new exhaust = too loud, any thoughts?

[paulb]

Hi, I finally got around to installing my new exhaust (been sitting in boxes for over a year) anyway its a full exhaust - catless headers, secondary cat delete pipe, c pipe & muffler. Its the typical cheap one you see all over ebay, I thing my brand was topspeed? everything fit great & its rock solid secure & no drone.

Problem is its just too damn loud when you get on it & at wide open throttle I can be heard for quite a distance. Its also a bit raspy & slightly higher pitched than i would like. Any ideas on how to tone it down a bit or tune the sound?

I was thinking of motorcycle exhaust baffle inserts to take the edge off, or even stuffing a stainless steel pot scrubber in there with the baffle. has anyone here tried that?

[Robert986]

Conrats on your new exhaust!

In general I would hesitate to put something restrictive in the exhaust, since it´s kind of contradicting to the whole idea with a more open exhaust. Maybe weld in a resonator in the midpipe to tune it down just a notch?

[thstone]

The easiest solution is to put the cat's back on - they act as a baffle! Start with the mid-pipes and see how that sounds. If still too loud, re-install the headers with cats. That might get it back to something socially acceptable and can be done pretty easily.

But remember, it might be darn near impossible to get a system that you can hear a low rpm's but that doesn't rattle nearby windows at high rpm. It's one big tradeoff.

[BYprodriver]

Originally Posted by thstone

The easiest solution is to put the cat's back on - they act as a baffle! Start with the mid-pipes and see how that sounds. If still too loud, re-install the headers with cats. That might get it back to something socially acceptable and can be done pretty easily.

But remember, it might be darn near impossible to get a system that you can hear a low rpm's but that doesn't rattle nearby windows at high rpm. It's one big tradeoff.

I would put the stock muffler back on for best power.

[thstone]

Originally Posted by BYprodriver

I would put the stock muffler back on for best power.

Why? My dyno test data (before and after with no other changes) shows that the Top Speed cat back muffler increases power over the stock muffler (not by a lot but by a measurable amount none the less).

[BYprodriver]

Originally Posted by thstone

Why? My dyno test data (before and after with no other changes) shows that the Top Speed cat back muffler increases power over the stock muffler (not by a lot but by a measurable amount none the less).

That conflict's with Jake Raby's Dyno testing many years ago, maybe Top speed has gotten better over the years but I wouldn't think it would be worth changing.

[rfuerst911sc]

I have played around a little bit with baffles to tone down a twin can GHL muffler . I inserted them into the exhaust tips and the baffles were wrapped with exhaust fiberglass . It did help but not enough on my engine . I am currently running a stock S muffler with a simple exhaust bypass like the PSE , but again it is too loud . I have a Mille Miglia single can muffler that I think will respond well to the baffles that is my next experiment .

[edc]

Originally Posted by BYprodriver

That conflict's with Jake Raby's Dyno testing many years ago, maybe Top speed has gotten better over the years but I wouldn't think it would be worth changing.

I also before and after dyno tested the cheapy eBay exhaust around 2012 and showed around +10bhp kicking in from around 3.5k rpm all the way to the red line.

[paulb]

Horsepower is not my reason for switching out the exhaust. I'll never turn down a hp gain. But really if I wanted more hp I would be playing around with a V8. The appeal of the exhaust is mostly to reduce weight (this swap = about 50# lost & should balance well with pulling spare out of front) & make car more tossable & give it a more aggressive exhaust note. Well, it is more aggressive sounding . I've got some baffles coming but it sounds like that's pretty minimal, if thats not enough & i suspect it wont be I'll keep looking for just the right combo.