Damn, I need another muffler

Soup Nazi

Soup Nazi

The artist formerly known as Don M
I have been testing some new 12 valve cam grinds in my own truck lately. This truck has a 5" exhaust. The noise at the back of the truck is insane. Way too much, IMO. The volume of air this thing is pumping out the pipe back there is almost comical. My idle is at 800 RPM.

Gimme a break. These engines are not supposed to pump this much air according to the head porters and their VACUUM porting methods.

Dont expect this radical SOB for a street truck. Your neighbors will hate you.
 
Thats funny you mentioned the "twister" type resonator/muffler system. I used them back in 2003 to rid my own truck of the drone. They worked wonderfully for this purpose, but top end power loss was completely unacceptable. Turbo spool was better too. The low end was better, but I lost over 50 HP on top. This was with a single turbo. Twin trucks will suffer even more.

This was a great idea for me and my passengers and I might put a twister back on my truck again one day, but not while I am chasing HP.
 
Soup Nazi said:
Thats funny you mentioned the "twister" type resonator/muffler system. I used them back in 2003 to rid my own truck of the drone. They worked wonderfully for this purpose, but top end power loss was completely unacceptable. Turbo spool was better too. The low end was better, but I lost over 50 HP on top. This was with a single turbo. Twin trucks will suffer even more.

This was a great idea for me and my passengers and I might put a twister back on my truck again one day, but not while I am chasing HP.
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ohhh really? 50hp is a lot. Would you not see a large increase in drive pressure over 50hp worth of back pressure?
 
I found my old post about the twister muffler in 2004. Two of the twisters subtracted over 100HP at the 480 HP level

I need to check my notes/book to be certain, but I think the single twister subtracted 62 HP, not 50. I had an HX40 during these tests. It was in 2002-2003 time frame.

It was so quiet. Softer than a stock truck.
 
Thanks Don. I don't really notice 50hp where my fueling is at now, everything is "slow". But damn, you got me wondering now. Thanks.....

The one thing tho, the FTE muffler does the drone job. The 17" model does have a nice sound.

I"m curious about a dump setup on a 5" exhaust. Is that possible? do the make dumps that big? I suppose some googling is in order
 
It is a simple deduction really. A quiet exhaust is going to subtract power. More restriction gives less noise and vice versa.

I miss my twister or in one case twisters, but I dont have them on my truck now for a reason. It seems stupid to build up power with injectors, turbos, and EGT adding mods and then bottle up the exhaust. Perhaps a 5" system is less restrictive and the HP loss is less? I tested a 4".
 
JasonCzerak said:
Thanks Don. I don't really notice 50hp where my fueling is at now, everything is "slow". But damn, you got me wondering now. Thanks.....

The one thing tho, the FTE muffler does the drone job. The 17" model does have a nice sound.

I"m curious about a dump setup on a 5" exhaust. Is that possible? do the make dumps that big? I suppose some googling is in order
Click to expand...

what's a dump setup? a turn-down?
 
Forrest Nearing said:
what's a dump setup? a turn-down?
Click to expand...

Some call them cut outs too.

Amazon.com: QTP QTEC40 4 Electric Exhaust Cutout Valve: Automotive

But I'd want something that uses the same tail pipe... I'm sure we have enough room under the truck to do this with 5".

In my best ASCII art:

motor straight Tail pipe
------------|------|----------
................ --------
....................FTE

(disregard the ...... in the ASCII art, pretend they are not here)

So, with the cutout open, passes though. With it closed it will be forced off to the side via a "Y" pipe though the FTE and back into another "Y".
 
Soup Nazi said:
It is a simple deduction really. A quiet exhaust is going to subtract power. More restriction gives less noise and vice versa.

....


Perhaps a 5" system is less restrictive and the HP loss is less? I tested a 4".
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Well "they say" 5" is pointless even up to well over 1000hp. 4" will flow more then enough. And there are plenty of trucks with straight 4" doing just that, making well over 1000hp on 4". 5" is for looks. And I agree. It did change the sound over the 4" but I know I gained nothing.

However, you maybe be on to something.. running a 5" with a FTE mitigates the restriction a lot less then that of the same style setup on a 4".

I suppose a new test is in order.
 
I think 800ish was done on the stock exhaust system... twin truck...

dude picked up like 25hp IIRC... 50hp at 420hp seems awful high... I don't think a stock muffler would eat up 50hp :confused:
 
JasonCzerak said:
Well "they say" 5" is pointless even up to well over 1000hp. 4" will flow more then enough. And there are plenty of trucks with straight 4" doing just that, making well over 1000hp on 4". 5" is for looks. And I agree. It did change the sound over the 4" but I know I gained nothing.

However, you maybe be on to something.. running a 5" with a FTE mitigates the restriction a lot less then that of the same style setup on a 4".

I suppose a new test is in order.
Click to expand...

I'm game for tests, as long as there is documentation...

It would be interesting to know the specs of the "twister" style muffler you were running when you lost the ponies (don)
 
JacktheBear3 said:
I'm game for tests, as long as there is documentation...

...
Click to expand...

I agree. A Test could be simple with some prep. pull everything from the axle back off. run a pipe to the axle, deal with the soot under the truck. Replace pipe with one with an FTE in it. Should take 5 minutes to swap with band clamps. make a few more pulls. Should minimize time wasted in a $100/hour dyno rental for those with out dynos in their garage! ;-)

There's no doubt in the world that the drone is SOLVED with your muffler. 17" or 30". doesn't matter, the pressure and headaches are gone. I don't think I would of stayed sane towing that boat for 600 miles with the straight pipe. :)

I didn't noticed a seat of the paints feel difference between the straight or FTE. But then again, I have gone backward in the HP game so, I'm not a good subject ATM
 
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