High flow catalytic converter... good idea?

ACC-HE

My stock cat has 800 cells, super restrictive, and the after market cat is ~250 cells, on special now for US$300.

Is this a good idea? or should I pass?

(for a 4-cylinders TSX that needs every ounce of power...)

B2L2

Depends on whether you have other mods and whether the cat is the bottleneck.  I doubt you will feel any diff just with this cat.

But with $300 less in your wallet, your car should be faster since you will be eating less during X'mas.  

shutterbug

Have you done intake and exhaust?  If not, do intake first.

ACC-HE

Got intake already, but it doesn't make much difference, maybe a little strong in mid-range rpm, but that's it.

The lightweight pulleys does magic though, so much better to drive.

From the TSX forums, exhaust doesn't seem to be restrictive, just the Cat on the '04-'05 are horrible... 800 cells. (400 cells for '06+)

This aftermarket cat I'm looking at is made by MagnaFlow.  The only concerns I have are... louder engine noise & slight chance of getting Check Engine Light.

Catpiano

I just got mine as well ..   not sure what cell, 100 or 200? I don't even know the different ..  how does those "cells" rating work??  I think it claims 25 more HP .. but I doubt ..  I will be happy to get 15.

Sadly, no chance to put it on now ...  car is under snow anyway ..  LOL  I read lightweight pulley is good too, but can't really find one ..

ACC-HE

Oh, what car you driving? the UR brand is pretty good.

How does those "cells" rating work??  Well inside the cat, u get some honeycomb structure... cell count is the number of cells in that honeycomb structure.  The less cell it has, the higher flow you'll get but you also get less filtering.

Catpiano

So .. the less cell .. is better? ( in term of performance )  but more noise?

And probely lower cost to build less cell?  and why they always focus on "HAND MADE CC" then? I assume machine built should be better?

shutterbug

Intake doesn't do much at low rpm.  It mainly gains in mid to high.

I'm not sure how restrictive is the stock TSX exhaust but it could be the bottlenect after you installed your cat.  It's better to do them both at once anyway.  Might just do the header as well at the same time   I think with stock exhuast, the new car could just be slightly louder that's all.  Check engine light?  It depends if the cat is as efficient as the stock one, if not it might pop a code.

Lik

Don't bother la. If you want something faster / more power, get a new car mah. The TSX is what it is -- an underpowered, understeering pig.

Environmental concerns aside (did you know that the Copenhagen Summit on Climate Change is happening these 2 weeks?), exhaust tuning is a matter of finding your trade off -- everything else being equal, you give up some low end torque to gain some high end power, or vice versa.

For a race car, engine operation pretty much lives exclusively in the high end of the rev range. As such, low end torque means absolutely nothing, so you don't care how much low end torque you give up in exchange for high end power. For a street car, however, low end and mid range torque is needed every single time when you start from a complete stop. Or when you're mulling around town. Or when you're cruising. Or when you are pretty much doing your normal driving on the street.

Another way to look at this is through calculus (certainly you've done that, right?). When you muck around with your exhaust, you are literally playing with the shape of your torque curve. The total amount of useful work you can do is the area underneath your torque curve. By changing the shape of your torque curve, you may or may not end up getting a bigger total area. But the bigger issue is, you need to know where your engine speed typically lies, and tune your exhaust to maximize that region under the curve. If your engine lives in the 4k to 7k range, you tune your torque curve to maximize the area under that range. For a street car, however, the most frequently used region is probably closer to 1k to 4k (or 1k to 5k for a Honda engine).

Think about the kind of driving you'll do, and see if the back pressure reduction make sense for your application.

-Lik

ACC-HE

No header, thanks.

Is the price reasonable for a performance cat?  US$300 free shipping to Pt Roberts.