ok... here's the deal. I'm supposed to be buying an SFP downpipe to go with their manifold on Monday. it's a 2.5" unfinished dp (you have to weld on the flange that would normally go to the cat). I was considering a test pipe since this is in FL and we don't have smog tests but it is still illegal to run no cat, but if it's not that loud they don't bug you. If I were to run a test pipe would, how would the o2 sensor deal work? just weld a bung in the pipe for the O2 sensor? My question is what would be the best way to setup the exhaust system?

Get the DP weld on a flange to connect to the stock cat, then run a 2.5" exh from cat back?

OR

Weld on a flange to connect to a 2.5" test pipe then 2.5" cat back. And in this case what would I do about the O2 sensor?

BTW: This setup will be on a 00 civic ex d16 with a t3 60trim,.60compressor/.48 turbine

EDIT: What exhaust setup do you D16 turbo guys run?


[Modified by CivicRyda2k, 11:24 AM 7/20/2002]

 

is this OBDI or OBDII?

if it's OBDI i suggest running the test pipe and welding the bung anywhere near where the cat should be. It really doesn't matter.

Don't use the stock cat because that defeats the pupose of going to a 2.5" exhaust system. the cat becomes a bottleneck.

if you're OBDII you can do the same. Go find yourself an o2 simulator for the secondary o2.

also if you can afford it...maybe you can purchase a 2.5" highflow cat and punch it out (so atleast it looks like it's there).

 

yah it's obd2. i heard about the o2 simulator... but what exactly is it? How does it work? And about how much would it cost?


[Modified by CivicRyda2k, 12:04 PM 7/20/2002]

 

If you're going to punch it out you don't need a high flow cat. You can always use one from a teg or something and hack the ends off so you can weld 2.5" pipe to it. For the couple of extra horses, I'd rather do good for the environment and actually use a functional high flow cat.

 

so how about this...

for now i might have to use stock exhaust

so i might do this for now 2.5" dp (flanged for stock cat)->stock cat->stock exhaust

then when I upgrade. I go with:
2.5" dp (reflange for 2.5 or 3" cat?)->2.5 or 3" cat->2.5 or 3" exhaust

how does that sound?

 

Sure. I have a 2.5" DP that flares to 3" at the cat, then I have a 3" cat and full 3" exhaust.

 

Just say NO to your

 

I would but my friend just got pulled over here in FL fo a loud exhaust... he's only lucky they didn't check for a cat. I don't really wanna risk it but on the other hand... it will be on a turbocharged vs an n/a (his was a b16 w/ ctr pistons, striaght pipe from header to muffler). So it might not be as loud. What do u guys think? In any case I think i might go stock cat and exhaust for now because I doubt i'll have the $$$ to buy the cat AND 3" exhaust by the time the turbo is ready to go on.

 

OK decided what it will be... since I can weld on whatever flange i want onto the downpipe. I will do this for now... just to get the turbo on and running
2.5" dp (wit stock cat flange welded on)->stock cat->stock exhaust

Then future...
2.5" dp (wit stock cat flange welded on)->3"cat stock cat (wit stock cat flange welded on)->3"exhaust

does that sound coherent?

 

if u are lookin for an o2 simulator, i got one for sale. make me an offer. greengangsta@hotmail.com

 

i've decided to go straight pipe because i heard that a cat wouldn't work on turbos because exhaust gases need to reach a certain temperature and the turbo being there will lower the temp drastically. anyone care to clear this up?

 

I had me 2.5" DP to my 3" catback b4 Hondata, just had a bung welded in the DP for the 2nd O2 and it worked fine..

 

The cat will work, it just takes substantially longer for it to "light off" becuase the turbo converts some of the heat energy to mechanical motion. The EPA guys really hate that. It will light off quicker if you use a wastegate that reconnects with the exhaust too. That wastegate exhaust is very hot.

The cat will work, eventually.

Randy

 

so, do mother nature a favor and just the cat? or is it a waste of money?

 

david... when u had the si exhaust did u run a cat or no? and what size is the greddy dp? 2.25"?