I was wondering if anyone knew of some good aftermarket but still legal and that have cats exhausts brands were? What would be a good setup for the stock twin turbo 93?

 

any catback is fine. you must have a stock precat and a main cat to be legal. greddy and hks have some CARB OE numbers i think for people who live in california, since califronia likes to abuse and make up their own laws (with some good reasons though). i believe racing beat may have them too since they are in CA.

 

There are three pieces to the exhaust:

1. Pre-cat, this attaches to the turbo manifold and runs to the center section. This can be replaced with a "downpipe", which is not street legal, but no inspector will know what it is.

2. Center section, aka stock cat, this runs between the pre-cat and exhaust sections. It normally contains the stock cat. May be replaced with a hi-flow cat, which is 50-state legal, or with a midpipe (no cats), which is illegal anywhere.

3. Exhaust section, aka cat-back exhaust. Runs from the cat back to the exit (hence the term cat-back). May be replaced by any exhaust that meets your local/state's noise ordinance. Has no effect on emissions and is 50-state legal.

As for good setups, EVERY FD should run a downpipe instead of the stock pre-cat section. It reduces underhood temps, allows faster boost response, has little effect on emissions once the car is warmed up, and eliminates the possibility of the stock pre-cat clogging and taking out the main cat with it.

You can replace the cat-back exhaust with just about any aftermarket piece to increase horesepower and noise levels. If you don't want to worry about being harassed by cops in Cali, then stick with one of the "true-muffler setups" like the Racing Beat, the HKS Hiper, or the Greddy SP/PE.

The center section should be left alone until you are more familiar with these cars and what the effects are.

With any of these mods, you should verify on your boost gauge that you are not exceeding 10 psi. If you do, you will need to install a manual or electronic boost controller to maintain boost at 10 psi. Many people have no problems running a downpipe and a cat-back exhaust without any boost control.

 

^completly agreed with what you stated above. I run a rx7stroe.net downpipe and apexi n1 duals catback as my only two mods, and I have not seen any boost spike at all, and I do not have a boost controller. I would go with the racing beat setup for more of a deep not so loud sound. Many people are happy with just the downpipe, it makes your car louders and now you can here the turbos spool. I swear for the first week you will not listen to anything but those turbos spooling. If you are not looking for something loud do not get the n1 duals....

 

cool. thanks alot fellas. but are most of the aftermarket parts 3"? so would i have to use a convertor for the size change in the partsor would it be better to go 3" with high flow cat, and cat-back?

 

I believe all Mazdaspeed products would be CARB legal. Price tag on their products is very expensive though.

 

i got pulled over with my racing beat once he told me to rev my engine he looked got in is car and drove away

 

he initially pulled you over because of the exhaust? cause that would be a first for racing beat if he did..people normally get racing beat for sound and to prevent harassment from cops and/or wrong attention..

 

No ****, that cop must have been having a hard day.

 

well off a set of lights i pined it to 60 which was the speed limit he pulled up behind me and told me not to do that i asked why i wasnt speeding he really didnt have an answer for me some bullshit about looking like a drunk driver. then he told me to rev my engine and well u know the rest of the story ........