Flattie DRAG BOAT Top Speeds...

[Sanger_Spectra]

My neighbor has an eliminator jet, jet pump is polished and he has headers, the thing is loud, he can break 110 and still have throttle left, may be we should get some jet guys to really talk about speed Sorry just my attemp to add a little humor. The pilots of these things going that fast are just flat crazy. WOW!!

[WESTERNAERO]

My neighbor has an eliminator jet, jet pump is polished and he has headers, the thing is loud, he can break 110 and still have throttle left, may be we should get some jet guys to really talk about speed Sorry just my attemp to add a little humor. The pilots of these things going that fast are just flat crazy. WOW!!

Damn, that's was rough! Lmao!

[2manymustangs]

Bruce, first off a "flattie" hull can mean many different things considering how many varieties there are. The fastest flatties are runnerbottoms and have pushed up on 180 mph, but many have crashed much slower. The non runnerbottom circle hulls have been proven at just a tick over 150 and according to some team claims (which aren't verified) upper 150's. Again many have crashed much slower. So, with all conditions and factors perfect one can figure the best runnerbottom right around 180 and the best circle flat low 150's until these marks are raised.

Yep, I do understand that there are variations/variables on the runners/steps/strakes/etc, that is why I lumped them all into one bucket (not knowing what the drag guys favor).

Can a legal drag/circle flat have ANY keel OR gull at all? IS a TRUE flat just what the name implies? What are the rules for CIRCLE and for DRAG ?

When you look at KILO records for this hull type and top speeds from back in the day with FUEL boats it leads me to believe that there is a limit but that is just my simple and UNexperienced view.

Are there more variations/changes that can be made to make them safe at 180 and up like additional bottom refinement/wind tunnel testing/wings/capsule shape/weight/balance?

At this point, 40-50 years later, have all of the LEGAL ENHANCEMENTS to the bottom been tried at this point?

Are there chine differences that are legal/not legal helpful somehow in high speed stability?

[Sharp shooter]

Can a legal drag/circle flat have ANY keel OR gull at all?

Yes

IS a TRUE flat just what the name implies?

Sometimes. Some true flats have a tiny amount of V and some don't and some true flats have dropped chines.

What are the rules for CIRCLE and for DRAG ?

You're crazy if you think I'm gonna list all the rules.YOU can look that up. Circle bottom rules are on line. Drag boat rules might be too, but I don't really know.

When you look at KILO records for this hull type and top speeds from back in the day with FUEL boats it leads me to believe that there is a limit but that is just my simple and UNexperienced view.

Are there more variations/changes that can be made to make them safe at 180 and up like additional bottom refinement/wind tunnel testing/wings/capsule shape/weight/balance?

Your guess is as good as mine.

At this point, 40-50 years later, have all of the LEGAL ENHANCEMENTS to the bottom been tried at this point?

I couldn't say...

Are there chine differences that are legal/not legal helpful somehow in high speed stability?

I have no idea...

Hope this helps.

[2manymustangs]

Yes



Sometimes. Some true flats have a tiny amount of V and some don't and some true flats have dropped chines.



You're crazy if you think I'm gonna list all the rules.YOU can look that up. Circle bottom rules are on line. Drag boat rules might be too, but I don't really know.





Your guess is as good as mine.



I couldn't say...



I have no idea...

Hope this helps.

With your first few answers I know more than I did a few minutes ago so YES, it does help...

Do you know anything about the bottom of the K69 Freedom Child (I'm thinking in terms of their KILO runs over the last few years at a buck 45+)?

[Sharp shooter]

With your first few answers I know more than I did a few minutes ago so YES, it does help...

Do you know anything about the bottom of the K69 Freedom Child (I'm thinking in terms of their KILO runs over the last few years at a buck 45+)?

It's an APBA legal K boat bottom. I'm sure it's blueprinted to the hilt.

[SnoC653]

My understanding is there are things that make the boat more stable in a straight line but hurts the ability to turn and vice versa. Chines and tunnels and strakes are examples. Reducing the wetted surface area also makes the boat faster (in theory). So the further back on the hull or plates the boat rides the faster it could be. But, too nose high is unstable and not high enough is too wet to be fast enough. And that just covers bottom basics. You still have a whole other topic of balance, HP, Torque, prop diameter, prop pitch, prop cup, and aero/fluid dynamics which all affect the handling and drive-ability of the boat.

[2manymustangs]

It's an APBA legal K boat bottom. I'm sure it's blueprinted to the hilt.

My understanding is there are things that make the boat more stable in a straight line but hurts the ability to turn and vice versa. Chines and tunnels and strakes are examples. Reducing the wetted surface area also makes the boat faster (in theory). So the further back on the hull or plates the boat rides the faster it could be. But, too nose high is unstable and not high enough is too wet to be fast enough. And that just covers bottom basics. You still have a whole other topic of balance, HP, Torque, prop diameter, prop pitch, prop cup, and aero/fluid dynamics which all affect the handling and drive-ability of the boat.

BTW, I stood back and quietly watched Dave meticulously adjust/check the plates mid way through the Long Beach event, for about 30-45 minutes... That was pretty amazing to see what he ended up with... (it might have been with Robbie on the SS1)

It was NOT AT ALL what I expected but it certainly made me say Hhhmmmmmm (thinking of the plates being an extension of the bottom...)


As for the bottom (blueprinted to the hilt), I agree totally. I'll wager the bottom of that hull (K69) has had more study than any one flat bottom out there knowing the last 6-7yr history and knowing Rank Daddy&Gordy...

[2manymustangs]

Just found this on the LUCAS DRAG BOAT site:

Top Alcohol Flat 641 Nightmare C.Heidemann/ J.Heidemann 165.893 MPH November 2011 World Finals, Firebird Raceway

[Sharp shooter]

Just found this on the LUCAS DRAG BOAT site:

Top Alcohol Flat 641 Nightmare C.Heidemann/ J.Heidemann 165.893 MPH November 2011 World Finals, Firebird Raceway

Not sure why you're posting this. Please elaborate.