Attached is the complete "official" report from MERC / TOHATSU Dyno Test. This is some good reading.....Enjoy!
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Holy *))&&&*&##$@@$
What the heck is wrong with this picture. when you have the guy who is dyno testing the motor and has a professional career in designing and engineering outboard motors tell you the motor should be in another class and you do not listen. Oh my God !!!!! I cannot believe we are even considering this. Did you all even read this report!!!
Regards,Dave Scott
Aim Marine Inc.
613-831-1246 8-5 Mon-Fri
Ottawa, Canada
http://stores.ebay.com/Aim-Outboard-Recyclers
DS(M)H - 20CE
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D2 class in the works
I think that we need to re-instate the D2 Class again.
Regards,Dave Scott
Aim Marine Inc.
613-831-1246 8-5 Mon-Fri
Ottawa, Canada
http://stores.ebay.com/Aim-Outboard-Recyclers
DS(M)H - 20CE
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I hear ya!
Originally posted by crankbearingWhat the heck is wrong with this picture. when you have the guy who is dyno testing the motor and has a professional career in designing and engineering outboard motors tell you the motor should be in another class and you do not listen. Oh my God !!!!! I cannot believe we are even considering this. Did you all even read this report!!!
Regards,17W
"You gotta do the work"- Pop Trolian
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As a proponent of single engine classes, at last thursdays commission meeting, I made a motion that the entire tohatsu project be terminated. The motion was brought to a vote and failed, but I did not stand alone. We need to determine if the Stock Outboard category should persue multiple engine classes or not. I realize that most members of the PRO & MODIFIED categories are in favor of multiple engine classes but we are STOCK Outboard. Our goal should be and has always been (in my lifetime) "I'll race my apples against your apples and we'll see who's better!" That's what Stock Outboard has always been about. We are supposed to leave these motors Stock. I realize we have gotten away from that lately but that should be our goal. It is wrong to expect any prospective boat racer to buy a motor based on the rules that we have today because we have already told them that the rules are going to change tomorrow. I believe that a large per-centage of our growth problem is the instability of our future. Basically, we don't have a clue what's going to happen next. We are not directing our sport in any particular direction. We can't just stick our heads in the sand and pretend we don't have issues. I've seen so many posts that say in effect" Stop with all the politics. Stop crying. Just go out and race!". Race what? What is Stock Outboard if it is not: One class = one motor(make it as fast as you can) WHITHIN the rules. Boats, designed within the rules. I'll bring my best, you bring your best and we'll find out who is better on "Any Givin Sunday". This is a stock outboard issue. Input is welcome from anybody but remember the perspective from others will be different. I guess I should have started another thread. Sorry! John Runne 2-ZJohn Runne
2-Z
Stock Outboard is all about a level playing field.
True parity is one motor per class.
It's RACING, not just another boat ride!
NOT a representative of Racing Outboards LLC.
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Clarify?
Wow---so if you're going to go that Doberman on the one engine per class concept, which C engine do you keep: The Yamato 102 or the 302?
My guess is that you would want to keep the 302, since you can't buy a 102 anymore, and the whole idea of SO is to have comparably matched, AVAILABLE Motors....
And if you follow that logic, what do you do with the A class? There's a ton of OMCs out there, but you can't find a new one. So, keep the Merc and throw all the OMCs under the bus?
What about 25SSR? We know how you feel about multi-engine classes, but the Hot Rod and the Yamato are the only game in town that you can buy (you CAN buy Hot Rod now, can't you? I'm not sure).
Point being, this is not as black-and-white an issue as you may want to make it.
R-19
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Good Reading.........................
Originally posted by bbackus17wAttached is the complete "official" report from MERC / TOHATSU Dyno Test. This is some good reading.....Enjoy!
Being a Wienandt customer I can attest that when Mike dyno's a motor the performance on the race course is consistant with his Dyno results. I find it interesting that very few current D Class drivers are expressing opinions here. Well, since there are very few left maybe that explains it!!!
Anyway, having been a D guy most of my life maybe it's best to let the class die a peaceful death as it is doing. The introduction of a $5,200 (plus shipping,tax and options) engine that will 'blow the doors off the Merc' seems strange. Why the Commish encourged this seems puzzling. "IF" there are drivers looking to go 82 mph plus out there, it seems that many, many Mercury Motors are still available to this end.
I tend to agree with 2-Z for once ...............multiple motor classes are not the perfered route to go unless no other avenue is out there. Having witnessed the success of the OMC A and Yamato 102 through the decades, both of which superseeded it's prediicessor, this should serve as a guide to our leaders! I would guess the Tahatsu project will help finish off the D class if (I mean when) Wienandt's observations pan out(Read his report).
Hope I am wrong..............
D Fan.
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Let's make it easy:
This report is for the purpose comparing the Mercury 44 XS and the Tohatsu M50D2, to evaluate compatibility.
The test includes dyno test data and observations of reviewing the Tohatsu engine. This evaluation was done by WIENANDT Performance Technology. WPT does consulting for Original Equipment Manufacturers (OEMs) along with specialty design & development projects for race teams around the world.
The equipment used is a Stuska water brake dynamometer with Harrison Engineering data acquisition system. The Dyno was built in 1978 and has been upgraded by adding modern computerized data acquisition system.
Present were Mark Wheeler, Don Allen Jr., Jon Wienandt, Jerry Wienandt and myself.
Mercury 44XS
The Mercury 44xs engine tested here is Mark Wheeler’s and the engine history is stated here by Mark this season: “ Constantine MI. I ran this engine both days. There were 10 DSHs. I won one of 4 heats. The field contained Brian P,. Fred. H., and Jim Sweeney.
Zanesville: I ran this engine on Sunday only. Brian won 1 heat,
Sweeney won the other. I was second both heats.
Big Rapids: I ran this engine on Sunday only. (Last day of the
season.) Brian won both heats, I finished second both heats, Sweeney
finished 3rd both heats.”
These are the fastest Ds in the country, so this engine is a great example of quality, top notch performing equipment.
This Mercury 44xs was race prepared by Jerry Wienandt, who has prepared the majority of the National Champions in the D class for the last 15 years. It was assembled by Mark Wheeler and Steve Wheeler. The engine tested had all modern tricks.
All testing was done with the engine cover on just as you would race it. Each engine was run on it’s respective drive shaft housing and used the tuner they would for competition.
Because the Mercury has been raced, no break-in was required. The Mercury started well and ran very smoothly through the rpm range. I installed a block temp sensor on the engine and all test runs were within a narrow range of engine temperature. The Merc was run with different Spark advance settings and Jetting was reviewed as well. All external tuning adjustments were optimized. We did find some increased performance from the way the engine was last raced. About 1 to 1.5 hp was gained by tuning on the dyno from where we started. The best results are quoted here.
Tohatsu 50D2
The engine was prepared for the dyno and all mounting parts had to be made, as I have not run one of these in the past. I had most of the hardware on the shelf for the 44XS. Neil Bass was very helpful in answering questions on dimensions as I made the Tohatsu parts required.
As I prepared and rigged the engine for the dyno, I have some observations that need to be shared.
The hand throttle moves the spark advance and the carburetors. It has a very stiff squeeze to the throttle. It requires the spring in the hand throttle to bring the spark advance back to low speed.
The choke plate is made of aluminum and can cause metal particles to wear off. I highly recommend that part be made in a nylon or a plastic type material.
The Carburetors do not have full butterflies. The butterfly screws are peened over at the factory so they won’t fall out. Removing them generally destroys them. This would need addressing to comply with current safety rules.
I ran the engine through a Dyno Break-in program that I use on our OPC racing engines. This Break-in Program was originally developed at Mercury Racing and I tuned it for my machine and the engine application. From this Dyno Break-in Program I am able to deliver OPC engines as drop on powerheads. No additional break in needed. Race ready. Again the block temperature was monitored and water flow is controlled.
During the break-in, a danger zone was identified as a “not to go there” zone. At 5000 rpms the engine shakes so much we could watch parts shed off of it. The bolts came out of the recoil handle assembly and it fell off. The bolts that hold the belly pan on all backed out. The Fuel flow went to a dangerous lean condition, all from vibration. Once you get through this RPM the engine settles down again. This is not uncommon for some engines to do this when mounted to a steel Dyno frame. It is not as bad on the boat, but the vibration point is there. I had to tie wrap the choke open so it would not close during the runs. The vibration made the choke plate jump up and down. The choke spring should be stronger.
When running power runs, it was observed the bottom two cylinders were richer than the top cylinder. The paperwork with the engine identifies the original jet set up as break in jets. Fortunately, the engine came with two main jets one size smaller. The leaner jets were installed and the power runs followed. The engine performed favorably with this adjustment. Now all plugs looked the same. The engine was run with the Spark advance set from the factory. There was adjustment still available so we advanced the spark about 2.5 degrees. This was all the spark advance that could be achieved without modifying parts. The performance also was improved. If it were mine, I would make more adjustment to spark advance. From the first runs, again, improvement was found with every external adjustment performed.
CBHP = Corrected Brake Horse Power.
Torque = Corrected Torque and measured in foot pounds.
RPM Merc 44xs CBHP Tohatsu CBHP Merc 44xs Torque Tohatsu Torque
3500 27.5 34.6 41.2 51.9
4000 33.8 40.8 44.3 53.5
4500 40.4 45.3 47.2 52.8
5000 45.9 47.8 48.2 50.1
5500 49.5 51.3 47.2 48.9
5750 51.3 55.3 46.7 50.5
6000 52.5 56.2 45.9 49.1
6100 53.1 56.2 45.7 48.3
6200 53.5 56.5 45.3 47.8
6300 53.8 57.0 44.8 47.5
6400 54.0 57.2 44.3 46.9
6500 54.4 57.8 43.9 46.7
6600 54.3 57.0 43.2 45.3
6700 54.7 56.1 42.9 43.9
6800 54.5 55.5 42.1 42.9
6900 54.6 55.1 41.5 41.9
7000 54.3 54.4 40.8 40.8
7100 53.7 53 39.7 39.2
7200 52.1 50.1 38.0 36.5
7300 51.1 48.4 36.0 34.8
When reviewing dyno data, it is important to understand what is really there, to come to solid conclusions. Fuel flow converts into Brake Specific Fuel Consumption (BSFC). This tells us if the engine is rich or lean and how efficient a given design is. The Mercury Deflector design is less efficient and requires more fuel, not for performance, but for lubrication, as this engine does not have good fuel flow across the connecting rods.
The Tohatsu has three carburetors with three V type reed blocks flowing directly across the connecting rods on the way to modern Loop scavenging, plus the advantage of pulse exhaust tuning.
This system is much more efficient and can run considerably less BSFC.
By changing the jetting / leaning the BSFC, the power curve can be changed. We ran the Mercury as lean as we dare. The Tohatsu we ran, as lean as we had support parts (jets) for. I would go leaner if I had the smaller jets as the Tohatsu pistons are still totally washed clean showing that the piston is still cool enough to not bake on any fuel deposits. If the Tohatsu could have been run leaner, that would add power to the top end of the powerband and I would not expect any loss on low end.
Also, the totally washed clean pistons show that we may not be at the optimum spark advance, yet I did not alter any parts. If the timing rod was threaded further, more Spark Advance could be achieved.
Based on the dyno runs, the two engines have different powerbands. With the additional Torque of the Tohatsu engine over a wide RPM range it can and will pull more blade area. Because the engine falls off at high RPM, more pitch would be required for top speed, and there is power to pull that pitch.
More Torque, equals stronger acceleration. At no place in the usable powerband are the two engines comparable. Two foot pounds of torque more can win big and here we have up to 5.6 ft lbs more. If your contention is, “well maybe, but it is low in the powerband”, the Tohatsu has the power/torque to pull the bigger wheel and still squirt out of a tight corner. This is boat lengths of acceleration advantage.
I saw the information the Mr. Bass put out about his gearcase. That the skeg is longer, is an advantage, not a disadvantage. In SST 45 we require a template so drivers don’t add too much to the skegs and all leading 45s have larger than OEM skegs. Big skegs handle better, and this allows you to go even higher on the transom. This opens the door to more speed yet. Better lap times result from being able to pitch the boat into a turn harder, and apply more power, sooner, exiting the turn. The Bass gearcase also has the added advantage of .350 inches less torpedo width (R dimension on Spec sheet).
My conclusion is the Tohatsu M50D2 is a fine engine, but I do not believe it should be in the same class with the 44XS. The SORC does not have a record of ever successfully balancing multiple engines in any class and these two engines have very dissimilar. The Tohatsu should have it’s own new class. Let them run combined, but scored separately, until you get more of them. When the Tohatsu’s are optimized, the 44XS will be ¾ of a lap back in a 3 lap race.
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page 2
I started doing Dyno development in 1978. This, with racing Stock, Mod, Pro and OPC, along with my background in engine design and development make my professional opinion solid. The two engines are not compatible in the same class. The Tohatsu will dominate the class, taking out many competitors not prepared to invest more into Stock Outboard racing. In it’s own class, it will not affect a solid class that now has some growth, possibly due to the efforts of people making new parts for the 44XS. I’m not sure we have a shortage of equipment, but a shortage of people who want to race at that level.
In a modified form the engine has even greater possibilities. It should not be considered as a D Mod, but as a Formula E. The Tohatsu’s porting design, three carbs and three V type reed blocks, along with a removable head, give this engine the ability to be over 85hp. Three cylinder pulse tuning will produce a much better power curve than a 4 cylinder with megaphones. The typical winning D Mod is about 60 to 65 hp on my dyno.
Respectfully Submitted
Mike Wienandt
WIENANDT Performance Technology
W6912 Fox Drive
Fond du Lac, WI 54937
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[QUOTE=sponsonhead]
And if you follow that logic, what do you do with the A class? There's a ton of OMCs out there, but you can't find a new one. So, keep the Merc and throw all the OMCs under the bus?
Nope ... transition the OMC "A" over to the mod category (FAR/FAH or AMod) ... then use the Merc exclusively for ASH/ASR and "J" (Bye-bye AXSH) In that way nobody gets hurt and everyone still gets to run. And, it solves the problem identified earlier on another post about the need to have a slower transition class for the very young and inexperienced drivers as well as the very old and ... well you know, old drivers!
PS: Did the SORC run the same kind of dyno testing with the Merc "A" and OMC "A"?Untethered from reality!
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I was just sitting back and being quite......but........
Originally posted by csh2zAs a proponent of single engine classes, at last thursdays commission meeting, I made a motion that the entire tohatsu project be terminated. The motion was brought to a vote and failed, but I did not stand alone. We need to determine if the Stock Outboard category should persue multiple engine classes or not. I realize that most members of the PRO & MODIFIED categories are in favor of multiple engine classes but we are STOCK Outboard. Our goal should be and has always been (in my lifetime) "I'll race my apples against your apples and we'll see who's better!" That's what Stock Outboard has always been about. We are supposed to leave these motors Stock. I realize we have gotten away from that lately but that should be our goal. It is wrong to expect any prospective boat racer to buy a motor based on the rules that we have today because we have already told them that the rules are going to change tomorrow. I believe that a large per-centage of our growth problem is the instability of our future. Basically, we don't have a clue what's going to happen next. We are not directing our sport in any particular direction. We can't just stick our heads in the sand and pretend we don't have issues. I've seen so many posts that say in effect" Stop with all the politics. Stop crying. Just go out and race!". Race what? What is Stock Outboard if it is not: One class = one motor(make it as fast as you can) WHITHIN the rules. Boats, designed within the rules. I'll bring my best, you bring your best and we'll find out who is better on "Any Givin Sunday". This is a stock outboard issue. Input is welcome from anybody but remember the perspective from others will be different. I guess I should have started another thread. Sorry! John Runne 2-ZDaren
DSH/750ccmh/850ccmh
Team Darneille
sigpic
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Daren, I guess I don't go back as far as you, but the only time I remember Merc & OMC race against each other in stock outboard was 1972/73 in 25SS. We used to have an OMC powerhead adapted to a Merc "A" quicksilver tower & foot. Mercury put the kabash on that fast, they did not want to race against the OMC. I could be wrong but I'm not. The old Chevy/Ford debate? Open up your wallet. Every time one team makes advances theother team screams foul. Next thing you know the rules change and the everybody is spending more money to keep up. That may be acceptable at that level but it's going to wipe us out. Rules changing year after year giving one motor the advantage this year the other motor the advantage the next and a competition commitee deciding who the winners will be. As for new available motors now? We are in a transition period with many of our classes.In with the new out with the old. Making the transition smoothe without a finite "PLAN FOR THE FUTURE" I'll agree will not work. I am not against Mr.Bass or the Tohatsu. Take the individuals out of the discussion. I believe that powerhead racing is very much part of our future, we all know big factories are not going to produce complete motors for us. Do you remember about three years ago the SORC invested 22,000 dollars in the Merc D tower housing? Maybe we should actually make use of that investment, who knows maybe some day we'll be able to offer drivers an inexpensive tower to put their new racing powerhead on. HEY, we might even get our money back some day. What about the commitment we (SORC) made to Mr. Scott. He was willing to take on the "D Revitalization" project. We support that effort and investment how? One year later we arbitrarily approve a motor to compete against our own investment.By the way, the 44xs project has made progress in spite of our mutiny. If we really support this effort we will have growth. What makes you think the SORC (which can change hands every year) won't turn its collective back on the Bass project? Two or three votes could make a huge difference as many votes are not strong majorities. Again a future without a finite plan is very unstable. As far as Hot Rod is concerned. Last year Hot Rod came to us with a plan, a five year plan for their companyand expectations of what they will do, as well as things they would expect out of the SORC. We agreed to and adopted that plan. To date they have done everything they said they would do. We have a real oppurtunity to solve our supply problem for years to come. The success of Hot Rod depends on the growth of our sport and how we make this happen is being debated right here right now. These discussions are helping us define our future and must continue. Next. Mr. Weinandt's experience in evaluating dyno-test results in relationship to competition is impeccable. Do you know why this dyno comparison was done in the first place? I didn't think so. Many of the people that we consider the best technical minds in our sport were able to determine, just by the spec. sheets that this motor would be able to dominate the D class in a very short time frame. We knew it last year, but it needed to be verified. And it was. These two motors do not belong in the same class. We are not eliminating the D class. We are( or should be) promoting the D class. The SORC did not encourage anybody to produce a "new" D motor, that was Mr. Bass' decision. As far as I'm concerned we were already addressing the D problem. The membership told us motor availability was the problem and thanks to Mr. Scott the The class will slowly grow.As far as negativity, there is none, there are just differing opinions. I expect both sides to be passionate.
Mr. Sponsonhead, Eventually the 102 will be obsoleted by the 302. When the time is right. Yamato made these motors very compatable, the 102 has a fifteen year headstart but the 302's are getting real close. Point being currently either motor is a decent investment. The OMC's and the mercs will eventually be replaced with the new A Hot Rod. The older motors will be phased out so we can support a manufacturer that is supporting us. 25SSR - The yamato was only put in there to bolster a dead class. It was a mistake, one made do to a lack of proper planning and trying to keep a couple of drivers happy. Not a good strategy for building a sport. Nothing is black and white. That's the problem. Too much grey area, not enough grey matter. If it takes you as long to read this, as it did for me to type it (with one finger) I'll have exacted my revenge! Your shot.
John Runne 2-ZJohn Runne
2-Z
Stock Outboard is all about a level playing field.
True parity is one motor per class.
It's RACING, not just another boat ride!
NOT a representative of Racing Outboards LLC.
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Originally posted by sponsonheadWow---so if you're going to go that Doberman on the one engine per class concept, which C engine do you keep: The Yamato 102 or the 302?
Originally posted by sponsonheadMy guess is that you would want to keep the 302, since you can't buy a 102 anymore, and the whole idea of SO is to have comparably matched, AVAILABLE Motors....
Originally posted by sponsonheadAnd if you follow that logic, what do you do with the A class? There's a ton of OMCs out there, but you can't find a new one. So, keep the Merc and throw all the OMCs under the bus?
Originally posted by sponsonheadWhat about 25SSR? We know how you feel about multi-engine classes, but the Hot Rod and the Yamato are the only game in town that you can buy (you CAN buy Hot Rod now, can't you? I'm not sure).
Originally posted by sponsonheadPoint being, this is not as black-and-white an issue as you may want to make it.Last edited by ryan_4z; 11-04-2005, 01:26 AM.Ryan Runne
9-H
Wacusee Speedboats
ryan.runne.4@gmail.com
"Imagination is more important than knowledge"--Albert Einstein
These days, I find it easier to look up to my youngers than my elders.
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Stock Outboard Changing.......
I just got a rig together for next season. It's not that cheap but reasonable to get back into racing. I could see two or three different motor makers for one class in stock, but we have to decide on those two or three motors and keep it that way for awhile. The thought to keep changing motors in a class is not very appealing at all. It is nice to get a new model when engines and parts are hard to come by but stock outboard must have stability. A moving target gets expense and people have a tough time making ends meet today.
Also, it's got to stink getting to the front of your class and they switch engines and props again.
Let's make our classes and run with them for awhile.
New 11-JEarl 11 J........ Dangerous when Wet Runne Craft- Earl said, " Driving a Runne Craft is like Cheating". Dude, ........ Where's My Boat!
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