Quote:
Originally Posted by Ecky
I can't think of very many mods for modern engines that would provide economic benefit. Much of the low-hanging fruit has been picked already by manufacturers. Toyota's smaller gas engines, as shipped, have close to the same thermal efficiency to the best automotive diesels. As I understand it, my Insight very aggressively increases timing, staying at the bleeding edge at all times, as detected by the knock sensor. Things like direct injection, eliminating the throttle plate by controlling throttle by varying valve open-duration as a means of throttle control, and building lean burn maps (as well as rewiring and adding the computers necessary) are well above the heads of most individuals and are not easily retrofitted. Most new engines already come with exotic coatings on pistons and cylinders to reduce friction. Adding hybrid systems and moving to electrical accessories often don't pay off for years (if ever).
Sometimes swaps are even difficult, even if one can get a modern high efficiency engine for near nothing, due to the electronics involved. The drivetrain from a wrecked Prius in an older Geo would yield fantastic results, but I wouldn't even know where to start.
I'd rather not be overly pessimistic about our hobby, but I think we'll be seeing fewer and fewer viable mods to add, as cars increasingly ship from the factory with them.
|
I don't know about petrol engines but in diesel engine's ECUs the calibration is total bull***t sacrificing A LOT of efficiency to meet emission standards.
And no, simply disabling emission HW such as removing EGR or DPF will not solve the problem because it won't affect the bad calibration that is there from the factory.
I have spent more than a year messing with VW's TDI PD engines and there are tremendous gains to be had only with properly modified maps and I'd imagine it would be very silimar case with petrol engines.
For example my Octavia with 2.0 TDI engine should get 41MPG combined (and that's very optimistic NEDC figure) stock and after modifying almost all the maps in the ECU and some very basic eco mods I have to drive like a maniac not to get 60MPG tank and my record trip was something like 84MPG
