Thru-Exhaust With 4 Banger

[45Auto]

Re: Thru-Exhaust With 4 Banger

I say do it. Why should only people who can afford big gas-guzzling fuel hogs be the only ones with obnoxious sounding boats. Heck, remove the muffler from a 2-stroke chain saw and mount it behind the seats if you really want to impress people. Or get some really big speakers with nasty music blaring all the time.

Do all 3 and you'd really be cool!

 

[sandersps]

Re: Thru-Exhaust With 4 Banger

I must say that I absolutely love my merc 3.0, But just being on the muffs in the driveway it sounds exactly like a tractor. Merc 4 cylinders are ment to be neither seen nor heard, just quietly chugging along. And yes, my boat does all its own stunts.

 

[JB]

Re: Thru-Exhaust With 4 Banger

I say do it. Why should only people who can afford big gas-guzzling fuel hogs be the only ones with obnoxious sounding boats.

Right! Pretend to be a rich and obnoxious lake hog. That is about as cool as flashing your main squeeze's Mom.

 

[Bondo]

Re: Thru-Exhaust With 4 Banger

Originally Posted by 45Auto
I say do it. Why should only people who can afford big gas-guzzling fuel hogs be the only ones with obnoxious sounding boats.

Right! Pretend to be a rich and obnoxious lake hog. That is about as cool as flashing your main squeeze's Mom.

Aaaaahhh, Yes,.... Boatin',.... Trailer Trash style...

Ya might be a Redneck if,..??.....

 

[smokeonthewater]

Re: Thru-Exhaust With 4 Banger

while ur at it get all your buds to go with you with spray on tans, gold chains (the more the better) and matching speedo's with the boat's name on the back









BAAHAHHAAAHAHAHAHAHAHAHA!

 

[CobiaXL]

Re: Thru-Exhaust With 4 Banger

Ya might be a Redneck if,..??.....

If I put a Y-pipe on my 4 banger and run DUAL thru exhaust?

 

[not enuf toys]

Re: Thru-Exhaust With 4 Banger

If I put a Y-pipe on my 4 banger and run DUAL thru exhaust?

Wow I missed that....it is an inline? Would it just be one thru hull?

 

[CobiaXL]

Re: Thru-Exhaust With 4 Banger

it is an inline? Would it just be one thru hull?

3.0 inline 4 cylinder single exhaust..Thinking about Y piping (2) 3" DUAL stainless pipes coming out the transom.Would I be a REDNECK?

 

[not enuf toys]

Re: Thru-Exhaust With 4 Banger

3.0 inline 4 cylinder single exhaust..Thinking about Y piping (2) 3" DUAL stainless pipes coming out the transom.Would I be a REDNECK?

I know lol

Thru all the Bs I forgot its an inline!

That would be sooo funny! Where do ya mount it?

 

[CobiaXL]

Re: Thru-Exhaust With 4 Banger

I know lol

Thru all the Bs I forgot its an inline!

That would be sooo funny! Where do ya mount it?

Where there is a will,there is always a way.
I made this thread hoping to sway the admiral in her decision making.After reading the posts,I highly doubt her mind will be changed.

 

[04fxdwgi]

Re: Thru-Exhaust With 4 Banger

3.0 inline 4 cylinder single exhaust..Thinking about Y piping (2) 3" DUAL stainless pipes coming out the transom.Would I be a REDNECK?

Kind of like some of those I've seen in PA putting tall stacks on thier garden tractors. What could possibly be the logic behind that, except annoying the neighbors while cutting the grass. Sort of like putting a 12" lift kit on the pick-em-up truck that is only driven to and from work everyday. Just a "look at me" tactic.

 

[DuckHunterJon]

Re: Thru-Exhaust With 4 Banger

Just a "look at me" tactic.

Which is exactly the reason for the thru-hull exhaust - regardless of engine size. Wish they would all just pass on it.

 

[CobiaXL]

Re: Thru-Exhaust With 4 Banger

Freeflowing exhaust makes more power.

 

[bekosh]

Re: Thru-Exhaust With 4 Banger

I would say that the only motors that should have thru hulls are ones that sound like this...
Turn up your speakers, especially if you have a sub woofer.

 

[45Auto]

Re: Thru-Exhaust With 4 Banger

Freeflowing exhaust makes more power.

But thru-hulls only contribute to free-flowing exhaust if the stock down pipe and thru-prop exhaust are the restrictions in your system.

Have you looked at your 4 cylinder combined intake/exhaust "log" manifold lately? I gaurantee you that the exhaust system downstream of your manifold is NOT the limiting factor in your exhaust flow.

A thru-prop exhaust is actually a very efficient scavenging system since the low-pressure area at the hub of the prop helps pull the exhaust gases away from the engine.

You won't see any performance gain with thru-hulls unless you seriously modify everything else in the engine's airflow system (intake manifold/cylinder head/exhaust manifold) to take advantage of it.

The 496HO big block (425 HP) in my 22' Crownline has selectable exhaust (thru-hull or thru-prop). It makes absolutely no difference on the GPS speedometer or the fuel flow gauge whether it's running through the prop or the thru-hulls. Only benefit of the thru-hulls is scaring little kids standing next to it on the dock when you fire it up.

 

[Icyharp]

Re: Thru-Exhaust With 4 Banger

Only benefit of the thru-hulls is scaring little kids standing next to it on the dock when you fire it up.

Too funny, I was crusing with mine shut this past weekend and had 4 jet fleas bouncing around behind me, I opened the the exhaust and they all stopped then turned away. Then I closed em off and went about my merry way.....

Really though, a 4cyl.......will sound my folks old Pinto wagon I had to use when I was a kid and the exhaust fell off......awful:facepalm: Bad enough being in a Pinto wagon with wood grain tape on the sides much less have to make a horrible audio noise as well, ya the chicks dig it.........lol NOT

 

[haulnazz15]

Re: Thru-Exhaust With 4 Banger

It has been widely shown that until you're at 500HP+, the use of thru-hulls doesn't gain you anything but noise. I just spent a day on a jet boat with a blown 468cu in BBC, the sound is beautiful for the first 30 minutes, the rest of the day it gets tiresome.

 

[H20Rat]

Re: Thru-Exhaust With 4 Banger

The 496HO big block (425 HP) in my 22' Crownline has selectable exhaust (thru-hull or thru-prop). It makes absolutely no difference on the GPS speedometer or the fuel flow gauge whether it's running through the prop or the thru-hulls. Only benefit of the thru-hulls is scaring little kids standing next to it on the dock when you fire it up.

That doesn't necessarily mean they are the same... If it was a forced thru-hull only, you could tune it to get a couple more horse out of it, but it wouldn't run well when back through the prop. Being selectable, the state of tune has to be a compromise to allow both conditions to run well.

Something similar happens in the PWC market. People put on high flow intakes without realizing what they are doing and the requirement of carb mods, and the engine either runs poorly or burns itself up. The capability to get more air through an engine by itself doesn't equal more power. In your case, you might be able to add just a little more fuel when running the thru-hull, and that is what would give you a little more power.

 

[CobiaXL]

Re: Thru-Exhaust With 4 Banger

thru hull would be one less boat blowing pollution in the water.

 

[45Auto]

Re: Thru-Exhaust With 4 Banger

Being selectable, the state of tune has to be a compromise to allow both conditions to run well.

Ignition advance is set by the knock sensor, fuel injector duration (fuel/air ratio) is set by the MAP (manifold absolute pressure) sensor based on manifold pressure. Increased flow would lower the manifold pressure thus causing more fuel to be injected (the fuel flow meter measures fuel injector duration), even if the power difference wasn't enough to cause an increase in speed (figure about 10HP required to gain 1 MPH). The computer doesn't know if the thru-hulls are open or not, all it sees is manifold pressure. If there was any difference in flow there would be a difference in manifold pressure, thus causing a difference in the fuel flow meter.

Can't use any more timing without getting knock. The computer will automatically inject more fuel if you were actually getting more flow. Exactly what "state of tune" would you recommend changing to optimize performance on the thru-hulls?

In your case, you might be able to add just a little more fuel when running the thru-hull, and that is what would give you a little more power.

The engine computer would inject more fuel when running on the thru-hulls if there was an increase in flow to justify it. It injects the required amount of fuel to maintain the correct fuel/air ratio. If there was an increase in air flow running on the thru-hulls, you would also see it in the fuel flow.