SlowRideL15B
Senior Member
- Thread starter
- #1
So I have seen and been a part of previous posts about hollowing a cat out and everyone says not to do it for various reasons. I have been looking to buy a test pipe but just lost my job and thought, wth, lets hollow this thing out.
So there was no metal maze or anything crazy on the inside. There was a sandy feeling carbon ash type looking stuff; probably asbestos. It was kind of gritty like sand [aper.
After hollowing this thing out completely I fired her up and loved the sound. Sounded pretty much exactly as it did before; Maybe idling just at a lower rpm and a tiny bit deeper or throatier sounding. When driving or revving high I can notice a little rasp and it seems to be a tiny bit deeper; i love it, sounds a little more racey, not ricey.
It is almost like Honda designed these with the intention of hollowing them out. After hollowing it out on the inside there was a type of reducer. Looks like it goes from like 2.5 inch to the hole diameter of the canister.I drilled everything out that I possibly could and that is what remained.
I ran a test pipe on my DSM right after the motor was built and think I passed emissions anyhow, except for the visual. I have a couple buddies in the emissions testing industry so was always able to pass one way or another.
I am really impressed with the fa ct that it didn't get crazy loud; no smell of boiled eggs, and runs and sounds better. Very negligent difference in sound unless doing wide open throttle reving or pulls.
I did change the oil and do a battery pull; however, the car seems like it is running / idleing noticeably better. I was surpriseed at how much shit I pulled out of that catalytic convertor; definitely obstructed.
i didn't think to take pics of the catalytic convertor but did take pics of the internal stuff that I removed. The material inside was grey and black and dusty or ash like material, i'm sure aweful stuff, probably contains some kind of fire retardant like asbestos.
Anyway, if you've done the research and are prepared to run a test pipe; either if you don;'t have to run emissions testing or maybe have a friend in the industry, then I'd highly recommend hollowing out the cat. It is the prefect design for it and converts nicely into a test pipe.
So there was no metal maze or anything crazy on the inside. There was a sandy feeling carbon ash type looking stuff; probably asbestos. It was kind of gritty like sand [aper.
After hollowing this thing out completely I fired her up and loved the sound. Sounded pretty much exactly as it did before; Maybe idling just at a lower rpm and a tiny bit deeper or throatier sounding. When driving or revving high I can notice a little rasp and it seems to be a tiny bit deeper; i love it, sounds a little more racey, not ricey.
It is almost like Honda designed these with the intention of hollowing them out. After hollowing it out on the inside there was a type of reducer. Looks like it goes from like 2.5 inch to the hole diameter of the canister.I drilled everything out that I possibly could and that is what remained.
I ran a test pipe on my DSM right after the motor was built and think I passed emissions anyhow, except for the visual. I have a couple buddies in the emissions testing industry so was always able to pass one way or another.
I am really impressed with the fa ct that it didn't get crazy loud; no smell of boiled eggs, and runs and sounds better. Very negligent difference in sound unless doing wide open throttle reving or pulls.
I did change the oil and do a battery pull; however, the car seems like it is running / idleing noticeably better. I was surpriseed at how much shit I pulled out of that catalytic convertor; definitely obstructed.
i didn't think to take pics of the catalytic convertor but did take pics of the internal stuff that I removed. The material inside was grey and black and dusty or ash like material, i'm sure aweful stuff, probably contains some kind of fire retardant like asbestos.
Anyway, if you've done the research and are prepared to run a test pipe; either if you don;'t have to run emissions testing or maybe have a friend in the industry, then I'd highly recommend hollowing out the cat. It is the prefect design for it and converts nicely into a test pipe.
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