4 replies to this topic

[dotnose2]

I have recently bought a superflow ST400 from mini sport as my existing exhaust has a hole in it, my problem is when i removed it today ive noticed i dont have a cat converter fitted and instead its a straight black pipe about 18" long, i had a look on mini sport and seen it listed as a de cat pipe to replace the cat converter. the rear end on the pipe has a flat flange and the new exhaust has the same shape plate but in front of it is about 1/4" of the pipe slightly wider preventing the plate going to the end, do i just line the plate and holes up and tighten up the bolts or is this the wrong pipe and should there be a recess for it to sit in?

sorry about the essay!
thanks

[SMP]

I've had exactly the same problem but on a different exhaust. The parts that you have will not fit together properly and will probably not seal.

The problem is the joints on the later catalytic systems are cup and cone (the cone is on the front end of the ST400 pipe). It seems the early cats and decat pipes have flat faces so there is no cup for the cone to mate with.

If you know somebody who is any good at welding what you can get them to do is to weld the pipe into the two bolt flange on the St400 and then grind the cone away to leave a flate surface to mate with the decat pipe. You will need to use a metal deformable gasket to seal the joint.

This is what I did - it worked very well - but I have all the equipment and experience to do it myself. So far I have not come across a decat pipe with the proper recess (cup) on the sealing face.

Cheers
Steve

[dotnose2]

Thanks for your reply mate, I don't really know of anyone who can help me out here.. I there a de cat pipe avalibe that will fit my type of exhaust? Looked on mini sport but there's no detail like that on there de cat pipes.

[SMP]

Best bet is to ring minisport and see if they have a decat pipe that will definitely mate with the exhaust that you have. You will have to explain the problem to them in quite a bit of detail - when I had this problem and rang my supplier it took a while before they knew what they I was going on about.

You could try ringing a few other suppliers to see if they have a suitable decat pipe.

Cheers
Steve

[dotnose2]

Rang mini sport today, the guy knew straight away what I ment and said the two they sell are the same as what I already have. He told me that all I need to do it grin the inside to a slight bevel so In will sit in a little
Bit and with a gasket should be sound. I'll give it ago as I've got nothing to loose, if it dosnt work I'll ring around see if I can find one