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Alan_Myers
04-30-2005, 09:38 PM
Hi all,

I just finished installing a new header and exhaust on my TR4 and thought I'd post some info about it.

After lots of shopping and comparison, I opted for a Falcon stainless steel header and sport exhaust system. I didn't want too large diameter robbing the car's low end performance and street manners, but wanted better than stock. The Falcon is roughly a 2" system, which seems right for my application, if only a modest increase from the 1-3/4" stock system. Primarily, it uses just one muffler, rather than the stock muffler/resonator arrangement, and the Falcon is a "full flow" muffler (Yeah, I know, there's really no such thing as "full flow").

A stainless steel header was necessary because full coverage (100%) header wrap will be used on this car to improve exhaust gas flow and reduce under-hood temps. (Note: A mild steel header won't hold up well wrapped and can only be wrapped about 75% coverage max. Any more will cause especially early damage due to the high temps trapped under the wrap. High temp "ceramic" coatings might be a better option with a mild steel header, but generally won't reduce under-hood temps as much as header wrap.)

TRF offers the Falcon stainless steel sport system and header, but had a sale on them in November or December and sold out pretty quickly. So the exhaust system was back-ordered for a few weeks, the header for almost four months. But, it all eventually arrived so that everything could be installed while the body is off the frame (Much, much easier!)

I think this header might be a new design for Falcon. In the past I've only seen illustrations of a 4-into-2-into-1, one-piece S/S header by Falcon, with a single tube intermediate pipe or collector used to join up with the rest of the exhaust system. But, what arrived is a 4-into-2, two-piece design, with a separate y-pipe collector/intermediate tube.

In other words, one piece of the header serves #1 and #4 cylinders, and a separate piece serves #2 and #3 cylinders. The four primary tubes are 1-1/2", collected into two 1-3/4" tubes that pass down in front of and under the TR's starter. A y-pipe collector slips on below and slightly behind the starter and ends in a 2" pipe, slightly curved to direct it over to the stock mounting point at the rear of the gearbox.

I like this two piece header design and construction seems excellent. The header's top flanges are heavy, equal to the thickness of the intake manifold, and designed to fit up to the TR 4 cylinder "high port" heads. (Unlike the old, mild steel header coming off the car, which has a much thinner flange and tack-welded on spacers to meet the TR's mounting tabs.)

Welding appears strong on the header and pipes, and both primary and secondary tube bends are nice and smooth, appear to be mandrel made to prevent any collapse of the tubing.

Some minor issues: The two inner header primary tubes (#2/#3) start their curve from the port just a little earlier than the outer ones. In my opinion these could make a slightly gentler transition, but this is being really nit-picky. And, a little filing was necessary on the two forward mounting holes of the outer header piece (#1/#4) to get it to bolt up snuggly without the use of a large rubber mallet. (Or, more importantly, make removeable without a large crowbar).

Starter clearance is fine on my car with a gear reduction starter installed. Judging by eye, a stock TR4 starter should fit fine, too, although it will be close to the angled, double tubes that run in front of it. The earlier TR3 bull-nose starter might present some clearance problems, but I can't really be sure because I don't have one to check. In any case, a starter heat shield might be a good idea, if header wrap isn't used.

I've got a 60 amp Delco alternator on this car now, so there is no clearance problem with the header there either. Judging by eye, the stock generator should fit as well. Again, it will be close and a generator/alternator heat shield might be a good plan, if headers aren't wrapped.

Some shielding for the nderside of the carbs/intake manifold is a good idea with unwrapped headers, too.

About the most serious header clearance issue I found is at the brake light switch, which on this earlier TR4 car is the pressure sensing type with bladed electrical terminals, that is screwed into the 5-way union, which in turn is fastened to the right/front frame rail. The pair of header tubes make the installation wider than the old, mild steel header (4-into-1, 3-1/2" collector). This runs the outer header pipe close to the frame rail and those brake pipe connections. I think I'll plug hole on the 5-way connector and change to the late TR4/TR4A type of brake light switch, mounted on the master cylinder bracket, to avoid any possible problems. By the way, when they were installed, I slipped some loose fitting heat shielding sleeves onto those brake lines running near the exhaust, just as a precaution.

Now a few fitting issues:

The dual "tails" from the headers were a bit long, forcing the y-pipe collector rearward so that it was tight against the frame rail and couldn't line up with the mounting bracket at the rear of the gearbox or the main pipe of the exhaust system. Simple solution was to cut 1-1/4" off the rear end of the header tube, to allow the y-pipe to slide a little further forward. Anyone doing this should measure very carefully how much can be removed and still leave plenty of length to fit the other end of the y-pipe into the stock mounting clamp at the rear of the gearbox. As fitted on this car, there is only about 1/4" now extending past that clamp.

Cutting the "tails" of the headers worked, to some extent. The bend in the y-pipe connector could have started slightly farther forward. On my car, it's still rubbing a little against the frame rail (but this frame has been modified and fully boxed in, so this might not be an issue with a stock C-shaped frame rail). Additionally, the y-pipe collector seems to have slightly too much bend in it, meaning it just barely meets up with the mounting clamp and main exhaust tube.

Also, it appears the twin down tubes of the header are slightly under-bent, meaning the y-pipe collector wants to route under the box in the middle of the cruciform frame, instead of through it as it is supposed to do. I used a jack positioned near the end of the y-pipe collector to gently encourage it up into place. That worked, but the main exhaust pipe is still a bit tricky to slide in, since it's not a precisely straight shot.

Due to the way the y-pipe collector meets up with the main exhaust tube, the pipe all the way to the rear is angled, including the muffler. Falcon stainless steel sport exhaust supplies a single, rear-mounted "free flow" muffler. It's about 24" long and 4" in diameter. At it's front, just behind the solid axle, the muffler is pretty well tucked up into the frame area, only hangs below by a half inch or so. However, at the rear, the muffler hangs pretty low, won't give a lot of ground clearance. A shorter muffler that fits better up within the frame rails and/or an oval design could have improved ground clearance a bit. Still, this setup does have a sporty, "retro" look.

The stainless tail pipe coming out of it is nice and long, and highly polished. The tail pipe is non-removable, permanently welded to the muffler.

As nicely bent as the header tubes are, the bends in the y-pipe collector and the long exhaust tubes were obviously not made with a mandrel and are a bit pinched on their inner radii. Maybe someday I'll replace or modify these items a little with better bends, plus do a little more tweaking for an overall better fit.

As it stands, this system needs to be installed from the front to the back. In other words, it would be impossible to, say, loosen and remove forward parts alone. Removing the headers means first taking off the muffler, main pipe and y-pipe collector, in that order. The tension throughout the system due to slight misalignments could make it all more secure, but might be a little inconvenient later when working on the car. With a bit of tweaking and additional fitting, it might be possible to slide and remove individual parts, without having to disassemble all of it.

There are no hangers or clamps provided with either the header or the exhaust system.

To make the system easier to disassmble later (a definite advantage of stainless over mild steel) I'd recommend using stainless t-bolts on the dual front pipe connection (1-3/4", Supertrapp or Five Star). The wide clamp of these will not crimp the pipes.

The stock 2" band clamp at the rear gearbox mount works fine with a little fitting (I'm referring to the TR4 version, I think the TR3 may be a bit different but don't have one to compare).


The exhaust system/muffler can use, just barely, the stock hanger at the side/rear axle mounting on the frame rail, if this mounting point is present on the car. This bracket is not found on all cars, seemed to be implemented on 2nd year TR4, approx. The stock hanger and clamp may not be ideal because the narrow bands of that clamp could indent the tubing making the joint hard to slip apart later. But it's unique to TRs and I haven't found a better solution. Just don't overtighten it and it might be possible to avoid crimping the pipes.

At the rear, use the stock type of hanger/clamp, or there is a tab welded jut behind the muffler that makes it possible to gain a little more ground clearance by fitting it with a short rubber strap that's bolted to the rear frame tube.

With the exception of the highly polished tail pipe and the slightly polished muffler, the entire system is "raw" stainless steel. Some of the tubing labels are still imprinted along them, where welding heat didn't burn it off. If desired, tubing and weld finish can be cleaned up a little. Some non-metallic 3M #000 artificial steel wool quickly removed the label ink, cleaned up around some welds and put a bit of a satin finsh on the tubes. A high polish could be done on the whole system, I'm sure, if someone really wanted to go to that trouble and extent!

I hope this helps someone who is shopping for a TR3/4 exhaust system. Overall I'm very pleased with the Falcon stainless steel header and sport exhaust system. I'll try to update with road test impressions, once the car is running and back on the streets.

Cheers!

Alan

05-01-2005, 12:21 AM
Alan, I just finished installing the Falcon stainless headers and sport exhaust on my TR6. My headers are also a two-piece system 1-2-3 and 4-5-6. I am running the true duals. The large, oval mufflers that came with the Falcon system are a real pain to mount under the 6 as they hang a lot lower than any other exhaust system, including the Monzas. There was absolutely no room for me to suspend the back half of the sport exhaust for it to have room to expand and vibrate so I had to rigid mount the entire rear of the exhaust, including the mufflers. This, of course, will not work with engine movement so I had 12" flex pipes made to fit between the header and the rest of the system. This works extremely well. The mufflers are mounted at their highest level (I have already flattened them even more going over bumps) with some extra bracing I added across the frame rails. The biggest point that I want to make is I used wide ss band clamps to hold the parts together (got them from Stainless Specialties in Fla.), 2" diameter variety. They torque down to their tightest level without crimping the pipes, allow zero rotation or movement and allow disassembly without having compressed the pipes at all. I looked everywhere for a clamp that would do no harm and luckily found these. I, too, had to modify two of the nuts holding the header flanges on to the head studs by rounding out a few corners, but the fit of the flange was excellent, using a thicker gasket helped.


Bill