”.  As a result, I will need to order the a pair of two “filament” amber bulbs.

Also, don’t forget the resistance of LED’s is different from tradition bulbs.  Therefore you must change the flasher to one compatible with LED bulbs.  Otherwise, the “blinking” won’t happen properly.

Here is the corrected list of bulbs if you wish to know:

  • 1156-A18-T in Amber – required 2 for the rear turn signals
  • 1157-R27-T in Red – required 2 for the rear running/brake lights
  • 1156-CW18-T in Cool White – required 2 for the rear backup lights
  • BA9S-RHP5 in Red – required 2 for the rear side marker lights
  • BA9S-AHP5 in Amber – required 2 for the front side marker lights
  • 1157-R27-T in Amber – required 2 for the front running/turn signal lights


Good Electrical Ground

A good electrical ground.

How many times have we read about the need of having a good electrical ground in classic cars?  Well, I’ve had my fair share of bad electrical grounds through the years and this weekend I fell victim to one.

Weekends are my time to enjoy driving bowtie6 and this past Saturday was no exception.  At a red light not far from the house some dipshit was fiddling with his phone instead of paying attention to traffic.  I reached down below the dash and tapped the single-pole momentary-on switch that controls the horn…

Nada.  Nothing.  Horn did not work.  At this point I had the default Whiskey-Tango-Foxtrot expression on my face.  Damn!  Electrical gremlins.  Fist thing that pops in my head is failure to have a good electrical ground.

And so, when I get back home I check the fuse panel under the dash that I made and controls all electrical circuits under the bonnet (click here for a more detailed post).

IMG_2825I checked all fuses and they all passed with no issues.  Then, I pulled each one out and made sure all connections were in order.  I know, the wiring is a bit busy – but this is rather hard work to do especially in the tight confines of the passenger’s side footwell.  I suppose this is what “bespoke” is all about!  😉

So, next was to go through the main power box.  This is located in the engine compartment (click here for more details).

IMG_2824As you can see, here is the main power distribution block in bowtie6.  The six red-capped affairs on the bottom are circuit breakers.  They feed hard voltage to each purple relay.  In addition there is another fuse panel located behind the relays as well as the engine’s PCM.  After careful inspection all this checked out just fine.  When I flipped the switch under the dash for the horn, the “horn” relay clicked as expected.  Still no horn – rats!

Which brings us to the next photo (a closeup of the featured image above):

IMG_2826 closeupThe entire circuit governing both horns relies on the ground made by the connector to the body.  As it turns out, I pulled this connector and ensured there was no rust.  Sure enough, after cleaning the connection, adding a little de-electric grease, and plugging the connector back in place all worked just fine.

And there you have it, the root of all evil… The lack of a good electrical ground.

ECOTEC ECM Tuning – Changes So Far

I mentioned in the last post I’d go into more details about HPTuners.  This time I want to talk about the Ecotec ECM tuning changes done so far.  I’m far from being an expert however one needs to start somewhere…

Vehicle Anti Theft System (VATS)

The first and most important task is disabling VATS.  This is a prerequisite when doing an engine swap such as what we did here.  Failing to disable VATS renders the engine inoperable.  On earlier ECM’s GM devised a system by which the ignition key had a special resistor that would match a receiver in the ignition key tumbler.  This “match” would enable the ECM to fire the engine.  With those early ECM’s it was possible to wire an inline module and basically fake out the key resistor.  With modern ECM’s such as the one controlling the Ecotec, the VATS became more advanced.  With the aid of HPTuners though, this is a simple change in the flash file burned into the ECM.

Mass Airflow Recalibration

In bowtie6, we replaced the stock plastic intake with a smaller, more direct intake manifold.  The reason was not for performance but because the stock intake was too big and got in the way of the steering shaft.  The air filter housing was also replaced with a cone-shaped K&N air filter.  There is simply no room under the hood of the TR6 for the large box that holds the stock air filter.  These changes forced relocation of the Mass Airflow (MAF) sensor.  As expected, the stock settings for the MAF did not match the new configuration.  This manifested itself in a rather rough idle and poor performance.

Tuning the MAF took some doing.  I won’t go into all the details but suffice to say it took a few hours worth of driving down the road and logging data with the VCM Scanner.  Using the VCM Editor I was able to dial in the low and high MAF tables to more desirable values.  This resulted in smoother idle and better performance.

Seeking Professional Advice

This is where the tuning process gets a bit pricey.  After going through several  books and reading many long hours’ worth of posts I decided to find a local expert.  Sure enough I found a person with a great knowledge and familiarity with HPTuners and tuning GM engines. However this came at a price.  The results though, made a huge difference.

As expected, fuel efficiency is the ahead of pure performance in the  stock ECM.  This shows up the way the commanded air fuel ratios are pre-set across the RPM range, spark tables and the way that power enrichment activates proportional to throttle angle – among other things.  After quite a few alterations the ECM is delivering more performance at the expense of fuel efficiency.  The results are astounding:  throttle response is much more livelier resulting in more power being delivered and overall the engine is much smoother across the entire rev range.  It is now very easy to make the Ecotec reach its 7000 RPM redline.

What next?

The next step will be to take bowtie6 to a dyno.  Been there, done that before but this time we will be tweaking the ECM  This will allow even more accurate dialing in for extracting that last bit of power.  Also, something that is yet to be modified are the VVT tables.  The 2.4 Ecotec has variable valve timing and this first tuning did not touch VVT.  Who knows what we can do with this?

Another avenue left for exploration is E85 Ethanol.  I’ve been intrigued for a long time about this source of fuel.  FlexFuel vehicles have a special metering device that allows the ECM to calibrate itself on the fly.  I don’t have that metering device but I have HPTuners and this will allow a special E85 calibration flashed into the ECM.  Where I live E85 is very easy to find – there is a very large fuel station just down the street from my house – so this will be a fun experiment.  Granted, flashing the ECM to run E85 without a metering device means E85 has to be burned exclusively.  However, changing back to straight fuel is easy to do, simply by reflashing the ECM.

In Summary

I realize to each his own and this is not for everybody.  However, having all this technology at your fingertips (literally) is remarkable.  Why would anyone want to waste time on those relics of fuel metering called carburetors is beyond me.

Stay tuned…  Soon bowtie6 will be the first E85 Ethanol powered TR6…  🙂

ECOTEC ECM Tuning – Intro

Gone are the days of “burning a chip” for engine computers.  Modern Engine Control Modules (ECM’s) can now be monitored real-time and then modified based on readings done after driving down the road.  Pretty cool stuff indeed but it adds a whole new dimension to engine performance adjustments.

The factory install of the Ecotec in a Pontiac Solstice at its core consists of the engine, wiring harness, ECM and the Body Control Module (BCM).  The ECM reads and controls engine signals while the BCM controls such things as gauges, door locks, lights, etc.  In addition, the BCM supplies data used in the information center on the instrument panel showing fuel consumption, engine temp, outside temp, etc.  Furthermore, the ECM and BCM talk to each other via a digital high-speed bus integrated into the factory wiring harness.

So, one of the challenges in getting the Ecotec to run in bowtie6 was making all this work outside of the factory install.  After doing a ton of research and reading the Factory Service Manuals, we were able to figure out what wires actually control engine sensors and what goes to the BCM.  This enabled us to change the factory harness to fit our needs.  Since we did not run the factory instrument panel and did not need to control lights and such, we did not use the BCM.

A disadvantage of this approach is the lack of cruise control.  In the Ecotec the throttle body is electronically activated – there is no cable in the traditional sense.  Instead, the electronic “gas pedal” inside the car sends a signal to the ECM via a small wiring harness.  This gets accomplished by coarse and fine potentiometer readings of the throttle pedal position (Click here for my Drive by Wire article).  There is also no Idle Air Control (IAC); instead idle is now controlled by the ECM cracking the butterfly angle as needed.  This is very amazing stuff.  As a side note, it is interesting to pay close attention when turning the ignition to the “on” position:  there is a very short “click” heard from under the hood.  It is the throttle body going through its pre-check.  But I digress… Bottom line:  my goal is to be able to integrate the BCM into bowtie6‘s wiring and by doing so, have a fully operational fly-by-wire cruise control.

Among the wires going to and from the ECM is a group that end up in a special plug called an ALDL connector.  This special connector is normally found in production GM cars under the dash on the driver’s side.  It is by the ALDL that the GM TECII scanner/programmer gets connected to the car’s ECM.  In my case I use my laptop along with an interface made by HPTuners to read and change the ECM’s settings.

Enter HPTuners

HPTuners is a commercially available ECM tuning package.  It consists of a Windows-based software running on a laptop and an interface with a USB connector on one side and a matching ALDL connector on the other.  This software package is quite remarkable in what it does; equally remarkable is the lack of documentation.  Sure it has online help but it is very lacking in detail and content.  In the hands of a newbie it can spell disaster to the engine; in the hands of an expert it makes an already great engine even more remarkable.

HPTuners has two main software components:  the VCM Scanner and VCM Editor.  The Scanner is the means by which the engine’s parameters get monitored real-time.  There are a number of different ways to display data:  charts, a gauge panel and tables.  Scanning is accomplished by connecting the laptop to the ALDL connector via the interface, starting the engine and pressing the “Scan” button on the Scanner.  Then you drive down the road and start logging data – the more, the better.  This data can then be saved to a log file for further analysis.  Another feature of the Scanner is to load a log file and play it back – this is very helpful in determining what to change.

The tool used to re-flash the ECM is the VCM Editor.  The process is quite simple:  read the ECM, make adjustments and re-flash.  The hard part though, is figuring out what to change and in what order.  It has been my experience so far this is a bit of a black science.  Information on the interweb is vast about tuning.  However, discerning truth from fiction is the true challenge.  There are several books on the subject and then there are tuning courses available, however they are pricey.  HPTuners is the tool but what to do with and how to use it, is a very time-consuming task!

In the next installment I’ll go into more details about HPTuners…