Originally Posted By: supton
Originally Posted By: DoubleWasp
Originally Posted By: supton
What is your definition of clean? Cleaner than what it was, or as clean as today's cars?
I'd be quite impressed if you could take a 30 year old V8 design, super-tune the carb, slap on a cat and meeting today's Tier-whatever. While making 15-20mpg.
There's nothing to it. I'd have to find the article, but one of the hot rod mags used a cat converter based on an industrial design, strategic air injection, and tuning to completely blow away California emissions testing.
This was done with a well-tuned Q-jet, and did pull over 20 on the highway, and something in the high-teens in the city. Car had an aggressive cam, long tubes, and a performance intake manifold.
The air injection system was reportedly far more advanced in execution than anything the OEMs ever cobbled together (multiple injection points strategically placed, and high-flow) and the cat of a higher quality than the OEM would ever purchase. Resistance was almost nonexistent, and had major capacity for converting gases.
The engine operated with no EGR due to camshaft profile (as with the LT4 engine that appeared in the 90s).
Sounds like Crusher Camaro. I will have to dig that up.
But color me dubious about it meeting today's standards. I'll eat crow if I'm wrong, but I have a very tough time believing a Q-Jet, no matter what is downstream, and 60/70's vintage combustion chambers with deep ring lands on the pistons, pass today's Tier whatever gram/mile limits.
Hey, if I can be proven wrong--actually, I'd like to be proven wrong. I wouldn't mind duplicating the result, actually. I've been perfectly fine driving around "gutless" I4's but if I could hit mid 20's on something with 300+ hp I'd be fine with that.
An LS1 F-body with a 6-speed would manage mid-20's on the highway even at extra-legal speeds...gotta love that double overdrive.