Quote:
Originally Posted by 1972RedNeck
I'm well aware that true duals work "real good". But if there was 10 or even 5 HP to be had out of an "X" pipe, why wouldn't you for the extra $50 it would cost?
|
Whether it was a lowly little LoadStar with a 345 cid V-8, or a FleetStar with 478 V8, or a C65 with 366 V-8, or C70 with 427, anywhere from early/mid 1960's to late 1970's, they all had true dual exhausts. I think that was to manage heat in the engine and exhaust system. The duty cycle on trucks is amazing, hours on end wide open, exhaust manifolds glowing orange hot except for 3-4 hot spots that are bright yellow hot. An H pipe would add several more hot spots, and X pipe probably one big one that could cause problems. Not sure what current production trucks have to run for emission equipment. Big Block V-6's definitely none,
5 or 10 hp added to the 205 or 235 net hp of the 478 or 125 hp of the 305 "Might" be noticeable. True story, Buddy and I driving identical tractors, 320 net hp, first loads one day I was 400# heavier than his 70,000#. He walked away from me every 10 miles or so for 175 miles. Coming home I was lighter by 250-300#, I walked away from him 5-6 times in the 175 miles, maybe could have done more but I wasn't trying too hard.
I think lightening the truck by a couple hundred pounds would make more difference than the hp. Added hp usually costs burning more gas, lighter weight saves hp and gas.
I really think it's more than just a coincidence that a Chevy, GMC, Ford, and IH with big gas V-8 power had almost identical exhaust design.