Exhaust Blown Out

[Supercharged SVT]

I just lost the guts to my 5th Muffler this one is a Dr Gas - 2 inlets and 2 outlets both 2.25 and have gone through 2 magnaflows, one NAPA, 1 Factory - Total of 5 - Blown insides, blown apart the seams, and split the magnaflow where they didnt even have a seam.



We are 11.2 PSI Blown, 487 wheel horsepower, closer to 600 to the flywheel, 105 Octane E85 only, No Cats, 2 resonators, and is tuned cleaner than a factory stock V8 -



Anyone have a great idea on a High Performance, durable muffler, that will go more than 5000 miles -



Looking for Ideas and Reverting to Stock or true duals is not an option (true duals to the last two feet is as close as it gets to keep the Adrenalin Tip)

 

[Mark k 4]

I would try and find a Borla. What size piping is the exhaust currently? It sounds fishy that you are burning out mufflers out at 5000 miles. You might be running too rich.



I asked about the piping size because I wonder if you have too much back pressure. I know that the popular belief is that 3" is needed for FI setups. I know I was running 2.5" on a 2.0 turbo and that was perfect. Since you are most likely running a 4.0 on 2.5" I would say you might want to look into running 3" with a nice Borla muffler since they are warrantied for a million miles.

 

[TRACket Paul]

Perhaps this company.

 

[Supercharged SVT]

From the origional post - tuned cleaner than a factory stock V8 -



Not rich - no back pressure - just pressure from boost we assume - I will call the Spintech guys next to see what they say

 

[Mike S 3]

i bet your issue is your restrictive exhaust tip, causing pressure buildup upstream, really the only thing that makes sense. for your power level you'll need at least a full 3" exhaust all the way back.

 

[Todd Z]

Flowmaster makes a straight through Hushpuppy mufler, Check that out as something with baffels is not for you...



P.S You get my emails ?



Todd Z

 

[EddieS'04]

Im with todd. Go with duals, with the flowmaster hushpower mufflers.

They are very streamlined. You could use a 2 to 1 for a 3" single tailpipe. To keep the Adrelin look.

 

[Supercharged SVT]

I wish it was that easy - We are a Y out of the muffler into a 3" tail pipe that is welded to the Roush Tip - Dr Gas just called and warrantied the whole thing - I am not sure I want to swing the labor again on the same muffler -

 

[Richard L]

Another option if you want to go to dual exhaust would be to exit the pipes out the side, just in front of the back tires. I think two large bologna cut chrome tips sticking out on each side would look great. Of course some states require exhaust to exit behind the rear wheels...:angry:



...Rich

 

[Dan Long]

What about a little fake out? Provided you have room in front of the tip, run true duals, probably 2.5" each, then turn them down and cut them off very short, so they're hidden under the truck. Next, have a short piece of pipe added to the back of your Adrenalin tip and just weld it to the oustide of the pipes to give it support and keep it in place in the rear bumper exit location.

 

[EddieS'04]

I am not sure I want to swing the labor again on the same muffler -

Take the free muffler. Sell it to make up some of your cost.



I would go with the 3" hushpowers, 3" Y into single out 3". The Roush 2 1/2" tip inlet can be cut and machine expanded to 3". 3" single exit should take care of the back pressure. The hushpowers are a flat oval glass pack, straight thru.



The other choice is do true duals, smaller pipe with a right side bumper cutting. For a second roush tip.



What size tubing are you using on your single system now? IMO, larger tubing or duals. 11psi has to go some where.

 

[Supercharged SVT]

We thought of a WOT Spring controlled Dump but we are still working on this - I spoke to a designer at Spintech and he assured me that the system is up to Sprint Car specs - Sprint Cars are limited in cylinder pressure - 9 plus 11 is still more -



We are back to the drawing board - on the dyno we occasionally saw a PSI drop at peak and they ruled out belt slip - Wonder how much the bottleneck muffler effects the overall tune -



It sure is a blast to drive - bawls all four under hard boost getting on the interstate on a dry road - this is my only issue nearing 36K miles

 

[Supercharged SVT]

A weeks worth of Diagnostics - the 3" bent tailpipe to the Roush Tip is the issue - imagine the pressure - the blower peaks 11.2 psi on this M90 with the race pulley set up -



on the dyno we peak at 487 hp and can't get another pony - at 6500 rpm the belt slips with a shorty and a GT500 tensioner - So here is why - the whole pressure system that has caused 5 mufflers to blow, split, or seam separate is all from pressure in the system - enough to choke the tailpipe and build the pressure back through the entire engine - through the blower enough to slow the twin screws and slip the belt -



So on the street, it peaks out and then the boost drops 4 psi the same time the shift happens - we cut the tail pipe off and sent it in to have a 3.5 mandrel bent piece created -



Now its a new machine - a hard launch breaks loose all 4 but keeps it straight and now at peak it grabs second crisp enough to bark 4 - yep - bark 4 on an AWD -



So when the pipe gets on, back to the dyno and see what we wer loosing from the non manderel bent 3" (which is 2 in areas) love to have a 500RWH daily driver vs 487rwh - lol

 

[Carey Frennier]

I'm impressed that your setup has held together. Especially with a little M90. 487whp is pretty insane but, then again, I hear people can do amazing stuff on E85.



The new owner of my truck emailed me a few weeks ago and said the truck has been acting sluggish and had less power lately. Wonder what would cause that.

 

[Supercharged SVT]

Wonder if it is at low or high rpm? Might need a BAP (boost-a-pump) to get a little more fuel at wot - I am not sure - I set mine up like it is a flippin mustang - we have an 1/8 mile here and I popped a 7.66 and took out a Challenger with a blower - Only one run but we have another month to play after the retune - the guy I beat says he is a 12:1 quarter car but who knows - its just a driver and boat puller -

 

[Lloyd Chaudoin]

Believe it or not I think I have the answer to your problem... It is not the muffler design per say... It is the fuel you are using. Now making the power level you claim I would atleast run a dual 2.5" exhaust. The dual in dual outlet muffler is fine. Even a dual inlet single 3" outlet would work fine. The ethanol (E85)/alcohol you are using is unique in the way it burns, specially if limited on spark. The fuel is known the have unburned raw fuel exiting the exhaust ports. When letting of the throttle ( particularly when being run hard ) the raw fuel pools/puddles up and collects in the muffler then burns off. This creates pressure spikes in the muffler case and eventual destruction. I think I have a cure for you though. Flowmaster makes a race muffler called "Outlaw Race Series" These are round small cased mufflers with attenuation rings in them. They do very little for sound cancellation but will help catch a lot of the fuel. I would install them ( one each side ) up stream of the muffler near where the stock cats would be. This will allow the fuel to burn off sooner in the exhaust and have half of the volume collected per side instead of the complete amount caught in the muffler. Alot of the pressure should be relieved in the muffler itself. You may even see a slight reduction in resonance in the cab too. Let me know, I think it will save you alot of money in future muffler purchases...

 

[Supercharged SVT]

Looking back - you are right - I did spend some $$ to have a mandrel bent 3.5" tailpipe engineered ($700) and that MagnaFlow lasted 700-800 miles - the cure came with true duals and as much as I didnt want to cut/chop - the over all is very happy - at peak output, I am just over 12psi vs the 11.2 from before and the boost does not fall off at redline -



I am headed back to the dyno before snow flies - this is what it looks like now -



[Broken External Image]:

 

[Gavin Allan]

Sweet! :banana: