Rear sponsons

Intlwaters

Help Support Intlwaters:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Side mount are adjustable without building new ride pads. Using either bolts or double sticky tape. Under the hull you will have to make new ones if they are not correct. Side mount is the better way to go if you do not know what it is you want.

Mike
 
Brian,

I would say it also depends on what width tub you plan on designing and if you are going to run a shoe. For a narrow tub I would say it better to have them on the outside for running in the rough stuff. On a 5" tub, I would run them underneath and keep the inside of the rear sponson around 3.5~4". Mike has a good point about screwing or sticky taping your early sponsons on the back so its easy to make asdjustments. Usually don't see gas riggers with a shoe, but.............

Tyler
 
I think having them on the outside makes the hull more stable in the "marbles", bigger wheelie bar back there... ;)
I agree Terry. For heat racing the further back and the wider apart the better. For record trial and perfect water the single shoe or sponson works great. I even used a deep vee transom on a couple of riggers that work great for record trials, but for heat racing you will be sorry when you hit the rough stuff if you don't have the training wheels.
 
I think having them on the outside makes the hull more stable in the "marbles", bigger wheelie bar back there... ;)
I agree Terry. For heat racing the further back and the wider apart the better. For record trial and perfect water the single shoe or sponson works great. I even used a deep vee transom on a couple of riggers that work great for record trials, but for heat racing you will be sorry when you hit the rough stuff if you don't have the training wheels.

Hi John,

I think if the foot print is taken to EXTREME widths on the front of the boat,we may find rear sponsons are not always needed.

Ron Jr
 
Lots of different Opinions Brian. They are ALL proven champions. Do what you think is best and work with it.
 
I think having them on the outside makes the hull more stable in the "marbles", bigger wheelie bar back there... ;)
I agree Terry. For heat racing the further back and the wider apart the better. For record trial and perfect water the single shoe or sponson works great. I even used a deep vee transom on a couple of riggers that work great for record trials, but for heat racing you will be sorry when you hit the rough stuff if you don't have the training wheels.

Hi John,

I think if the foot print is taken to EXTREME widths on the front of the boat,we may find rear sponsons are not always needed.

Ron Jr
Do you remeber the "Raptors" in the early to mid 90's? We took the front sponsons way wide with shallow rears under the hull without a shoe. Those boats could put down some oval times, and won several E & F 1/3 nats trophies. The water condition was rarely an issue. Even the F single engine could run at full speed with twins. With much effort and Marty's help we found speed by going deeper with the rears. Maybe a shoe was the way to go.

Now, your new 21 hull appears to have much more narrow front sponsons....I like!!! I hope it is sucessful.

MG
 
Brian,

Your Whip has no rear sponsons. Think for awhile how it runs. Do you think it would be any smoother, faster, predictable better through the corners, or more stable with rears added?
 
I think having them on the outside makes the hull more stable in the "marbles", bigger wheelie bar back there... ;)
I agree Terry. For heat racing the further back and the wider apart the better. For record trial and perfect water the single shoe or sponson works great. I even used a deep vee transom on a couple of riggers that work great for record trials, but for heat racing you will be sorry when you hit the rough stuff if you don't have the training wheels.

Hi John,

I think if the foot print is taken to EXTREME widths on the front of the boat,we may find rear sponsons are not always needed.

Ron Jr
I agree they are not always needed. So long as the boat rides predictably without rears the boat can only go faster without those things hanging on the back of the boat. Especially if they touch the water at speed. They can be like brakes.

Let me think why we would want to use them.......... Reason one........They are used as wheely bars to make the boat stable. Much like brakes when they hit the water. Reason two.............As the primary riding surface having the fronts dance lightly above the water. Three.........They can form an air dam for ground effects when we use little or no recurve on the hull bottom. Reason four........They can be floatation on skinny hulls so the transom doesn't sink when the boat stops. Four.......They can be training wheels so when a front sponson bounces up, the opposite rear sponson trips it back in place. Five..........left rear deeper than right rear to hold right sponson to the water in a turn. Six.........right sponson deeper than left to compensate for torque roll. Seven.........the original; keeps the transom up in the turns and they fly out of the water in the straightaway for reduced drag. Eight........Center shoe to aerate the prop at slow speed and help on the launch. Nine...........keeps the boat from getting too much of a positive angle of attack when you let off the throttle at high speed so the boat doesn't blow off the water. Sounds like there is merit to some of those reasons, so it looks like a lot of experimenting before punching the ticket on the new boat.
 
I think having them on the outside makes the hull more stable in the "marbles", bigger wheelie bar back there... ;)
I agree Terry. For heat racing the further back and the wider apart the better. For record trial and perfect water the single shoe or sponson works great. I even used a deep vee transom on a couple of riggers that work great for record trials, but for heat racing you will be sorry when you hit the rough stuff if you don't have the training wheels.

Hi John,

I think if the foot print is taken to EXTREME widths on the front of the boat,we may find rear sponsons are not always needed.

Ron Jr
I agree they are not always needed. So long as the boat rides predictably without rears the boat can only go faster without those things hanging on the back of the boat. Especially if they touch the water at speed. They can be like brakes.

Let me think why we would want to use them.......... Reason one........They are used as wheely bars to make the boat stable. Much like brakes when they hit the water. Reason two.............As the primary riding surface having the fronts dance lightly above the water. Three.........They can form an air dam for ground effects when we use little or no recurve on the hull bottom. Reason four........They can be floatation on skinny hulls so the transom doesn't sink when the boat stops. Four.......They can be training wheels so when a front sponson bounces up, the opposite rear sponson trips it back in place. Five..........left rear deeper than right rear to hold right sponson to the water in a turn. Six.........right sponson deeper than left to compensate for torque roll. Seven.........the original; keeps the transom up in the turns and they fly out of the water in the straightaway for reduced drag. Eight........Center shoe to aerate the prop at slow speed and help on the launch. Nine...........keeps the boat from getting too much of a positive angle of attack when you let off the throttle at high speed so the boat doesn't blow off the water. Sounds like there is merit to some of those reasons, so it looks like a lot of experimenting before punching the ticket on the new boat.



Now thats a mouthfull
 
Steve Speas built me a new computer and I was excited to use it. I guess I got carried away in the moment.
Yeah no more waiting, the letters now actually pop up on the screen as fast as he can type them. :lol: :lol: :lol:
 
Last edited by a moderator:
Thanks for all of the input.

Our sport hydro turns very well and it doesn't have rears obviously and doesn't have a chine on the side either. Our new gas "rigger" is not going to look like a typical nitro rigger so we will make them adjustable and removable if need be. I see some benefit to having them, but see some negatives as well. Our sport hydro (approaching 10 second laps) is faster than most gas riggers, so this tells me if we design a rigger the way a sport hydro should be designed without rules...we should be that much better. What do you say Mr. Finch...want to play?

Thanks for all the input!

Brian
 

Latest posts

Back
Top