TucsonDrivers.com

Hi guys . Friend or mine told me Your Tuc has 2 catalitics, take one out youll get more hp . What you think guys?

Ohh and the header i would like to repalce the exhaust manifold with an stainless steel header but my tucson has 2 o2 sensors and im looking 97-01 is 2.25"and 02-07 is 2" whis one should i get ??

No only one cat on mine

If I find a cat on mine, it will be short one of it's nine lives

Don

well mine has exhaust manifold, catalitic, resonator, catalitic , exhaust. Still wich header should fit better?

wow... what year/model is your tuc?

Mine is a 2005 4 cyl I live in Puerto Rico Usa version i suppose. I took one of the cats good improve that can be feeled. Still my tuc has 2 o2 sensors and i want to drop a header but the one of the old tibby has 2 o2 but it comes out in a diameter of 2.25" and the newer tibby has only one o2 sensor but in 2" still which to get
?

Well, there are several questions you need to ask yourself. Firstly, do you intend on replacing the exhaust system from the cat back? If not, then I would suggest the header system that ends in 2 inch. If you do intend on replacing the original exhaust, then possibly the header that ends with 2.25inch. The larger diameter exhaust will enable your exhaust gasses to flow with lower back pressure, thereby increasing your horsepower, particularly at higher RPM. Unfortunately, this can also come at a cost of torque.

As for the second O2 sensor port, have one fitted on the 2 inch header.

Now the trouble that you will encounter in removing the cat just after the exhaust manifold is you will get a cell light. The first O2 sensor monitors the engine tune, i.e. being rich or lean with the computer constantly changing the tune as a result of what is measured by the O2 sensor. The second O2 sensor monitors the efficiency of the cat. Normally, changes in the first O2 sensor are followed by changes in the second O2 sensor, - a degree of change caused by the cat. Removing the cat takes away this degree of change and what is measured by the first O2 sensor will be experienced directly by the second. There will be no difference between the two, and a cell light will be thrown.

I know this as I have removed the cats on my V6 and replaced them with 2.25 inch headers (on the secondaries), and I do get a cell light. My cell light shows its ugly head after constant speed driving for about 30 minutes or so. Luckily, I can reset the code with my scan gauge. There are several things that can prolong the time between cell lights such as port extenders, blank plugs, additional resistance, electronic add on, etc, but you have to remember, the computer is expecting the second O2 sensor to report close to what the first O2 sensor is reporting within a tolerance. How lucky do you think you will be in adding the exact sized resistor, port extension, blank etc that will offer the required changes. The ods are stacked against you.

That being said, there is several HP to be gained by doing this. The choice is entirely yours.

well i took the second cat an leave the resonator and converted the stock 4cyl like the 6cyl because its the same shell of the exhaust so i opened the hole welded the tube there and it is exiting faster than the stock side and sound is louder than stock. you think that the 2.25 header work leaving the stock 2" tube without cat with resonator to the muffler??

ohh and almost forgot the man that did the cat removal job told me that the tube coming down the manifold is a little bigger

I believe that it will work fine. Plus you now have the option of increasing the size of the rest of your exhaust to match the header at a later date.

How about posting some photographs? It would be nice to see and may inspire others.

Oh when i get home i will take photos and post them. Ohh another question beta 1 is the same block as beta 2 the only difference is the cvvt? so te later model tiburon fit to the betta 2?

Here are the photos!! hope you like =)

The rear looks like a V6 or a CRDi now.

I believe what you have said regarding the blocks for the Beta 1 and Beta 2 is correct. I do believe that there is some difference in headers to fit a manual or an auto, slightly different bend apparently, but I ma not sure. I have read other posts on the subject. My car is a V6 and had to be modded quite a bit because of the transfer case.

How about some photos of the headers/exhaust mod when you are done?

Here is a link to a post that shows my exhaust and headers. The first lot of photo's are from 31bravo with his supercharged sportage. Mine are next, N/A at the moment.
http://tucsondrivers.com/viewtopic.php?f=12&t=3840&sid=5456cc780318947ac8e0ec5df9af64da

But then is it the same block and produces the same hp, why the non cvvt headers arre 2"inlet 2.25" exit and the betta 2 with cvvt is 1.75 inlet 2" exit ?? still

Good question. I do not know the answer to that one.

With an understanding of fluid dynamics, the narrower you make a tube (i.e.1.75" vs 2.0") and with the amount of force pushing a gas through it (i.e. piston rising on the exhaust stroke), its velocity will increase through the tube. Although, even though its velocity increases, the time taken for all the gasses to escape will remain the same. Now, given that the intension of VVT was to maximise fuel efficiency as well as power development, perhaps an engine with vvt will in fact take less fuel and air to produce the same amount of power at a given RPM and load. If this is the case, you could reduce the tube diameter because there would be no need to be larger for that particular quantity of exhaust gas. If a larger exhaust header were fitted, then maybe the loss of back pressure would cause a loss of torque.

This is only theory, and I do not know the real answer. If anyone can provide additional incite, please chime in!!!

The question is: why does the earlier model I4 engine without CVVT have a larger 2.0" tube vs the later model I4 with CVVT have a header with 1.75"

Regards
Terry

So i guess ill be getting te 2" one. So what u guys think?

Go with the 2.0", particularly if you intend on at a later date to add CAI and improve plow through the intake as well.

im getting that one but ill need to weld an o2 sensor bung . Do you guys know the size?

Sorry, I don't know that. I am sure an exhaust shop will.