Anyone here work at a Ford dealer?

[raz-0 1,259]

I respectfully disagree. The necessary engine management technology was not in the mass market back then. ECUs from the 90s were more primitive and dealing with the turbocharger dynamics was an afterthought. Your 90s 4 banger was dumping fuel at high output and running inefficiently in some manner in almost all load scenarios. And it was probably a dog off boost with its low compression (I'm assuming, I don't know what truck you had). Today's engine control has a much higher sample rate and can adjust output before the next rev. There are many more sensors which influence the various algorithms. There are many more maps that the ECU uses in its strategy and these maps are much larger in dimension than before. Knock strategies are much improved from the old "pull all timing" method.

 

Dumping fuel to quench the charge air and prevent knock is still done. It's done with rapid throttle change. Are the ECUs more primitive? Somewhat. from 1990 to 2005, there is a bit more polling (about 25% more from the bits I understand enough to compare), but also about a 50% reduction in ECU cost. (about $1200 1996 dollars vs $630 2005 dollars to replace). THe knock strategy back then was pull timing till you can't, dump fuel into it if you can, and failing that, cut off fuel delivery briefly. For my 2005, it adds in the ability to mess with the variable valve timing. What new things have they come up with to prevent knock? Yes, the maps are bigger and thus finer resolution. There are also more because variable valve timing adds to the need for different maps. My 1996 ride wasn't a truck, neither is my 2005 ride. Variable valve timing helps it not be a dog off boost, as does displacement. the 1996 was a 2.0 the 2005 a 2.5. Stroking the 2.0 to 2.3 made a significant difference in how the vehicle behaved off boost (not mine, but I got to meet one). As for compression. 1996 NA version fo the block? 10.5:1, turbo version of the block 9.5:1. 2005 NA version of the block 10:1, turbo version of the block, 8.2:1.

 

The Ford EcoBoost uses a wideband o2 sensor which allows it to remain in closed loop much more often. Cars from the 90's went open loop practically off-idle. Variable valve timing was not present on mass produced cars (I'm not talking VTEC here).

 

This is something that is newer. Is this making it into vehicles that are sub $30k though? Wideband is best, but it isn't like they weren't around back then, they just didn't shell out the money to put them on the car at the factory, and thus unless you replaced all engine management you just used them to tune your maps if you added one later.

 

You put 180k on a turbo 4 but that is not typical.

 

For the 4G63 engine, it wasn't that uncommon, it was a nicely engineered engine and pretty beefy.

 

Oil in a turbo engine degrades much faster from the extreme heat cycling and engine wear is usually quite higher in terms of metals found in the oil during analysis (even changing it twice as often). And as the center cartridge gradually wears out of spec coolant can be introduced into the oil and oil finds its way into the charge air increasing probability of detonation. New turbochargers have benefited greatly from better materials which result in much tighter tolerances and improved service life of the turbo compared to a turbo that you'd find in a mass produced car in the 90's.

 

Unless you are going with a ball bearing turbo, or variable geometry, the turbos now are more or less the same as then. Heck, the make and model of the turbos are the same in many instances. Granted, we are just starting to see some weird new designs hit in mass market vehicles akin to some of the wackiness of the $30k+ crowd circa 1995.

 

As for intercoolers, when they were actually used in mass production back then they were usually undersized and placement in the engine bay was too much of a compromise.

 

You have got to be kidding me. Yes, placement was usually sub optimal, and they usually weren't the maximum size you could have without inducing undesirable quantities of pressure drop, but what vehicles were not shipping with intercoolers? Heck, the last time I met a production car without an intercooler on the turbo was my mom's 1984 dodge daytona. The 1987 shelby version had one. The only place I commonly saw very low compression and no intercooler were ill conceived add on kits for NA engines that used a spacer and very low boost to do a not very good job of turbo charging an engine that was not designed that way in the first place.

 

Mitsubishi, toyota, saab, mazda, nissan, porsche, audi, and volkswagen are the cars I remember being turbo charged back in the 90s. They ALL had intercoolers. I'm pretty sure the turbo diesel trucks did to. What was not packing an air-air or air-water intercooler with a turbo charger.

 

My NA headers have a surface temp of around 200 *F after I shutdown. My turbo downpipe and turbo have a surface temp of 500 *F after I shutdown. And the turbo is a much larger object radiating a lot more heat than NA headers. There is a big difference in the heat radiated and explains why underhood plastics get brittle and break, batteries explode and parts melt (heat shield or not). Heat management still has a long way to catch up to the current technology.

 

Batteries explode? This was not a problem I saw people complaining about. Shortened life span perhaps, 3.5 years out of a 5 year battery wasn't that uncommon. But I have never seen a battery hit it's rated life span in any car I have owned, turbo charged or not. The plastics getting brittle, I don't know if I blame the heat that much, but even if I give it to you that it was heat and not exposure to the elements and road salt, etc. that made the connectors get dodgy, my 88 camry and went about the same number of years before the plastics got sketchy and about 35k more miles than my eclipse. My legacy isn't quite to the halfway point of eclipse yet mile wise, but is about 75% in terms of hours of environmental exposure. The plastics are faring much better, so I would suspect there ahve been improvements there.

 

What parts have you had melt? NOTHING on my turbo cars has ever melted except for an ill conceived replacement made out of radiator hose to cover for a torn intercooler pipe connector. I take the blame for that though as it was an inappropriate choice for materials. Even so it lasted WAY longer than it had any right to. Now once again.. bolt on kits to an NA engine... different story.

[H.M. Murdock 0]

You're killing me with these late replies. Like playing chess over snail mail. I'll come back to it too