eyecandy

iTrader: (19)

Tried the search but couldn't come up with much..

How much reliablity do you sacrifice with streeting porting a NA 89-91 13B? Nothing to large, just like a moderate to small street port..I would like a turbo, but i thing that would be less reliable than a streetport.. but not quite sure, thats why i am asking..

And i here that you cannot turbo a NA motor because of plates in the exhaust ports, does anyone know how important those plates are and what purpose they serve?

Mark'sMazda

I wouldn't worry much about the port efecting reiability, so long as it's done by somone that knows what they are doing.

Also, you CAN turbo the NA engine, look up AaronCake he is one of the few to sucessfullly do it.

Rxmfn7

iTrader: (4)

A streetport really shouldnt sacrifice any reliability at all. And whoever told you about "plates in the exhaust" is probably thinking of something else, but I dunno what. Many have turbo'd an N/A. Read this for a great amount of info on that subject,
http://www.aaroncake.net/rx-7/naturbo.htm
and also do some searches on the forum.

Icemark

The baffles in a N/A exhaust serve two purposes, one to angle the exhaust into the exhaust manifold for expansion control, and the second is to lower the noise level (the Turbos have the turbo's impeller in the way to do it for them).

There is no real performance increase removing the baffles unless you are increasing the exhaust port size, the draw back is though that the velocity changes with them removed, which may lower low speed torque and operating power, but give you gains at WOT.

85TIIDEVIL

iTrader: (2)

On a LIGHTLY modified N/A, the baffles/plates/diffusers (whatever you choose to call em') inside the exhaust ports DEFINATLY INCREASE low end throttle response.

On my 90, my motor had the complete exhaust sleeve/s removed, not just the diffusers. My car lacked umph BIG TIME in the lower end. I took a pair of messed up housings, removed the sleeves and put them back into my exhaust ports. What a diffrence. It was like night and day. The throttle is MORE responsive. (Yet it still feels the same at WOT/topend, *remember lightly modified). Not to mention the noise level was REDUCED BIG TIME.

But these diffusers would be nothing except an additional restriction if they were still in the motor and you turboed it.

eyecandy

iTrader: (19)

Thanks for the replys! I am trying to figure out mods that i can do to the engine, to get more power, but keep the reliablity up.. I plain on going to a track atleast once a month, so its going to get a workout..

85TIIDEVIL

iTrader: (2)

Leave the engine alone for now... Do as many bolt on upgrades as you can before the motor needs an overhaul and then worry about porting and internal engine mods. By the time that happens you should have more experience as to what's best for your needs.

What year 2nd Gen is it...? What's done so far...?

BDoty311

So has anyone gotten any proven performance gains in removing them? I removed mine when I was in there, and they look like a big restriction. But I see people all of the time using TII rotor housing for that purpose?

Can someone give me some insight?

eyecandy

iTrader: (19)

85TIIDEVIL, well actually i am looking to acquire one still, trying to find a Series 5.. I am just getting ready for when i get one, which i hope is real soon! I orginally wanted a FD, but i thought since it is my first rotary i should start out with a NA, plus if something breaks on a FD it is going to be more costly to fix.. Also since i will be using this for the track atleast once a month hopefully more, i think driving a FC will help me learn to handle at the limit of a car with it being less powerful... Early this summer i went for a 20 lap ride in a friends FD that was probably making 270-290 RWHP and i thought "My god! I am not going to be able to handle a car like this!" I was seriously speechless!

85TIIDEVIL

iTrader: (2)

I'll sell ya' my 90 GTU... It only has 12K miles on a NEW motor, Konig rims, Nitto tires, Eibach springs, tokico shocks, NEW exhaust... Red w/a Blk interior. Plus ur only in PA. PM me if ur interested. I love the car but it's impractical to get back and forth to work (drinks gas like a *****) and I can't put my daughter in it. I'll let it go for ALOT less then I've spent on it so far.