basicmods

Hello there. I've got a couple really quick questions concerning the exhaust on my '91 hatch -

First - I had to pull my exhaust and am giving thought to hollowing out the cat while it's off the car. It got some crap in there from when I had to drill out the broken off bolts, and I can't get it all out. It's also got a couple of small dents in the material. Can anyone give me a good reason to NOT hollow it out? I don't have emissions to worry about, so that's not a problem.

Secondly - I have a new 2.5" BRM catback that I am installing with the possibly hollowed out cat and a high flow K&N drop in filter on my otherwise stock KA24DE. I'm going to be removing the emissions junk this summer, but I'm curious if this more open exhaust will cause issues that will need to be remedied with an aftermarket ecu. Will the system run leaner now? I read someplace on the interwebs that hollowing your cat can cause damage to fuel system. While I highly doubt this is the truths, I don't want to break something like the fuel system.

Sileighty_85

Hollowing out the cat will cause turbulence in the exhaust system therfore creating more back pressure and cause you to loose a few HP.

Its not worth it to get a test pipe or hollow it out on a basically stock N/A 4-cyl engine
you gain 1-2 HP at the most


blow out the dirty shit with an air compressor.

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後輪駆動車１番
1991 Built SR GT2871R -363whp 1998 S14 W/RB25- Rebuild in Progress

basicmods

Ok, thanks for the info. Any idea about the tuning?

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'91 240SX hatch complete with super rare sunroof insert and bag!

Bigsyke

no, dont need to tune.

s0apgun

do not hollow the cat

you will lose power

get a test pipe or high flow cat

no point in using an aftermarket ecu anyways for a stock car anyways