joe603 wrote:
This depends. Not all FI apps are equal...

Supercharged engines need some back-pressure to build substantial boost (roots type systems are affected the most). Therefore, headers and test pipes may actually hinder performance. Now a turbo is different. It needs a wide-open exhaust to perform well.

Roots type build more boost because of back pressure yes, but that's not a good thing. No back pressure and a smaller pulley or bigger charger will make far more power more efficiently.

So headers don't hinder performance per se, they hinder the amount of boost a SC can make at any particular rpm. This is the main reason roots blowers are huge, because they need to be in order to move enough air to generate boost on a motor that is functioning at peak efficiency.

More flow in/out is free hp. This is not the same with a centrifugal type or turbo since they actually compress the air.

The key is to have a motor that can move the highest amount of air in/out of the motor across the rpm band, then figure what type of power adder will be the best. I say across the rpm band because some headers may give you more peak power, but fail where we actually need the power the most. But peak numbers are what sell parts...just be leery when it comes to high hp claims for a set of headers or a cat back.

WD

i always thought headers would give little to no HP's, it was torque you are looking for in headers...... please correct me if i am wrong.

You're not going to gain one without the other, but you may gain one more then the other though.

In my searching out some good HFCs I think that RANDOM TECHNOLOGY has some really good cats, but they are not cheap!

Kenrik wrote:Remember guys the G35 has TWO cats... one ceramic and one metal.. 2X because of the dual pipes and you get a total of 4 cats...

I don't know exact numbers but you can expect large gains by going HFC or Test Pipes.. (test pipes being the cheaper but more dangerous route)

I dont have a clue as who gave you this info but....................................you are wrong.The g has 2 cats and by eliminating them is illegal but it will net you about 20rwhp.

superchargedg wrote:I dont have a clue as who gave you this info but....................................you are wrong.The g has 2 cats and by eliminating them is illegal but it will net you about 20rwhp.

NO you are WRONG.. I know because have seen it..

There is a ceramic comb then an empty space and another metal comb... so TWO cats in each side.

I say go for HFCs if you can afford them... the G35 with test-pipes smells like a 1980s Ford Econoline Van..

I would love to put the pedal to the metal while driving in front of Al Gore though..

Kenrik wrote:
I say go for HFCs if you can afford them... the G35 with test-pipes smells like a 1980s Ford Econoline Van..

I would love to put the pedal to the metal while driving in front of Al Gore though..

You are sooo funny

Damn you all for making me want to mod my G. Now I want headers back!!!

superchargedg wrote:I dont have a clue as who gave you this info but....................................you are wrong.The g has 2 cats and by eliminating them is illegal but it will net you about 20rwhp.

Kenrik wrote:
NO you are WRONG.. I know because have seen it..

There is a ceramic comb then an empty space and another metal comb... so TWO cats in each side.

I say go for HFCs if you can afford them... the G35 with test-pipes smells like a 1980s Ford Econoline Van..

I would love to put the pedal to the metal while driving in front of Al Gore though..

Thats funny cause when i installed my greddy twins and replaced my cats with test pipes i removed 1 cat per side.I think you might want to do a little research.....or better yet call up the dealer and ask them.Im not trying to start a war....................but on my 2003 there are only 2 cats total.

To my knowledge, Infiniti/Nissan has been installing 2 cats per exhaust pipe for quite some time.

One is a smaller heated pre-cat and then a normal cat. The pre-cat is designed to work on exhaust during the first few minutes when the exhaust isn't hot enough to catalyze with the cat elements.

This is what I've heard/learned.

Could be but when i installed my greddy twins i had to remove the exhaust manifolds and the cats.I only removed 1 cat per side ......now if inside the cats there are 2 different catalyst materials i dont know and dont care.If you put any g or z up on the lift and look there is only 1 cat per side for cars sold in this country.....period.

If you all think that im lying just go on any other g or z site or ask the dealer how many cat convertor units are on each side and you will find the truth...........................case closed.

I now realize why i havent been on this site for quite awhile.................the lack of knowledge here is bad.

You're such a nice guy. Thanks for your wonderful attitude and countless contributions to our forum

6mt takes the cake as far as G forums with a lack of knowledge. We have a very well informed G group here. Sorry we don't have FSMs hardwired into our brain stems.

superchargedg wrote:Could be but when i installed my greddy twins i had to remove the exhaust manifolds and the cats.I only removed 1 cat per side ......now if inside the cats there are 2 different catalyst materials i dont know and dont care.If you put any g or z up on the lift and look there is only 1 cat per side for cars sold in this country.....period.

If you all think that im lying just go on any other g or z site or ask the dealer how many cat convertor units are on each side and you will find the truth...........................case closed.

I now realize why i havent been on this site for quite awhile.................the lack of knowledge here is bad.

Arguing with one member hardly constitutes a general lack of knowledge...

I know quite a few guys that enjoy helping and educating people, perhaps you are not one of those. For that I'm sorry I'm sure we'd benefit from having your experience around here, but if you can't handle a simple disagreement with another member then perhaps YOU should reevaluate your stance where online forums are concerned

WD

WDRacing wrote:
Arguing with one member hardly constitutes a general lack of knowledge...

I know quite a few guys that enjoy helping and educating people, perhaps you are not one of those. For that I'm sorry I'm sure we'd benefit from having your experience around here, but if you can't handle a simple disagreement with another member then perhaps YOU should reevaluate your stance where online forums are concerned

WD

Brian, he has to compare the size of his automotive certifications with everyone else. Then he is justified in speaking as a God, since we are just mouthbreathing window lickers, who don't have "Certs", and obviously know nothing about cars in general.

Beancooker wrote:
Brian, he has to compare the size of his automotive certifications with everyone else. Then he is justified in speaking as a God, since we are just mouthbreathing window lickers, who don't have "Certs", and obviously know nothing about cars in general.

Speak for yourself coffee boy I have a background in thermal dynamics, BS in the principles of forced induction and a masters in smack talk. I will do battle with anyone alive

But point noted...unless you are certified you know nothing. Guess when I built my own multi stg alcohol injection system and ran 28 lbs of boost on a stock ecu, stock injectors and stock maf still means I'm a lamen when it comes to making a boatload of power on boost. But then again if I do know nothing I can stay right here on Nico where apparently I belong

WD

When I put my HFC's on, I could only find 2 cats also. I guess thats because the 2 are combined into one massive heavy piece of metal?! Correct me if I am wrong.

I apoligize if i came off the wrong way and you guys are right about arguing.What ticks me off is when someone posts about what he thinks he knows and its totally wrong and then dosent do any research first.I just think you should know what you are talking about before you post wrong info.

And again sorry for being an ***.

No worries man I do the same thing all the time

I gotta admit, i love when the moderators get involved and shamelessly mock people into submission!!

Def not put into submission at all cause i will and do blast people for posting bs.If you cant research and find out what you need to know then dont post..............................................unless you are a tard.

it wasn't you they blasted