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Triumph TR6 - Exhaust Headers - Questions
|I like my TR - it's plenty fast. Of course, I'd like to be even faster when pressed. It currently has the stock dual manifold ('73) with ANSA exhaust. I'm wondering if a dual header set-up with the same exhaust will yield a significant performance boost. What does the group have to say about this?|
|Tried on my 72.years ago. No noticable diff. Mine were not coated so increased engine bay temp. and caused carb and intake heat problems. Very close to each other in there.|
|I have run headers on a TR6 and went back to using the dual outlet cast manifold. Here are the things to consider if you are going to run headers on a street car:|
1) They are almost never a direct bolt on, you have to grind/fiddle/fit the things. Port matching will have to be done or it is definitely a wasted effort to install headers. On a triple DCOE intake manifold, you not only have to fiddle with the headers, you have to grind a pretty good size flat on a couple of the manifold runners to clear the factory pattern headers. There may be a clearance problem on cars with triple CD175 set ups, don't know for sure, have no experience with those.
2) Unless either wrapped or flame sprayed, they put alot of heat into the engine compartment. Think about that all that heat right below those ground flats on that DCOE manifold.
3) There is very little clearance between the frame rail and the header. Just a little bit of motor mount collapse and the header goes right into the rail. The result, a broken header that now has to be repaired or replaced. If you had it flame sprayed, the coating has to ground away before you can even think about making a weld repair. If wrapped, you have to strip the wrap and then rewrap when finished.
4) Mild steel headers will not last long, especially when wrapped. Stainless steel headers are a bring money item and are still fragile, but at least won't rust away before your very eyes.
5) Worst of all for all this trouble, they only make a small difference in power output at best. I know one person that runs in SCCA ITS and found they actually made more power (dyno verified) on their car with a cleaned up stock manifold than with cleaned up set of headers. Car is not a TR in this particular case.
"Having been there, done that a couple of times before the lesson sunk in," I am just not too keen on the idea of headers for street driven street cars in general and especially on the TR5/250/6. My recommendation, stick with that dual outlet manifold. If you want to run a larger diameter single pipe, have one the dual manifold set up downpipes modified into a 2 into 1 collector to match the larger diameter single pipe. For those with early carb TR6s and TR250s, the later dual pipe manifold will fit those cars as the exhaust port spacing is the same across the board on these cars, it is the inlet port spacing that is different. Just a little something to keep in mind.
|Steve--Your points are well worth considering. For the average Joe, the problems you point out are ample proof that headers aren't worth the bother. If you want to kick the stock manifold up a notch, you could polish the runner interior surfaces using an extruded abrasive process (http://www.extrudehone.com).|
|Thanks, Bill & Steve. I had read/heard soon after I got the car 12 years ago that the stock dual exhaust manifold was really pretty good when teamed with a "free flow" exhaust. That's why it's still on there. Better to hear it from someone that's actually tried things out, though.|
Rick - I had some industrial experience with Extrudehone even befoe I got the TR6. Unless things have changed (the $$ list on the site didn't show any $$) it would be at least $300 to do the exhaust - probably more. Neat process, though!
This thread was discussed on 05/11/2003
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