Category Archives: bowtie6

Ecotec Powered Triumph TR6

Ecotec ECM Tuning – Changes So Far

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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…  :)

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Ecotec ECM Tuning – Intro

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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…

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You Never Know…

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I’ve been driving bowtie6 quite a bit these days…  A bit cold, but with the new kicker heater it is nice and toasty.  I guess since we are getting around, you never know when you are going to get a mug shot.

My friend and fellow TR6 owner, Adam Beasley sent me a text message yesterday with this photo.  The photo was taken at the parking lot of a local barbeque place (they have really good BBQ there!).  Turns out a friend of his took the photo and sent it to him.  Since he knew Adam owns a TR6, Adam told me he made the comment that he had “…seen this red TR6 and it was in decent shape.”.  Well, yeah!  So moral of the story, one one drives a “classic” car rather than having it in a garage all the time, you might get your picture taken!  :)

As a side note, yesterday I had a chance to visit a car show that is held every year here at the Expo Center.  Mainly, it is a showcase of new cars where one has the chance to check out new cars without the pesky, ignoramus “car salesmen” flying around like underfed vultures.  At any rate, several things I learned last night:

  • They had the full lineup of CTS Cadillacs.  The CTSV’s no less.  They had a new coupe and the sedan both with the kicker supercharged LS engine.  Both were clad in a very awesome metallic black paint.  Very nice indeed.
  • The new Ecotec 1.4 turbo is awesome!!  There were several Cruze examples with the new 1.4 and man is this engine impressive.  Physically, it is smaller than the 2.2 or 2.4 Ecotec and should be a really good candidate for transplants.  The turbo on these is tiny!  It is unknown though, if a five speed gearbox will hook up to the back of the engine.  Then again, maybe if we get a pair of pliers and a blowtorch we could medieval on it…  ;)
  • Had a chance to get an up close and personal view of the new Fiat 500.  They had two of them.  A hard top and a convertible.  Well…  Hate to say it, but what a POS.  I had a chance to sit in one and the ergonomics are all screwed up.  The shifter is in the wrong place and talk about cramped.  These things are expensive and I hate to say it but looks like they are not going to “make it”.  And from what I have been reading, they are not exactly selling lke the proverbial hot-cake.
  • Supercharged Vette was also very impressive.

 

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bowtie6‘s ECOTEC

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Quick post for today…  Just wanted to show what the whole shebang looks like these days…  The ECM box has a nice cover on it.  Looks pretty cool, huh?

Click on each picture for a larger image…

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TR6 Bonnet Rod

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After installing countless sheets of Dynamat Extreme all over the place ($$), thick sound proofing carpet backing, new carpet, plugging up the firewall for any small holes, modifying the exhaust and misc other improvements, bowtie6 is very quiet now.  While this is a great thing, it also brings with it the ability to notice other smaller aggravating sources for noise. I started noticing a very annoying squeak from underneath the bonnet (the hood).

This darn squeak would happen on bumpy roads as well as smooth blacktop.  Since it was coming from under the bonnet I started adjusting stuff.  I made sure the two rubber bumpers were up to snuff, made sure the latch was nice and centered and double checked all bolts.  Fender bolts, hinge bolts, grille, the works.  Still – squeak city.  Damn.

While visiting with a buddy of mine that works on TR6′s – Mike Richardson – over the holidays, I discussed the annoying squeak.  We went for a ride, and Mike laughed and said, “It’s the bonnet rod!”.  Duh!

Mike suggested a couple of things.  The first was to tighten the nut holding the rod in place.  Mike reached into his toolbox and pulled out a 7/16″ wrench and tightened the nut just a tad.  Since Mike restores TR6′s back to “original” I figured this might do the trick.  Well after chewing the fat for a while, I headed back home.  Damn squeak was still there.

Remember I said above he suggested two things?  Mike suggested that if after tightening the nut it still squeaked, to take a closer look at the rod and see if there was any evidence of it rubbing on the rod guide on the body.  Sure enough, there was a shiny spot on the rod where it touches the guide.

Properly mounted the rod nut should be a loose fit.  This enables the rod to fall in place into the recess on the rod guide when the bonnet is lifted open.  If the nut is too tight, then gravity cannot let the rod fall in place and one has to manually intervene, which is not good.  Mike said this is out of the “Original Restoration Handbook”.  Hmmm…  I guess I never read that book.  Shame on me.

However, leaving the nut a little on the loose side – according to Mike – the rod has a tendency to bounce and move around.  This is how that shiny spot forms on the rod and thus the source of the squeak.  Hmmm.  I guess the “purists” know a thing or two I don’t know.  Imagine that.

“So, how do I fix this?”, I asked Mike.

Mike looked at me and said: “Get some shrink wrap and cover up any shiny areas.  This will solve your squeaks”.

So when I got back home, I opened my toolbox with all my ‘lectrical stuff in it and found the appropriate size shrink wrap.  I cut an appropriate length, aligned it over the shiny areas and let the hot air gun do the rest.  This is what it looks like:

I put the nut back on, careful not to tighten it too much (in accordance to the “Original Restoration Handbook”) and went for a ride.

Well folks, that did the trick.  No more annoying squeak.  Imagine that.

So if you have an annoying squeak under the hood that is driving you nuts, you might be able to do a similar fix as shown above.  Mind you, it will not score you many points with the judges but I can’t stand squeaks.  Of course, in my case…  who cares what the judges say!

Thanks Mike!!!  :)

 

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Intake Repaired

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After careful inspection and a thorough cleaning, the intake was repaired by my cousin Jim.  We did find another small crack that had developed on the outside of the plenum – not a leak, but more of a stress crack.  At any rate, with some new weld beads, the runners are all repaired now.  This is what things look like, after the repairs:

Here is a closer look at the affected area:

The face of the flange was found to be ever so slightly not 100% flat.  With a little machining, it is now level and flat.  I started putting this all back together last night.  Should have it all running today…

 

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Backfire!

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Looks like 2011 ends in a bang.  Literally.

Yesterday morning the sun was out so I decided to take bowtie6 to work.  Unfortunately, I did not press the “Start” button long enough, the engine turned for just a split second and backfired when I let go of the button.  I’ve had this happen twice before with no serious consequences but this time, we had a problem: the “bang” cracked the intake.

There is nothing wrong with the design of the intake or with anything else.  This was my mistake 100%.  I just call this a risk of running non-factory parts.  The new intake is all aluminium; this is what the intake looks like:

We had to make this intake up because there is no room for the original plastic intake.  Actually there is, but it would have required the steering column to be relocated bigtime and it was just not worth the trouble.  The intake you see above is made in several pieces.  The flange that bolts to the head came from GM Performance Parts and is water jet cut aluminium.  This all has to be made in pieces and welded in place as such.  The four intake runners are aluminium tubing, cut and bent to fit the oval ports on the GMPP flange.  They were welded to the flange from the outside otherwise there would be a lot of machining to make the flange perfectly flat again.

The runners then were fitted to a flat piece of aluminium which made the intake side of the long plenum on the top.  There was a bead ran on the inside of that plate.  Then, the rest of the plenum was shaped and welded in place.  The seams were filed smooth and it all looks like one solid piece.  Finally a flange was made and welded where the throttle body gets bolted with four screws.

All good, except that the four runners ended up with a delicate bead around them, on the inside of the intake plenum.  So, when the backfired occurred it caused the seam on number 4 runner to assplode.  Take a look:

Obviously, it doesn’t take much for the thing to have a major vacuum leak and cause the engine to fail to run.  Needless to say, with this crack RPM’s went through the roof!  One interesting thing about all this is the ECM was smart enough to figure this out, and basically shut things down.

The outside of the runners needs to be welded again (duh!).  Had we not had the backfire, this would have not been a problem.  The seal has been flawless but unfortunately the thing just could not cope with the force of the assplosion.  As you can see, the intake has been removed and will be welded back today.  I hope to be back on the road hopefully tomorrow.

Here is a picture of engine-side of things:

Sorry for the picture being so dark, but you can see there is not much distance between the intake valves and the actual intake itself.  Not at all.  Also, the gasket seems out of place because it is not pushed all the way up against the head – in reality it fits perfectly with the intake opening.

No worries though – this should be a quick fix…  :)

 

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bowtie6‘s Custom Wiring – Inside the Cab

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The last and final installment of the bowtie6‘s custom wiring takes us to the inside of the cab.  This will be the last on wiring – I know this is getting boring but I just want to show what can be done with a little creative thinking.

So what do we have here?

The picture above shows the quilted maple dash we made, it is mounted to an aluminium backing dash which in turn is bolted to the stock TR6 mounts.  The vent is fully operational with a bit of a twist – I’ll have to write about this later…

Behind all this you can see what I call the “cab” wiring.  Here are two spade fuse housings holding 7 of 8 fuses.  The ones on the left side are constant “on”; the ones on the right are switched.  In the middle you can see four relays.  Here is a closeup:

Why the missing fuse?  I am not completely done with the interior wiring and this circuit will be used at a later date when I add the final details to the inside:  fully operational door activated interior lighting.

Relays & Fuses

Four relays are mounted on this plate.  They control the following:

  • Heater and windshield wipers.
  • Turn signals – one relay controls “left”; the other controls “right”.
  • Parking lights.

As with all the other switches, the heater and windshield wiper switches make “ground”.  They in turn activate the electromagnet on the relays.  The B+ to the electromagnet side of the relays are fed by the fuses on either side.  I did not use circuit breakers here, I just used the spade fuese.

The turn signals are controlled by a stock TR6 turn signal stalk.  The turn signals feed goes through a “blinker” switch and from there, a wire is sent forward to control the front signals and a matching wire is sent rearward to the back turn signals.

The same process is done for the parking lights.  The parking lights and headlights are both controlled by a universal park-light/headlight switch.  I bought this from the same supplier I bought all the wiring from and is commonly used in street rods.

Two banks of fuses flank the relays.  The left ones are constant “ON” and supply power to the ignition switch, ECM and dash clock.  Yes, we have a clock in bowtie6!  I’ll have a writeup on the VDO gauges soon.

On the right, the fuses are switched “ON”.  These fuses supply such things are the control side to the relays as well as instrumentation lights and such.

In Summary

Once again, I guess you must be saying “this guy has a lot of time on his hands”.  Then again I wanted to make this flawless and 100% reliable.  I imagine you are asking yourself if this can be “seen”.  Well, I made sure to hide this as best as possible.  You have to get on your knees to see the fuse panel.  If you don’t know about it, you will never see it.  Finally it is mounted high enough that it does not get in the way of your knees and/or feet.

Another great advantage about all this is that all three panels are very easily accessible.  If for some reason a fuse blows it can be easily found and replaced.  When I built bowtie6 the first time, the fuse panel was in one central location.  It was VERY difficult to get to and was not easily serviceable.  I made sure to make it this time very “user friendly”.

And Then There is More…

See anything “unusual” in the pictures above?  There are two small details that do not exist in a stock 1972 Triumph TR6.  See if you can spot them.

If not, stay tuned and there will be more about this soon…

 

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bowtie6‘s Custom Wiring – Trunk

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The last post talked about the harness and fuse box under the hood.  Today’s post shows the wiring in the trunk.

Since we are far from “original”, I wired up bowtie6 in a practical way.  There is a fusebox in the engine compartment (as discussed previously), one in the cab compartment (to be discussed) and one in the trunk (discussed here). Why go through all this trouble?

Well, for starters I wanted to keep things simple.  But mainly because there was not enough room underneath the hood!  Besides, it makes sense to control things where they belong and in the trunk there are several things to control…

Battery

The Optima Red-Top dry cell battery in bowtie6 is mounted in an aluminium enclosure pictured above.  The B+ terminal has a welding machine cable attached to it and it runs inside the TR6′s cab and ties into the firewall post.  The ground terminal is also a welding machine cable going through the body and securely bolted to the frame.  In the engine compartment, there are two more welding machine cables grounding the body and the engine to the frame. Finally, there is a B+ lead from the battery to two circuit breakers mounted in a special mount that control the following:

  1. Fuel Pump
  2. Backup Lights
  3. Brake Lights

Fuel Pump

The ECOTEC needs a high pressure fuel supply.  This comes from a GM high pressure pump as fitted to late-model Corvettes.  We used that pump because it is very small, has a filter “sock” and can be mounted in a small enclosure.  In the picture above you can see the fuel pump enclosure – that is the aluminium box resting on the trunk’s floor.  I’ve written about this before but basically that is an external tank plumbed to the main custom made all aluminium fuel tank.  We have about a 300 mile range in city driving with this setup.  I am sure it will be more once we do a long, highway trip.

The picture above shows two circuit breakers and three relays.  The fuel pump has one of the relays and one of the circuit breakers.  The control side of the relay is fed from a signal from the ECM.  When done right, the ECM sends a 5 second signal and energizes the pump.  This primes the fuel rail and gets things ready for ignition.  Once the engine fires, the ECM re-energizes the relay and that keeps the pump running until the ignition switch is turned off.

Backup Lights

The AISIN 5 speed gearbox has a built in switch that makes ground when the stick engages reverse.  I took advantage of this to make the TR6′s backup lights work.  Basically since this is a switch and it makes ground, I wired this into the control circuit of a relay.  This minimizes wear on the switch and voilà, we have backup lights.

Brake Lights

Ah!  Brake lights!! As you had guessed, I used a relay to run the brake lights.  As with the fuel pump and backup lights there is a hard voltage circuit from B+ on the battery to the relay.  This is controlled by breaking ground on the brake pedal switch.  Simple.  Brakes work flawlessly and will be there forever – the brake switch breaks ground.

 In Summary

Once again, I realize this is borderline overkill.  However, this makes things very simple and easy to fix if need be.  Setting this back circuitry together took little time and works like a charm.  As with the engine compartment fuse box, I added red “booties” to the circuit breakers.  You can also see the trunk floor is fully covered in black carpet now.

Here is a closeup of the rear wiring:

If you look close enough you will see several things here…

  • The lid to the battery box.  The box is made from aluminium and bolted securely to the side floor of the trunk.  This is mounted on the passenger’s side to even out weight distribution.  As mentioned previously, the battery is a dry cell Red Top Optima battery.  They are very durable and although they are expensive, they are very worth the cost.
  • The black plastic background.  That is ABS material pre-bent and cut to fit the sides of the trunk.  There is one on all sides, including the inside back of the trunk.  I used this because it is very easy to work with and can be shaped with simple tools such as scissors and a break.  This stuff is also very durable and looks very clean.  Much superior to the crappy cardboard “trunk liner” kits sold by the Big Three vendors.
  • The aluminium plate holds three relays and two circuit breakers.  I’ve discussed these above.
  • Finally, if you really look close you can see two rubber hoses right behind the circuit breakers.  What is this all about?  Well, my bowtie6 is from the very fine 1972 vintage.  In 1972 a special “tank” was affixed to the inside of the passenger’s side trunk.  This tank had two lines attached to it.  The first line came from a vent on the fuel filler neck.  The other line was routed to the intake.  This ensured all fuel tank fumes get routed back to the engine.  This has been retained and is fully operational in bowtie6.

Attention to detail?  Hell yes.

There are so many small details on bowtie6 that get overlooked!  However, I know they are there and this makes the difference.  With this TR6, there is not only killer looks in the form of a very shiny paint job, a powerful engine and a great handling frame but there are also countless details that separate this from even “restored” examples…

 

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bowtie6‘s Custom Wiring – Under the Hood

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After nearly 1,000 miles on bowtie6 since the ECOTEC conversion, I have a ton of stuff to detail out.  This is where you spend tons of time for little to show for.  Sure, I could just leave it “as is”, but there is no fun in that.  Sweating the details is what sets my car apart from all others.

Today, I spent some hours refining things in the main fuse box under the hood.  I’m not 100% done with it yet, but I figured I’d take a few pictures of it so far and write about it.  Maybe somebody might get some inspiration from all this work.

This is what the main engine-compartment fuse box looks like…

Big deal, huh?  Well the silver box is located in the area where the windshield washer bottle used to be and also the area where the dealer-installed air conditioning system was installed.  What is so special about this?  Well other than the fact this is all hand-made aluminium, take a look at what is inside the box…

Now it gets interesting…

  • Starting at the bottom of the picture are six circuit breakers.  Today, I added the little red “booties” to prevent any short circuits.  The middle breaker shows what they look like under the red “bootie”.  Two terminals stick out and this is what the “booties” protect.  Don’t want any electrical short circuits to happen here!
  • Above the circuit breakers are seven relays.  They control the most important basic functions underneath the hood.
  • Above that towards the right is a fuse panel with 8 modern spade type fuses.  These are used on the control side of the relays.  Basically they make the electromagnets in the relays trip when a switch makes ground.
  • The finned box with the three big connectors is the Engine Control Module (ECM) running the show on the ECOTEC.  This is “factory” supplied from the donor engine.
  • To the left of the ECM is the solid state electric fan controller.

Circuit Breakers

These guys act as fuses.  They feed the hard voltage from the B+ terminal through the firewall to the relays.  What B+ terminal?  Since the battery is located in the trunk, we ran a welding-machine cable from the battery’s B+ terminal through the firewall by means of an insulated bolt.  This is where we get voltage to the underhood fuse box and also to the inside of the cab (on the inside side of the bolt)

This is a close up of what this all looks like:

At the very left you see the post where full B+ voltage is supplied to the circuit breakers.  The body and frame is ground so how does this keep from shorting out?  The bolt is fully enclosed in a phenolic ring thus insulating the terminal.  On one side of the circuit breakers is the hot B+ terminal – this is the one nearest to the camera.  On the other terminal is the supply of power to the relays shown above.  On the middle of each circuit breaker you can see the little black dot that acts as a “reset” button.  I used circuit breakers because these are 100% essential to the electrical operation of the system.  If they trip a simple push of the black “reset” button has me back in business.

Relays

Seven relays run the show for the main switched hot lead, ECM, headlights switch, high/low beam, electric fan, horn, starter and ignition switch.  All the switches on bowtie6 break ground.  There is no hard voltage going through any switches.  The advantage of this is longevity.

So basically when a switch is activated, it “makes” ground.  This in turn causes the electromagnet in the relay to trip and that makes the circuit hot.  There is no hard voltage through any switch except for one:  ignition.  I am using an industrial strength switch for this, rated for much higher amperage than what the Optima battery delivers.  This will last past my lifetime.

Fuses

There are 8 fuses under the hood.  These supply power to the control side of the relays as well as to the ECM and the electric fan controller.  I used modern style fuse housings and bladed fuses.  Glass fuses are just too poorly made and prone to failure and that makes them very unreliable.  Not acceptable for bowtie6.

ECM and Engine Harness

The “brains” controlling the ECOTEC is the GM factory E67 ECM.  The wiring from the ECM to the multitude of sensors on the ECOTEC is basically a factory harness from a Chevy HHR, modified to act as a Pontiac Solstice.  We modified the harness by changing pin-outs and removing unnecessary circuits.  This makes the harness much simpler to work with.  Furthermore we cut many wires to make them shorter or longer depending on where they were located.  This is the beauty of doing it “yourself” as opposed to buying something.  Anybody can “buy” stuff…  It takes talent to make you own.

Like I said before, the harness came from an HHR.  GM went through a lot of work in making a very durable and well engineered harness.  In my opinion, the quality of the wire is superb and the connectors are not only expensive but of very high quality.  The harness is basically divided into three “plugs” (you can see them in the picture above).  One has 56 pins; the other two have 73 pins.  Not all are needed though and having a Factory Service Manual will be instrumental in determining what circuits are kept and which need to go.

To make the ECM work outside of the “factory” setup, one must remove the VATS.  This is the “Vehicle Anti-Theft System”.  You do this either sending the ECM out to somebody or by using a software package such as HP Tuners.  We used HP Tuners.  This also enabled us to tune the ECM.

Speaking of the ECM:  make sure you get the right one.  The ECM’s come in two varieties depending upon the type of gearbox used.  An automatic gearbox ECM will not work on a 5 speed gearbox.  Also, there are certain E67′s that will just won’t work.  You will need to make sure you get the one with the right OS, otherwise it won’t work.  This is why it is very important to get the ECM that came from the donor vehicle.

Solid State Fan Controller

This little device is trick.  It has a built in relay and has B+, ground and a wire hooked up to the temp sensor on the block.  This is where the device gets its temp signal.  Here is the beauty of this device:  on 99.99% of all street rods I see, folks stick a nasty looking probe in the middle of the radiator core.  This not only looks awful but eventually wears a spot in the radiator’s core causing it to leak.  I think this way to wire a controller not only looks crappy as hell but is very sloppy.  The controller we use is not cheap, but it has a fully adjustable rotary knob that enables setting the proper temp to kick the fan on.   In the photo above the controller sits on top of the ECM but I am planning to move it to a different location to make it look a little more elegant.  Again, it is the details that count!

In Summary

I realize this is not everybody’s cup of tea (a polite way of saying “I don’t like it”) but once again this works for me and the car has been built to suit me not anyone else.  I wired the thing, I know each circuit and quite frankly I am proud to say it is bullet proof.  I blew a fuse one time, but that was my dumbass-self making a mistake.  Again, one can source a ready made wiring harness but what do you learn by doing that?  I spent a lot of time learning about circuits and how relays, fuses and circuit breakers work.  This takes time but the result is very rewarding.

If you do decide to undertake something like this, there are a few things I would highly recommend:

  • Every single terminal (and there are many) is soldered – nothing just crimped.  This is extremely time consuming but worth every moment you spend on it.  Soldering ensures a perfect connection and if you are going to spend this much time, you want it to be dead-nuts-accurate.
  • I used the expensive shrink wrap that has the sticky stuff inside of it on every joint, every terminal and every splice.  Why?  This makes the connection water and moisture proof.
  • Anytime I had to join parts of the harness, I used Weather Pack connectors.  They are not cheap, take a long time to crimp and assemble but they are water and moisture proof and last forever.  This is the only way to go.  By doing the harness this way you can ensure certain parts can be take apart without removing the whole shebang.  There is a bit of strategy to play here but you will be very happy with the result.
  • I spent quite a bit of resources on only the best quality wire.  All my wire came from an industrial supplier, not from a home-improvement store.  This is industrial strength. The real-deal.  I did this the first time with the V6 and it lasted flawlessly for 5 years.  This time around I expect it to last much longer since we are braking ground instead of switching hard voltage.
  • Relays – buy only the best (mine are Bosch) and don’t be stingy.  Relays are the way to go.  Once you get the basic principle of how they work they are fantastic.  This folks, is not rocket science and is not black magic.  Relays work and if you do it right, they last forever.
  • Use the proper tools.  I say again:  use the proper tools  I used good quality nippers, soldering gun, heat gun and crimping pliers.  The Weather Pack connectors require a special crimper.  Use the best you can afford.  Otherwise you will have crappy connectors and this will lead to electrical problems and the dreaded “Lucas Syndrome” where wiring turns into very expensive blue smoke.

I could write about this forever but then again, I would bore the hell out of you.  If you have any specific questions let me know and I can address them in a separate post.

Go do some wiring!  It is not as complicated as the harness “makers” make you believe it is…  :)

 

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