Should I get a header if I am keep the OEM cats?

[fortunato]

I am putting a Fabspped exhaust on my car and wanted to know if it makes any sense to put a header on at the same time even if I am going to keep the OEM cats. I have an 2003 2.7 with manual transmission

Is it worth the investment? There are several on ebay for about $150
would love to hear all of your thoughts.

[chaudanova]

It should be definitely worth it... your '03 has 4 cats... one on each header, and then one on each midpipe. If you put on the headers you speak of, you'll be getting rid of 2 of the cats, not to mention the aftermarket headers flow better than the oem exhaust manifolds.

[mikefocke]

You only have a 2.7 flowing through those headers. You are keeping all the downstream restrictions on the exhaust. So why bother.

Compute the cost (and risk...heard of head bolts breaking off several times) per advertised HP...and ask for dyno'ed results..as advertised and reality are sometimes very different.

[edevlin]

I did a series of dyno runs when I was doing mods to my 2000 2.7L Boxster. As I recall adding a full exhaust system (headers, 100-cell cats, high-flow muffler) only added 5-10 hp to my car. And that was with a ECU chip that was specifically designed to take advantage of higher-flow exhaust system.

I know others have have found big increases in HP with just the addition of headers or mufflers, but that has not been my experience. If you just like to mess around with your car like I do, and/or if you are not concerned about potential CEL issues that can come up with exhaust mods, and/or you have the funds available, go for it.

Even if you dont realize great HP increases, your car will probably sound like it's much faster, and that works for me. BTW, if you have not already done so, I strongly encourage you to do a baseline dyno pull to see what your car is making in stock condition. That way you will be able to judge how effective the mods may be, have fun.


Ed

[jhandy]

Get the maxspeed motor sport headers with cats, for 799$. and get the cat delete pipes for the secondary cats. No CEl and definate increase in power. Maybe about 15-20 hp. but the sound is awsome and fun to drive.
I will have dyno results soon. I did this mod to my 02 s and it really woke it up.
James

[Cloudsurfer]

If you're installing the FabSpeed exhaust (either the "new" or the "old" system), they utilize proprietary midpipes, so unless you go with FabSpeed's own catted headers, you will be catless. If you want to utilize the "eBay special" headers (which are non-catted), and you want to keep the factory secondary (now the only) cats, you will not be able to use the FabSpeed system.

For what it's worth, I'm running TurboWerx headers (non-catted) with FabSpeed's "new" exhaust (yes, I"m cat-less) with my DME flashed to RoW software, and it is fantastic. There are definite power gains to be had by getting rid of the horrible factory headers, and the much lower back pressure helps throttle response quite a bit. Sound is intoxicating as well No CEL if you run the German software.

Hope that helps.

Patrick