Question on down-pipes. One or two piece?

[mrbuyit]

Hello board. I have a 1987 GN with 31k that I am goign to add a few mild upgrades to this spring. One of those upgrades is a new, 3" SS down-pipe. I have seen that there are one and two piece designs. Not sure which to go with and/or what are the advantages/dis-advantages of each?

I appreciate any feedback.

Thanks

Jeff

 

[DailyDrifter]

Depending on you goals, a 3" Terry houston DP is gonna be your best bet. Or you can go to a 3.5". I would go with a one peice, I'm not familiar with the "2" peice.

 

[gnbooster87]

stay away from the 2 piece since its a stock style replacement downpipe...id go with a 3" from RJC they have the best fitting downpipes out right now

 

[russgoodman]

The 2 piece uses the factory elbow. What you want is a one piece that replaces that elbow and pipe. I went with a TA perf 3" and I couldn't be happier. I really believe that the stock downpipe was holding me back a ton. Car just feels so much stronger now.

 

[turbojd]

Plus those 2 piece downpipes are notorious for exhaust leaks.

 

[TURBOV8R]

Plus those 2 piece downpipes are notorious for exhaust leaks.

Oh yeah!

 

[gnxtc2]

Plus those 2 piece downpipes are notorious for exhaust leaks.

Really

Oh yeah!

Not if done right.

http://www.turbobuick.com/forums/stage-ii-tech/275948-aluminum-downpipe-done.html

Billy T.
gnxtc2@aol.com

 

[TURBOV8R]

Oh great! Just when I thought I was done conjuring up more fabricating projects,your post pops up!!....Nice stuff BTW!:biggrin:

 

[turbojd]

Really



Not if done right.

http://www.turbobuick.com/forums/stage-ii-tech/275948-aluminum-downpipe-done.html

Billy T.
gnxtc2@aol.com

That does look nice!

 

[christians87]

when is it suggested to get an upgraded downpipe? In other words what are the limits to the stock unit, and what kind of gains could I see considering the mods in my sig. thanks.

 

[gnxtc2]

The biggest downfall of the stock DP is the 90* coming out of the exhaust housing.

A TH style DP helps regards of performance level.

Billy T.
gnxtc2@aol.com

 

[ANDYS87]

Buy the 1-piece....do it right the first time and be done with it! I have the 2 piece, because I didn't know better. Was a pain to seal. I don't like the way it looks(having an exhaust clamp where they meet)...plus its pretty cheesy where it meets the factory exhaust elbow. I had to use hi-temp silicone(which will probably burn off in the near future).

This spring I am going to buy the RJC one piece unit.