this time on engine masters presented by AMSOIL we're gonna find out what happens
when we try and cram six hundred and twenty horsepower through a two and a
half inch muffler or a three-inch muffler and you're gonna find out a
really easy combo for 600 plus horsepower from a simple 454 Chevy but first you
know I have to do this right
ready
ok scientific analysis 3 inch muffler says
ok not much difference let's get into the real science
here is the poor innocent big block Chevy that we are gonna attempt to
strangle with mufflers when this thing is running with open headers it makes
six hundred and twenty horsepower and five hundred and eighty plus pound-feet
of torque with a curve that looks like scott wyland cardiogram let me tell you
how we're doing it it has pretty much a bone stock forged 454 bottom in
doesn't Wiseco pistons interpret ending a quarter to 1 compression the cylinder
heads are edelbrock XT what does that mean maybe X tra there are
oval port that's been CNC ported they're actually pretty good
up top we've got a matching oval port Edelbrock Performer RPM air gap intake
Holley nine hundred and 50 CFM alter XP carburetor and we're going to be
shutting the exhaust gases through a set up two inch hooker under chassis headers
today then there's the camshaft we have a solid roller in this thing if the Comp
Cams XR 284 are got two hundred and forty eight degrees and duration at 50
on the intake low the exhaust is 254 the lift is 654 and 661 and it's on a
hundred and ten degrees lobe separation angle and now we're gonna roll it into
the dyno and find out what happens when you try and shove all about power
through a complete two and a half inch exhaust system
this looks ridiculous but it's actually really good because we're going to mimic
exhaust system just like it might be in your car or crew cab dually it may be
because this really long but the difference between the two and a half
and three and muffler isn't just gonna beat them up
well it's gonna be the area of the exhaust tubing in the whole system and
that's why we've set it up this way and why we've included bends like the over
the axle like a tailpipe turnout so this is gonna give us a real world
example the difference between that two and a half inch Magnaflow and later on
a three inch this time we have oil options there's the AMSOIL z-rod 10 30 or the premium
protection 10 40 the z rod is more formulated for a performance kind of guy that they
had kind of a nicer option for someone who's gonna let an engine sit for a long
time sort of in a typical hot rod that might have 600 horsepower like this but
we've been running the premium protection 10 40 in this big block and
that's what we're gonna go with this time
bam I spilled it everywhere sounds of silence
did you rev up the water pump that's weird that's the 600 horsepower solid roller motor
well it was yeah we know this thing made nearly six hundred and twenty horsepower
the last time we ran it now we've got the two and a half inch exhaust on here
too much power it kills it is so quiet I know you like that how much horsepower you give up about to
find out exactly how much the thing I'm interested in actually is how its gonna
change the tune up is it gonna run richer because they can't get air out of
the motor we've got no two meter so we'll find out you know what you really
want that two and a half inch exhaust because an engine really likes back
pressure and and really you lose torque if the exhaust is too big oh yeah yeah watch that's
already proven and a established fact I read on the internet you've becoming an internet expert I've heard
ok we just took our engine that made six hundred and twenty horsepower and turned it into a 600
horsepower engine and we've used to make what was it
580 585 pound feet we turned that into 556 right now we're gonna pull up the
test with it on open headers with an 18 inch collector extension and no muffler
whatsoever
wow so here's the curve looking at the black line with two and a half inch
mufflers and full exhaust the red line is open exhaust with an 18 inch collector
extension you can see you're losing power everywhere
strangely enough down here 3200 and below but I'll remind you a lot of
people like lots why drive my car anyway this is all at wide open throttle not
necessarily indicative of what you're doing on the street at part throttle
because if you're on it you're going through 3500 rpm really quickly
especially if you have any kind of decent torque converter
the other thing that all low is the exhaust system thats the longest exhaust system I've ever seen over the axles and
turnouts and now look at used the same fuel making less power so is it richer
this comparison is looking at the air fuel mixture here with no mufflers and
here is with mufflers so higher on the chart is leaner meaning less fuel and
lower is richer meaning more fuel it did get richer with the mufflers because
it's not moving as much air through the engine I think it's probably has to do with the link
awake signal the carburetor I mean that whole air track doesn't start or end of
the intake manifold it starts carburetor and ends at the tip of the muffler all that is changing the resident
wave the reflected wave throughout the whole air system and so probably just a
different signal to the carbon so what we're looking at here with the two and a
half inch exhaust system its five hundred and fifty-six pound-feet of
torque 600 horsepower so now we're gonna go put on the three inch hopefully
improve that little bit it's got to it has to I bet it makes it louder right think so
then we can hear it run it is depressing we threw away 20 horsepower and how many pound feet
thirty you know when your out in the street car those really really short exhaust systems that
are way too loud but just your head so after thirty miles yet to get out and
beg for someone else to drive your car check your pulse no I'm afraid its time to go
what we just learned is that if you really hate horsepower and want to kill torque
the two and a half inch exhaust system is the perfect product for that so now
we're gonna step up to the three incher and find out what happens but i wanna make a
couple points first we're using the exact same model of magnaflow muffler
for both of these tests and importantly they are the same length and width in
both cases because that really makes a difference now have a look at that shot
of a two and a half inch system versus the three-inch system kinda obvious
what's going to happen here isn't it when I was working on oil rigs my
my crew boss would probably fire for double wrenching like this
this has to make it better right but if it doesn't it's gonna help a lot take off the two and
a half inch exhausting throwing the three on right now looking to find or 620
horsepower again we'll get there no I was pretty close we wanted to put an o2
sensor in the exhaust we can see if the air fuel ratio changes with the different
exhaust sizes but I didn't feel like welding anything so this is a clamp on
oxygen sensor band with a little gasket so you can install without having to weld
were using these Magnaflow stainless steel mufflers and these are good because
check it out there straight all the way through no obstructions no chambers no
baffles just a perforated core and some packing in there in fact I think one of
the things is this test will be more dramatic if we used to bad muffler these
are pretty good
ok Dulcich what I need you to do is run out there and calculate the total different in pipe size for the full length of two and a
half versus three the cuban capacity right can you
do that do that in cubic inches or cc's whats 25 feet times three inches times pie r squared yeah thats it
essentially as good as open exhaust very impressive very close its way louder 570
pound feet of torque 640 horsepower and look how flat that crazy torque curve is
boom the three-inch is better everywhere except for down here below 3500 where
the I'm guessing the engines just not moving enough air to really matter
really care but here it's freight training so call it open headers with it
18 inch extension on it so now we're looking at a blue line that indicates an
open header with an 18 inch extension blackline three inch exhaust red-lined two
and a half inch exhaust it interesting that way down here
3200 and below that we making more torque with exhaust system on it we're
thinking a function of basically the collector extension length before
airflow actually starts to take over and then as soon as there's some demand for
air flow open headers the way to go but look how close the three inchers
matching it up here never really close
the three inch is definitely the way to go
once again I think we proved the obvious on engine master we do it so well I know it's true three inch
exhaust enough makes more power than two and a half inch exhaust the thing that
surprised me the most is that those Magnaflow three inchers almost didn't
kill power and all I mean I don't think enough that would be noticeable by
the seat of your pants they may be obvious but that might be the ammo well you need to take your muffler guy
when you say I wanted three inch exhaust system he says your crazy thats way too big and you need the back pressure I know thats happen to me so many times you get a
muffler shop are ya you know your engine needs a little bit of back pressure I
think we disproved that right now at two and a half inch system killing a bunch
of power compared to three and even the open headers for that matter that's true
zero back pressure the other thing that we did off-camera is that we weighed both the exhaust
systems and that was a surprise to me and me to the three inch exhaust only
weighed 10 pounds more than the two and a half inch exhaust and we had a big
hanging long exhaust system on this thing I was expecting a whole bunch more like you know twenty twenty-five
pounds this part might surprise the audience you know how much that complete
three inch exhaust system weighed eighty two pounds thats a lot to be lugging around that might be a new argument for turn downs I was
surprised that the two and a half as at 72 pounds I was expecting 40 or 50 pounds I know you don't know true facts till you do the measurement you weigh it you check it you dyno test it and
you find out and that's exactly what we do here on engine masters presented by
AMSOIL come back to us next time but meanwhile check out Motor Trend on
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come back for more dyno violence on engine masters presented by AMSOIL hey
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masters 30 days before anybody else and there's an exclusive show on there with
Dulcich and myself that's called roadkill garage now here's a sneak peek
at the next episode of engine masters that the live right now on motor trend
on demand this is your camshaft for a girly hydraulic roller lifter this is
your camshaft for a manly and violent solid roller lifter and this time on
engine masters presented by AMSOIL here gonna help you decide which one is right
for you
check out this engine masters now at Motor Trend on demand
scientific analysis
not much different
ok two and a half of 2013 ready
no real difference