questions on cats. engine bay temperatures and so on...
 

While my car is exempt from testing, I'm deeply considering installing a metal substrate GESI catalytic on my turboed '80. Would the slight restriction cause the downpipes to run hotter or is it a tossup? I'm kicking between not having a "smelly" car and reducing boost creep ( as I understand it) to saving the cost of the cat and saying to hell with it.

I am not running an air pump, and it seems the GESI units don't have the air injection port anyways. BNR internally wastegated turbo and Haltech... if that helps form opinions.

probably a toss up? a normal cat has a pretty low temp limit, so you need to keep EGT's down to keep the cat from melting. (cat starts working at ~450c and melts at 650c...) its why a stock S5 or later runs so rich
the hope with the GESI cat is that you have a higher temp limit

so like a non cat engine might be hotter because you don't have that tuning limitation, but ymmv!

no, you just need the proper cat converter.

HJS out if Germany provides the best imo for both street and race use, the motorsport cat is good for 1050°C maybe, very light too, very high flow depending on sizing and cpi rating. I ran them on my RX8 without issue passing OBD2 testing with the 100 cpi motorsport race cat. Not going to have a CARB etc number though.

https://www.hjs-motorsport.de/homepage.html

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1050c is higher than the engine is happy with, so its perfect.

the website now says 950°C (1750°F) for the lower cost Motorsport Cup catalyst, but no mention for either the PE or UL catalyst. The first I bought and used for two years was the Cup. It was the only type then. I sold it and moved back to the stock class in 2008, which required an OE cat. The second one I bought in 2010 was the PE type and ran it for 3 years, then let someone else use it as I was changing to a class that didn’t require one. He’s still using it on his RX8 Renesis. The UL version is new to me, no experience with it.

so I’m pretty sure they used to say 1000° or 1050°C rating, but am not sure if they changed it or not. Looks like the same guy is still over the Motorsport division, so I could probably drop him an email and ask.
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FEED does something like this, probably would work well in a high power setup
https://cimg6.ibsrv.net/gimg/www.rx7...6efff1ef9b.jpg

that is interesting, but outside of where I need to be at this point.

I put a GESI cat on my T2 last spring and ran it for the Summer. Happy with it and power/sound is still great, but I don't have any data or logs to quantify anything. Just enjoying the car.

GSI 85030
GESI G-Sport 300 CPSI EPA Approved 3in Inlet/Outlet x 4.5in Body x 7in OAL Catalytic Converter

I called up a few shops and the lead time was two years. Or so I was told for GESI. Im looking at Kooks. which from what I can tell is is of similar quality.