If you've ever read a performance part's features and saw an advertised gain of Xhp and Xtorque and made your decision on that along, here's why not to.

This is just an example of a performance part (DC Sports 4-1 header) for the tC. I didn't choose this product because of its brand or anything other than making a point.

I did an overlay of the dyno graphs they provided and here's what I came up with:



Now you can visually tell that there is almost nothing at the bottom end (2krpm or so) but take a look at 3krpm and the gap between the red torque curve (DC Sports) and the blue torque curve (OEM). There is quite a visual difference from there all the way to redline. Think of this in terms of a drag race.

1st gear - launch at whatever rpms and go from 2-3krpm up to redline
2nd gear - shift into 2nd with rpms at 3krpm (or so) and continue to redline
3rd gear - shift into 3rd with again rpms at 3krpm (or so) and continue to redline
etc. etc.
As you could imagine, spending the most time in the areas with high gains is what you're looking for if you're wanting to race. These areas are what you're looking to add to.

Where the peak gain numbers can be misleading is that it can take away from certain areas and have a very peaky area of power (i.e. remove low end torque only to add high end hp (5krpm-6.3krpm)).

This is how some companies sell their products... Advertise 15hp gains but in reality the product shifts the power by giving in certain places and taking from elsewhere.

Bottom line, do your research. Ask for dyno charts with mods listed and environmental factors listed BEFORE you buy your product or don't complain when you don't get your money's worth.

Use your knowledge of the pwoer curves to combine parts that will be helping each other instead of contradicting each other. Stay away from manufacturers who do NOT answer questions you have for them and their products.

This has been a "Bored on a Saturday" production LOL

-Matty-tC

 

It's actually a 4-2-1 header. That's what I love about AEM and DC; they go for what's useful, not for the most. AEM's intake, if it comes into existence, will have the same max power as the others but supposedly 90% of their R&D goes into making power in the middle of the RPM band.

Good find.

No loss of power anywhere, good to know.

 

Good find also, but to bad it sets off your CEL

 

tc05: i made this thread for a general reference in researching and purchasing performance parts. i wasn't highlighting the dc header for any other reason than they did good r&d and have proven it with their dyno sheets.

but to fix your problem, pick up one of these:
http://clubsciontc.com/ccproduct.php?productid=1009

put it in place of where you o2 sensor is now and put your o2 sensor into it and you will fix the CEL problem

 

Yeah that caption was on the sheet from DC/AEM. I didn't add it.

I believe the Alphawerks header would be a nice 4-1 that should have dyno sheets like this so people can see though ;)

 

Yea, crazy companies posting the wrong stuff about their own products.

It's because it's a race-only header and almost all of DC's headers that are race-only are 4-1 designs.

Alphaworks doesn't have the same amount of power down low. The difference is negligible in racing though.

 

useable power and dyno power are different beasts

 

If you're redlining when you shift, you end up closer to 4-4.5k depending on the gear. I have an Alphawerks header and Blitz exhaust. It FLYS through 1st and 2nd gear. My friend has a 97GSX runing 12s and he hasn't been in my car since the mods (Lives in FL). He came back for the weekend and said it felt much faster on the top-end since the last time we beat on it. I'm racing this Wednesday if the weather holds up. Debating on what kind of weight reduction I can do to make up for the wing, 18s, and body kit haha...

 

pull off the wing, get some lightweight 17's, and remove the body kit LOL

 

Matty, no pun intended i was just stating it set off the cel, and thanks for the non fouler advice as soon as i get the money im going to get the dc headers and the non foulers, but one question do i just put it on the o2 sensor that goes into the header or both?

 

you put the antifouler on the o2 sensor bung and screw the o2 sensor into the antifouler

 

on the s pipe. the sensor on the header is the air fuel sensor not the O2. when you goto pepboys its in the help section. part number is 42002 or 42009. you want to use the one that has a gasket and not the tapered one.

 

so when i open up my hood its not the sensor i first see right? so im guessing its below the car, sorry for noob question but i didnt have to worry about the Cel problem in my eclipse the Greddy headers didnt set it off, any pic's?

 

doh
thanks for clarification

 

i got DC headers with anti-fouler installed, and NO CEL.

alot of people say a resistor chip also helps prevent the CEL to come on.. thats what i got too.... drive this tC for 2000miles already and no CEL.

i like my headers. i notice differences with my header, damper kit, and chip. except my intake, its just there for sound...haha

 

ok thansk for clarifying

 

There is always a tradeoff. When you open up the exhaust ports or header, you are going to give up power down low to flow up high. It's physics, the scavenging effect. There is a middle ground to satisfy you, but it won't be the best of both worlds.. it will be "half" of both worlds.

Same with turbo kits. You put a big16g on a 2.4, we (DSM world) have already proven how high it will rev on what boost. If your heads flow better than ours, then your limit will be lower than ours. When you go to a bigger turbo, you get more power, but takes longer to spool.

 

interesting...so which header would u guys recomend...sry but i dont have too much free time to search; alpha, dc, or Megan???...and i was going to do a fully custom exhaust, including s pipe, so let me know wat u guys think thanx

 

i'm purchasing an alpha

 

Alphawerks all the way. It looks as good as it performs and the welds are PERFECT.

Just make sure you wipe the entire header down with alcohol after the install (and before you start it) or it will stain from the heat (caused by grease from your fingers).