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Thread: Looking for some history help ...T850 rules difference in 1995 compared to 2000s

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    Question Looking for some history help ...T850 rules difference in 1995 compared to 2000s

    One of our T850 racers was searching some race sites in Britain and noticed that a British T850 racer had set their T850 record at 72 mph in 1995. I checked the UIM record for 1995 and found it to be 76 mph. The last UIM record is in 2008 and it is 65 mph. We started our version of T850 in 2006 and use the same basic rules. Our yamaha 70CES boats run in the 65 to 67 mph range. Does anyone on the site know the reason why the 1995 boats were so much faster???

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    Hi Don,

    Perhaps the boat weights are lighter than ours. Also, can they run low pick ups on the gear case? That is 3-5 mph right now! Some of our guys are getting 70-72 mph, and a couple are 73-74mph with bridgeports.

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    The UIM records are all 70CES yamahas as you can see. No 56 OMCs. It is the difference in speeds with the same motor that do not seem correct.

    3678 2008 T. Gilderdale GBR CIRCUIT CLASS T.850 TORNADO YAMAHA 65,85 MPH
    3657 2007 J. Owen GBR CIRCUIT CLASS T.850 TORNADO YAMAHA 64.93 MPH
    3370 1997 B. Owen GBR CIRCUIT CLASS T.850 TORENVLIET YAMAHA 53,22 MPH
    3369 1997 B. Owen GBR CIRCUIT CLASS T.850 TORENVLIET YAMAHA 54,41 MPH
    3277 1995 B.Owen & D. James GBR CIRCUIT CLASS T.850 TORENVLIET YAMAHA 52,66 MPH
    3269 1995 S. Brath NOR CIRCUIT CLASS T.850 SEAFLYER YAMAHA 76,52 MPH

    Here is a 1991 race with the first version of the yamaha 70CES. They look similar to our boats.

    http://www.youtube.com/watch?v=7RtnQ...14873&index=12

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    Hi guys,
    Hopefully I'll be able to shed some light on it for you.

    back in the early days there were no weight restrictions for the class. Late 80's a guy in the UK ( think it was 88) ran over 80mph using a Selva.
    The main difference in speeds as well was that the 1995 record was set with a wing boat which tended to run more like a cat, the shape was very similar to the GT15 / GT30 boats you see today and were mainly developed by the Italians.
    Records by Bill Owen & Dave James were actually 1, 2 & 3 hr Endurance records that were set at the Windermere 3 hr Enduro running with a mixture of boats that included offshore boats of all shapes and sizes and anything circuit wise up to an F1 cat. This event used to take place at the end of Windermere Records Week in the UK.
    When Tom and Joe set their records the class had become weight restricted and the hulls they were using ( which are still in use today) did not have the straightline speed of a wing boat. Just one more thing none of the records were set using low water pick ups as they were not allowed.

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    Thank you. That helps a lot.

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    I too thank you. I was just forwarded a current copy of the UIM T rules and they are based on STOCK motors and hulls as you describe. Now this leads to another interesting point.
    The T750 record was raised from 55 mph to over 66 mph. It is posted on this site. Looking at the video that record boat, it sure looks like a GT30 style hull and one would think not legal.

    http://www.boatracingfacts.com/forum...K)-T750-Record

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    I think the wing style sides are legal. Just no air entrapment under the hull. The bat boats that run offshore are fast, get over water, and have the wing sided design.

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    In Canada our T750 class is in its early stage. We have 3 Deltas with OMC 2 cylinder motors, a Delta with Mercury power, a new florida Allison with OMC power, another florida Allison with Mercury power and an Oasis with Tohatsu power. We hope to add a Critchfield OMC and a 4 stroke Mercury to the class next year.
    IT IS A GREAT CLASS! The racers have found it very easy to get their boat the run 50 to 53 mph. It is more difficult to get one in the 55 to 56 mph range and you really need the complete package of boat, motor, set up and especially driving skill to run in the 57 to 60 mph range where our top guys run. We have a lot of experience in the class and several racers run both a T850 and T750 boat. Our boats shouldn't make the 66 mph mark, but I think we will see low 60's.

    Here is an example of a top T750. This one is a Delta OMC.
    http://www.youtube.com/watch?v=vdsi1bARVZc

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    Quote Originally Posted by Hounddog;
    Here is an example of a top T750. This one is a Delta OMC.
    [url
    http://www.youtube.com/watch?v=vdsi1bARVZc[/url]
    The video also has the Canadian version of a VP75 boat. In the video you do not see many of the the other boats in the heat. The one you do see is a red Critchfield. The two boats were racing for first and second. The red boat was powered with a 49 cubic inch OMC. The motor was a short shaft where as VP75 uses the long shaft. We had followed the VP75 class history and we wondered if that motor would be competitive with our T750's. We decided it was TOO strong for the class even though Jake was able to beat it in this race.

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    The boat is legal for the T750 class and is a development of the GT15 /30 hull. It ran with the 3cylinder 50hp 2 stroke Tohatsu . It started the week off at low 50's and was developed over the course of the week by altering engine heights, weight distribution and different props . The 66mph run was achieved with a 12" x 22" off my sons F4S boat
    There is work in progress in the UK to build a boat to take the Mercury 60 EFI Race that we use in F4s.
    At the end of the 80's I averaged 72.71mph using a Yamaha 60 DE. I managed a one way run of over 75mph before coming to grief at the end of the kilo !!

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