Has anyone checked damage to their metal substrate, specifly melting of the core or the core loose inside the housing? Random Tech remarked their cores were melting when being used by the RX8.. Mine is showing signs of damage

 

The RX-8 has a higher EGT than the FD and the 4" core didn't dissipate the heat fast enough. Now they've switched to a 5" core.

I'm using a 4" core with lower cell count (200 vs 300 for Random) thus less restriction. Also most metallic core available for the FD are 4"

 

I know another RX7 owner who has the same problem as myself so this problem is not just specific to the RX8. Both of our car are running single turbo's and when we went to dyno our cars, the HP & TQ numbers were low. Btw both of our cats have been in the car over a year. When we called Random Tech to inquire we were told the cats are most likely overheating, (melting and shrinking after cool down) thus impeading flow......If you take you midpipe/cat out and shake it and you hear it moving inside, your unit is damanged.

 

Hi Jack,

why even run a metal cat? I know you are running a track dedicated car. Go with a midpipe and you'll have no worries !

 

Stink, exhaust noise, boost creep...I guess I'm getting old...

 

Jack,

Ever since I've been on this forum, I've read many bad things about Ramdom cats (not necessarily metallic subtrates) having problems on rotaries. I went with the Dynatech metallic cat in hopes that it will last a little while. I never had any problems with my old Bonez so I'm hoping the same luck with Dynatech.

 

Unfortunately, mine and my friends are both Dynatech metal cats...

 

Really? I didn't think Random used Dynatech's substrate. I've read conflicting information around the web of them being different but nothing on Random's site saying it's the same (unlike on the PowerCat site: https://www.rpmoutlet.com/ezRetail/s...php?msg_id=706).

 

Both Random and Dynatechs (along with many other companies) are made by Metal Substate and rebadged as there own. According to the guy at Metal Substrate, if its a 300cpi core its theirs, and if its less cpi then its Arvin Supreme's (Supreme Performance).

WOW! I just noticed they upped the price from $99 to $179. I should have bought two of them last week.

 

well that sucks!

how many miles on your cat? Were you tuned rich? Airpump or not?

 

I believe that $99 was a display mistake.

 

Yes I think so too, because when I order it he asked the price and said 179, but I told him the webpage was listed at $99.

I would like to know how you were tuned as well. For street use with a good lean cruise, you shoudl not need the air injection, although maybe with it too lean the EGTs are getting to hot. I have been thinking of installing an egt gauge beofre or after the cat to get an idea of what the gases are running, OR take an infrared reading on the cat body itself.