high speed f1 tunnel for straight aways

[bign]

needing help. looking to build a brushless out board f1 tunnel boat that is capable of getting close to 70mph on straight aways. or if this is even achievable. any info would be greatly appreciated

[JestDanny]

As you can see there is not much interest round here for outboard or tunnel boats. I run a little 24" Dumas Sprint on 4s, with the Aqucraft UL 1 motor an ESC ,K&B lower, runs 44mph. your gona need a bigger boat. I've been thinkin of a second outboard tunnel boat, in theory on 6s, a good 2000kv motor spinnin a X642 prop should get ya into the mid 60's, so yea I think 70's is with in reach. A Leopard motor on a good bottom end, 30" hull your in the ballpark.

[bign]

Thanks for the info

[RandyatBBY]

A 1515 Neu .5Y and a V937 on 2S will get you to 70tie.

[HTVboats]

High speed outboard tunnels are very difficult so many people gravitate to easier hulls. The problem is not power it is keeping the boat from becoming an airplane. Just adding forward weight is not the answer as the increased wetted area negates speed and handling suffers greatly in corners. Only a small group I know of have run consistently above 70 MPH. They are in the record book. Hulls under 28 inches are light and easy to go fast but terminal air speed starts around 50 MPH. A .45 nitro hull with 2-4 watts of power will get you to high 50's and capable of low 60's. 1515-1521 or 40mm diameter X 74 to 82mm length. 6s will be easier on ESC's pulling less amps. Our P tunnels with a 1515 1y run over 50 but pull 150-170 amps. More prop faster but more amps. The larger hulls will stay on the water better.
Above 70 MPH is attainable at the price of breaking a few hulls tumbling in the process, plus you need a stout ESC. An MGM 28026 is compact and fits in the limited space under a tunnel cowl. Add a NEU 1521 / 1600kv on 6S and props in the 545-645 range and you will get into the 60 MPH range. That setup will prop up into the 70's but will require a lot of testing and only a few passes will eat up a lot of m/amps. A great challenge and rewarding watching a tunnel approach 60 mph. Good luck.
Mic

[bign]

thank you very much for sharing your knowledge and info

[JestDanny]

High speed outboard tunnels are very difficult so many people gravitate to easier hulls. The problem is not power it is keeping the boat from becoming an airplane. Just adding forward weight is not the answer as the increased wetted area negates speed and handling suffers greatly in corners. Only a small group I know of have run consistently above 70 MPH. They are in the record book. Hulls under 28 inches are light and easy to go fast but terminal air speed starts around 50 MPH. A .45 nitro hull with 2-4 watts of power will get you to high 50's and capable of low 60's. 1515-1521 or 40mm diameter X 74 to 82mm length. 6s will be easier on ESC's pulling less amps. Our P tunnels with a 1515 1y run over 50 but pull 150-170 amps. More prop faster but more amps. The larger hulls will stay on the water better.
Above 70 MPH is attainable at the price of breaking a few hulls tumbling in the process, plus you need a stout ESC. An MGM 28026 is compact and fits in the limited space under a tunnel cowl. Add a NEU 1521 / 1600kv on 6S and props in the 545-645 range and you will get into the 60 MPH range. That setup will prop up into the 70's but will require a lot of testing and only a few passes will eat up a lot of m/amps. A great challenge and rewarding watching a tunnel approach 60 mph. Good luck.
Mic

So what hulls are the top racers running, also what bottom end are they running?

[HTVboats]

https://nebula.wsimg.com/58f35d295373e5201a9f9cb134f44b3c?AccessKeyId=ACA7381D2BFC72351748&disposition=0&alloworigin=1http://www.namba.com/content/records.asp?EventType=10

There are actually a variety of quality hulls out there. Vans Racing's Lynx-Shaman-Warhead, Ml Boatworks now PTI, Vision 21 & 45 Hulls, and Kris Flynn's Dragons. ML has the fastest speeds so far with a Q. Before that the Warhead held that record. Brian Buaas has the NAMBA P record with an AQ TS-3.
As for lower's the smaller motors use OS and lawless, larger boats Lawless and K&B. Your preference there on what works on your hull.
Mic