I have an 05 450 6.0 lariat crew cab. Have installed Airaid filter. Also have heat gauge 3 " from turbo in exhaust down pipe. Maximum temp seen to date, in the mountains 850 degrees. Normall puling 15000 lb rv 600 degrees. Question is would 4" or 5" turbo back exhaust with new Magna flow 4" or 5 " catalytic make a significant change in mpg or temp??? All input appreciated. Thank You Trayder

 

Welcome to FTE, trayder.

(thread moved to 6.0L PSD section)

 

Well you have your Pyro mounted "Post turbo" which is not very accurate. The temperature can read lower than actual by 200-800F and is not linear. You could easily be seeing 1650F Pre-Turbo with the 850F post turbo readings you are seeing. You need to re-mount your Pyro in the drives side exhaust manifold to get accurate Pre-turbo temps. Pre-turbo temps are the ones you care about.

Also lose the A/M air intake, the OEM Donaldson air intake fiters better than any filtration system on the market and flows more air than the 6.0 can use until you reach 500+RWHp. Also the A/M air intake can void your engine warranty.

A 4-inch turbo back exhaust system (such as MBRP), will lower the EGT some, gas mileage changes will negligible at best. The down pipe from turbo to Cat will be 3.5-inch (factory is 3-inch) as a 4-inch will not fit without major firewall surgery, and the larger down pipe robs low end power. A 5-inch exhaust system has no gains over the 4-inch system unless your are running and extreme race motor, and actually the 5-inch exhaust will reduce low end perfromance. An A/M cat is a waste of money, leave in the factory cat. Some have installed a cat delete pipe, just be aware this is against Federal law (and some state laws) and will result in your dealer denying your warranty work.

Hope this helps

 

Question, does that Airaid use an oil impregnated media? If not, I might be interested in that for one of my rigs. Every AM cat I have seen is inferior to the OEM unit. And as mentioned above, removing it is illegal in the US. I am surprised that the EPA is not cracking down on the catless systems. Often fuel economy sufferes from removing the cat, since it messes with the fuel management systems.

 

This has been gone over a few times now in this forum. While that is true on most gasoline powered vehicles it is not true on these trucks. On our truck pretty much all the Cat does is collect soot, and now that we have ULSD there isn't much of that being put out, so it is really practically useless.

As far as the Airaid intake and filter goes, yes there filter is oil impregnated. However, according to there info it is a special oil that is formulated not to stick to the MAF sensor parts.