ARMA Super Modified Twin for 2010

[fordman21]

George is right, you want a third bearing out there and a .250" axle. I was just looking at a 4130 1 1/4' jackshaft that I had in my machine this summer and noticed that it is twisted about 3/8" from one end to the other and it is only 16" long, it almost scares me to think how far I would have had to of twisted it to get it to stay that far. If your using a jackshaft with a horizontal engine don't be afraid to use four bearings on there too.
The tube you have in there up high under your tunnel behind your seat you might want to hold off on until you get your axle mounted if your using the big tire, it might be in the way of the bearing cassettes. I think my axle was mounted up there pretty good, about as high as you could go. With the top plated in I don't think you will need that tube.
I'm a little worried that the seat is so low that you won't be able to get the chain back to the rear axle, the chain usually rides a bit under the seat at the front.
Your doing a fantastic job Jerb, keep up the good work.

[Old school racer]

Looks really good ....keep it up.

[jerb]

thanks guys, yes im definately gonna run a 3rd bearing, just waiting on axle to figure where to place it exactly, with me being a small guy, and a smaller seat, i believe i have room for the brake on the left side, which leaves me some more room on the right side for sprocket, just have to see, still kinda up in the air over a vertical with a ragb or a horizontal with a jackshaft, guess it depends on what i can find locally, i was reading Ryan that you were considering a 30'' twin, i have found a few of those, they pretty common around here, or more common anyways, whats your opinion on them?? again thanks guys!

[Cromwell C4]

Looks great so far. Keep up the good work! Like George said, make sure it's high enough off the ground in front that if you change to kart tires you won't be too low. Once you race mower tires on these chassis you'll want to change, trust me. And def set it up to run hoosiers or american racers on the rear. You have to add a ton of weight to get lawnmower tires to hook up the way a racing tire would.

And you can make the 30ci vanguards build plenty of power.  I'm running a small ci vanguard on mine, and i've got more power than i really need. I'm not even going to put my big engine on it. It would be even harder than it already is to put to the power to the ground. But good work so far

[Old Goat]

Lookin' good, Tim! I'm looking at all the supermods I can, cause I'm thinking about building one, too. Are you going to leave the motor offset, like it was originally? I built one of those frames a couple of years ago and I just flattened the frame where it's raised up beside the motor, with a 3 lb. hammer, and then welded some re-enforcement underneath the frame where the motor mounting bolts go. Then I centered the motor on the frame. It worked out pretty good and it's still running that way. I hope you didn't mess up and have to relocate your seat. You get three lashes with a wet noodle for mounting the seat before the rear axle

[swmoracer]

But you have to be able to sit in it and make motor sounds with your mouth!!!!That is what keeps you building on it when you get mad cause your wrench slipped and busted your nuckle.And by the way Tim it looks awsome!!!I wish I had the cash to build a twin!!!!

[Rooster]

Lookin' good, Tim! I'm looking at all the supermods I can, cause I'm thinking about building one, too. Are you going to leave the motor offset, like it was originally? I built one of those frames a couple of years ago and I just flattened the frame where it's raised up beside the motor, with a 3 lb. hammer, and then welded some re-enforcement underneath the frame where the motor mounting bolts go. Then I centered the motor on the frame. It worked out pretty good and it's still running that way. I hope you didn't mess up and have to relocate your seat. You get three lashes with a wet noodle for mounting the seat before the rear axle

As for leveling the engine mount, on one of Larrys he put a strip of 10 GA under one side, and on top of the other..saves the beating and gives you reinforcement.

[jerb]

well had a minor mess up with the front axle, i used 4" end plates, and somehow managed to weld them on at about 15 degree angle, so i cut them off today and redid the axle, used 5'' this time for more adjustability when using different tires, so now with a 13'' tall tire my frame sits at 2'' off the floor with a 3/4'' adjustability up or down, gets some more pics tomorrow, as for the engine mount, if i use a verticle engine, yes i plan on centering the engine and as for the seat old goat....i did plenty of measuring before i mounted it, so of course it will probably be wrong...

[fordman21]

There isn't enough room for an mcp caliper on the left side with that frame, The sidewall of the American racer or Hoosier tire will rub on the caliper bolts even if they are ground down. Everything I'm building now has the caliper mounted on the right side. You want no less than one inch clearance from anything and the side wall of the tires.
The little vanguard I had was small but not exactly junk, you'll have to try a bit harder with less cubic inches but its not impossible. It had enough hp and traction to twist three 1 1/4" 4130 jackshafts that were only 16" long with four bearings.

The twist doesn't look as bad in the picture.

[jerb]

wow...thats some horsepower doing that Ryan....

[Cromwell C4]

Good job Ryan.    Always abusing parts   But that really does take some serious power and traction to twist like that. Wow.

[George Herrin]

Jerb they make several different size rear tires as you can see. The bigger 8.5 wide tire, that will not allow you room for brake on left side however you have several other choices available. For example the pt# 42500 which was my choice is the same basic overall measure of the turf pros on a 8x8 wheel, this way you can use the turf pro for mock up. Need more room they have a 7" wide also. I wouldn't use the 6" wide but its there. The 7" wide and the 8" wide can both be mounted on the 8x8 wheels we use already. If you have any questions Call Neil Cowman at Hoosier Direct (574) 784-3152 from 7:30 AM to 4:30 PM eastern time tell him I sent you and he will give you any info you need. He has been the most open and helpful of any I have spoke with on these tires.
 
Item/Number Tire Size/Tread Pattern/ Tread Width / Approx.Dia/  Approx. Circ / Recom.Rim / Measured Rim / Section Width / Compounds
42400         15.0/6.0-8       aa                6.0"             15.0"           49.0"            6"              6"                 7.4"               D12, RD20   
42450         15.0/7.0-8        Q                7.0"             15.0"           49.0"            6"              6"                 7.5"               D12, RD20   
42500         15.0/8.0-8        Q                8.0"             15.0"           49.5"            7"              7"                 8.5"               D12, RD20   
42550         16.0/8.5-8        Q                8.5"             16.0"           53.5"            9"              9"                 10.5"             D12, RD20

[fordman21]

Outlaw/Supermod = Go big or go home      The guy who gets the most traction wins with these machines.
As far as the jackshaft goes, I can't believe the little 1" cast iron crankshaft doesn't break. I'm going to have a crank support on my latest set up and increase the primary drive ratio close to 5:1.
If you go with a jackshaft remember that they take much more abuse than the rear axle due to the primary and secondary ratios.

[George Herrin]

MAybe so but at what price or cost of broken parts. I still don't get paid to race or win, which means it still comes out of my pocket, thus I want fast and reliable, Reckon I don't have enough HP cause my 3/4 jaft is doing fine so far. Which is OK by me, To finish first first you must finish.......... Couldn't resist that one.... besides my auto traction control still working to my advantage

[fordman21]

 My intentions were to save some of these guys the trouble of making the same mistakes that I already have in the past......... save them time and money.