Hi. i have already done a cat removal to my car... instead of the cat i have a pipe ... but know ive been reading here in the forum and the guys only talk about the precat removal..

Taking them both off(cat and precat) is ok? or is there any particular reason to talk only about removing the precat and not the cat?

Remind that i am searching for power power power

 

Is it ok? It's illegal, but other than that it's "ok". You'll need an o2 sim. Pulling both cats off isn't always a good way to make power, remember, without some back pressure you won't make any torque.

 

i dont have an o2 simulator and my eml light is off... but that o2 simulator.. how does it works?

I have my car tuned and i think i need o2 "data" to send to MTH(it goes in the file)

Or am i saying something really wrong??

Back pressure... if its related with the exhaust pressure that goes through the exhaust i can say that is very high.. i have never seen a mini that "throws" so much "air" with so much pressure through the exhaust..

NOw i think i said something really wrong..

Sorry for my lame english!

 

Backpressure refers to the restriction in the exhaust, not the air that comes out, that's normal pressure .

How an o2 sim works exactly i'm not sure, but the idea is to simulate your o2 sensor so you don't throw a check engine light. With both cats removed you would have nowhere to put your o2 sensor, so if you have both removed, and have no CEL, I don't know what to tell you, that's how i've always seen it work .

Your english is better than some native to the US, no need to apologize.

 

In general, closed loop EFI cars won't run as well without the cat. The ECU is looking for a differential between the frist and second 02 sensors within a certain range and adjusts the air-fuel ratio accordingly. However, as long at the readings are within that range, it may not throw a code... yet... Depending on where you live, the ECU may calibrated different than a US-spec car for fuel quality reasons.

Keep in mind that in the U.S. emissions related systems are heavily regulated. Thankfully... as otherwise in certain urban areas we'd be walking around with oxygen tanks by now...

 

I would remove the cat and precat but the o2 sensor will still be there... both of them(i think that there are 2)


Here in my country the emissions are not very regulated...

And my car without the cat passed the emition tests!! and no EML!

So... Remove it or not....?

Need more power ... i want to smeel a stock cooper S *** and i am getting near!!

 

You won't find the benefits you are looking for by removing the cats. It will hurt the performance of your car and most likely make it sound like crap too. A K&N drop-in would probably do more to help increase your car's power than deleting the cats. I did it on my previous car and regretted it for many reasons. I would never do it again.

 

maybe my list of mods would be helpful...

I've already in another "stage"...

KN panel Filter
NGK Iridium
Mth Remap(tuner file)
Cat removal
Cooper S 6spd gearbox...(163bhp)
Mini Cooper S throtle body

When the car was remaped i only had the kn panel filter...and with that only i had 130hp(98 octane fuel)

 

Why would removing the cat/s hurt performance?

 

Then get ready to spend a lot of money.

Simply put, the Tritec engine in the R50 is already pretty efficient and the only way to get more power out of it is to push more air and fuel through it. Deleting the cat will basically gain you nothing without seriously revising the input side of the engine to make use of the additional exhaust flow. We're talking head work, cam, increased compression ratio, boring & stroking, reducing internal rotating mass, and then probably a custom ECM system to make it all work.

Basically: old school hot-rodding.

However, keep in this mind: Horsepower is a function of fuel burned and OEM's increase performance in one of a few ways: increasing displacement, forced induction (supercharging or turbo) or increasing revs (the "Honda way") which all basically achieve the same thing: combine more air & fuel in a given engine rotation over a period of time.

Or think of it this way... F-1 engines squeeze huge amounts of power out of tiny little naturally aspirated engines. How? Simple - they're revving the little buggers to 14K rpms (and beyond) thus turning more fuel into horsepower over a given time.

 

Ecu remaping to adapt to the cat removal... no problem...


In my plans, i have the bmc cda in mind(with some custom adjustments(like Der Abt has)) and a obx header...

After that and a Ecu remaping to all this stuff i will be very near to 140\145bhp... later a schrick cam...

With all this well tuned with the afr ratio correctly adjusted and with the help of the cooper S gearbox with quickshift i will be able to "smell" a cooper S ... i will only have in max 10\15 bhp diference...

So is achievable without spend BIG bucks...!

BTW i have a cooper S engine to take off everything i want!! So.. no problem if i want to work the stock head!!

 

almost forgot.. its minimal.. but i also have the cooper S fuel pump... 0.5bar diference comparing with the stock one! so... do you still think it's impossible?

I have another post where you can see my dyno....

 

It will sounds horrible, ricer IMO

Jack

 

ricer? sorry.. dont know the meaning of the word.. i am not english!!

Do you really think it will sound horrible...

Anyone with a sound clip for me to ear it?

my car after the cat removal sounds nice... it just pops a little bit more...but very "normal"

 

I'm afraid you are overestimating the amount of gain these mods will give you. Historically, it just hasn't been the case with dyno results. Consider this: I have yet to hear of a MC (R50) with an aftermarket turbo making the same dyno numbers as a stock MCS and this is one of the big reasons why the kits are not common.

IMHO, the better to improve performance (power:weight) is to hit this from the other side: reduce as much weight from the car that you can. Lighter wheels, lightweight flywheel, and so on. Mods like this will help you in real-world situations where the performance differences in the models is less horsepower dependent.

But in a straight up drag race with a stock S and equal drivers, a Cooper is going to lose, no matter how much you do to the engine.

 

i am not going to drag my One..... just one a one with... "grunt"... just that.. nothing more!!!

And i really dont think i am overestimating...

130hp.. are there.. i measeured it in the dyno...

with bmccda, obx header, cooper s throttle body, cat removal etc.. do you really think i am not going to get 150? plus the schrick?

hmmmm..

BTW .. if you say i wont achieve it... i will only get more ways to prove you wrong.. you will see!!

 

Dynos lie... and unfortunately they have for years... and can be inconsistent... so I don't believe them much.

So no... w/o going inside the engine and replacing the ECM (not flashing it - replacing it) I don't see a believable 150 hp from a n/a Tritec. Not when previous attempts at what you're trying (none of your mods are breaking new ground here), plus adding a turbo have failed to reach stock MCS numbers.

But if it makes you happy, have fun.

 

There's no perfect dyno i know.. but it can give us a good idea of the evolution of our cars...

i am not going to turbo my car or put the cooper s compressor.. but i sure do hope to reach the 150bhp barrier...

I have a lot of ideas that i have never seen talked here and i will explore them...

Then... if i have results.. i will post them here!

Only testing and "retesting " will make me closer to that barrier.. and i will try my best to show you i dyno graph of my car reaching that barrier...

In my head... its just a matter of time!!

 

THat's the spirit.....

I'm glad I have a Cooper over an "S", more challenging that way.

I have been checking my improvements with a Gtech. Just got 3-4 hp increase and about the same in the torque after adding a OBX header. Putting the head on next week. Cam next.

Still doesn't compare to the time I could gain from driver skill alone.

 

I believe that with your current mods (software, BMC CDA, obx header, Cooper S throttle body and cat. removal) 130hp is realistic.

Software will add an average of 6hp, the CDA adds at least another 3hp at peak power, but through the rev line, it can add much more.
The OBX header will only add torque and very little (if any) hp.
I know people with a Milltek header or Supersprint header on their car, and they gained maybe 1-2hp, but they did gain a good amount of torque.
The Cooper S throttle body will work well together with the BMC CDA and together the gain with the intake will increase.
And last but not least, the cat. removal is good for at least another 4hp.
Total : 6 + 4 + 1 + 4 = 15hp.
Let's say your car runs between 113 and 115hp stock, add to that 15hp and you will see 128-130hp.
Those are realistic gains with your mods.

However, to get to 150hp, a lot of mods are needed.

Kelleners reached 144hp with custom software, custom BMC CDA setup, Kellener camshaft, sport cat., cat-back exhaust, gasoline cooling, iridium spark plugs and a Sachs clutch.

Lohen reached 150hp (but only just) with the following mods : Superchips Bluefin with Lohen LO3 map, Milltek Cat-back exhaust, modified manifold and high-flow cat, Pipercross Viper kit, iridium spark plugs, Lohen performance head, camshaft, exhaust valves, Lohen 58mm throttle body, replacement gaskets & head bolts.

Kind regards

Der Abt

 

Before more replies here are my current mods:

KN panel filter
MTH tuner file(to 98 octanes fuel.., it was tuned when i only had the KN).
later(and without any "retune")
Ngk iridium
cat removal
cooper s throttle body
Cooper s fuel pump (+0.5bar)
Cooper S gearbox(no engine mod here but maybe you should know)

The future mods will be:
bmc cda
obx header
Cams(kent or schrick but maybe kent)
And a good exhaust
Retune and AFR adjustment

The car went to a dyno only with mth and kn.. 130bhp..(but i prefer to say i have 125.. more realistic)...

with the extra mods..

maybe... i have 130...

i think by just retuning my car right know i would gain 4\5bhps..

135 + (your 15bhp) 150

Am i beeing to positive?

btw the current top speed is 220kmh in straight line..

 

FYI - Some info from Webb Motorsport's web site FAQ section:

[SIZE=5]Why do you only use headers that have a catalytic converter?

[/SIZE]Because I care for the environment - just kidding (not that there's anything wrong with that).
This question goes to how the MINI determines the A/F (Air/Fuel) ratio. There are two basic functional modes the ECU: open loop and closed loop. Closed loop is your friend, as it uses real time, actual fuel burn to determine the A/F ratio. This is determined through the O2 sensors, located in the header. The spent combustiable mixture passes out of the cylinder head and into the exhaust system. The O2 sensors can tell the ECU what the fuel ratio was, and the ECU trims accordingly to maintain the desired ratio. OBDII (On Board Diagnostics II) uses the O2 sensors to monitor catalyst efficiency.
Open loop is used when the O2 sensors can no longer handle the flow rate. This is pretty acuurately described as a "best guess" A/F determination. It is a very accurate guess, but real time data is always the best.
The MINI has two O2 sensors, one pre-cat and one post-cat. The sensors measure the temp difference and convert it to voltage, which is monitored by the ECU. Because of the OBDII, it needs to be sure the cat is functional. If there is no change in voltage, the O2 sensor assumes it has failed and the ECU functions in open loop.
So, the reason I use only cat-equipped headers is so I don't lose the accurate closed loop ECU function.

 

Add the BMC CDA to that setup, and 130hp (maybe 131/132hp) is very possible

Add those mods on your car, and my guess would be 138hp (maybe 140hp).

MTH software with a panel filter is good for maybe 122hp.
Here's a group of Dutch owners who did a dyno test with the MTH software and other mods.



Here's the result of a German owner who has MTH software on his Cooper.
He has no other mods, just software.
He produced 120,6hp.
Link : http://www.newmini-technik.de/images...dyno-liste.pdf
His car is the only Cooper on the list (number 11).

I meant +15hp on top of stock with these mods :

BMC CDA
MTH tuner file(to 98 octanes fuel.., it was tuned when i only had the KN).
later(and without any "retune")
Ngk iridium
cat removal
cooper s throttle body
Cooper s fuel pump (+0.5bar)
Cooper S gearbox(no engine mod here but maybe you should know)

I think with all your mods (including your future mods), 138/140hp might be possible.

Kind regards

Der Abt

 

Just do all the mods.
It doesn't really matter if you have 138 or 150hp.
The car will drive better anyway

Kind regards

Der Abt

 

here is a soundclip from my cooper ; afe cai - ss header - ss pipe (cat replacement) - magnaflow ...