Does Transom exhaust really help?

[bryont]

Simple question. Thinking about putting in a thru transom exhaust on my Yamaha <br />4.3 V-6 210hp I/O. I am wondering for those that Have done it, was there a <br />performance improvement or not? I do not plan to replace the manifolds, just a <br />transom exhaust. Looks like about $300 or so to do but I don't know if I want <br />to do it for just the sound.<br />Funny thing is that I have a friend that has a Maxium 18 runabout that has a <br />Merc 4.3 V-6210 hp. He told me that all he did was install a transom exhaust on <br />his and he is now running a 23 pitch SS prop and almost getting 60 mph out of <br />it. My boat with a 19 Aluminum will do 48-49ish. I checked my speedometer with <br />a GPS and it is pretty accurate at speeds above 25. I did not run his boat <br />because he got orders to Germany before we had the chance to run our boats <br />together. Is this possible with just a transom exhaust? Is the outdrive exhaust <br />really that restrictive? Both boats are 18ft runabouts.

 

[golfer]

Re: Does Transom exhaust really help?

I know this might be controversial, but here is what I have found...I have had a few boats with big blocks, all had silent choice exhaust. I really did not notice any difference with thru hull or thru outdrive...Maybe 1 or 2 miles per hour on top end...I do however completely believe that having no thru hull exhaust makes a boat sound like a wheenie, lol...If you have a boat that is high performance, you really should have the sound to match, if you have a regular boat, who cares anyway...Just my opinion.

 

[golfer]

Re: Does Transom exhaust really help?

Oh, I re-read your question and failed to notice the propeller comment the first time...A prop can make a huge difference!!! I have gone from 52 miles per hour with a 19 pitch aluminum, to 64 with a 23 mirage stainless...The biggest factor there being the pitch change, and not so much the aluminum to stainless, however, I do believe stainless is far superior, and does make a difference. Watch your RPM's, very important when messing with pitch...To small (like the 19) and you will over rev (good low end though), too large of pitch (if I would have put on a 25), you are under revving and will have a really hard time getting up on plane.

 

[johnkc]

Re: Does Transom exhaust really help?

have you ever heard a v-6 with open exhaust ?nothing like a v-8.more like a big chainsaw.

 

[DJ]

Re: Does Transom exhaust really help?

bryont,<br /><br />If you think you are going to get 10-11 mph. out of thru hulls, think again. I think your buddy is pulling your chain.<br /><br />If your boats are not identical. You're comparing apples to oranges.<br /><br />The right prop. will help more than anything.<br /><br />I tend to agree with johnkc, a v-6 with open exhaust has an annoying exhaust note.

 

[bryont]

Re: Does Transom exhaust really help?

Don't get me wrong I understand what you are saying. This is my first boat and I am having a ball with it. I do note the exhaust tone will not be even close to a V-8. I just can not understand why (if it is the truth) his 210hp V-6 will pull to 4800-4900 WOT with a 23 pitch SS prop and my 210hp V-6 with a 19 Alum. prop pulls the same 4800-4900 sometimes at WOT. My boat is in a good state of tune as well. 4 inches of extra pitch to me seems like a lot and I just do not see it pulling to the recomended WOT with that prop on, not to mention the bottom end will be gone. I know that they are not the exact same boat but can 2 18 ft. pleasure bow riders be that much differant. It does not feel underpowered or anything like that. I am just curious where this extra pull is coming from with a 18ft bow rider with the same hp rating as mine. I am starting to see that the money can be spent in better places though. I do appreciate the comments..

 

[bryont]

Re: Does Transom exhaust really help?

Oops. The boat will always pull 4800-4900 with the 19 pitch prop. It would pull to 5000 right before the rev limiter kicks in if I would let it but I only let that happen twice with just two people in the boat. <br /> Oh since you guys have been so helpful here is the biggy. I have realized that it is hard to get expert advise on this Yamaha (YEMS) I/O. Apparantly Yamaha only produced I/O's from 1991-1995 I believe. They say that because of the ECU and numurous safey's that either you get a good one or you have constant electrical/adjustment problems. I was just looking for someone that wouldn't mind helping me when the time comes. I am a good auto mechanic but I am not even going to touch a thing until I have too. I still need to get the engine manual, I have the outdrive manual already but still looking for the 4.3 engine manual.That is probably a better place to spend the money....Thanks again..

 

[mkast666]

Re: Does Transom exhaust really help?

Why don't you borrow his prop for testing?<br />Any reputable prop shop will let you borrow a used prop for testing, you pay for any damage. A friend has a 19 footer, weighs 2650 lbs. empty, my 23 footer weighs 2650 lbs. empty, just because both boats are 18 footers doesn't mean they will weigh even close. Remember back at the drag strip when V 6's first came out and headers were installed? What's THAT NOISE? It's a V6! They sound funny with open exhaust.<br />Rather than spend $300 ( I don't think you can get thru hull exhaust for that price)on the exhaust, buy the land and sea varible pitch prop, you'll leave him in the dust.

 

[magster65]

Re: Does Transom exhaust really help?

You're right, don't do it. The V6 is a good motor but they just don't sound good at all. Keep propping it up until you fall out of the recommended rpm range (full fuel and 2 people). If you're bumping into the rev. limiter you can use more prop for sure! Try waxing your hull, or at least the area that in the water at high speed and experiment with your outdrive trim. In my Banshee I found that if I put more weight (gas, battery, cooler, etc.) nearer the bow the boat wouldn't 'porpoise' as easy so I could use more trim and got a few more mph. Free speed. Keep your boat light too, if you're just going to race your buddy, keep your life jacket and take everything out of your boat except for what you absolutely need... all the little things add up! I think your buddy's speedo is out... I wish I could see the look on his face when you start to pull away

 

[DJ]

Re: Does Transom exhaust really help?

bryont,<br /><br />I do not recall what type of boat you said you had.<br /><br />There can be HUGE differences in two 18' -pleasure boats. Particularly weight. Not to mention hull design, center of gravity, the list goes on and on.<br /><br />I think you may be a bit underpropped. A good SS prop. will give you a few more MPH.<br /><br />Leave your transom solid and fine tune your prop. selection.<br /><br />All I've heard about the Yamaha drive has been good. The engines in your two boats are virtually identiccal. The drives make little difference UNLESS there is a big gear ratio difference. There may be.

 

[bryont]

Re: Does Transom exhaust really help?

I wish I could borrow his prop but his is a Merc and mine is a Yamaha outdrive both rated at 210hp(4.3 V-6 with a quadrajet). Plus we are both out of country(both Air Force guys).<br /> I have messed with cars/bikes pretty much all my life with a little racing and I am suprised at how little I know and how much there is to know about boating if you want more than just turning the key and going. <br /> The big surprise is the statement about weight that mkast666 posted. I was completely in the dark. I had no idea that there could be that much differance from boat to boat. Lesson learned.<br /> The varible pitch prop caught my eye though. Do they work pretty well? Is there a good web site that I can take a look at. That seems like something to look into if it works. <br /> I do not race my boat. Mostly used for pulling water toys and skiers. I rarely hold it at WOT but I was curious at the differances between between our boats, hence the post. I am afraid of loosing my low end for the toys and skiing so the varible pitch thing may not be a bad idea. Any body have thoughts on the varible props??

 

[Bondo]

Re: Does Transom exhaust really help?

try this...<br /> http://www.land-and-sea.com/public/marine/marine.htm <br /><br />I've got one... Powered by a Big Chainsaw.....<br />I built my own 4 1/2" SS pipes when I installed the 4.3

 

[golfer]

Re: Does Transom exhaust really help?

bondo!!!!!<br />How do you like the torque-shift prop????

 

[Bondo]

Re: Does Transom exhaust really help?

I LOVE the prop....<br />with the 11" at low gear, i drop my bennetts, + my trolling speed is down to 3/4mph(as in Less than 1 )...... break it just off idle, + i'm in walleye country... at about 1000rpm or so, i'm running salmon speed... bring the tabs up, drop the throttle, you're Crushed into your seat.... alittle up trim, + i'm running 44mph accross lake Ontario in a Full Dress 21'Starcraft Islander Fishing Machine.. in the salt, i've gotten 53mph gps.... <br />My pipes, 4.5" SS, run straight off the risers to the outside of the transom... then a 7* tilt to the outside, follwed 4" downstream by a 45* drop to the outside.... they end just aft of the tabs.... from the dock, till it breaks on plane, they are dead silent.... after that, it's the ChainSaw.... <br />And I Like It....

 

[golfer]

Re: Does Transom exhaust really help?

So, you are saying it is night and day better than the regular props, like a stainless steel prop...? Any dislikes (exceopt the price) that you have? I have a 27" Fountain Fever with HP500 Merc., and am contemplating this prop...I just don't want to spend that much if it is only slightly better, or if there is even a tiny chance it will injur my new baby (Fountain)...

 

[mkast666]

Re: Does Transom exhaust really help?

I know a lot of people don't what to hear about the price of the Land and Sea prop, "How much? I'll never spend that much for a prop in my life!" The truth is it's the best money to spend on the boat as far as speed is concerned. Watch the video at the web site. Everyone I know who has put one on has raved about it.

 

[Bondo]

Re: Does Transom exhaust really help?

We're getting abit off-topic,but...<br />Well, i wouldn't have spent the retail price for one, But i bought it on ebay, 6/01, for $271.50, to my door.... another $100. or so for tuning parts....(Rick,or ****(rick, with a D), at L&S call center, is a real A--hole, real cocky,+ not much help) <br />I'll make NO claims about what it'll do for Your boat, But, it's the Best spent money on MY Boat(+ there's been alot of it$$$)......<br />I didn't gain much for topend,but BOY, You Really Get There, in a Most Violent Way !! we're talking a Full Dress Fishing Boat...<br />I've only talked to 1 guy, who didn't like his... But he didn't take the time to tune it to His Boat... + he boated in a VERY Sandy area.. Of course, i try to keep mine Away from any Real Estate.... <br />I just started a New Project Boat.... When completed, the L&S will NOT go with the old boat.... If i had to rate my toys,<br />#1 is the L&S prop..<br />#2 is the auto-pilot..<br />Etc....<br />For MY Boat anyway....

 

[Doug Durako]

Re: Does Transom exhaust really help?

Great info on this forum! Bondo---I have been thinking about the torque-shift for several seasons but I can't find anyone who can tell me what happens when you hit something hard enough to put a ding in a normal Stainless Steel prop?<br /><br />Have you broken a blad yet or busted a spring in any of the the cam mechanisms? Is the prop easy to tune?<br /><br />Thanks.

 

[Bondo]

Re: Does Transom exhaust really help?

This Thread is Supposed to be about my 4 1/2" Pipes... Not my Prop....<br />I'll tell ya 'bout the prop on that thread, when I find it...

 

[Doug Durako]

Re: Does Transom exhaust really help?

Thanks, Bondo. Not sure why this forum is limited to engines and drives----prop is a critical piece of the power puzzle in my book. I've been over to the prop forums and they are all hung up on outboards, jack plates, etc.<br /><br />I got fired up when I saw this discussion. You can drop me a line at: doug.durako@countryfinancial.com if you have time and do not want to use space here.<br /><br />Thanks, again. I am learning a great deal reading this forum.