Don Ferrette or Nitrocrazed please help!

[Don Ferrette]

How much farther back???? :blink:

 

[Ian Inverarity]

Don,

As the boat has nothing in it right now I cant actually say exactly where the CG is, and I didn't write it down, but I thought is was one or two inches behind the rearmost point of the turn-fin.

Ian.

 

[Don Ferrette]

What's the distance from the rear of turn fin to transom??

 

[Ian Inverarity]

Don,

20-3/4"

Ian.

 

[Don Ferrette]

Well if the CG was an inch or less behind the fin you should be fine. Even under two inches should still work. You mentioned earlier that you could launch about any prop you tried, that tells you it's not tail heavy. I'm still thinking your biggest issue was the set up on the rear sponsons. Go back to the thread on the sport & scale page & do what we talked about first. Then let's see what she does.......

 

[Ian Inverarity]

Don,

Thanks for the help! B) Once I have made and bought a few more bits I will give it a go again with revised rear sponson settings!

Ian.

 

[Don Ferrette]

Set your front sponsons like I mentioned in the beginning of this thread as well. Same angles, zero on the strut angle too. It should kick a$$ as a 67 hull. B)

 

[Mark]

Don,

From the rear of the rear boom tube to the rear of the tub my Bird is pretty close to 25.1". I can't tell you exactly because I had just put a coat of epoxy on when I remembered.

BTW, how many coats of resin do you put on your riggers. Is one enough. I'm using automotive 2 part paint for the colour.

I was wondering if this boat is capable of 100mph with the Mac 84 on a SAW run?

 

[Don Ferrette]

"From the rear of the rear boom tube to the rear of the tub my Bird is pretty close to 25.1". I can't tell you exactly because I had just put a coat of epoxy on when I remembered."

I just wanted to see if your tub was standard Hummingbird.60/80 length, it is

"BTW, how many coats of resin do you put on your riggers. Is one enough. I'm using automotive 2 part paint for the colour."

Usually two. The carbon sides of that tub are very porous & you will find a third coat after sanding may be required. When you think you're ready for paint, put some denatured (rubbing) alchohol in a spray bottle & hose down the tub. It will uncover any pinholes you missed. It will also flush out any pinholes filled with sanding dust that would blow out first pass with paint gun.

"I was wondering if this boat is capable of 100mph with the Mac 84 on a SAW run?"

Seriously doubt it. The power to weight ratio is there but with the aerodynamic properties of that boat you will probably see it leave the water after about 85-90mph. It will be a very fast heat race boat BUT you will have your hands full as it is kinda small for a 80 class hull. Myself & John Finch found this out early last year. :blink: :blink:

 

[EatMyShortsRacing]

Hmmmm all very interesting...

I cant remember if or how my setup differed from the instructions since I thought I had a little too much front sponson angle, and Ian added some shims to the front to increase it again... Dont tell me I actually have to measure it all up again??

Don, what prop do you suggest for a MAC 67 (early engine... better buy me a new one soon). All my props for my old Eagle 67 dont seem to bite

Ian, Can I have my 'bits' back???



Oh and a cowl with a little more (read some) downforce and one that actually covers the carb on a MAC (What was the manufacturer thinking?? the rest of the boat is pretty spot on but the engine mounting and cowl???) should see it in record contention.

EMS Racing Adding to the confusion

 

[Ian Inverarity]

Craig,

I added shims based upon where I ended up with mine. And you didn't have problems with the front end, just hopping at the back! Get the rears off again and re-set them as Don says, hopefully that will get rid of the hopping. B)

You might even pull a stock 1667 with that. Let me know! But Don probably has a much better idea!

Did you want to borrow my cowl mould? I designed mine to have some down-force. Should also clear the carb, altho you may still need to trim the venturi a bit.

The other bits should take a few weeks. B)

Ian.

 

[Don Ferrette]

Craig -

I'd try a 1667 cut down to 64mm with the MAC 67. B)

 

[EatMyShortsRacing]

Thanx Don

Ian, Ya know I do want to run that boat again this year hehehe... No rush really but soonish would be nice

EMS Racing I want it yesterday

 

[TimD]

Craig,

Pitched up H30 or 1662. Drill out the spray bar in the carb. Big fuel lines. Parabolic pipe with the stinger drilled out. That seems to be the setup that the MAC guys here are using for heat racing. Give Brett Ward a yell - his goes OK and he is down your way.

Tim.

 

[Ian Inverarity]

Craig,

What for, you will just wear it out! Dont you go better with stuff thrown together as you are travelling to the event?

I'll get the bits back to you as soon as I can. B)

Nitrocrazed racing: Any time right now....