Posted by Ed Tavernier on Wednesday, November 28, 2001 at 2:47AM :
In Reply to: Cummins exhaust question.......gary? posted by John on Tuesday, November 27, 2001 at 10:00PM :
John,
I have a 98.5 24 valve 5 speed turbodiesel with a 4" exhaust, K+N airfilter and bigger injectors/exhaust brake. Since the exhaust gases need to go through the turbo first, as long as the exhaust is big enough whether it is a single 4" or dual 2.5" shouldn't make any big difference. There is a company making a 5" exhaust for the Cummins turbodiesel.
I would think that the turbulance caused by the improper division of the spent gases might hinder the the flow; as such the connection that divides the gases after the turbo should be smooth and not abrupt to try to limit said turbulance.
As an aside there is a redesigned exhaust brake,(pacbrake?), that has a twisted butterfly valve to enhance flow out of the turbo when the exhaust is open, I think they claim a 30% reduction in turbulance through the brake, which enhances the removal of the spent gases/heat.
If you are really into it, I would recommend an exhaust gas temperature guage, as well as a boost guage.
My 2500 club cab long bed towing a triaxle flatbed + '55 C3PW will pull away from an unloaded brand X with ease.
Eddie
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