[Burninrock24]

I was WOT at about 6K and it got more muffled sounding and stayed that way til the end of the race. It's a straight pipe exhaust on a 4-2-1 D16A6.

It was the weirdest thing. It runs smooth, I didn't feel a significant loss in power, and it looks like the exhaust is in one piece. I just don't know what would cause that.

Any ideas?

 

[crackerjack1.6]

Its possible something could have let go inside your muffler.

 

[Burninrock24]

No muffler though. Just a flex pipe. and then straight pipe. What would there be to 'let go'? It runs and drives fine, so it's not like we lost a valve or anything. Exhaust leak maybe?

 

[jpciii]

I suppose it's possible that the inside of your flex pipe peeled back and is restricting flow.

 

[Burninrock24]

That's the only thing I can think of. It runs fine so I'm ruling out spark plugs. No huge losses of power so I can't imagine it'd be something in the head. It has to be the exhaust, but I don't know what could have possibly made it quieter.

 

[the hoove]

Can you unbolt the exhaust? If so look for those restrictions. Then fix accordingly.

 

[Burninrock24]

Well yes and no. The whole thing, flex pipe and all is welded to the header. So I can unbolt the header from the head, and check there with a long pipe cleaner, otherwise I'll have to chop up the exhaust and see what's up.

You don't think it would be head related or anything though do you? Idles fine, drives fine, etc. Just a lot quieter. I can post a vid tomorrow. You can hear when it gets quieter during the race.

 

[Burninrock24]

Is it possible it could be a throttle position sensor and when I thought I was at WOT I really wasn't?

 

[crackerjack1.6]

Do the rpm's go as high as before? Thats strange check your tps it could be i your probolem it sounds kinda like limp mode but its obd0 correct

 

[Burninrock24]

It's hard to tell because I was running a different line when it happened, and it also threw me out of my focus for those couple laps. But it seemed to get relatively just as high. I mean at max I lost like 100rpms. But that could have been my driving, not the car.

 

[90civichillclimber]

Is it quieter at all rpms now or just above 6k. Maybe it's you and not the car

 

[HiProfile]

Sounds like the flex pipe collapsed. The inner sprial tubing breaks off at one end and tightens the spriral into a fraction of the original I.D. You may be able to push the outer wire weave apart and push in a pick to investigate. The worst case I've seen from that was a car that was still making 300+ HP (down from 500), it ended up ruining the turbo as it over-spun into oblivion trying to increase boost.

The only other option is you got 20yrs older in an instant. Are you having sudden urges to play golf, move south, or drive slow?

 

[crackerjack1.6]

^ Lmao i think the part you need may be a hearing aid, ill try to find the part number for that let me call honda quick. J/k

 

[90civichillclimber]

Some old people drive really fast!

 

[monster111]

your ear is spoiled

 

[Burninrock24]

Is it quieter at all rpms now or just above 6k. Maybe it's you and not the car

Nah, you can hear the exact moment that it happened in the go pro too. I thought it was just because I passed a loud car. But it was still quiet once I got some distance on him.

Sounds like the flex pipe collapsed. The inner sprial tubing breaks off at one end and tightens the spriral into a fraction of the original I.D. You may be able to push the outer wire weave apart and push in a pick to investigate. The worst case I've seen from that was a car that was still making 300+ HP (down from 500), it ended up ruining the turbo as it over-spun into oblivion trying to increase boost.

The only other option is you got 20yrs older in an instant. Are you having sudden urges to play golf, move south, or drive slow?

Awesome. Thanks for the help! I'll get right on it.

 

[SheAngel19]

Because race car......

But in all seriousness....if it was an internal restriction would it cause it to backfire?

 

[the hoove]

Not necessarily, he could still be running fine but feel a difference in power. I vote on the collapsed pipe but go through it to make sure.

 

[2000redCIVICsi]

Definitely a collapsed flexpipe. If youve explained all the symptoms accurately, your felxpipe is most likely the cause.