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Message: [QUOTE="CurtisF, post: 1399430, member: 829"] It's not exactly "detuning" per-say, but my old truck towed frequently and often very heavy loads (up to 25K lbs) all at elevation..... with 200% nozzles. EGT's weren't an issue, and that was just with a little 38R. There is something I wanted to point out along those lines as to why it is possible: Yes, a more efficient burn can help decrease lower exhaust temps. However, there is something else that happens between small vs large nozzles. When you drag pulsewidth out too far, EGT's begin to rise exponentially. This is regardless of how good the atomization is and how small the droplets are. Too long of a pulsewidth creates way too much heat. This is why EGT's skyrocket on small or stock nozzle injectors when attempts are made to "empty" them out. It's why it's near impossible to tow heavy loads up a mountain pass in a common race tune on stock injectors. In comes larger nozzles. Sure they aren't as efficient in terms of atomization, however they are far superior in delivering greater amounts of fuel in a much smaller amount of time. This enables greater power levels to be achieved without an astronomical temperature spike. Larger nozzles have the ability to inject more fuel into that small window, especially as RPM's increase and that injection window shrinks. My old truck could tow with a higher power level under the 250/200's then I ever could with stock injectors. EGT's were less with the bigger injectors at equal power levels. Towing with a 300+ hp racing tune on stock injectors netted EGT's well over 1400 degrees while trying to tow up a mountain pass. Towing with a 300+ tune on 250/200's would peak under 1200 degrees. This is with the same turbo setup, same exhaust, same intake, etc. Is it "detuning"? Well not exactly, but there are ways to dial in even larger nozzles to behave. Is it easy? Absolutely not. I was constantly tweaking tunes trying to find the right balance. I was a novice tuner at best, I'm sure a professional probably could have dialed it in much quicker than me. However I did manage to get it running like I wanted. Is it for everyone? Again, absolutely not. If you want to experiment, by all means have fun with the larger nozzles/injectors. But if you want something solid and proven right out of the box, go with Jay's recommendations. That was all. Just a different observation. In reality I do agree with Jay, but just wanted to point out something that is important and a very good reason why larger nozzles exist in the first place: to create more useable power. [/QUOTE]