Qingdao

iTrader: (3)

All the air pump does is pump fresh air into the exhaust. If you have a factory exhaust it will work just as it should. Without the other factory emissions equipment this extra leaning of the exhaust will make it backfire more frequently.

Because by moving air from the front of the car to the rear of the car makes the engine produce less carbon emissions. I have yet to figure this stupid hippy idea, but whatever helped the engine pass emissions.

NatAsp12A

So let's say I cut off the muffler and did a 3 or 4 in straight pipe back from the cat and kept the resonator on, would that work?

Qingdao

iTrader: (3)

If you have a 4" exhaust pipe and you are running a good 12:1 afr you won't have to pump any air into the exhaust. It'll backfire plenty.

NatAsp12A

Would a 4 inch exhaust be a little excessive for a street car though? My brother has a 3.5 inch I believe for his 1999 Cummins (but right now it's coming right out under the cab since his original straight pipe fell off) and the cops haven't pulled him over yet.

Qingdao

iTrader: (3)

Two COMPLETLY different animals.

6bt turbo diesel. Exhaust flow sub sonic. Turbo. Its moving a LOT of air relatively slowly.

12A N/A. Super sonic exhaust. no turbo to snuff it up and its moving a small amount of air like a bat out of hell.


4" strait pipe will make your ears bleed. That's no joke I'm pretty sure it would.


3" is too big for my tastes, but lots of people do it.

If you open up the exhaust be prepared to do some carb jetting to match the air you are gonna move through. Its not a diesel and its not fuel injected.

NatAsp12A

So what would be an acceptable size for a exhaust size? I atleast wanna get a __ to a 4inch tip for the end. Isn't the stock piping like 2.5 inches?

Qingdao

iTrader: (3)

That's a good question. I've never seen a stock exhaust.

My turbo car has a 2.5" exhaust. Its loud enough for me, but I'm getting older.

The trouble comes into making the axle hump. I squeezed a 3" pipe on my old SA. I've seen 4" pipes make it through, but I don't see how.


If you just want to shoot flames and you are replacing your exhaust soon with a good exhaust just poke a hole in the bottom of your mid-pipe. The excess air there will make it backfire.

NatAsp12A

Okay hahaha thanks!!! Oh just curious, there's postings of rx7s around my area ranging from $1000-$3000, what's a good price for one? Not that I have the money for it right now, but I wanna know how much would be a good price for a SA in pretty good condition

Qingdao

iTrader: (3)

Wait... you don't have a car?

My first priority would be to get a car, and keep it running. If you buy a 30+ yo car its gonna need more attention than just a large diameter exhaust.


That aside, its all up to you and your abilities. 3k will get you something you'll have to put some effort into to get it reliable IE tires, front end parts, maybe brakes and hoses. 1k will get you something you'll need to overhaul the engine soon, and do all of the for mentioned things.

NatAsp12A

Right now I have a Chevy cavalier but I'm hoping to get a rx7 over the summer! I've looked at a few that are in good condition (one asked for $2750 and only the accelerator pump is shot). I live in the Wisconsin so that also kinda brings the values down, a lot of people ask for under $3000 that seem pretty clean and almost in great shape, although they do have a lot of miles

NatAsp12A

Right now I have a Chevy cavalier but I'm hoping to get a rx7 over the summer! I've looked at a few that are in good condition (one asked for $2750 and only the accelerator pump is shot). I live in the Wisconsin so that also kinda brings the values down, a lot of people ask for under $3000 that seem pretty clean and almost in great shape, although they do have a lot of miles so that would make me a little sketchy. Honestly I don't think I've seen that many 12As over $4000 around my area, but I've seen a lot of GSL-SEs ask for over $6000

Qingdao

iTrader: (3)

When buying an older vehicle you gotta understand that rubber doesn't get as affected by millage as it does by age.

Another words, after 5 years regardless of millage the brake hoses, belts, coolant hoses, tires, vacuum lines yada yada yada are all starting to go bad. Internal coolant seals can suffer from this too.

However, millage does affect things like engine/transmission wear. A higher millage engine will have more wear than a low millage engine. Another words its closer to needing rebuilding. Same with transmissions and other driveline things.

Front end parts really don't care about miles or age, but the rubber boots surrounding them need to be attended too. However, swaybar endlinks are made of rubber (or some kind of silicone) and they do deteriorate with age.


And the biggest problem you'll run into up in Wisconsin is RUST. You are gonna see the nastiest rust ever up there. unless you are handy with a mig and not afraid to get your hands dirty, a good rust free car will cost you.


All that being said, don't let it diture you from getting the auto you want.

NatAsp12A

I've already told myself "NO driving the Mazda in the winter once you get it!" I figured I'd wash it before I stored it, store it properly, then bring it out of hibernation in the spring. I'm not too scared of the engine failing right after I buy it, I do plan to be very ocd about making sure everything fluid is good on it and everything is in good condition, and either way my dad grew up in the days that had older car parts like vacuum lines and carburetors and ect ect. I plan on taking him with me when I go to look at said rx7, and also take a buyer's guide with me. I'm feeling confident about this!