I still call placebo on most of the gains. You see that big cloud of smoke, and You get an instant *****. (ahh to be 16 again) It effects Your perception.
If it's adjusted correctly You should get decent acceleration, and not a ton of smoke.
Again, Your best gains will be with just a small smoke trail, at full throttle. that big cloud of smoke does no one any good. It's unburned fuel. It robs performance, raises EGT's, and lowers fuel economy. Not to mention the impression it leaves on fellow motorists.
In these days with the Greenies in charge, and the whole 'Climate Change' deal. We should be thankful that they haven't outlawed these older diesels. You KNOW that the peeps that are running around with poorly adjusted fuel pumps are going to effect the whole diesel community. These Greenies remember one idiot blowing a ********* cloud a lot more than the hundreds of thousands of peeps that are tuned properly.
If Your going to run around 'Rolling Coal'. Just remember, when they bend Us over and force DPF's on older diesels, Don't whine about it! It all came from the irresponsible tuning of a few.