Tag Archives: TR4

Details About an ECOTEC Powered TR4

After the success we had with bowtie6, my cousin Jim and I had many conversations on improving the concept.  I remember countless hours of discussions next to the space heater in Jim’s well equipped shop several winters ago.  We quickly zeroed-in on the engine:  the Ecotec as fitted to the Pontiac Solstice mated to the Aisin 5 speed gearbox would supply a powerful and reliable drive-train.  It would also offer a PCM that we could tweak with a laptop.  We also decided a Triumph or MG would be a good platform for the Ecotec.  Finally, we would subscribe to the ideas that Anthony Colin Bruce Chapman based his designs upon:  keep wight at a minimum.

Eventually, we got word there was a local fellow with several cars in his basement that had to be sold  Needless to say, Jim and I quickly grabbed our gloves and jumped in the shop-truck and headed out to this fellow’s basement.  Sure enough.  We found a 1964 TR4 as well as a Datsun 2000 roadster.  The Datsun was our first choice since it is the more “exotic” of the pair however it was missing entirely too many parts.  Jim decided the TR4 would be the best choice.  A few days later we arrived with a trailer and brought the TR4 home.

I could write about all this for hours but I think you want to see pictures and not a bunch of words, so let me fast forward to the present and show you what Jim’s TR4 looks like today.  Unfortunately I cannot cover the entire car in one article; I’ll break this up into several.  Today, I’ll start with the outside.  After all, beauty can’t be only skin deep, right?

As you can see in the picture above, the nose of this TR4 incorporates many subtle changes.  For starters, the turn signals are gone.  They are now hidden behind that hand-made aluminum grill.  The front bumper is also gone and the oval air inlets below the grill have stainless mesh behind them.  Finally there is a hand formed “air dam” with two “nerf” bars on the roll pan.  Jim likes his “nerf” bars – Steve if you are reading this, I am sure you will agree with me.  🙂

The picture above shows the new bonnet.  When I mean “new”, I mean this piece was formed entirely from aluminum.  If you look closely, you will see the “bulge” is missing – I guess it is a matter of choice but this is the way Jim decided to build the bonnet.  The trick to making this bonnet was piecing together several sections.  They were all carefully formed on the English wheel and TIG welded together.  The following gallery shows what the back of the bonnet looks like.

But… Before you start clicking on all these pictures take a look at the first one of the set.  There is a small recess, wide enough for two fingers to be used to lift the bonnet once the latch is released.  Pretty cool, huh?

Next you can see the backbone of the bonnet.  This backbone is also made from aluminum and is not welded, instead it has been bonded to the backside of the bonnet with automotive epoxy glue.  Finally, take a look at the third picture.  If you look close enough, you can see some of the hammer marks left from when Jim formed the headlight bulges.  Yes, all this was carefully welded and shaped just like it in the glory days of hand formed bodies.

The next gallery shown above, displays the hard top Jim made for the TR4.  This top is entirely made of aluminum and just like the bonnet, is extremely lightweight.  Again, many pieces formed by hand and on the English wheel, TIG welded and carefully finished.  If you look at the surface of the top (see second picture) you will see ridges formed by Jim’s Pullmax machine.  These ridges are there to add strength and to prevent the top from oil-canning.  Finally, to keep weight down Jim used thin Plexiglass in the windows instead of glass.  Oh and the side windows open; Jim made special hinges to allow the side windows to pivot.  The following collection of pictures shows what the top looks like from the back and from the sides.

The back third of the top has a small taper.  It is also formed in such a way to give the rear glass a curved look.  At first, one would think this would hinder visibility but the seats are very low in this car, and outward visibility is excellent.  I think it looks very cool!

Finally is this picture from the back of the car.  The bonnet is also different from stock.  Yep, you guessed it.  It is also formed from aluminum.  Jim made a similar backbone frame for it and it is extremely lightweight.  As if that were not enough, take a look at the rear bumper.  This one is not as wide as the ones Jim made for bowtie6, but is just as lightweight.  This bumper also is different from mine in that it’s finish is made by simply wiping it with ScotchBrite.  This gives the aluminum a muted, matte finish.

I hope you have found this interesting.  I’ll have more about Jim’s TR4 in future articles, so stay tuned!  😉

Triumph TR4 Surrey Top – modified

Well – here’s a new one for you…

There is the concept of a Surrey top for a TR4/250.  OK – they are nice but they are hard to find.  They have glass and they are heavy.  They do offer a removable centre section and yes, they are pretty cool.  But here is a variation on the theme…

My cousin Jim’s TR4 has been an awesome car so far.  The ECOTEC has been magnificent providing plenty of power and lots of fun.  However summer is upon us and it gets a little hot to go topless the whole time.  What to do?  Order a canvas top and look like any other TR4?  Nah.  How about this:

Jim’s TR4 has a rollbar bolted to the bespoke frame on special mounts.  Off the hoop, there are two tabs offering a way to mount the hand-made aluminium “bikini top” shown on the picture at left.  The three “ribs” have been formed on a Pullmax machine.  All total this top is not heavy at all, maybe a couple of pounds.  Not exactly “stock” or “original”, but what the hell.  Jim is a master craftsman and this car is indeed unique.

Here is another shot of the new top.  It shows the mounts on the rollbar.  The front attaches to the factory mounts on the windshield frame.  Two bolts will hold that in place.  Jim has made this in such a way that the side glass can be rolled up and it will be perfectly aligned with the edge of the new “top” – and by doing so, the car could be driven with light drizzle and this would prevent one from getting soaked.  This is the inspiration to the new “top”.  Granted, this is not everyone’s cup of tea but what the hell.  It certainly looks trick!

I realize the top looks a little “crude” – it was only made today and has not been totally finished yet.  We were kicking around the idea of fully polishing this top – after all it is aluminium.  The idea would be to make it as shiny as chrome.  Then again, it might just get painted either body colour or some other contrasting shade.  We were also kicking around the idea of covering it with some convertible top canvas to give it a faux look.  One thing we can be certain of:  take a look at the following picture:

Check out the little tab…  That is a small proof-of-concept:  yes, the top is going to have a mild NASCAR “wing” on it.  This will not only look good, it will provide some downforce at high sped.  And believe me:  the TR4 needs it.  With the extra pop of the ECOTEC, the car certainly can use a few free pounds of downforce.  After all, all the pressure would be transmitted to the rollbar, mounted directly to the frame right above the rear axle…  Pretty cool, huh?

Engine Fitment in the TR4

A fact has been brought to my attention:  “Amazing that in the TR link, with all the hype about the engine, there is not a single pic of the engine in the car!”.  My bad.  Time to make amends; time to really document the engine in the car.  Some facts:

  • The engine is a 2.4 litre VVT ECOTEC from a Pontiac Solstice
  • The transmission is a five speed AISIN also from a Pontiac Solstice
  • The wiring harness has been lifted from the Solstice and modified.  It has been vastly simplified.  How?  RTFM.  Seriously, all the info is available in the Factory Service Manuals – trick is finding it.  😉
  • The ECM has been reflashed in order to disable VATS.
  • This ECM is fully programmable – in this case we have HPTuners on a laptop.  Right now, we are running the stock configuration – hopefully soon we will spend some quality time on a dyno and then tweak the thing.
  • The stock plastic intake has been replaced.  The intake you see in the pictures was all hand made from aluminium and welded to a flange in order to make the runners match the intake ports.  This is done for a reason:  the original plastic intake does not give enough room for the steering column in a TR4.
  • The stock throttle body with its fly-by-wire controls has been retained.
  • The exhaust manifold has been discarded.  Like the intake manifold, the header is all hand made from stainless.  This is also welded to a special flange in order to match the ports on the engine block.


As stated above, the throttle remains fly-by-wire.  There is nothing ‘weird’ about this.  Actually it is extremely fast and the throttle body reacts to small inputs as well as full throttle acceleration (done that many times).  Matter of fact, my wife’s HHR (it has a 2.4 Ecotec as well) has the same fly-by-wire setup and it is very responsive.  I have no problems running this furthermore this is the way more and more modern cars operate.

The intake and exhaust manifolds have been altered and this is done for a reason:  the body needed to remain intact.  There has been some work done to the tunnel though.  A new transmission cover has been made as well as the driveshaft cover between the seats.  I don’t have a way to show that since the TR4 is assembled now.  However when I put bowtie6 back together once his ECOTEC is in place, I’ll have better pictures to show of how that all fits.

If you have questions and/or comments, please make an entry here – I’ll try to answer back!  Keyword here is:  dialogue!  🙂

What is an ECOTEC Powered TR4 Like?

In my post the other day about the ECOTEC TR4, I mentioned a video.  Got one to share – it is short and wobbly, but you’ll get the idea.  Now, before we get started keep in mind a few things:

  • Note how quiet the TR4 is.  Video was made with the windows up and the aluminium hardtop in place.
  • The engine has a redline of about 6500 revs.  You can hear the engine spool up and the powerband is indeed very sweet!
  • Some sorting out of the rear springs has to be made.  The car is a little bouncy.  The front is dead on, but a new set of rear springs has been ordered that will certainly make things even nicer
  • The ECOTEC has a handmade header.  It dumps into a 2.5″ pipe attached to a single baffled muffler and at the end a special made adapter with Supertrapp discs.  The Supertrapps really are nice and enable fine tuning of how much exhaust noise you want.  I think this one is spot on.

Well take a look…

I made this video with my iPhone4; it is not exactly great but you get the idea.  Hopefully I’ll post a better video in the next few days.

Hope you found this interesting.  The ECOTEC is indeed a very viable and excellent performing engine.  You have comments?  Questions?  Sure would like to hear from you, just fill in the “Comment” box below.

Riding and Driving the ECOTEC TR4

We have been riding and driving the ECOTEC TR4 on the road and it is quite simply amazing!

Today, I had a chance to finally ride and drive it.  As with every project it will need some debugging, adjusting and fine tuning but out of the box I can tell you it is one awesome ride.  Quite frankly, I can’t wait to get the 4 mile crate ECOTEC in bowtie6.

So what is it like?  The powerband on the ECOTEC is quite impressive.  Add to that a very lightweight body and you got yourself a very nimble sports car.  The 2.4 litre version is the way to go – the extra torque over the 2.2 is very pronounced and the extra hp’s are very welcome too.  The gearbox is quite amazing.  This is an Aisin five speed and it shifts very quick – the gear spacing will take some getting used to.  Another thing that will take some getting used to will be the clutch.  It travels very little before it engages.  It is not bad, just different.

The ECOTEC is fly by wire.  This means the gas pedal is not connected directly to the butterfly in the throttle body via cable.  Instead, the pedal is wired to the ECM and then the ECM tells the throttle body how much to open or close.  This is the exact same setup in my wife’s Chevy HHR.  This is very nice indeed!

I know all these words mean nothing unless they are backed up with a video.  No.  I don’t have one today, but maybe next weekend if the weather cooperates I’ll be able to make one and post it here.  So stay tuned…

Folks, the days of the 3.4 V6 as an option in British cars are over.  I can’t explain how awesome this four cylinder engine really is.  This engine revs to about 3500RPM’s very tamely.  The fun really begins around 4000RPM’s when the variable valve timing kicks in.  From there up to about 6500 (where the rev limiter jumps in) is just awesome – it really pushes you back in the seat.  Of course, the rev limiter will be coming out as soon as we can hook up a laptop and make a few ‘adjustments’.  That will be fun!