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HOW WE CAN GET MORE INTEREST BACK INTO T CLASS

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 PostPosted: February 8th, 2020, 8:32 pm   
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mattmak wrote:
I don't think I have a really good back to back comparison to take meaningful conclusions from.. Setup has evolved over the past few years, and the 70hp motor I use on the Voodoo is now a different motor than when I first ran it with a large case. (if I remember correctly, prev owner ran a Yamaha drag 14x22, at 55mph. And when I put on a small case and a un-worked Ron Hill semi-cleaver, I saw 55.5mph)

I'd say though that a Yamaha 70hp 2stroke is not a strong 70. I think Tom's Merc Formula Race 60 is stronger (2 or 3mph faster). Not sure how Dok is seeing his speeds (don't know his mods). My 70's are old and stock. Actually, I think Dok's top speed and Tom's are the same?

I'd have no problem saying that an untouhed Yamaha 70 2 stroke (large case) is slower than the top T750 boats. My voodoo with a 1987 70hp and a small case sees 61, maybe 62 on a cold crisp day.. Heavy hooked boat though.


Matt, I have an old and weak stock 70 with a CES style tuner and the choke plates removed on my carbs. My head is cut but it only makes 125ish compression. I also have a CES block but I blew it up the first time out (at Gravenhurst) and I haven't used it since. One day I'll put it back together and we'll see if I can keep it together and get some real compression...still no match for an SST60 but I like my junk lol.

I ran with the 750's in Haliburton and I could out accelerate them from the start but once they got rolling I was done lol. The 3 front runners are faster than me lol. I took it easy at the start because I didn't want to screw with their points but I started trying after half a lap and ended up spinning trying to keep up...

I ran the big case on my Delta (Paul's) and I think it was close to 60 with one of Don's props...I didn't have that combo for long.

Tom's 60 is for real in terms of top end but it's definitely harder to get settled and acceleration is a bit off due to the weight (of both the boat and the motor likely).

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 PostPosted: February 8th, 2020, 8:48 pm   
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DoktorC wrote:
Tom's 60 is for real in terms of top end but it's definitely harder to get settled and acceleration is a bit off due to the weight (of both the boat and the motor likely).


Yeah, I'd have to agree that the torque curve is completely different between the F60 Mec and the 2stroke Yamaha 70, even if the top speeds are the same. The 2 stroke Yamaha has more torque down low, and we can disable the rev limiter (unlike the Merc 4S 60).

I did run the Voodoo this past season with both a Yamaha 70 and a 55. My racing at PTBO 2019 saw 59.0mph with the 55hp. And earlier in the summer I had a long shaft Yam 70 with small case 1.85 gears and saw 61.2mph or thereabouts. The older (1987, not rebuilt) stock 70 is noticeably stronger and smoother than the rebuild 55. So I guess with the large case it'd bring the 70 back down to the 2cyl level of performance?

I want to see Thom run a 3cyl on his Critch.

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 PostPosted: February 8th, 2020, 9:04 pm   
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mattmak wrote:
DoktorC wrote:
Tom's 60 is for real in terms of top end but it's definitely harder to get settled and acceleration is a bit off due to the weight (of both the boat and the motor likely).


Yeah, I'd have to agree that the torque curve is completely different between the F60 Mec and the 2stroke Yamaha 70, even if the top speeds are the same. The 2 stroke Yamaha has more torque down low, and we can disable the rev limiter (unlike the Merc 4S 60).

I did run the Voodoo this past season with both a Yamaha 70 and a 55. My racing at PTBO 2019 saw 59.0mph with the 55hp. And earlier in the summer I had a long shaft Yam 70 with small case 1.85 gears and saw 61.2mph or thereabouts. The older (1987, not rebuilt) stock 70 is noticeably stronger and smoother than the rebuild 55. So I guess with the large case it'd bring the 70 back down to the 2cyl level of performance?

I want to see Thom run a 3cyl on his Critch.


Tom's boat is a Rapid Craft or Baker I think??? I'd like to see his F60 on a light critch to see if he could get out of a corner quicker. The boat always impress me because it has a full size adult driving it lol...not like that Coulter Kid :).

I don't have a good feeling about messing with T750 to be honest (even though it's more my pace). At the end of the day the fast guys will run the fastest version of whatever the legal motors are and the rest will be slow...and you'll have what we have now. The turn out for OPBRA is back to being impressive so the boats are out there. I'd love to see a "formula or Lake Racer" class for the lake boat guys but we don't have the luxury of that much time in the day. Take my opinions with a grain of salt since I don't actually show up lol.

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 PostPosted: February 8th, 2020, 9:13 pm   
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DoktorC wrote:
mattmak wrote:
DoktorC wrote:
Tom's 60 is for real in terms of top end but it's definitely harder to get settled and acceleration is a bit off due to the weight (of both the boat and the motor likely).


Yeah, I'd have to agree that the torque curve is completely different between the F60 Mec and the 2stroke Yamaha 70, even if the top speeds are the same. The 2 stroke Yamaha has more torque down low, and we can disable the rev limiter (unlike the Merc 4S 60).

I did run the Voodoo this past season with both a Yamaha 70 and a 55. My racing at PTBO 2019 saw 59.0mph with the 55hp. And earlier in the summer I had a long shaft Yam 70 with small case 1.85 gears and saw 61.2mph or thereabouts. The older (1987, not rebuilt) stock 70 is noticeably stronger and smoother than the rebuild 55. So I guess with the large case it'd bring the 70 back down to the 2cyl level of performance?

I want to see Thom run a 3cyl on his Critch.


Tom's boat is a Rapid Craft or Baker I think??? I'd like to see his F60 on a light critch to see if he could get out of a corner quicker. The boat always impress me because it has a full size adult driving it lol...not like that Coulter Kid :).

I don't have a good feeling about messing with T750 to be honest (even though it's more my pace). At the end of the day the fast guys will run the fastest version of whatever the legal motors are and the rest will be slow...and you'll have what we have now. The turn out for OPBRA is back to being impressive so the boats are out there. I'd love to see a "formula or Lake Racer" class for the lake boat guys but we don't have the luxury of that much time in the day. Take my opinions with a grain of salt since I don't actually show up lol.


Sorry, Tom = Mr.4S Merc, Thom = USA prop man.

I also want to see you run with T750 so that the Coulter Kid has someone to chase down, even if your points don't count.

There is a good argument to have a beginner's class (or lake boats class, as you say), because the top T750 boats are well ahead of the young kids or lake boats. I've seen Spec classes (like our T750) become very competitive and no longer ideal for beginners in other motorsports too.

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 PostPosted: February 9th, 2020, 11:08 am   
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Thanks Matt and Rick, I've learned a lot from the last few posts.
I had thought Rick was just playing with the T750 guys, now we know that was not the case.
I have over-rated the 60 hp [6H2] yamaha with the big lower unit....it's going to need the small lower unit for sure especially with the 850 lb. minimum weight. Matt, I also have an early style 70B power head and it is a bit better and my later model block.
The OMC 60 hp big lower unit is also going to have trouble with the pure T750s. Thom can get it competitive, but he is likely the only one who would put in the time and money. Plus they may enter TWO boats.
There has always been 2 or 3 top boats that are better than the rest. Those racers deserve to run out front. The rest of the field can be a mix of different motor sizes and different boats. When you have a number of similar competitive boats, they can become a class within the class. You don't need to add an additional race. HOBBY CLASS races with VP75 we can do the same. With the 12 year old minimum age now in T750, It would be safer for them to race at 50 mph. Now they don't necessarily need a pure T750 race boat. They could run a LAKE BOAT VooDoo, Kennedy, Checkmate etc. or even a 40 Hp new Delta or Critchfield which they can legally run on the lake.


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 PostPosted: February 10th, 2020, 9:56 am   
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Hounddog's theoretical rule book

T-750 & HOBBY CLASS OVAL
RULESRULE 10 • T-750 & HOBBY CLASS
1. Age requirement 12 minimum. Special circumstances for 12-15 year old racers**** - Both parents must be at the
event site to sign minor participant waiver
2. Follow General/Competition Regulations - Oval classes and Safety
3. Approved Hull Type - Fiber Composite Construction V Bottom. Minimum
competition boat dimensions 12'8"L, 4'7"W, 1"3"D
4. Cable and Pulley steering recommended. Mechanical or Hydraulic systems
permitted.
5. Post race minimum weights 594 lbs/725 lbs/850 lbs (includes boat/motor/propeller, running gear,
driver, helmet, life jacket, etc.)
6. Motors: T750
a. Production Stock And Altered Stock 40 to 60 hp
b. 2 cylinder models up to 849cc................................................594 lb. minimum weight
c. 3 cylinder models up to 750cc................................................594 lb. minimum weight
d. Mercury 3 cylinder [twin carb] up to 49ci................................725 lb. minimum weight
d-1 OMC 3 cylinder 60 hp up to 849cc.......................................850 lb. minimum weight [must run large lower unit]
d-2 Yamaha [6H2] 3 cylinder 60 hp up to 849cc.......................850 lb. minimum weight
6A Motors: Hobby Class
a. Production Stock 40 to 60 hp
b. 40 hp models up to 750cc.....................................................594 lb. minimum weight
c. 60 hp up to 849cc..................................................................850 lb. minimum weight
e. Low emission and 4 stroke models are encouraged.
f. All T750 motors limited to 160 psi compression. All Hobby Class motors limited to their Stock compression.
g. Rev Limiters may be raised or removed
h. Any combination or configuration of factory available parts.
i. Aftermarket parts must be direct replacement
j. T750 air intake may be modified, must retain stock carburetors. Hobby Class must be stock & not modified
k. Minimum 15" midsection
l. Gearcase must be shiftable from drivers seat F-N-R
m. Nose cones permitted, NO low water pickups allowed. Hobby Class NO nose cones permitted, NO low water pickups allowed.
n. T750 24 V systems permitted..Hobby Class 12V only
o. Power transom lifts /jack plates must be disabled
p. Pump gasoline up to 94 octane only, No fuel additives or Nitrous Systems
7. Class rules may change at any time to allow for equality and growth


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 PostPosted: February 11th, 2020, 2:29 am   
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Zach (and Craig lol) talked me into letting him run t750. So there will def be one more for sure! I have all the faith in the world in his ability, should be lots of fun!!
See ya'll in Gravenhurst !

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 PostPosted: February 12th, 2020, 7:56 pm   
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Great the yellow voodoo will fit right in


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 PostPosted: February 12th, 2020, 11:52 pm   
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Streamin wrote:
Great the yellow voodoo will fit right in


Hes super excited to learn and progress. Should be fun

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 PostPosted: February 12th, 2020, 11:59 pm   
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MarkStein wrote:
Zach (and Craig lol) talked me into letting him run t750. So there will def be one more for sure! I have all the faith in the world in his ability, should be lots of fun!!
See ya'll in Gravenhurst !


When i read this back to myself it sounded cocky lol. When I said I have all the faith in the world in him I by no means meant I thought he could win. I simply meant i have faith in his ability to control the boat in a safe manner, learn and build skills, relay back information, take advice etc.
I honestly feel none of you will have any concern being out there with him

Cant wait, cheers!

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2 x OSCA Factory street champion
Current KOTS motorcycle record holder 7.83 @ 182 mph
2019 OPBRA Formula Champion


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