Exhaust question

[Jim Dockerty]

I am thinking of upgrading the stock exhaust system on my 2004 Dmax. What kind of performance improvement would I see with a 4" exhaust? Everything on the truck is stock right now

[Kennedy]

Very little perceivable gain, but it is there in small amounts throughout tire range, concemtrated more on the response time when you accelerate. The bigger gains come from the electronic enhancements, BUT the exhaust is a recommended supporting mod...

[Heartbeat Hauler]

I added a 4" exhaust to mine and I think(can't prove it)my turbo spools up quicker. Plus, the 4" will keep your EGTs lower when towing or when a power product is added.
JP

[sonofagun]

Banks says they have dynoed +20 HP. The big gain is reduced heat when towing and better breathing.

Bob