I'm thinking about replacing the exhaust system in my 55 Tbird and am looking for some advice.  Currently, I have stock 57 iron exhaust manifolds with NPD pipes and mufflers existing through the bumpers.  The diameter of the NPD pipes is small, probably 1 3/4".    The entire system is made up of a number of slip together sections. The pipes rattle and pop as they heat up and cool off.

What I would like are a quality set of headers and a custom made fully welded exhaust system with a crossover pipe. It would be great if the pipes could exit through the bumpers.  My question is, what diameter pipes can I use and still get them to fit through the frame and the bumpers?  If the bumpers are the problem, I could live with dummy exhaust tubes.  Advice?

The exhaust system on the mid-Fifties Fords with the real ‘Police’ engine option was 2”.  That would be a good starting point.  Personally I would go as big as the undercarriage would permit with 2½” being the limit.  I have a full 3” exhaust system on my ’66 Fairlane with a streetable but stout 390 and it’s happy with that.  That car also has 2 1/8” tube headers with 3½” collectors so the 3” exhaust system compliments that.  It was initially dyno tested with several different pipe sizes and as the pipes became longer, the sizing of the exhaust system had to increase accordingly.
 
I have found no performance benefit on the Y in using a H or X pipe in the exhaust system.  Putting an H or X pipe on the Y tends to kill its distinctive exhaust note while also making any transmission or clutch work more difficult.

Lorena, Texas (South of Waco)

I hear you on the X pipe.  Servicing my O/D transmission is bad enough without it.  FPA headers look to be the best tube headers.   I'm not racing my TBird. It's current performance is fine.  Nothing wrong with more power.  I'm wondering if headers are worth the price on a street YBlock or should I keep the 57 iron manifolds? 

From an under the hood stand point, the cast iron manifolds will be quieter.  On the flip side of this, the performance level does jump up significantly with the FPA headers if the exhaust system is upgraded accordingly.

Lorena, Texas (South of Waco)

Ted. Thanks for the input.  I know it's hard for you to answer this question, but here goes.  As you know, my 292 is mildly modified with 57 parts and a mild Isky cam.  If I ditch my iron manifolds for FPA tube headers and build a new 2" exhaust system, how much of a power increase could I expect?  Would keeping the iron manifolds with the new 2" exhaust make much difference?  FPA headers are about $700 plus freight.  In your opinion, will I get my money's worth?

Florida_phil.  Forum member Oldmics has a set of FPA headers on his '56 'Bird.  Hopefully, John will have some feedback for you on his experience with them.  Vic Correnti also has a set of FPA headers on his white '55, too.

While Ted's observation that use of an H or X exhaust pipe would obstruct access to your o/d transmission or clutch seemed to resonate with you, I think that Ted's other observation was equally significant.  You may be be more disappointed by how the H or X pipe would eliminate the unique and distinctive y-block exhaust sound your 'Bird presently exhibits.  From a performance standpoint, my recollection of Ted's shared exhaust header tests showed that the historically touted use of H or X pipes in an exhaust system proved to be statistically insignificant in y-block horsepower and torque curve results.

My recollection is that Vic Correnti shared info about the exhaust system pipe size, shape, and mandrel bending used on his '55 in a previous Forum thread you participated in.  You may want to re-visit that archive entry.

Hope this helps.  


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

I believe this discussion is relevant to many forum members.  Dyno results can not always be felt by a driver.   Everything is a compromise.  Adding multiple carburetors is a good example.  I have experimented with trips and dual quads, both had positives and negatives. After spending about $3,000 to find out, I am satisfied that a single four barrel is the best option for me.  

Our cars are set up differently, we drive them differently and our expectations are different.  I suppose the only way to answer my question definitively would be to have a side by side before and after drag strip comparison.   Since this most likely will not happen, We must rely on input from individual members.  My major complaint with my current exhaust system is the noise and rattles coming from the multiple slip tube connections.  If I am going to replace the entire system, I might as well upgrade the diameter of the pipes.   I'm not sure adding $700 headers would do much for me driving around town.

Sanderson headers with 2,25 inch pipes on my 'Bird, Magnaflow mufflers.  I'm happy with the performance and the sound.  2.25 is also as large as you'll get through the original outlets. 

Don

I would not order the uncoated headers, especially for Florida.  The ceramic coated FPA's for the '55 Thunderbird are over $1200.00 with the kit for steady rest.  I have two sets, and they make great power, look beautiful.  The ceramic coating will help with heat reduction in the engine compartment and last much longer.   Joe-JDC

JDC

$1,200 for the kit alone?   Add in another $600 or so for the mufflers and custom pipes.  That's a serious chunk of change for a little more HP..  That answers my question.   Thanks.