RON98 said:Isnt that guy running a supercharger?
Since supercharger is not effect by exhaust flow, taking off the cats should not effect the air intake of the engine.
If it where turbos, the extra flow could over power the ability of the waste gate to dump exhaust to the point where the WG could be fully open and the turbos still making boost.
The reason from my understanding your car picks up more HP is cause cat causes restrictions on the exhaust flow. On the exhaust stroke and a few degrees into the intake stroke, the extra presure in the exhaust manifolds allows more already burnt ( some what inert ) gasses to remain/enter back into the chamber. Since already burnt gasses (co2 and nitrogen mainly) does not burn, your not getting as much fresh air as you would if you had less restrictions in your exhaust, more air/more fuel = more power.
Also the engine does not have to work as hard to push out the exhaust on the exhaust stroke which probably frees up something.
A/F in my mind would be changed a little ( put enphasis on little ) bit depending on if your car was tuned with the cat or with out. However in open loop, the ECU reads off the O2 sensor and will compensate for the little extra bit of air coming in so your back to square 1.
Also, with a SC FI system, your car will be running on the rich side anyways! So leaning it out a little (little) bit is no biggy and will product more power in close loop when the ECU is working blind off the preprogrammed fuel map.
Used test pipes for a long time now, have had no problems. It acturally does not smell like rotten eggs.... more of a gas smell... but definitly no rotten eggs. Cats are there to burn up extra gas left over from the combusion process. The stinky smell is from sulpher in the gas you buy. So if it gets stinky, change a different brand of gas. :tongue:
"With CATS, the pressure in the system is ever so slightly higher in fact it is so slight it is really negligible."
As for the post above... I dont think so. Have you seen a cat.... at least 20% of the passage is blocked by the honey comb material..... so thats at least 20% less back pressure due to the cats ( if i over estimated then something like 10% flow is still pretty big )
Took off the cats on my turbo supra..... it was night and day. Although the SC does not work off exhaust gasses, the removal of the turbo from my supra which lead to much quicker spool times and better HP can be used as a illistration of less back preasure.
btw screw high flow cats. dont do something in life half ass. Your neither saving the envorinment or full HP protential.
Worry about the environment? Ride a bike. If you drive a car, cook with wood, matural gas, electric stove and anything else short of solar power, your killing something. I want dead babie bunnies and cute little beavers to shoot out my exhaust at all times during my driving experience. Less crying about the enviornment and more killing baby animals you hipocrites :biggrin: I cant spel, bite me.
WOW!! What a post!
I just carefully opened the box my test pipes came in, afraid all those dead animals would fall out.
I am glad to say I only found the remains of what appeared to be a fly. Obversely part of the test run on the pipes to assure their lethality.:wink:
I now feel like I will become the "Dark Lord of Planetary Extinction" if I dare use these things. I have quietly resealed the box; with the remains of the fly still inside it, and hid it up on a shelf in the darkest corner of the garage, stored next to my "Detroit Mussel Forever" jacket.:roll eyes:
I will go on a retreat this weekend to ponder this moral dilemma.
Thanks Ron98 for opening my eyes to the "HORROR of TEST PIPES"; I feel this may become a Steven King movie.:biggrin:
Bob
