temperatures/pressure

[Stout]

Being new to this... ... ... where do I find specs or info on "normal" temperature and pressure ranges, i. e. , EGT, boost, transmission, etc? Mine is a 01, 3500, 4X4 dually w/ AT. Completely stock, no mods or gauges yet.

 

[TomGolden]

Well, from asking the same questions myself, I can answer some of these for you.



Safe EGT range PRE-turbo is <= 1250*F

If you have a POST-turbo thermocouple, I have always heard that you should add about 300* to what the gauge says.



Boost depends on what turbo you have, if you have any sort of a boost module (boost fooler), etc... Since you have a completely stock truck with an auto, you [should] have the HY35 turbo. The ECM (I think) will automagically defuel you at around 20 PSI of boost. A boost module intercepts the boost signal before it gets to the ECM and regardless of what your real boost level is, the ECM never sees anything over about 19 or 20 PSI, so it never thinks it needs to cut back on your fueling. With the HX and HY35 turbos, I believe your optimal boost range is <= 30 PSI. Those turbos can go up to almost 40 PSI, but they are then way out of their efficiency range, and you are actually heating up the air so much at that point, that you are actually loosing the benefit of getting more air into the cylinders than at say 25 - 30 PSI - with those small turbos.



I have a 6 speed, and I do have a gauge in it, but I do not know what the safe temp for an auto transmission is. I believe for the manuals, anything < 220*F is in the safe range.



One more, very important thing I will point out. Next to an EGT gauge, arguably the next most important gauge is a fuel pressure gauge. I say arguably, because with a stock truck, the ECM will basically keep you from ever getting your EGTs too high to damage your engine, so an EGT gauge is not critical, but still very good to have. However, regardless of being totally stock, or with a thousand BOMBs, your OEM lift pump is quite likely to die on you, and it could also take out your very expensive VP44 injection pump. So a fuel pressure gauge is absolutely critical!! Good fuel pressure ranges are: idle >= 12 PSI, cruising at normal speed >= 10 PSI and WOT (Wide Open Throttle) >= 8 PSI.



Enjoy a great truck



Tom