Header/exhaust question

[23109VC]

I have a 2000 2.7L 5 speed.

I have desnorkeled and have a pedro muffler. my headers and midpipes are stock.

I am thinking of adding an exhaust/header setup. I like how my car sounds now, but wouldn't mind more power.

I have seen the dirt cheap chinese headers on ebay - I've read some threads here where people have liked them, others said they were too loud, or threw CELs...

I believe my car has cats in both the headers and midpipes. I believe my O2 sensors read before/after the front/primary cats and that's it. So if I remove the midpipes to cat delete pipes - I still have the cats up front and my o2 sensors won't know the difference - BUT, I've read that of the two sets of cats - the fronts are the more restrictive ones... not sure if that is true or not.

SO - if I want to maximize power - then I should get rid of the headers and put on some that have NO cats, but then relocate my O2 sensors to after the secondary cats... which migh require some welding, adding extension to the O2 wiring, and installing some bungs onto the midpipes.....

I could just blow a big chunk of change and buy a full NHP system that has cats in the headers and in the midpipes..they claim they are high flow cats... but I'd rather not blow big $$ on a sysstem if I don't have to.

my goal is to maximize performance, but do it on a budget.

what is the consensus here?

am I beffer off getting rid of the front/primary cats or the secondary cats? is one more restrictive than the other?

I live in CA and so I must run some kind of catalytic converter - while the visual might mater which one I have - I kinda think I could squeek by as long as there is SOME cat on the car. so many smog stations are ignorant about porsches and they see so few cars they will have no clue if I am supposed to have one or two sets... as long as it has some on it, and it passes the sniff i'll be okay.

I Just smogged the car, so i'm good for the next two years anywya.. so screw it. but i don't want to run catless as that is illegal and would be a big nasty fine if I was to be caught - so I have no desire to do that.

so - do I get rid of the front set or the rear set? will one make more of a difference in power gains? will one or the other being removed affect the noise level / sound of the exhaust?

the cheapest route I can think of right now is to add cheap chinese headers - $100 or so - and then reroute some of the O2 sensors rear of the secondary cats... then I still have two cats - but I have a high flow header on the engine.

will that make my car louder? crazy loud?

if I opted to get the NHP heders that have "hi flow" cats in them - will it really make any power - or is the fact that there is a cat in there going to clog it up a log more than the chinse headers. i would have to think that NO cats in there is going to obviously flow the best, and even a 'high flow" cat has to have a bunch of restriction...

suggestions? also - is all this a big waste of money? i mean, how much hp will I pickup on a 2.7 by doing this???

also - would I need to redo my ECU to take advantage of this? are those chips any good? i know they are not cheap - i have seen them and I belive most of them are $1000+ just to get a new flash. unless it makes a noticabel gain in power - that's a lot of money...

okay - another questio - do those chips help on a stock car??? or are they only good after you do intake/exhaust/etc

thanks!!!

[jhandy]

1. having no cats at all will give you CEL and horriable A/F ratios. Bad idea. Unless you flash with Euro DME. good luck finding that in the US.

2. Lose the secondary cats, you will get a little improvement, no CEL. cost about 100$

3. Lose the headers and primary cats, keep the secondry cats. This has been done, it is a huge headache. The O2 sensors convert thier findings to an electrical signal that inpart is bascially a resistance number. The longer the wires, the more resistance, the closer and farther, the hotter and cooler the 02 sensors are, there is a difference in readings. If it is not perfect, and I dont see how you could even begin to calculate the correct place to put them, the CEl will come on and read #1.

BUT replaceing the headers will get you the most gains.

Also if you read my other post or serched in this forum, you will see the china headers can BURN your car to the ground. It is poorly made and gets very red hot, and it may not work with automatic cars because of a fluid hose and the power stering hose often gets burned up as well. Bad choice. Very expensive 1000$ in repair costs if you get to it before your car catchs fire.

4. Maxspeed headers (700$) and custom made bypass pipes (100$) is the best way.

5. There is almost no gain from a muffler. Aside from weight savings, your pedro muffler will be more than enough.

So the cheapest way to do it without HUGE headaches is about 800$ and install it yourself.
Also buy NEW HEADER BOLTS. trust me, for 12$ you will save yourself big problems. Mine fell out seveal times on the road untill i got new ones.

You have a nice german sports car that is worth 15-20,000. Why do you want to do something so cheaply you rig something up that will need to be fixed every weekend?

That is what I did until I got smart. Smart people make mistakes, Smarter people learn from other's mistakes.

I finally did it right and gained 30 hP and 30 ftlbs torque, proven on the dyno.

James

[funkdefino]

Questions for 23109VC:

Obviously these "$100 bypass pipes" you speak of would be done at a custom shop. What kind of place would someone go looking for this kind of work? Is $100 a realistic price or is that a shop around price?

Basically I was considering going with the setup you just described above. I have a 2000 S that I would love to do this on... Any thoughts or recommendations?

[jhandy]

Fabspeed sells a strait pipe for 400$. If you went to a muffler shop with the OEM pipe and cat in hand, they could make it for you.
However will they is the question.
It is againt the law to modify a car and remove the emission controls, IE the cats.

So that is why you will have to bring the pipe in apart from the car, and with a wink and a nod, they may do it for you.

No local shop would do it for me in my town, so I bought the fabspeed pipes.

[Lil bastard]

IMHO, now is the worst time to be blindly trying to upgrade the exhaust.

If you carefully re-read some of Jake Raby's posts on the subject, there do not appear to be many exhaust systems out there which outperform the stock factory setup. Easy to blow $2k and get a reduction in performance, more than wasting your time and money.

If it were me, I'd wait a few weeks until Jake reports more of his ongoing research on the matter.

[Topless]

Tuning and emissions nightmare. Way more trouble than it is worth in Calif. IMHO.

[spine911]

Originally Posted by Topless

Tuning and emissions nightmare. Way more trouble than it is worth in Calif. IMHO.

I agree, be prepared to spend significant $$$ when doing any type of performance tuning project coupled with compliance with strict Ca. smog rules.

[23109VC]

I'm going to wait for Jake's results.

Also - if it truly is going to cost me $2000 for a new exhaust - I will just pass. If I'm going to drop $2000 just to get another 5-10 hp out of my 2.7, I might just rather bank the money for tires, other expenses, or hell - upgrade to an "S" model....

[spine911]

Originally Posted by 23109VC

I'm going to wait for Jake's results.

Also - if it truly is going to cost me $2000 for a new exhaust - I will just pass. If I'm going to drop $2000 just to get another 5-10 hp out of my 2.7, I might just rather bank the money for tires, other expenses, or hell - upgrade to an "S" model....

A COMPLETE exhaust performance project can easily cost $2000 (depending on the brand)
New Muffler, High Flow Cats, Headers, etc..etc.. Plus Labor costs.
CEL issues(if any) can nickle and dime you close to your budget.

[spine911]

[QUOTE=funkdefino]Questions for 23109VC:

Obviously these "$100 bypass pipes" you speak of would be done at a custom shop. What kind of place would someone go looking for this kind of work? Is $100 a realistic price or is that a shop around price?
[QUOTE]

Im assuming these are the "across the border" type of place.

[jhandy]

If I where back in Arkansas it would not be a problem, If you know the shop owner, and they know they will not get in trouble for it, then in economic times like this, they will do it for 100-150, materal cost is about 40 total.
It is just a strait tube.