down pipe
 

I just wanted to share my latest project,
I just replaced the turbo downpipe on my 1982 300td with a home made 2.5" unit I made for about $80. I ordered a 2.5" 180 degree mandrel bend from summitracing.com and a 2.5" diameter and 10" long stainless flex coupling off ebay. I copied the bends off my stock pipe that had a massive hole in the old coupler and cut them out of the mandrel bend and then welded it all up using the flanges off the old pipe so that everything bolts up just like stock. I used a grinder to open up the inside of flanges to 2.5". I'm pretty happy with the way it all fits. Here is a pic:

Looks good -- nice job. Now let's see how long it holds up.

nice job! the effort has saved you lots of money as the dealer oem price is quite hefty.i did something similar with my 80 300sd paying approx$100 for a stainless flexpipe from canadian tire.i had the pipe sections made up at a local muffler shop.welded it myself and saved at least half the dealer cost :cool:

Thanks for the kind words,
I think it should last quite a while, It is mostly 16 gauge tubing and the flex section has an inner braided sheath covering the bellows in addition to the outer braided sheath. only time will tell-out here in cali exhausts have it a little easier than some places :D

Yeah as I said it does look good. The OEM pipes generally split open in the flex section...

If and when my 300SD needs pipes I would love to do a 3" mandrel bent system to a flowmaster muffler.....

got mine shipped from Rusty for $120 (came with a UPS sticker on the pipe sans any other packing !!) and was truly a 30 min install.

I dont know what your time is worth to you, but cutting, bending, welding and the price diff is only $30 -40 doesnt sound like its worth it to me :)

looks good though

was that pipe from Rusty a stainless one? Do you have a picture?

I don't get paid for my free time and I enjoy working with my hands so there's that. The whole fabrication took me a few hours working carefully. Also, I think this is a significant upgrade in durability of the flex section which seems to be the common failure point. Don't forget the awsome increase in performance from the stock ~2.25" to 2.5"! Actually I do like the idea of being able to slowly uppgrade everything to 2.5" when the time comes so this is a good investment in future uppgrades. I don't expect more absoulute power but the turbo should spool up a little quicker with less back pressure in the exhaust system. I've seen in other turbo applications improvments in booth spool up time and fuel economy with larger down pipes(not at the same time-it depends on how you drive it!). I almost just ordered a stock one because of convenience and for most people that is probably a good idea but I'm glad I took the time to do a custom piece. The way I look at it I got a chance to build something cool without spending any extra money given the fact that I needed the part anyway. To each his own I guess

Does that down pipe make it any quieter in the cabin? Mine is a non-OEM replacement, and it seems especially growly at lower RPMs.

It's actually quieter as the exhaust leak in the old one is now gone. I would check to make sure your flex section hasn't sprung a leak. I would also speculate that it could also be hitting something if it isn't installed correctly-more likely to occur at low rpm. Good luck with it