Category Archives: Bespoke Frame

New custom built Triumph TR6 frame

bowtie6‘s Frame Failure – Revisited –

I have a few pictures with the rear section of the original frame on bowtie6. This frame was as about as pristine as could be found when I bought my car several years ago. There were gussets made and welded onto the frame, as well as reinforcement plates. Every weld on the frame was gone through and reinforced. Yet with all this work, after some 15,000 miles the frame failed.

The following pictures show the seam that failed. Granted the rear is far from stock, but this goes to show that you can weld on the original flimsy frame but this does not guarantee it will survive. The original frame might be OK for the anemic tractor engine that powers “original” TR6’s, but if you are going to put some real horsepower (and torque) in front of a TR6 then you might want to rethink if the frame will hold up or not. In my case, sadly the frame gave up the ghost.

The picture above shows the Nissan R200 “long-nose” differential we used. This diff came from a 280ZX and worked very well – however, it was quite heavy and did not have posi-traction. The ratio was quite nice – actually a 3.90 to 1 – and this was the reason we chose the 3.80 to 1 for the solid axle currently being installed. The picture above does not show the coilovers however, that can be found on my “old” website. The failure happened on the left side (the passneger’s side) and the following picture shows more about it…

In the above picture you see the crack on the tower that supported the coilovers. Here is another shot:

As you can see, the top section of the frame “lifted” off the rest of the beam.

Finally the above picture shows what the rear of bowtie6 looked like. The diff is in the centre, with the custom made halfshafts. The Nissan diff is held in place by the two bridges, the dual exhausts can be seen as well as the rear sway bar. This was a nice setup and would still be in place except for the crapy Triumph TR6 frame giving away…

Seriously folks. No joking aside. I spent a considerable amount of resources on this “original” frame with the work we did to it. Yet, it failed. No, I did not abuse my car but I did get down on it in such a way that I could enjoy the upgrades. For anyone remotely thinking about doing an engine swap using the original frame: think and double-think what it is you want to do.

The original diff will never hold up. Eventually after you put enough miles on it, it will fail. Ditto for the frame. Once again, the section that failed might have not been “original”, but we had a pristine frame to begin with. I hope these article and pictures are of value for you.

Final Pics of the New TR6 Frame

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Here is a final set of pictures of the new frame serving as bowtie6’s backbone. The body has now been permanently bolted on, so this is the last set…

Some misconceptions have surfaced as to the origin of this frame. Suffice to say this is NOT (repeat, IT IS NOT) a RATCO frame. Those folks produce a nice aftermarket frame but this one is all bespoke and designed for the ECOTEC and the solid rear axle specifically.

Why so many entries on this blog about the frame? Well, simply put: I am very proud of it. My cousin Jim Thompson has put together a very clever, lightweight and strong frame using modern frame-building techniques and materials while being able to retain some of the original TR6 bits.

The front suspension is almost all stock TR6. The “A” arms, ball joins, steering rack, sway bar, trunions, hubs and rotors are all stock Triumph. The calipers are Wilwood. The springs/shocks have been replaced with coilovers. The coilovers offer several advantages: no spring compressors, spring interchangeability and the ability to control ride height. However, they are not cheap but worth every penny.

The rear is all new and it is trick! The axle is an 8” Ford, custom sized. It was cut on both sides and custom cut axles have been sourced from Moser. The gears are from Motive; posi-traction (of course) with a 3.80 to 1 ratio. Disc rotors and calipers are used on the rear end (with full emergency brake capability using the original TR6 cables and lever), as well as matching coilovers. There is a four point suspension holding the axle in place with Heim ends on all four control arms. We tried polyurethane ends, but they did not survive the power from the ECOTEC. Enter the Heim ends. Again, only the best have been purchased. These are precision ground steel (normally used on sprint cars) along with special boots to keep debris out. Brake and fuel lines are all hand made, hand fitted and hand formed from stainless tubing; with teflon lined, braided lines going to all four calipers. Again, only the best has been sourced.

This is the second frame built using this design. The first frame is under Jim’s TR4 and it has proven to be astounding. It is very stiff – gone is the ‘flex’ that the original frame exhibits. The new frame is made from much stronger square tubing. This tubing is a solid square, not a “U” channel with a cap spot-welded as in the original design from Triumph. I repeat, this is very strong stuff.

Finally, the ECOTEC 2.4 litre engine sits on special plates (on the frame side) that allow the use of the original Solstice engine mounts as well as tranny mount. The mounts are really nice because they are made with rubber to help isolate vibrations. Furthermore, the GM mounts have a locking mechanism that if the rubber ever fails the engine will only rock a very small distance and the locks keep it from making undesirable and expensive damage.

Finally some thoughts:

I realize this frame has nothing in common with the ‘original’ frame. My condolence to the purists – but the idea is performance and this frame works and works very well.
I’ve read where folks discuss the shortcomings of the AISIN gearbox and say the gearing is all wrong. Depends what you want to do: bowtie6 is not built as a drag car. Yes, first gear is a bit tall and that might not sit well with folks. I don’t mind it. From the experience gained from my prior setup and my cousin’s TR4, the car excels like a dream in second, third and fourth. These three gears are quite simply awesome. What about fifth? Well, suffice to say that at speed and in fifth gear all you have to do is punch it and the car will take off.
The last thing about the new frame has come as a bit of a surprise to me. In my cousin’s TR4 the steering “effort” has been reduced significantly. The “far-back” engine placement has something to do with this. But there is also the extra pressure of the original spring pushing on the “A” arms that has been deleted. The new “feel” is much more positive, lightning-quick and a delight to use at parking-lot-speeds.

Here is the final picture gallery of the frame prior to the body being permanently installed.

bowtie6‘s New Frame – Check It!

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The new custom frame is done.

After much anticipation, the new custom frame is finished. It has taken a lot of work by my cousin Jim and I could not be happier. There are plenty of pictures – they are at the bottom of today’s entry in a gallery, but first here is what we have:

The frame looks different from the original setup. This was done for several reasons, but mainly for strength. The next was the ability to mount the rear solid axle. One of the main concerns I always had in the back of my mind was whether the hubs/halfshafts would fail. This time, the new axle will handle all the power on tap with no reservations. This time, the diff is posi-traction with a 3.80 to 1 ratio.

The rear calipers I had on the old frame have been adapted to work with the new axle. As you will see, the front calipers are the same Wilwood’s from the original build. The original mounts were retained. All brake lines going to the calipers are the ones used in the past build – braided teflon lined. And, there is also a picture below showing the location of the Wilwood proportioning valve. All brake lines have been scratch made from stainless tubing fitted by hand. They look killer!

Coilovers have been used on all four corners. This part took a bit of research and the spring rates took some careful consideration. These are the same settings used on my cousin Jim’s TR4. Not only do they look awesome but they perform equally well. They are quite pricey but just the fact there will not be any more spring compressors involved makes it worth the trouble.

The ECOTEC 2.4 engine is now mounted using the original Solstice mounts. Special pads were made to go on the frame and this is where the mounts anchor. Ditto for the transmission mount. This is all done with a very specific purpose: to make room for the exhaust and have nothing ‘hanging’ below the frame.

There is a ton of more subtle details – I am sure you will find them. If you have any questions/comments drop me a line. Here is the new frame gallery. Enjoy!