astonishing!

 

whoa for such a short sentence that took a ton of code to write. props dawg

 

Here's an interesting read for you: http://www.importtuner.com/features/...l/viewall.html

A 1 hp gain catless in comparison to a high-flow cat.

 

Ok for a stock car that said in the article,but in the article said too that if your running a more modified car the hp will be higher, look i been modifying mani cars of different mades,(for competition), and one of the first things you do to gain hp is discarting the cat, because when you ad a bigger turbo,downpipe, uppipe,headers,inyectors,better flow fuel pump,bigger ic,nitro,bigger exhaust piping,ecu, the cat is like a cork in the A,and it will melt like ice cream when you hit that pedal to the metal, and you will be defeated ,so if you are in serius modifiying loose that stinky cat

 

The stock cat works fine even on track if your car is running correctly. Tracked mine hard in aftermarket JCW like trim for 2 years without any problems & passed smog with flying colors. The majority of aftermarket cats are not as clean as stock and you may have MIL issues once they wear in and/or be dirtier at smog (if you pass at all). Even if you get 3-4hp from a modified motor by swapping the cat the gain is insignificant & won't be of use even on track. My aftermarket header needs a new cat after only 1.5 years and I doubt I'll be able to pass smog in its current condition.

 

hi 4wheels, im wondering what mods does your car have?

 

first off
i thought da ghost already made it clear that we werent aloud to use other cars as examples.
second
i didnt bother to read that article since it was clearly doing everything it can for the sake of trying to get the readers interested to try to prove that catless cars dont make more hp which I know isnt true.
third
....1hp? what does that prove? a car can easily vary 5hp in either direction between dyno pulls without any changes being made to the car. there are many different variables that will change the way the dyno reads like ambiant temp, humidity, heat soak, even elevation...ect

also high flow cats are notorious to melt and throw codes on our cars so i dont really consider them an option. and until someone gets a dyno sheet up here of a modded mini showing one heat soaked run of it with a cat and then another heat soaked run going catless as the only change on the same day, relativity the same time, and in the same shop, no one can say anything about it. all i can tell you guys is that i can definitely feel a difference with mine being out.
you can think whatever you want

 

Hold on there.... I've never said people weren't allowed to use other cars/makes as examples... but you have to compare apples with apples... You may get 20hp out of a catless V8 (IT'S AN EXAMPLE, NOT A FACT), but it doesn't mean you'll get the same result from a little 1.6L s/c.... If you want to prove me it's ''worth'' it, show me a dyno with and without a cat on the same Cooper S, no other changes. Because, no, I won't care if you tell me you get X amount of hp out of a Honda, not the same engine/setup.

Like I've said, unless it's a big gain, I don't think it's worth throwing more NOx and crap in the atmosphere for the sake of a couple hp. No matter the country or the regulation, I don't find it right for a street car, but it's my opinion. I'll run a cat on mine even if I track it almost every week!!

 

[QUOTE=Da_Ghost;3571225]Hold on there.... 20hp out of a catless
that was a nissan 300zx stock and it was for track only dude better read right man:

 

[quote=pmxgm;3571232]the 20hp thing was not directed at you as you clearly said it was a track car

 

no one said you would be getting 20whp out of a catless mini. and i wont be proving it to anyone since i dont have a dyno and it wouldnt be "worth" it to cut and weld up my old cat and do dyno pulls comparing them just to show you guys what you should already know. also i was under the assumption that this was a conversation about both street and track cars.

of course its not going to be a big gain, hardly anything you do to our little cars is. even our beloved pulley swap barley generates much real hp unless you tune for it. anyone saying you can get 20hp out of a pulley is lying through their teeth. realistically were talking maybe 5whp out of a catless mini depending on your mods. if your car is really built up and is tuned for it of course there would be a bigger difference. but that goes for anything you change on our car. how much hp do you really think your getting from a stepped header? unless your car is built around and tuned for it, it wont be making a huge difference. and if your modding your car for the track or street im assuming your trying to get every bit of power you can get from our little motors and going cat less is just another step in the game

once i finish my classes my school is going to let us run our own cars on the dyno and i will see how much hp is really gained running all the mods i have on my car with the stock tune. im not expecting much from it. mods dont make the real difference until you tune for it. tune is everything

 

RMW 1.8L (bored w/sleeves, forged rods & custom forged crank), RMW Jesus head with larger valves, lightweight retainers, double springs, race cam, shorty header, 550cc injectors, JCW muffs, JCW intake, fluid damper, 17% pulley, custom software tune by me, OS Giken clutch & LSD, and plenty of other crap I'm forgetting... but it looks almost stock.

I did this "radical" upgrade after owning the car for several years & tracking it for a couple. The stock cat in these things is pretty damn good compared to most of the aftermarket. With my aftermarket header I had to modify the ECU tune to accommodate the lower cat efficiency and different o2 saturation limits, and change the downstream o2 voltage effect on LAM trim.

 

hey 4wheels, i like your style. when are you gonna go turbo? lol

also what kept you from doing the full 2.0 bore?

 

You can't rev out the 2.0's as much as the 1.8's

 

Hey 4wheels you have a little monster there, so you are runnig a aftermarket cat and you said that the stock cat is better, why dont you put a test pipe when you race(at the track) and modified a stock cat to put it when you drive(on the street) that way you get the most of your mods when you need it

 

Test pipes are made for this exact reason. I already have planned the way I want my exhaust to be done and I'll have flanges on both sides of the cat (in case I get the infamous cat melting that some people are talking about) and one just before the muffler (in case I get pulled over and I have to change the muffler). While I'm at it, I will get a test pipe made just to get a dyno sheet comparison. I'm both curious AND annoyed by the lack of it as this is a subject that comes around every now and then here on NAM.

 

thats what i meant by weld the cat. weld flanges on it to match the test pipe so it becomes a bolt on cat. im curious what muffler your talking about tho?

 

I went for a Dynomax VT, only thing is that center/center for this model is 3''. I'm doing a ''straight'' exhaust setup (battery box removed), I have no idea how it will sound and cops can be annoying over here if it's too loud.

 

so then you wont have any mufflers anyway?

 

By ''straight'', I mean that with the battery box removed, the exhaust will go from the header to the muffler in a straight line, no funky curves!

 

Hi there , im just curious where you put your battery in the trunk i guess

 

okay gotcha
generally when i think of a straight pipe i think straight pipes not mufflers. as in straight gangsta

 

who is it again that makes batteries that are only like ten pounds and the size of a chihuahua?

 

here Steve i think you will find this helpful.

http://lmgtfy.com/?q=light+weight+automotive+batterys

And as far as you feeling a difference on removing the cat, did you ever consider its psychological...
I see zero reason to remove the cat from the system in anyway. it smells and it puts unwanted pollution out.
Also I do remember an article about Supercharged Miatas making better torque with cats on then not.
I wont bother to find the article because you are convinced we are all wrong regardless of what we say because of your butt dyno.

 

That but dyno must be verry sensitive to be able to feel anything under a 5 HP gain. Most professionaly trained buts cant do that.

Maby its because he is running more than one header on his car, dont see too many MINIs with headers.

Odessy makes a pretty good small battery, I have had a PC680 in my car since 2008. I only had to replace it once because after a year of being parked while I was in Iraq the thing was DEAD! Didnt even have to pay for the new one though, their waranty is good aswell, so I put that money into a battery tender.