Joined: Aug 2002
Location: the golden state
2.8l DOHC 5 valves per cyclinder
10.6 to 1 compression
190hp @ 6000rpms
206ft @ 3200rpms
3.8L pushrod 2 valves per cyclinder
9.3 to 1 compression
Ford AJV 3.0L DOHC 4valves Per cyclinder
10.0 to 1 compression
The VW passat 2.8L has a more efficant engine, especially when your a 2.8L Double Over Head Cam engine that uses 5 valves per cyclinder, --VS-- a 3.8L push rod engine with 2 valves per cyclinder. The 2.8L allows more air in and out at a time. And it also revs higher than the 3.8L. On top of that it has a higher compression, which also helps it make more power from a smaller displacement 10.6:1 but that's not all the story. That little 2.8L is not making the low end torque that the larger engine is, so it has to rev higher, which also means that the gearing needs to reflect the power and torque curves for that engine. Give that passat our gear ratio's, and it will be a slug. This is the reason why you don't see the Ford AJV 3.0L DOHC engine in the mustang, it makes more hp 220hp@6300rpms but it makes less torque 192ftlbs@5000rpms, which is way too high to push our Mustangs, especially with the gearing in the T-5's. Ford needed to keep the T-5's and the AODE for abuse factor too. The gears can handle the abuse. Put in the gear ratios that the ford 3.0L and the VW2.8L engine uses, and then throw in the bad habits of mustang drivers, and you will get alot of granades. That's why the next gen Mustang is going to get the 4.0L temporarly untill they finish the development of the 3.5L DOHC engine that will go in around 07/08. I would expect the 3.5L to use the same T-45 gearing as the GT,s and I would expect the 3.5L to rev just as high.
The 3.8L engine was originally designed years ago compared to when the VW 2.8L was designed. The 3.8L engine does not have alot of delevopment from Ford, matter of fact, the 3.8L is nothing more that a copy of the Chevy 3.8L engine. If Ford did do a lot of development from scratch, you wouldn't have the poor head gasket and water coolant design that has pleagued the 3.8L/4.2L engines. The head and water coolant design would be more comparable to the 5.0 and 5.8L engines. If you was to compare both the Chevy 3.8L and the Ford 3.8L you will find a tremendous amount of similarities, from the internal counter weight to the head designs. You should see the dynos from the Chevy 3.8L, you can pratically lay it over the ford ones and have the same torque and hp curves.