JAE Heat racing

[mtruex]

I guess i am just getting frustrated .There is a race comming up in few weeks which is a22 hour drive and i have some new boats i am trying to get dialed in an may have bit off more than i can chew..

I am having issues for them too but the parts on the way should solve that...

The strut is one from jim M and non adjustable and i would like to get a degree or two neg in there and try it.

The turn fin is from Zipkit.

How would you suggest working it.

I will go and put the boat on my board and get back to you.

I have tried 1450 reduced in dia.1450 right out of the bag s/b and a h7 i can pull them all with my engine the first one seems to be the best.

the strut level is good or a little down, i dont see any difference in it, take a side profile pic of your boat with a mark where it balances out and try and have the turn fin visible if possible...are you having to use a lot of rudder throw to turn the boat ?

 

[moparbarn]

shim the top of the strut to give a degree of negative, & let us know what happens...............

 

[tmunn]

it's the non adjustable one ... are you thinking spacer between the top of the strut and transom ?

 

[Jim Mamaril]

If I had only not cut the apex buoy coming to the start, that heat would of been mine. Every year we start the racing out in Marysville and every year I hit a stick and do not finish a heat. Kicked a rudder this time with no steering. Last year had a big chunk stuck to the rudder. The year before broke off the rear of the turnfin sponson with the turnfin attached. It just seems that I always start off in a hole. Oh well. Good win Jim. Now on to Duval and you are going down!!!!!!!

Mike

OK I guess we'll have a good battle this year, I think I got a little more left than what it showed last weekend. Remember that I am new to running these riggers,however I am a fast learner.See ya in Duval

 

[tmunn]

Martin , you want the balance with no fuel in the boat? I was trying some lead weights on the top front of the tub but then i stopped for the night...

heading to bed now...

 

[moparbarn]

it's the non adjustable one ... are you thinking spacer between the top of the strut and transom ?

exactly !! or shim stock, .012" should be close to 1/2 degree of change/adj. B) .

 

[Jim Mamaril]

it's the non adjustable one ... are you thinking spacer between the top of the strut and transom ?

Terry, If you want to put some neg angle in it you can always file the back of the mounting area very carefully.Another thing you can try is to notch your ski where the strut sits so you can lower it another 1/16". With your turn fin make sure the sharpened area is at least a1/2 wide and the curl is about 40 degrees. I have not had any problem with unhooking or the right sponson lifting. I am going to try a few things myself and see how it works. I will post the results here.

 

[Ron Jefferson]

I was out testing my 21 jae and it kept blowing off and or hopping in the turns it is fast but for heat racing in chop or a little wind or even crossing your own wake on lap 2 .....I am not impressed i have the boat setup per instuctione etc...and I will prolly get beat up on here but i am not that impressed....YET

Mine is built right and true and square...

Fire when ready

no need to fire! the boat should not blow off.. i seen where jim mamarill had his blow off too, i have run well over 80 and NEVER blown off the water,i have also NEVER had any hop in the turns with the jae style boats..what turnfin are you using? i tried the turn fin from zippkits and it was very very lifty for me, rf sponson wouldnt stay on the water,if thats what u have you may have to work on it...what props are you guys running and what is your strut angle? also, put your boat on a table sitting on sponsons and ski, the bottom of the tub should be level to the table, if its low in the back that is no good...something is definently not right, there are lots of these boats running great out there so it is there you just need to find it...MT

Martin,

If you build the kit exactly as it comes and use the existing boom tube holes with the ski attached, you will have a tub that is low in the rear. Approx 7/8" in the rear and 1" at the front. To get the effect your talking about where the tub is level front to back, you would have to raise the rear boom almost 1/8". This being the case, should the ski be taller or should the rear boom be raised? Raising the rear boom would drastically change the sponson attack angle. How did you get the attitude of your hull flat from front to back? And what is your angle of attack on your front sponsons?

Ron

 

[Rick Cesati]

no need to fire! the boat should not blow off.. i seen where jim mamarill had his blow off too, i have run well over 80 and NEVER blown off the water,i have also NEVER had any hop in the turns with the jae style boats..what turnfin are you using? i tried the turn fin from zippkits and it was very very lifty for me, rf sponson wouldnt stay on the water,if thats what u have you may have to work on it...what props are you guys running and what is your strut angle? also, put your boat on a table sitting on sponsons and ski, the bottom of the tub should be level to the table, if its low in the back that is no good...something is definently not right, there are lots of these boats running great out there so it is there you just need to find it...MT

Martin, what turn fin would you recommend?

Thanks,

R-

 

[Ron Zaker Jr]

I was out testing my 21 jae and it kept blowing off and or hopping in the turns it is fast but for heat racing in chop or a little wind or even crossing your own wake on lap 2 .....I am not impressed i have the boat setup per instuctione etc...and I will prolly get beat up on here but i am not that impressed....YET

Mine is built right and true and square...

Fire when ready

Put your boat on a flat table and take some pics with a scale showing some dimensions of where things are at. I also have NOT been even close to blowing off (in some 25 mph winds). Something is not right. My email is [email protected]. Oh and ps you WILL be IMPRESSED when we find out what's wrong.

show the following:

front sponson tips dimension off the table.

sponson insides to tub outside (at booms is fine)

levelness of tub

turn fin bend in relation to tub(side view)

strut depth and angle

Let's start there for now.

 

[misshydro]

I guess i am just getting frustrated .There is a race comming up in few weeks which is a22 hour drive and i have some new boats i am trying to get dialed in an may have bit off more than i can chew..

I am having issues for them too but the parts on the way should solve that...

The strut is one from jim M and non adjustable and i would like to get a degree or two neg in there and try it.

The turn fin is from Zipkit.

How would you suggest working it.

I will go and put the boat on my board and get back to you.

I have tried 1450 reduced in dia.1450 right out of the bag s/b and a h7 i can pull them all with my engine the first one seems to be the best.

Martin, my boat is 2mm aprox 1/16 lower in the rear than the frot of the tub say under the sponson area...

Our friend Rick Reisinger made a plate where his strut bolts on to.. he can adjust the posion of his non adjustable strut.. going to see if he makes me one..

 

[Mike Larson]

Terry.... these guys have hit it on the head..... I had an issue with the Mamril strut upon final paint assembly ( my own fault, the piece, is a good piece)...... Basically, use a straight edge on the bottom of the ski, and extend it enough, and it will reveal your strut angle..... I set mine on the same plane with the ski bottom along the length of the strut.... ie; maintaining the angle...... I did, file, and shim, accordingly per robin to make it run parallel, with the ski bottom angle....

right or wrong, my boat, ran amazingly well right off the stand.....

Hopping, well, i'm not even close to knowing, with variables to consider.... lower lift prop. Mark, sent me an H 6 to run, which, again his talent astounds me, that, has me smooth, and mid 60's without even trying..... He'll easily match up with what you need, and, is definitely on target with the prop/Jae needs....... Check that '50 you're running. SHARP, blades the same?.... Be prepared to tune the boat with props accordingly.......

I had, a little prop walk issue, that, was solved in about 10 minutes after checking stance....

Make sure, your fin is sharp and blended, and i did, with instruction, and same straight edge, start the fin level wiith the water line ( measured with the boat tabled).... no tip, to the best you can.....

Be patient, and work on it. i built mine, to the best of my ability, as I'm sure you did.... i'm not even close to a hydro authority, but this thing is all but hang on to it, and I'm impressed. The basic quirks can be solved easily..... good luck, and get some laps in..... mike

 

[Niklas Edlund]

I was out testing my 21 jae and it kept blowing off and or hopping in the turns it is fast but for heat racing in chop or a little wind or even crossing your own wake on lap 2 .....I am not impressed i have the boat setup per instuctione etc...and I will prolly get beat up on here but i am not that impressed....YET

Mine is built right and true and square...

Fire when ready

no need to fire! the boat should not blow off.. i seen where jim mamarill had his blow off too, i have run well over 80 and NEVER blown off the water,i have also NEVER had any hop in the turns with the jae style boats..what turnfin are you using? i tried the turn fin from zippkits and it was very very lifty for me, rf sponson wouldnt stay on the water,if thats what u have you may have to work on it...what props are you guys running and what is your strut angle? also, put your boat on a table sitting on sponsons and ski, the bottom of the tub should be level to the table, if its low in the back that is no good...something is definently not right, there are lots of these boats running great out there so it is there you just need to find it...MT

I opened up the original drawings of the JAE .21G2 and it looks to me that the boat built as stock will have an slight positive AoA of the tubs bottom - depending on what plywood sheeting one uses of course on the sponsons and ski... See attached picture.

 

[Jim Mamaril]

I was out testing my 21 jae and it kept blowing off and or hopping in the turns it is fast but for heat racing in chop or a little wind or even crossing your own wake on lap 2 .....I am not impressed i have the boat setup per instuctione etc...and I will prolly get beat up on here but i am not that impressed....YET

Mine is built right and true and square...

Fire when ready

no need to fire! the boat should not blow off.. i seen where jim mamarill had his blow off too, i have run well over 80 and NEVER blown off the water,i have also NEVER had any hop in the turns with the jae style boats..what turnfin are you using? i tried the turn fin from zippkits and it was very very lifty for me, rf sponson wouldnt stay on the water,if thats what u have you may have to work on it...what props are you guys running and what is your strut angle? also, put your boat on a table sitting on sponsons and ski, the bottom of the tub should be level to the table, if its low in the back that is no good...something is definently not right, there are lots of these boats running great out there so it is there you just need to find it...MT

I opened up the original drawings of the JAE .21G2 and it looks to me that the boat built as stock will have an slight positive AoA of the tubs bottom - depending on what plywood sheeting one uses of course on the sponsons and ski... See attached picture.

If you add the overhang suggested in the build plans it will raise it even further, I checked mine last night and there is about 1/16 difference.

 

[HOTWATER]

I was out testing my 21 jae and it kept blowing off and or hopping in the turns it is fast but for heat racing in chop or a little wind or even crossing your own wake on lap 2 .....I am not impressed i have the boat setup per instuctione etc...and I will prolly get beat up on here but i am not that impressed....YET

Mine is built right and true and square...

Fire when ready

no need to fire! the boat should not blow off.. i seen where jim mamarill had his blow off too, i have run well over 80 and NEVER blown off the water,i have also NEVER had any hop in the turns with the jae style boats..what turnfin are you using? i tried the turn fin from zippkits and it was very very lifty for me, rf sponson wouldnt stay on the water,if thats what u have you may have to work on it...what props are you guys running and what is your strut angle? also, put your boat on a table sitting on sponsons and ski, the bottom of the tub should be level to the table, if its low in the back that is no good...something is definently not right, there are lots of these boats running great out there so it is there you just need to find it...MT

I opened up the original drawings of the JAE .21G2 and it looks to me that the boat built as stock will have an slight positive AoA of the tubs bottom - depending on what plywood sheeting one uses of course on the sponsons and ski... See attached picture.

If you add the overhang suggested in the build plans it will raise it even further, I checked mine last night and there is about 1/16 difference.

Hey Jim! ...Have you tried added any neg to your struts? Just curious since it has been brought up here...

-Kent

 

[mtruex]

I guess i am just getting frustrated .There is a race comming up in few weeks which is a22 hour drive and i have some new boats i am trying to get dialed in an may have bit off more than i can chew..

I am having issues for them too but the parts on the way should solve that...

The strut is one from jim M and non adjustable and i would like to get a degree or two neg in there and try it.

The turn fin is from Zipkit.

How would you suggest working it.

I will go and put the boat on my board and get back to you.

I have tried 1450 reduced in dia.1450 right out of the bag s/b and a h7 i can pull them all with my engine the first one seems to be the best.

Martin, my boat is 2mm aprox 1/16 lower in the rear than the frot of the tub say under the sponson area...

make sure the fin is sharp and blended back at least 3/8..if the fin curl runs paralell to the bottom of the tub and the tub runs low in the back then the fin will lift , the fin should be set to the ride attitude of the boat on the water.. i would fix the ride height , but some negative in the strut will help..

 

[mtruex]

I was out testing my 21 jae and it kept blowing off and or hopping in the turns it is fast but for heat racing in chop or a little wind or even crossing your own wake on lap 2 .....I am not impressed i have the boat setup per instuctione etc...and I will prolly get beat up on here but i am not that impressed....YET

Mine is built right and true and square...

Fire when ready

no need to fire! the boat should not blow off.. i seen where jim mamarill had his blow off too, i have run well over 80 and NEVER blown off the water,i have also NEVER had any hop in the turns with the jae style boats..what turnfin are you using? i tried the turn fin from zippkits and it was very very lifty for me, rf sponson wouldnt stay on the water,if thats what u have you may have to work on it...what props are you guys running and what is your strut angle? also, put your boat on a table sitting on sponsons and ski, the bottom of the tub should be level to the table, if its low in the back that is no good...something is definently not right, there are lots of these boats running great out there so it is there you just need to find it...MT

Martin,

If you build the kit exactly as it comes and use the existing boom tube holes with the ski attached, you will have a tub that is low in the rear. Approx 7/8" in the rear and 1" at the front. To get the effect your talking about where the tub is level front to back, you would have to raise the rear boom almost 1/8". This being the case, should the ski be taller or should the rear boom be raised? Raising the rear boom would drastically change the sponson attack angle. How did you get the attitude of your hull flat from front to back? And what is your angle of attack on your front sponsons?

Ron

either add a little to the ski, or take a little off of the bottom of the sponsons.....when i build my boats i make sure that the tub is level because i just know thats the way it should be..there is no reason to move the boom tubes, my aoa is the same as the kits and the plans at 4 degrees..

 

[Jim Mamaril]

I was out testing my 21 jae and it kept blowing off and or hopping in the turns it is fast but for heat racing in chop or a little wind or even crossing your own wake on lap 2 .....I am not impressed i have the boat setup per instuctione etc...and I will prolly get beat up on here but i am not that impressed....YET

Mine is built right and true and square...

Fire when ready

no need to fire! the boat should not blow off.. i seen where jim mamarill had his blow off too, i have run well over 80 and NEVER blown off the water,i have also NEVER had any hop in the turns with the jae style boats..what turnfin are you using? i tried the turn fin from zippkits and it was very very lifty for me, rf sponson wouldnt stay on the water,if thats what u have you may have to work on it...what props are you guys running and what is your strut angle? also, put your boat on a table sitting on sponsons and ski, the bottom of the tub should be level to the table, if its low in the back that is no good...something is definently not right, there are lots of these boats running great out there so it is there you just need to find it...MT

I opened up the original drawings of the JAE .21G2 and it looks to me that the boat built as stock will have an slight positive AoA of the tubs bottom - depending on what plywood sheeting one uses of course on the sponsons and ski... See attached picture.

If you add the overhang suggested in the build plans it will raise it even further, I checked mine last night and there is about 1/16 difference.

Hey Jim! ...Have you tried added any neg to your struts? Just curious since it has been brought up here...

-Kent

Kent, I have not tried it yet. I have been pretty happy with the setup so far. I will machine about 1 degree neg on the back of my mount and give it a try then report my findings. I think I will also try nothching the bottom of my strut where it sits on the ski and get it down a little farther. I have not experienced the symptoms that Terry has mentioned with hopping but it makes me curious as to the cause.

Jim

 

[Geraghty]

I was out testing my 21 jae and it kept blowing off and or hopping in the turns it is fast but for heat racing in chop or a little wind or even crossing your own wake on lap 2 .....I am not impressed i have the boat setup per instuctione etc...and I will prolly get beat up on here but i am not that impressed....YET

Mine is built right and true and square...

Fire when ready

no need to fire! the boat should not blow off.. i seen where jim mamarill had his blow off too, i have run well over 80 and NEVER blown off the water,i have also NEVER had any hop in the turns with the jae style boats..what turnfin are you using? i tried the turn fin from zippkits and it was very very lifty for me, rf sponson wouldnt stay on the water,if thats what u have you may have to work on it...what props are you guys running and what is your strut angle? also, put your boat on a table sitting on sponsons and ski, the bottom of the tub should be level to the table, if its low in the back that is no good...something is definently not right, there are lots of these boats running great out there so it is there you just need to find it...MT

I opened up the original drawings of the JAE .21G2 and it looks to me that the boat built as stock will have an slight positive AoA of the tubs bottom - depending on what plywood sheeting one uses of course on the sponsons and ski... See attached picture.

Niklas,

Thanks....I never saw that deviation in the plans before you pointed it out to me,thank you for pointing that out......but here is the bottom line.......In a perfect world we would like to see the tub bottom dead flat with the water but truth be known a 1.5MM rise in the front will do nothing to the boat performance that a good set-up can't solve...

I am sitting here looking at the original JAE .21 G2 Prototype and it has that 1.5MM rise in the bottom also....I remember Martin saying when he tested the prototype he thought he saw the boat was a bit loose so he just made sure the strut was down on to the ski sheeting and put a bit of negative into the strut and the slight loosness he saw immediately went away.....Martin said he had probably had the prototype running somewhere in the 70's in heat racing trim with absolutely no blow-off tendencies......

Aero-dynamically speaking,there just isn't enough boat tub and sponson width frontal area for the JAE.21G2 boat to be a blow over queen.....We also have never seen any blow off tendencies with the .12 boat either.....JAE boats do not run loose,they run very free on top of the water....there is a difference.....

Now I don't know exactly how many JAE boats we have running worldwide,but I am guess-timating somewhere well over 100 have seen the water........these are kit boats and boats built from plans...this also includes nitro and FE boats.....

To date I have been contacted by exactly 4 people that have had set-up problems .....What is wrong with this picture?????...Or should I be saying what is right with this picture????.....I have also probably received 40-50 emails complimenting the JAE team because the boat they had built ran great right off the table.....I would estimate 90+% these boats were built by novice inexperienced builders that are not racers......[going away the non-racers follow building instructions much better than the racers do]

These unsolicited comments from a very pleased group of novice worldwide boat builders really impresses me......

I have talked to Zippkits and Joe said he will make a 1.5MM [1/16"] adjustment in the kit cutting program to insure the boats in the future will have their bottoms absolutely dead flat with the water so we can remove this design variation out of the equation......

 

[Jerry Dunlap]

If I had only not cut the apex buoy coming to the start, that heat would of been mine. Every year we start the racing out in Marysville and every year I hit a stick and do not finish a heat. Kicked a rudder this time with no steering. Last year had a big chunk stuck to the rudder. The year before broke off the rear of the turnfin sponson with the turnfin attached. It just seems that I always start off in a hole. Oh well. Good win Jim. Now on to Duval and you are going down!!!!!!!

Mike

Mikey,

This almost sounds like "SNIVELING."

JD(Not sniveling over hitting a sunken log in the last heat of 20 Sport and ripping the transom )