Erv187

I was just wondering, can anyone explain why the 8 is designed to run so rich?
If you install a nitrous system (dry) wouldn't it drown the engine if it runs rich already or do you need to get a fuel management computer to lean it out if you want to run nitrous? Also what do you think would tear the engine up quicker nitrous or turbo?

zoom44

from all i have learned over the last couple of years i believe the real reason to be catalytic protection. all cars to some degree use extra fuel to cool the cat to make them last longer. there are more lengthy discussions and posts regarding this but short story- new fed regs require cats to last 120,000 miles. since one measure of longevity is the temp of the cat and rotary exhaust is hotter than piston engines Mazda needs more cooling. but they have managed to lean it out some since the original K flash.

as far as nitrous look in major hp upgrades section for the nitrous thread by charles r hill. there is a wealth of information there you will need if you go nitrous.

crossbow

The odd thing zoom44 is...the Mazda 6s is even richer then the 8. We have 4 cats, and a 9.7:1 A/F mixture at 6500 rpms. So depressing.

guy321

Hmmm, If you were to run a dry system it would be better that the engine runs rich. That way you wouldn't end up running too lean when you add nitrous. Nitrous is not a fuel like gasoline, it's compressed air, so to handle more air you need more fuel. Most dry systems wouldn't work on the 8 anyway because of the returnless fuel system. If anything, you would use fuel management to RICHEN the mixture, not lean it out.