I'm looking to put new mufflers on my 1991 N/A convertible. But i need to know what size inlet the muffler should have. I need to know the size of the piping after the cat. I thought it was 2.25 but i'm not sure. Thanks for the help

 

I wanna say the stock NAturally Asthmatic exhaust is 2.25" ?

Racing Beat power pulse mufflers , btw..

 

2 1/4 is doubtful considering after market exhausts are 2.5" , but I could be wrong.

The largest point may be 2.25" but where the mufflers connect to the y pipe will be smaller then where the y pipe connects to the cat.

 

More accurately , the question becomes ID or OD.

From what I can find , it varies down the line.

Since we are on the subject of doubt, did you ever pay your mom back for all your car stuff ? :-D

 

That would definitely be my choice for a convertible.

The rotary engine's exhaust is louder, stronger, and hotter than that of piston engines. If you are planning to replace them with mufflers that are not sold to specifically for the car then you are setting yourself up for failure. Therefore, rather than shopping by dimensions, you simply order mufflers that the aftermarket manufacturer made for the car. Racing Beat makes mufflers that will bolt directly to the OEM pipes. You can also order bolt-on catback exhaust systems from Racing Beat, Rotary Performance (Bonez 50mm), and Apexi (N1 Dual w/90mm tips). The catbacks from Pacesetter, GReddy, HKS, and the Apexi N1 Dual w/115mm tips will also work, but they will be a little loud because they are sized for turbocharged cars.

Also, I would make sure the existing components are in good shape and can be easily disassembled. Sometimes they are damaged or rusted together, and I would want to order all the required new parts at once because it is usually less expensive that way. Also check the rubber exhaust hangars to see if they need to be replaced.

 

Actually i bought this car myself and i've used my money for everything but thanks for your concern

 

if you do a search under my name i've measured the stock exhaust and posted the measurements.

i think its 50mm ID piping from the manifold to the main cat, and then after the Y i think its 42ish ID pipe.

Mazda uses a fairly thin walled pipe, although it is wrapped and has a heat shield over it. the stock FC mufflers are just normal baffled mild steel, so while they weigh a ton, they aren't really constructed any differently than any other stock muffler.

 

Well since im not working that many hours right now because of football I cant get a catback racing beat or apexi exhaust which is what i want to do. So I was going to get glass packs 2.25 inlet 2.25 outlet. Along with an exhaust tip that goes from 2.25 to 3 just so there isnt a red rocket hanging out the back if my car

 

Well glass packs may not be "budgetary" in the long run as the heat of the exhaust will eventually just burn the guts right out of them.(Punch in Cherry bomb and take a look)
The y is 2.25
the pipes on the y are 2"
and the Muffler inlets I am sure is 1.75.

The pipes on the y are heat shielded and look bigger,but when you take that shield off it is like "twiggy's legs".

You could always look at Bosal mufflers on their site and they should have specs on the Replacement they make,just to conform pipe size.

But really you can put something a little bigger there with a few aftermarket clamps and an adapter or two.

 

glass packs are bad.

1. the fiberglass WILL die very fast. it can't handle the vibration/pressure waves, nor is it good at handling heat.

2. if you're buying a louvered core glasspack, they flow horribly, and you need one that is like twice as big as the pipe

i used glasspacks for presilencers, and the packing was dead in about 4 laps, and after 2 track days they are actually sagging, because they are melting

 

That's what I was afraid of. The glass packs will be too loud, which will annoy your neighbors and you will get a ticket from the police if they hear it. Also, regular glass packs can last as little as 3 days before the rotary engine burns them up, although I had a friend who managed to drive for two weeks before his melted.

Edit: I see that j9fd3s beat me to it.

If you are short on cash, then just patch the existing mufflers for now.

 

Well dang. I guess there's no cheap way to get out of my situation

 

What situation? Is there something wrong with your mufflers?

 

Wasn't talking to you, bud. The person in question knows who he is.

 

Oh sorry haha.

 

one of the tips is rusted off and they are both rusted through

 

Rock Auto has Bosal mufflers @ $96.79 each + shipping, but use code 1733170114654117 for a 5% discount until 11/17. The code is entered in the how did you hear about us area.

 

I found some for $55 4in outlet. Kool Vue stainless steel mufflers

 

Muffler $55 dollars.
Ticket for excessive noise $200.( 4 inch out.Toss a silencer on that.)

 

Here's the link to the jc whitney page

http://www.jcwhitney.com/kool-vue-st...887y1991g989j1