Home Made Down Pipe
Jerry Turner - jfturner@cswnet.com
Introduction
For those of you who like to do things yourself or can't afford one of the "custom" built downpipes, can possibly do what I've done-I made my own version....I call it a JTDP :->)

Folks, I sure by now that you know I don't have the gift of gab (can't explain myself to well) so I've attached a picture of the final product in hopes that the adage "a picture is worth a thousand words" will apply in helping those that wants to try this "at home" modification.

The final results is a much quicker turbo spool up and the exhaust noise is considerably quiter, and above all the satisfaction that it works well and you did it yourself saving a BUNCH of money.
What Parts Do I Need?
I used a three inch mandrel bent 90 degree elbow (NAPA) and the stock turbo elbow (86-7 TR). Both the stock turbo elbow and the 90 degree elbow pipe will have to be modified in order to make it all have a smooth transistation from the turbo into the downpipe. If you perfer the same thing could be done using a 2.5" pipe and would be much-much eaiser to do.

One note-I had a 3" mandrel bent downpipe that I've had on the car for sometime BUT it had the same hookup to the turbo elbow as the stock unit does.
Procedure
Here is the way I did it:
  • Jack up the car and remove the right tire/wheel so access to the downpipe can be gained in order to cut if off.
  • I cut the downpipe off as far back as I could reach with my reciprocating saw at back of the inner fenderwell opening.
  • Make cuts to the turbo elbow that leaves only the bolt flange portion of the elbow AND the "bulge" that covers the wastegate flap/puck.
  • Grind out the flange and the "bluge" (do this a little at a time, checking for fit) until the end of the 3" 90 degree pipe fits (tight) inside the stock elbow flange.
  • Bolt the modified turbo elbow back onto the turbine housing and start making cuts to the 90 degree pipe (do this a little at a time) until the other end of the 90 degree elbow pipe comes into line with the cut off end of the downpipe.
  • Mark both the modified elbow and the 90 degree pipe elbow, remove and take to the weldor for welding.
  • To simplify the final hookup to the remaining downpipe (where cut was made) and the end of the new downpipe from the turbo, I use a short piece of 3" flex pipe welding it on to the end of the opposite end 90 degree elbow that attaches to the turbo, then use a band clamp to hook the two pipes together where the downpipe cut was made


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