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TJ
09-20-2004, 15:45
I have a buddy who works at a muffler shop. We have set up a plan to cut off my crossover ends and install a 3 inch pipe onto them. This is bigger than the stock crossover. Has anyone tried this?

TJ

1998 Optimizer 6.5L Intercooled Turbo Diesel

Dvldog 8793
09-20-2004, 16:14
Howdy
If I understand things right then you want HIGH-temp HIGH-velocity gasses flowing in the crossover. I put in a direct replacement size ceramic coated mandrel bent pipe. It made some difference, not great but some. I would think that just by welding bigger pipe onto the same small ends that you will be creating a cooling chamber and also loosing some velocity.
L8r
Conley Janssen

markrinker
09-20-2004, 16:22
I'd wager that it works as good or better than stock. Increased flow = increased volume of gases to turn the turbine. Pressure might take slightly longer to build (turbo-lag) but that never has seemed to be a problem with the stock set-ups.

Billman
09-20-2004, 17:17
I think it has been said here before about this subject that the pipe isn't the only restriction. The flanges on the manifold are less than 2.5".

tanker
09-20-2004, 17:39
I'm no expert on exhaust, but going from say 2" to 3" then down to 2" again, does not sound good. Might work :rolleyes: but I guess you would need to do some testing prior to the new 3" system then test again afterwards. If my experience in flowing liguids serves me right, you'll lose pressure when increasing the ID of the pipe, but then going back to a smaller outlet may cause a restriction, unless you are using a flow reducer to prevent turbulance. Keep us informed as to your findings. smile.gif

RT
09-21-2004, 17:03
Why not just install mandrel bent pipe instead of the crimped factory parts? I think Kennedy sells or sold a 2.5" mandrel bent replacement that was ceramic coated. I wrapped my factory crossover with header insulating wrap to hold the heat in and keep the gas velocity up. Noticeable difference, no turbo lag, none. RT