Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 5th July 2007, 01:28   #1
Senior - BHPian
 
ananthkamath's Avatar
 
Join Date: Jul 2005
Location: USA
Posts: 1,194
Thanked: 46 Times
Default Removing a Catalytic Converter (Cat Con) - Do you guys think its worth it?

A recent post by some guy on another board made me think - Are we doing the right thing by advocating removal of the cat on our cars in exchange for the supposed HP gain?

Some things we need to think about before removing the cat -

1) Do we need to remove it in the first place? What gains are APPARENT & MEASURABLE from this?

2) Is there any published data on the gains from removing a cat either on our Indian engines, or from similar engines abroad?

3) What is the impact on the environment?

Why not do some research and form a conclusion before senselessly contributing to slaughtering the environment more than necessary?
ananthkamath is offline   Reply With Quote
Old 5th July 2007, 17:49   #2
Distinguished - BHPian
 
Mpower's Avatar
 
Join Date: Mar 2005
Location: Bangalore
Posts: 10,432
Thanked: 1,682 Times
Default

I think every car will respond differently to this. Some will show a lot of gain and others negligible..but generally it will improve top end power.

Late model cars which are designed for LEV and ULEV emissions have a catalyst that is stuck into the manifold that prevents any kind of header installation. Thats another problem.

Another thing to worry about is what is the ECU going to do when it detects a missing cat. Might need a remap for that.
Mpower is offline   Reply With Quote
Old 5th July 2007, 18:27   #3
Senior - BHPian
 
n_aditya's Avatar
 
Join Date: Oct 2005
Location: Namma Bengaluru
Posts: 5,206
Thanked: 2,742 Times
Default

Quote:
Originally Posted by Mpower View Post
Another thing to worry about is what is the ECU going to do when it detects a missing cat. Might need a remap for that.
Wouldnt the ECU "remap" itself as it is a self learning thingy? If the battery is disconnected and reconnected after few mins the ECU gets reset and would "learn" the new inputs. Wouldnt this work at least to some extent?
n_aditya is offline   Reply With Quote
Old 5th July 2007, 21:07   #4
Senior - BHPian
 
mail4ajo's Avatar
 
Join Date: Mar 2006
Location: San Antonio, TX
Posts: 1,834
Thanked: 222 Times
Default

Quote:
Originally Posted by n_aditya View Post
Wouldnt the ECU "remap" itself
ECU cannot remap itself. But it will learn the new values and work based on the map loaded.
But we are not fiddling with any sensor, right? So will there be any difference in the values at all??
mail4ajo is offline   Reply With Quote
Old 5th July 2007, 21:14   #5
BHPian
 
Join Date: Feb 2005
Location: Bangalore
Posts: 86
Thanked: 5 Times
Default

I think considering the damage to the environment........it is strongly recommended not to remove the CAT CON.
AUTO_CRAZY is offline   Reply With Quote
Old 5th July 2007, 22:29   #6
Senior - BHPian
 
veyron1's Avatar
 
Join Date: Mar 2005
Location: Mumbai
Posts: 1,426
Thanked: 37 Times
Default

1) Removal of cat-con is unnecessary unless the car is being tuned for serious performance gains (Upwards of 30%). Even more unnecessary if CC of engine is below 2000.

2) For anything below, cat-backs should suffice; the muffler & expansion chamber (pre-exhaust) reduces the EG velocity by a greater margin than the cat-con itself.

Quote:
Originally Posted by Mpower
Another thing to worry about is what is the ECU going to do when it detects a missing cat.
Most ECM's won't detect the cat-con; lambda sensor's at the exhaust manifold, na...there aren't separate sensors for cat-cons in most cars...at least not the non-expensive ones...
veyron1 is offline   Reply With Quote
Old 5th July 2007, 22:42   #7
Team-BHP Support
 
theMAG's Avatar
 
Join Date: May 2006
Location: Long Island, NY
Posts: 7,033
Thanked: 1,470 Times
Default

Quote:
Originally Posted by ananthkamath View Post
..
3) What is the impact on the environment?

Why not do some research and form a conclusion before senselessly contributing to slaughtering the environment more than necessary?
I hear you man. I'm all for healing the environment while still making our lives exciting. Thats a very difficult choice curently.
theMAG is offline   Reply With Quote
Old 5th July 2007, 23:34   #8
Senior - BHPian
 
mail4ajo's Avatar
 
Join Date: Mar 2006
Location: San Antonio, TX
Posts: 1,834
Thanked: 222 Times
Default

I was just wondering if removing the CAT will give more pickup while driving on LPG. I wont be damaging the environment a lot since LPG creates minimal pollution.....
mail4ajo is offline   Reply With Quote
Old 6th July 2007, 00:25   #9
Senior - BHPian
 
veyron1's Avatar
 
Join Date: Mar 2005
Location: Mumbai
Posts: 1,426
Thanked: 37 Times
Default

LPG, hm...now there's a thought...why not have a dedicated high-compression engine for LPG? We could do away with cat-con altogether...

We have Diesels. We have petrols. Why not consider LPG as an alternate fuel..? Could make for some really interesting powertrain designs...and even more interesting specs...
veyron1 is offline   Reply With Quote
Old 6th July 2007, 00:55   #10
BHPian
 
Join Date: Mar 2007
Location: gurgaon
Posts: 39
Thanked: 0 Times
Thumbs up

Quote:
Originally Posted by veyron1 View Post
LPG, hm...now there's a thought...why not have a dedicated high-compression engine for LPG? We could do away with cat-con altogether...

We have Diesels. We have petrols. Why not consider LPG as an alternate fuel..? Could make for some really interesting powertrain designs...and even more interesting specs...
thats an interesting topic but do you think that india has the resources and technical saport for designing and developing a new engine for only LPG ..?? LPG is also a kind of non renuable energy source .. which in turn cannot make it a alternate fuel .. if we actualy care for mother earth we should try and develope a solar or hydrogen car that can be as easy to use and run as a internal combustion engine ..
devilvtec is offline   Reply With Quote
Old 6th July 2007, 03:43   #11
Senior - BHPian
 
ananthkamath's Avatar
 
Join Date: Jul 2005
Location: USA
Posts: 1,194
Thanked: 46 Times
Default

LPG and other alternate fuels aside, the point I'm trying to make is that there are lot of guys out there who think "Hey, that cat con is robbing me of 15 hp, so lets remove that, I dont care about the environment anyway".

I dont think that's the right approach. But we dont have any figures to prove that. Has anyone come across data which shows the flow losses across the cat? At any rate I doubt its above 2 psi of loss which means a miniscule amount of power on a "street tune" engine.

Now if you're planning to improve the torque of your engine significantly through a turbo or NOS, the answer is clear. Get a high-flow cat. Or ditch it if you're racing. Stock engines are already flow-challenged on the exhaust side so when you do these mods its imperative you improve on that end.

But what about stock and street-modified engines? Post away, guys......

PS: My access to the SAE paper database is down for some reason but I'll try and come up with something when its up.

Last edited by ananthkamath : 6th July 2007 at 03:46.
ananthkamath is offline   Reply With Quote
Old 6th July 2007, 04:04   #12
Senior - BHPian
 
ananthkamath's Avatar
 
Join Date: Jul 2005
Location: USA
Posts: 1,194
Thanked: 46 Times
Default

I found this through google:

http://www.fluent.us/direct/dieselnet-listing/ex185.pdf

You can see in Fig. 3 that the velocity loss through the cat is negligible, and the contours prove that the velocity in the headers is the same as that in the cat. But the pressure loss is considerable as in Fig. 4. Is this enough to hurt flow and thus power? We dont know yet.
ananthkamath is offline   Reply With Quote
Old 6th July 2007, 06:14   #13
Senior - BHPian
 
Join Date: Apr 2007
Location: Pune
Posts: 2,451
Thanked: 955 Times
Default

Ananth,
I second you.
We should not harm the environment.
In fact we should help our RTOs to gear up and nail down such modded vehicles on Indian roads. Pune and Bangalore have had enogh of air pollution already.
And automakes are spending so much on Euro 4 and 5 requirements and the consumers are being passed on some part of that cost...the so called car enthusiasts that moodify the exhaust for "audible power" should be heavily penalised.
anandpadhye is offline   Reply With Quote
Old 6th July 2007, 13:17   #14
BHPian
 
Hellcat's Avatar
 
Join Date: Jul 2005
Location: Bangalore
Posts: 222
Thanked: Once
Default

I have one question for all you guys who have removed you Catalytic Converter. What about emissions standards? How do you manage to get you emission certificate?

Hellcat
Hellcat is offline   Reply With Quote
Old 6th July 2007, 13:20   #15
Team-BHP Support
 
tsk1979's Avatar
 
Join Date: Feb 2005
Location: New Delhi
Posts: 22,953
Thanked: 15,644 Times
Default

Unleaded Petrol when burnt without a CAT gives out Benzene apart from N oxides and other undesired stuff.
Benzene is highly carcinogenic.
tsk1979 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Think Volvo Buses, think safety? Think again! rahul_intlad Commercial Vehicles 89 14th April 2016 12:09
Wagon R: Noise from Catalytic converter? EDIT: Cat Con is GUILTY. bblost Technical Stuff 26 12th July 2012 15:08
2011 i10 Asta A/T - its Korean, its new, its fast, its red, and its coming. nirupesh Test-Drives & Initial Ownership Reports 1 8th January 2011 10:45
Settings gone after removing HU and removing key achopraa In-Car Entertainment 14 15th December 2007 22:18


All times are GMT +5.5. The time now is 11:35.

Copyright ©2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks