Conference oass::racers

    Does anyone here know of a place with a mendrel bender?  Somewhere near
    Nashua, NH would be great but it looks like I may have to go some
    distance for this.

    I need to have some custom exahust pipes made to mount a pair of
    Super-trapps to my 86 RX-7.

    Any comment on Super-trapp?  I am considering the CD (concealed disc)
    model.  The car is used as my daily driver and some Solo I type time
    trials, but I am planning on turning it into an ITS car for next year.

    -=Chong=-

    	What we usta do was to buy pipe and various bends from JC Whitney
    and weld them together to make a system.  I'm not sure that a long tube
    can be mandrel bent.  I think that the mandrel implies an internal
    support to keep the tube from collapsing.  The internal support would
    have to be inserted from one end or the other to do this.  Another
    possibility is to stuff the pipe full of sand and plug the ends and
    then bend it on a conventional bender.  It won't be perfect, but if you
    really ram the sand in tight it shouldn't kink or collapse too much.
    	If you want to buy the stuff from JC, you can bring it out to my
    place and learn yourself to weld.  You also might be able to find a
    shop that will do it for you either with or without you supplying the
    bends.  
                                         John

    >If you want to buy the stuff from JC, you can bring it out to my place
    >and learn yourself to weld.

    Thanks, John, I will probably take up your offer.  I had always wanted
    to learn welding anyway.

    I will have to see what pieces I need.

    -=Chong=-

    re. John,
    
    HEHEHEHEHEHEHEHEHE!!!!
    
    The Mad Weldor....Jim

    Re .4
    
    Are you trying to tell/warn me something, Jim?  :-)
    
    -=Chong=-

    	I didn't say I was going to do any teaching, I said he'd learn
    himself.   (not that it's hard, I'm self taught (as far as it goes),
    and I think that TMW is also.)
    					John
    

    No Chong,
    John will set you up just fine for welding you exhaust system. Then
    ,like he said, he'll sit back and watch you.
    
    The Mad Weldor....Jim
    
    btw Are the Supertraps really that good? I think they look like 
    motorcycle mufflers that someone desided to stick on a car.

    >Are the Supertraps really that good?
    
    I am considering Supertraps because it allows me to tune it to anywhere
    between street legal to completely open, by just adding or removing
    plates, which takes just a few minutes.
    
    A decision I have to make now is the pipe size.  The catalytic
    converter outlet is 2.5".  It then split up into two branches of 1.75"
    each.  I need the section between the cat and the two Supertraps.  The
    best and easiest way is to go 2.5" throughout, but 2.5" is awfully big,
    and will take away some undercar clearance.  I think 2.25" pipes will
    be sufficient, but what about 2"?  I can't go dual pipe completely
    because the rules disallow it.
    
    This is a stock 86 RX-7, which may become an ITS car next year.
    
    -=Chong=-

    	Go with the 2.5".  If you hit the stuff will flatten out, but not
    enough to reduce the cross section significantly.  If you tuck it right
    up against the floor with some sort of heat shield, it shouldn't bother
    clearance too much.  If you are actually planning on turning the car
    into a real race car that really might get crashed, you might consider
    bludgeoning the floor pan to make a little more room.
    						John
    

I agree with John, go 2.5" all the way back.  If you tuck it partly
into your center hump you can probably improve your clearance a bit.

As far as Supertrapps go, I've never been impressed by them.  Though
they are adjustable in terms of back pressure, I've heard that they
don't flow very well for the amount of noise you end up making.  That
is, to stay within legal dB limits you may have to accept more back
pressure than another, quieter muffler could provide.  I have no first-
hand experience, however.

I also find their sound quite unappealing.  On a rotary engine car, they
produce a raspy staccato noise that sounds like a chainsaw at best.  You
may feel differently.

Plus they're butt ugly, but you know what a stickler I am for aesthetics! :-)

Carl

    >I've heard that they don't flow very well for the amount of noise you
    >end up making.
    
    Yeah, I have heard that too.  I heard the Borla XR racing mufflers are
    much better.  I think SuperTrapps suit me better right now because I am
    still driving my car on the street.
    
    >Plus they're butt ugly
    
    The new CD (Concealed Discs) series has the discs...concealed so it
    looks like a hugh tail pipe.
    
    -=Chong=-