Turbo Downpipe Show 'n Tell

[Dave Barbieri]

Since I bought my truck, I've been kinda concerned about the 'kinks' and constrictions in the stock dp. While putting the truck up on jackstands, I had a chance to take a close look at the pipe. dang!! That sucker looks crushed in a couple of places! I ordered a 3" mandrel bent dp from JetCo, and pulled the old one off. Wasn't very hard - four bolts hold it to the exhaust pipe, so I soaked them in Deep Creep for a couple of days. All four came off with a ratchet. The V-clamp that holds the pipe to the turbo outlet was easy, as well. The new dp arrived, and I decided to take some pics for comparison.

 

[realmenramit]

haha yeah GM in its glory.

i bought a 4" aluminized exhaust for my 96 1500 6.5TD.

3" DP to 4" straight pipe, sounds exactly like my dads '80 big block camaro i recommend doing it, youll love it.

 

[Dave Barbieri]

Actually, the PO beat me to it. From the flange back, it's a 3" straight pipe back to the shortest muffler I've ever seen. Then the system Y's into two 3" duals that exit at the back of the truck. Seemed really odd to spend all that money on a free-flowing system and then just leave that crimped up clamped up downpipe in place.

 

[JLDickmon]

I think it IS/was crushed...
I just finished doing head gaskets on a friends, and that one was perfectly round compared to yours

 

[Dave Barbieri]

I think it IS/was crushed...
I just finished doing head gaskets on a friends, and that one was perfectly round compared to yours

See, that's kinda bothered me ever since I first saw it. There didn't seem to be any reason for it to be crimped like that. Plenty of clearance - the new oversize dp fits just fine - and I don't see how you could mechanically do that to a piece of tubing without serious damage showing up somewhere else. Very wierd...

 

[Dave Barbieri]

DP installed, whew!

Finished the install of the Auto-Jet downpipe this weekend. It seemed to be pretty simple - just cut the flange off the exising exhaust pipe and slip the new dp into place. uh-huh. Two hours later, it was finished. Man, nothing is ever simple! I used a chain-type pipe cutter to cut off the flange and about 4" of pipe. Geez - that exhaust pipe is THICK! After the flange was removed, I slipped on the new dp. And discovered that it doesn't 'quite' line up with the turbo exhaust flange. I wound up disconnecting some of the frame-mounted exhaust pipe hangers. Then it lined up, and I got everything connected.

One problem I notice with the dp in place is that it's impossible to gete to the #6 glowplug. Guess I'll worry about that in a couple of years!;p

 

[DieselFreak]

I think it IS/was crushed...

L O L , my thought exactly Bear.

Just bought a 4" Stainless straight-through with 3" DP all mandrel bent exhaust system. Installed easily in a few hours - what took me the longest was getting the old exhaust off.

When I got the OE-dp off, I thought "*** !!"... at first I really thought mine had been broken too, looking so beat up *gg* ;p

Sounds AWESOME btw )

 

[97gmc6.5]

I made a 3.5" down pipe for my 6.5 i started with a used duramax exhaust and a 6' straight pipe and made it 3.5" straight piped from the turbo to back side of the tire and its not loud at all with the turbo!