Which is the best downpipe for the stock cat? I keep hearing that 3" is the best, but if you have the stock cat, it defeats the purpose of the 3". That eliminates the helix. I know the Helix bolts to the stock cat, but what's the point? I know 3" makes more power, but with the stock cat won't I be better off with a 2.5" such as the HKS one?

 

Buschur makes 2.5 downpipes. HKS is 2.75 btw not 2.5.

 

Whatever the measurement of the HKS I heard it bolts well to the cat. Still doesn't answer my question though.

 

How about this just remove the stock cat and get a cat delet or at least a hi-flow cat. I am in way advising for you to buy a hi-flow cat

 

No I want to stay with the stock one...the reason? Can you show me a high flow cat that will guarantee not to throw a CEL and pass state inspection? And not fail after years of use? Gotcha there didn't I?

 

best bet is to get the buschur one then get a 3inch catback to finish it off

 

I have the AVO downpipe...it lines up PERFECTLY w/ stock cat. Excellent quality, and clears both lower tie bars w/ no spacers.

 

isn't the Avo 3 inches??? then it defeats the whole purpose if it is.

 

Actually...

HKS is 65mm...which equates to roughly 2.56" in diameter, which is the correct internal diameter. www.hksusa.com


Inariv5573 - I was considering going with the Fujitsubo 2.70" inch or Espelir 2.75"........but I think for maxium boost on the low end...the HKS would probably be the best bet.....or the Buschur.....

However....If you live in CA....and you have a new car....ur looking about rougly 6 yrs before you even smog it....(unless u get pulled over and searched).....

.....I'd say HKS....good quality...and I'm sure the techs there know what they are doing....

 

i love my HKS DP , fits like it came with the car . small but good power added .

 

I had my hi-flow cat for one year and I never got a cel. I never had it checked out for inspection, but how hard is it to bolt back up the stock cat? Not very

 

I have no cat and NO CEL and I can pass Inspection, GOTCHA THERE DIDN'T I!!! WAH WAH WAH!!!!!!!!!!!

 

What kind of cat do you have? As far as I know every cat I have seen has thrown a CEL one way or another, UR, Random, Helix, etc.

 

No cat, I uses a 02 Sensor mod that everyone esle uses. Stock Cat will cause you High RPM Knock if you are looking for power, trust me, it is by far the most restrictive unit on your car.

 

No cat, sorry I didn't see that. NOW let me ask you this, how do you pass inspection? There is just no way. I am sure when they place the probe in your tailpipe, the hydrocarbons etc. go off the charts! Not to mention you probably have that terrible smell and excessive fumes coming out the back.