Muffler failure caused a 200hp loss.

[Marc s]

I thought some of you might like this though. Be careful with old chambered mufflers.

I had a customer bring his supercharged 800 hp Cobra to the shop because all of a sudden, he says it's significantly down on power. While on the dyno, I noticed that the exhaust flow out of the left side was surprisingly low but the boost was really high at 23-24lbs. So I aborted the dyno session and cut the Flowmaster apart. I found that one of the baffles had broken loose and plugged the exit. I have seen this before with chambered mufflers so I replaced both mufflers with Magnaflow's.

 

[W3bb3r04]

Theres your problem! lol Thats why I run straight through mufflers, well just one now.

 

[fdjizm]

ouch!, straight through mufflers for me all day!

 

[NotQuik]

Chambered generally sound better but that's a fine example to one of the downsides to them.

Theres your problem! lol Thats why I run straight through mufflers, well just one now.

I think I've seen a couple videos of your car on youtube, what muffler are you running?

 

[Greg Hazlett]

Had the same thing happen to me at the track except it was a cat that came undone.

 

[chandlern]

Had the same issue with my flowmasters, on occasion the boost was up and power down on top of the insane rattling when they were cold. When I replaced them with magnapacks it looked like the previous owner had already been in the drivers side, maybe ill cut them open just for shits and giggles when I get back home.

 

[W3bb3r04]

Chambered generally sound better but that's a fine example to one of the downsides to them.




I think I've seen a couple videos of your car on youtube, what muffler are you running?

On my videos online I have Borla Stinger AB's now I am running a single 3" Magnapack off the downpipe.

 

[Marc s]

Going back on the dyno now.

 

[Zodiac]

Damn that's crazy. I bet the customer is happy to have his power back.

 

[Department Of Boost]

 

[lethe]

That definitely caused a little restriction haha

 

[SoCalGT]

thats crazy

 

[stkjock]

I think we've seen enough times, chamber mufflers + boost = TROUBLE

 

[05yellowgt]

I think back now and wonder if the chambered Bassani mufflers I had on my car were part of the reason I was seeing 27psi on a 4.3" pulley, where others (like 05stroker) saw 20psi max. The differences in our HCI shouldn't have caused a 7psi difference in boost. I also wonder if they were a major restriction, what kind of power I could have made. The next time I go bat shit crazy on a boosted car, it will not have a chambered muffler.

 

[BruceH]

One more thing to worry about, shit.

 

[skwerl]

I've blown out 3 separate stock Bullitt mufflers only running 7-8 lbs boost already. I guess I'm going to need to shop for different mufflers soon.

 

[NotQuik]

On my videos online I have Borla Stinger AB's now I am running a single 3" Magnapack off the downpipe.

Any video??

 

[Captainstr8edge]

why would you put rustmaster mufflers on an 800hp car?

 

[Marc s]

why would you put rustmaster mufflers on an 800hp car?

The customer had the exhaust done somewhere else.

 

[stkjock]

Marc - do you know how long those were on the car?