muad dib

Here is my SUT PRO: (I just need rear shock tower and chassis braces). I also just ordered a set of OFNA super shocks and diff oil F-7k, C-30k, R-3k. This is so much fun to drive, it handles great; super responsive, turns on a dime without flipping over, unless you are really moving and turn hard from a straight line. It's mostest Awesomesterly.

TheQuakeKing

My Feedback: (23)

nice

dryvr

Glad to see and SUT on here. I'm currently building mine. Nice work.

muad dib

Thanks, if you are using the pro chassis you need to put two pieces of fuel tubing in each drive cup as the center dogbones are too short, the universals are even shorter. I would just use the dog bones as they fit better (with the fuel tubing) I am going to sell the universals I bought.

dryvr

I'm using the Fioroni chassis. Thanks for the info, I'll remember that if I run into that problem.

muad dib

You probably already know this but the Fioroni chassis needs holes drilled for the motor mounts so that the mesh with the larger spur gear won't be too tight. The intent of this message was to make sure you knew about the pretty large/informative file at gsracing.com, "How to race tune your SUT", Im sure you probably have read/downloaded it., but just in case I think it's pretty good except it does not mention the center drivetrain issue. Have you ever considered using a center spool and like a 65T spur gear. I might try it someday, I think OFNA's center diff stuff will work, the radio tray may need to be cut or replaced for the huge spur. I just ordered 4 OFNA rear super-shocks. Do you know of another manufacturers dogbones or universals that will fit. Please post some picsupdate when your done, I have only seen a couple of others that don't look stock.

fhm101

Did you try the center universals? They may measure shorter than the dogbones, but on the Pro buggies I've converted to SUT's they are working with no problems and these trucks are getting pounded. I've done Pro buggies that where on the GS Pro chassis as well as the latest Fioroni chassis and I have not heard a single complaint from any of the owners about driveshafts popping.

muad dib

I tried them but they end up being shorter, they barely reach the other end. I'll try it agin later, when you mount them, did you have to move them forward on the end of the pinion gear? GS only has the one type of center universals right? I wonder whats up? I'll post some pics later.

fhm101

This is only true if you are using the RTR engine mounts. The (lower) Pro mounts will work with the Fioroni chassis with no mods and allow the use of a 13T bell if you want. This is also true of the GS Pro buggy chassis. With the pro engine mounts you can use a 12 or 13 tooth bell with no mods to the chassis holes and no clutchbell hitting the chassis issues. The only fitment problem I've run into so far has been trying to use a Dynamite center diff carrier. It's lower than the stock plastic or the Pro QD mount. I mounted one up this way and didn't bother to check fit and not only was the main drive gear hitting the chassis cutout (just a tad, but hitting) it was also hanging below the chassis.
One note on using the Pro engine mounts, you will also have to use the Pro flywheel or your RTR flywheel will stick through the bottom of the chassis. You can also use a Kyosho Kanai flywheel as it's the same diameter as the GS Pro unit.

fhm101

I don't remember exactly where the shafts wound up in the center outdrives, but it must not have looked too bad or i would not have let it go and as much racing as the trucks i did have been in since, I would have heard about any problems by now. You could try moving the shaft further in toward the center diff, but i would think you would need to shim whatever gap you wind up with between the end of the universal and the diff case to keep your ring/pinion mesh right.
I just took a look at my old storm buggy and the center drives are well into the diff cups, but it's a Pro built on a gen 1 Fioroni chassis which is the shorter (RTR) version of the storm plate.
I'll see the guy with the Fioroni SUT this weekend and i'll get some pics of his center setup for you.

Tater Head

My drive shafts are to short in my sut.

muad dib

Try the fuel tubing "fix" mentioned above, it seems to work fine. I going to try the universals again. I looked again they might work out better I don't know what I was doing before but I was in a hurry so who knows. I'll use the dogbones and fuel tubing until I get bored and break the chassis down for cleaning or sumpin.

dryvr

Actually a friend of mine is building it for me, got to give him props. (thanks J.D.) Using the Fioroni chassis the drive shafts are too short. However, the universals work fine. I know this because that's what he did to his SUT. As far as drilling holes for the engine, it's not necessary, everything bolts up fine. I would like to use a Fioroni sliding turbo clutch and I wonder if the pro engine mounts would bring the flywheel low enough to use on a starter box. As you all know, the Fioroni flywheel is smaller and thinner than stock. I'm just a fan of that clutch, I use it on my buggy and have never had a problem out of it.

muad dib

I was just trying to recall something from memory about that chassis, guess I remembered wrog, doh. I'm going to try that clutch out myself, I have read good things about it. I think the universals will probably be fine, I was probably doing something wrong and didn't have anything bolted down yet while fitting them, I guess I'll put those suckers on this weekend when I oil up the diffs. What diff oil, if any are you using, I am following GS suggestions but Im using 7k in the front instead of 10k cuz I couldn't find any around. When the center diff "unloads" does that mean the drive train is not rotating as fast as it should, thus robbing you of power. For the most off the line power or speed would you want the the thickest oil possible, would ofna's 120,000 cps diff lock oil suffice. Anybody knowledgeable on this matter, I am one step above completely ignorant.

dryvr

Believe it or not, we're running 5-7-3 and it works great. In fact another friend of mine used this setup at the Battle at the Beach race in Ft.Walton Beach, FL and won the unlimited monster truck A-main with his SUT. The track was blue groove and technical. I would like to know the answers to your questions as well, hopefully someone with more experience will answer them.

fhm101

That would not have been Don from DHN would it? I don't know him personally, but we've raced against him several times. he's always tough.
I used 7KF 100KC 3 or 1KR depending on what the individual wanted. If you don't use a very heavy center diff the front wheels will unload at high speeds and coming off corners. One of the guys has dropped his center diff to 60K and likes it. We tried 50K and it was too soft so I would say 60K for the center would be a good starting point.
The more diff action you allow, the quicker the driveline will unload to the wheel with the least amount of traction. The lighter the diff oil the more diff action you get. You can sim your diffs up tighter that usual, but it will only accelerate wear.
Another thing that helps tire unloading is stiff foams in your tires. ProLine supplies Bowties with foam that is far too soft for racing. Trinity or Panther both have excellent foam for racing.

muad dib

Thanks for the advice, the only other suggestion is the one on the GS site which says to use 30k, I think I'll put the heavier stuff in first. I have noticed the foams I have are really soft and I want to switch them. Is there any chemical that will eat the CA glue, I think I used a bit too much and I dont want to ruin the wheels or tires. Any tips? Also my carb is sticking at the closed and 3/4 throttle positions. Will this cease after heating up the engine and moving the carb from open to closed a few times?

dryvr

fhm, yup it's Don.