Whats a real speed for 21 tunnel

[offshoremodels]

Was wondering what a good speed for a 21 tunnel is and what the fastest speed recorded is. I seam to be doing real good with my two 21 tunnels mod and short but need a goal to shot for and what to get.

 

[Propjockey]

Anything over 100 MPH is respectable... ;D

Unless you got it off eBay...then it's expected!

Seriously though, 45 - 50 is smokin' for a 3.5.

I believe Tommy Lee holds the IMPBA record at 64.212 MPH.

 

[lightsonyet? nope]

kind of like this?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...&category=19166

why waste hundreds and hundreds when you can buy one of these to get over 50 with a tunnel

I'm thinking about stopping all of my R&D, and just buy from E-bay :-*

 

[Propjockey]

Thunder Tiger is a good engine...but it ain't THAT good.

 

[nitrotoys]

I would also say 45-50 is about it.

and Ebay has the fastest boats out there. Even the dumas with the TT motor, 50 plus.

If your running between 45-50 your doing well.

anything over 50 they are to small and to light and they fly.

 

[Slideblues]

Yep 45-48 stock, 48-53 mod,

There has been a few take it past 60 SAW, but it's expensive and

a very good chance ya not gonna get yer boat back

Gene ;D

 

[offshoremodels]

ok now how do I go 55

 

[Jimmy Whitbeck]

ok now how do I go 55

maybe a differnt hull?? ;D ;Das i know i been playing with ob. for awhile and they are some thing to get right! as i fliped and broke many things and not to pull any one leg but I have realy gone over 60 with my tunnels made out of wood thanks to Rod Gearty for a copy of his dwg.'s as i made a straight away boat and it flies!!

Jimmy

 

[Slideblues]

My advise would be:

28 to 30 inch hull min.

Nova/Rossi or Rossi powerhead

K&B 7.5 or Lawless lower

ABC H-4 dia reduced and cupped

60% nitro

RTR of 4 3/4 to 5 1/2 lbs

Outta get ya close

Gene ;D

 

[offshoremodels]

running modified toms cats very lite and small

 

[Slideblues]

Eddy, less than 28" and its a tapdance to keep one on the water around 50 ;D I tried it with a modified Sprint @ 24"and it got ugly 8)

Gene ;D

 

[offshoremodels]

it would be fun to try

 

[Jimmy Whitbeck]

running modified toms cats very lite and small

it's realy time to get a new tunnel a tom cat thare were good at thare time as i had a fiberglass one. but I will never go back to it. try a john otto hull if nothing else. they are light but don't let it cook in the sun on a trip . as it be junk from the heat.

 

[offshoremodels]

glass ones were junk for sure but the wood kits with a little mods work great.

 

[TimD]

Thunder Tiger is a good engine...but it ain't THAT good.

I have built one that ran 50 - but I had modified the living s#1t out of it!

 

[Propjockey]

I hear ya, Tim!

 

[nitrotoys]

Best way, and cheepest way of doing 60, put her in your car and get on a main street.

You dont have any damage to fix, any broken cowls.

and if you wish to sell your 60 mph boat, Ebay, they have the fast ones.

 

[Bob Kensill]

My best speed to date was 58mph at the 94 internats. I used my "NOVA" prototype and a Novarossi "TOP" powerhead. I took first place in B tunnel SAW. I also took first in D tunnel SAW with a speed of 49mph!

 

[GTR]

Hi Bob

D tunnel is 67 class isn't it? That's scary to be that much faster with a 21 than with a much bigger boat. I guess the bigger they are the more 'scale like' speeds they seem to go. What's the record for a D tunnel?

What prop were you using to run that speed on a 21 and whaqt lower unit on your NR Top? Any and all info greatfully accepted. ;D

GT 8)

 

[Bob Kensill]

D Tunnel is a 45 motor in IMPBA. Used a K&B lower unit, custom pipe and modified Prather 220 prop. The motor "double staged" on the pipe and that is why all the speed.