So today I went to put on a single n1 apexi muffler. With out doing much research at all, I chose a 2.25 piping from the last cat to the muffler.

The performance is stellar, heel toe like a boss, revving much better, still keeps plenty back pressure.

My question/ problem is that I noticed the exhaust get much much hotter than stock. MUCH. Should I be worried? heat shield it more? Increase piping size to 2.5 like all other after markets?

What should I do?

If you have stories, it'll help. thanks.

 

totally forgot, more info that would help

87 fc na
no engine mods

purely suspension and brakes

 

What makes you think that the exhaust got hotter?

 

I felt the air coming out was super hot. Even like a good 8 inches away my hand was barely able to with stand the heat.

I was wondering if airflow wasn't passing through thoroughly enough and getting caught and heating up way more that it's suppose to.

Never had an exhaust on this car.

 

When you say air, do you mean the exhaust coming out of the pipe?

If so, I would chalk it up to higher exhaust gas velocity. Lower exhaust gas velocity means it stays in the pipe longer and cools.

 

The temperature at the header is typically about 900F at idle and about 1,700F at full load. The metal in the exhaust system absorbs some of this heat, but the output at the tail pipe is still extremely hot. This is why you don't want to park your RX-7 over dry leaves or tall dry grass.

 

Yes i do mean the exhaust out of the pipe.
And that would make sense.
I just thought it might be something to do with too much pressure making the temperature extremely hot or something.

Haha, i parked my car over my crash to wash her today! Good nothing happened.
But okay I see. Thanks for the data.
I'm guessing that the old stock piping was just REALLY good with cooling down that air and not letting it all come out at once.

 

If your butt dyno says the new exhaust is good, than keep it.

The stock muffler are good at slowing the exhaust down. Also, since you went single exhaust, its all coming out of one pipe now. Don't worry about it being hot, you want it to be hot and coming out as fast as possible.

 

I put a racing beat header and went straight back into 2 magnaflows on my 88 n/a, even when its first fired the exhause coming out've the mufflers is HOT, so its to be expected. Gotta remember too that a rotary runs hotter than the piston counterpart

 

Indeed

That is very true. All in all Thanks for everyone's input.

I'm that type of owner who gets worried when the slightest thing seems off.

 

the stock exhaust is good at absorbing sound waves, it is actually not a huge source of restriction.

a 3" single exhaust with Borla XR-1 puts down nearly the same as the stock dual catback does at 300-325whp. perhaps the cans are blown but you still can't hear the car from 2+ blocks away so i doubt it. i actually keep the stock catback on my car more than it sees the single these days, it's quieter than even the racing beat duals but i'm sure the stocker is restrictive quicker than they are.

 

The apexi is fairly quiet. Just gives a good low power sound when pushed. Oh and it also makes the rotary more noticeable. I like it.

the stock is definitely good at absorbing sound. I think since it is SO good at trapping the sound in the can, that it does create a bit of restriction.

And also, I'm guessing since all the filling in the can is slowing down the air, its getting time to cool and lose velocity when flowing out; which is probably why it wasn't nearly as hot as now.

At least this is what I interpreted from the poster above

 

I have never had factory cans on the back of my car, so maybe I should shut up about them.

Now I want a set so I can play with them.

 

The stock cans have some awesome heat shields. I actually think they were pretty nice. Gave a nice purr. But I wouldn't go back. The performance side of things is just no match.