I found a second gen 4" downpipe that i can get a real good deal on. It is for a wastegated turbo housing with the exhaust elbow........

Now, can i just get a exhaust elbow, put it on my 18.5cm housing and bolt up the downpipe, or can i not put the elbow on the 18.5 cm housing....


Thanks for the info.....


Jeff

 

I think you'll be better off welding up your own or calling Rip. Seems like the 2nd gen dp's were way different, and that cast elbow doesn't seem like it'll do you any favors, EGT-wise.
g

 

Greg

I thought about the EGT issue with the cast elbow as well. I think i'm just gonna fab up my own downpipe. It shouldn't be too hard. A couple 90 degree bends with a 4" - 3" reducer. I think i'll end up making my own piping over the axle as well.

Jeff

 

I don't think the 2nd gen setup makes a tight enough turn to clear the cab.

 

''I think i'm just gonna fab up my own downpipe.''

That's part of the charm of owning a first gen truck. Not being able to ''click'' and ''check out'' every last BOMB gets the 'ol gears turning more often. Keeps you sharp and makes the truck more 'yours'.

g

 

In almost every case an aftermarket DP will require some significant mods...by that I mean you'll have to make 'pie cuts' and welds to get it down slope properly....
The guys with auto's have a bit more trouble due to the auto dipstick tube...you need to be careful how much you "fiddle" with that cause they have a single o-ring on the tube were it fits into the trans case..and if it's disturbed too much it'll leak for sure. Just take yer time is all.
The DP will need to have a pretty near immediate 80*-90* downturn very quickly so it will clear the rubber cowling for the heater area. You can use some header wrap or even used exhuast wrap off another auto maker's trucks to cover the little area around the cowling section.

pb...

 

SteamDave has a cast elbow and modified 2nd gen downpipe on his truck. The cast elbow clamps right on.

It sure seems to me that the best solution would be to make a pipe that was 3" at the turbo and upper 90, and then gradually tapered out to 4" for the lower 90. You could get a tight radius smooth turn at the top, and would not have the effective restriction of a sudden change in pipe diameter . . . When I put a new exhaust on my truck, that is my plan FWIW.