Ragnar The Redneck
Well-Known Redneck
A modern, properly designed and sized turbo will virtually eliminate lag. I have been building turbo engines since the early 80s, started with Ford's 2.3L Lima engines, back when turbo lag was measured in minutes (being sarcastic, but you could definitely count several Mississippi's). Nothing like having a 500hp Thunderbird Turbo Coupe in the rain... (Garrett T4 in place of stock T3, plus fueling mods, charge cooler, water/alcohol injection and EEC-IV programming, 2.75bar).
Sadly, many manufacturers are just using a smaller turbo to eliminate turbo lag, and letting the engine run out of breath in the upper rpms. The new 2.3L turbo in the Ford Explorer runs out of breath about 2k rpm before redline, but has awesome torque and the engine feels much larger than it is. Mitsubishi does the same thing with the 1.6L turbo in the Eclipse Cross, but with the CVT, they keep it in the powerband more often. VW and their low horsepower version of the 1.8L turbo is a dog, but it was designed to be less expensive in base models and was designed more for economy than outright power. The Kia/Hyundai turbos are decent, the earlier 2.0L engines had some lag, but the later 1.6L and 2.0L turbos are much better in that regard.
Modern twin scroll turbos, like what BMW currently uses, turbo lag is milliseconds, and still has good power very near redline. As a matter of fact, BMW's N55 I6 single, twin-scroll turbo has boost earlier than their N54 I6 twin turbo set up (one small for low rpm, and one large for higher rpm). The earlier twin-turbo N54 I6 is still better at producing top end power, though. The newer BMW 2.0L turbos are just as good, and have a natural feel, until you get into a heavier 5-Series or fully optioned X3, then they start to feel a little low on power.
Another way to reduce turbo lag is to have a shorter distance from the turbo to the valves. The more piping between the turbo and valves tends to slow down boost production as there is more volume to fill. While more complex, a water to air charge cooler is the best to use, as the cooler can be placed immediately after the turbo and just before the throttlebody.
As far as oiling, that is very important, but modern turbos are more forgiving than those in the past. High quality, synthetic lubricants are a must if you want any turbo to last. I change the oil in "Rocket Pig" about every 7500 miles, but then again I use synthetic LiquiMoly, and the oil still looks good, and tests good as well. I could probably extend it to 10 to 15k, but I'll err on the side of caution with 440hp at the tire. Before starting the restoration on my Supra, it was changed every 5k miles with Royal Purple synthetic.
Sadly, many manufacturers are just using a smaller turbo to eliminate turbo lag, and letting the engine run out of breath in the upper rpms. The new 2.3L turbo in the Ford Explorer runs out of breath about 2k rpm before redline, but has awesome torque and the engine feels much larger than it is. Mitsubishi does the same thing with the 1.6L turbo in the Eclipse Cross, but with the CVT, they keep it in the powerband more often. VW and their low horsepower version of the 1.8L turbo is a dog, but it was designed to be less expensive in base models and was designed more for economy than outright power. The Kia/Hyundai turbos are decent, the earlier 2.0L engines had some lag, but the later 1.6L and 2.0L turbos are much better in that regard.
Modern twin scroll turbos, like what BMW currently uses, turbo lag is milliseconds, and still has good power very near redline. As a matter of fact, BMW's N55 I6 single, twin-scroll turbo has boost earlier than their N54 I6 twin turbo set up (one small for low rpm, and one large for higher rpm). The earlier twin-turbo N54 I6 is still better at producing top end power, though. The newer BMW 2.0L turbos are just as good, and have a natural feel, until you get into a heavier 5-Series or fully optioned X3, then they start to feel a little low on power.
Another way to reduce turbo lag is to have a shorter distance from the turbo to the valves. The more piping between the turbo and valves tends to slow down boost production as there is more volume to fill. While more complex, a water to air charge cooler is the best to use, as the cooler can be placed immediately after the turbo and just before the throttlebody.
As far as oiling, that is very important, but modern turbos are more forgiving than those in the past. High quality, synthetic lubricants are a must if you want any turbo to last. I change the oil in "Rocket Pig" about every 7500 miles, but then again I use synthetic LiquiMoly, and the oil still looks good, and tests good as well. I could probably extend it to 10 to 15k, but I'll err on the side of caution with 440hp at the tire. Before starting the restoration on my Supra, it was changed every 5k miles with Royal Purple synthetic.
). I don't want something that can be heard a mile away, there are too many bro dozers around here, and I don't quite fit in that demographic.
