Not sure of your questioning why I'd have propane in a diesel truck. Is it that you don't understand how propane mixed with air and diesel fuel elongate the burn, produce another 50-75 horses, actually reduce thermals, and though it aids in MPG tho that is countered by the cost of the propane. As far as giving it a very, measurable boost, it rocks. Or is it you just don't like propane mix and prefer methanol/water or nitrous. Far as it goes, I have it on there because it really works would be my answer. As to the wastegate, I'm looking to reduce the pressure that would be exhausted thru the EGR, if I hadn't deleted it. Thank you for your insight as to my question but maybe it was lost by the terse nature of my request for information. Have a pleasant day
Propane is an excellent modification for someone if they are using it with the sole intention of increased fuel mileage. It can actually do pretty well in that department. I would not, however, be using it to increase horsepower. I have heard too many horror stories. It's not my truck though, it is your truck. Do with it as you wish.
I actually don't prefer any additives for additional horsepower to be honest. I am fuel only horsepower kind of guy. Some guys like to spray nitrous to achieve their goals simply because 6.4's seem to love nitrous. With the poor cylinder head flow and the amazing fuel potential of the 6.4, it is only natural that nitrous can be used successfully.
Most people that are out to make power definitely don't go with water/meth kits. Methanol has actually been proven by one performance shop in the industry to wear on the valve stems. It can be used in moderation (20% mix with 80% water for example) and more than likely not cause issues, but you're not going to see much of horsepower gain using a safe mix like that.
In the 6.4 performance world, nitrous seems to be the most accepted power adder beyond conventional adders like tuners, turbo's, bigger fuel systems, injectors, etc., simply because trucks that make 700 HP on fuel with small compounds and massive amounts of fuel can spray to 1,000 HP +. Hell, Rudy's Diesel Performance had their truck on the dyno a year ago at their dyno event.....made 790 on fuel and just over 1,200 with nitrous. That's over 400 horsepower gains from nitrous.
The point of my "shocked" question was that you don't typically see guys using propane on their 6.4's. I wasn't saying you are wrong for doing it. Just surprised it's being done.
Now back to the wastegate discussion.....
You don't need a wastegate on your truck if the sole purpose is to prevent head gaskets from blowing. It won't help you all that much. If you are looking to decrease the amount of back pressure and boost you are making, it's a good upgrade. Back pressure isn't an issue with stock fuel and stock turbo's though. Since you have propane in the equation, you may been seeing excessive back pressure and boost.....kinda like trucks that spray nitrous. Excessive back pressure can cause valvetrain damage and blow up-pipes. It's rare to see problems like that though. It takes a lot of back pressure to hurt the stock valvetrain and blown up-pipes seems to be hit or miss. I mean they blow on stock trucks....so of course they are going to have a chance of blowing on a 550-600 HP truck.
Man....that was a lot of typing.