Surprising..what dia. is it?. The OEM core is rather large in dia.

Factory gen3 internal cat dia measures 118/119mm (has thick cast iron walls). the outside circumference of the cat in the ebay dump is 358mm = 114mm dia. The metal casing/piping on the dump is say half a mm, so 113mm internal approximately, so about 4% smaller in cross section area compared to factory.

The ebay dump/cat is also 8.8kg lighter compared to the gen3 factory item, including the 2 lower brackets.

Cheers

why cant you just get a dump pipe and buy a high flo cat put in on your mid piping somewhere?

I think if you want to minimise the number of large angle bends and the length of the exhaust, it becomes tricky to achieve in the mr2.

Cheers

that.... and try match an aftermarket dump pipe with a cat for $140 delivered.

That is surprising, didn't know they were over 100mm, so provided they are actually 120 cell and reasonably decent quality, they should flow close to stock specs. trouble is your still looking at a DP & cat worth $100 which makes you wonder what quality they actually are.

In my case I had to modify the DP anyway, as the berk exhaust was sitting off the bottom of the pan by only 2mm, and ATS pipes are designed to raise the b-pipe..same as berk exhausts do. Berk + ATS don't mix. Installing a cat in the b-pipe means dropping the pipe to install it, which means (a) less ground clearance (b) 1300deg F under the oil pan (c) it's not the stock location, so it's not legal.

So by adding a 100mm, 100 cell metal cat to the DP, the modification only cost the price of the cat ($250). It's a decent quality cat & DP, it's in the stock location, as close to legal as your going to get, and will out flow pretty much anything else you could think of doing.
Certainly worked for me.

The weight saving doesn't come into it if your looking at replacing an existing ebay DP with one of those cat pipes, but if you only get a year out of them before they crack, that's a lot of replacements/repairs as opposed to a decent quality DP. Hope they work for you guys..time will tell.

the only reason i removed my cat from under the oil pan was for the temperature reasons i didnt have any problems that i could see but didnt have an oil temp gauge or anything so didnt want to risk it i still have it so i can use it if need be

artymr2 - thanks for those measurements they will come in handy later on im sure of it

im just waiting for a newer version to come out that will have a metal cat inside it rather than the ceramic one thats in there atm

i will look into getting something like mumans once this one breaks

How are these dumps going for the people that bought them?
 
The one on the car seems to be performing very well, only had it running for a few weeks, but all seems good.  I noticed the stainless has turned a little yellow/blue in parts due to the heat, cant really see it but it doesn't look pristine any more (not that it worries me).
 
I re-used the factory gasket at the turbo, as it looked much higher quality than the one that came with the pipe.
 
Cheers

Reviving a dead thread.
 
But how have these held up over time?

The one on the car still going good. Car doesn't get a huge amount of use but also been on the track for a decent workout and no issues.

Cheers