Old school, big power

[mattymac]

just a test fit... had to trim the front hood hinge and the hood louvers on the right side front/center but other than that... these things are a work of art to fit the way they do!!! Downside is apparently Jaws doesnt supply springs with custom pipe orders which I didnt know until they arrived... Lucky for me I have a 5 gallon bucket half full of exhaust springs! Especially since I like running two springs per tab.










Powervavle clearance is gonna be tight. I was planning on running STM valves but I dont think theyll work with the clearance of the mag pipe coming around. Ill probably end up running the stock APV caps, no cables with the valves pulled fully opened with some spacers.

Also the top right outlet on the front cooler comes up and does a 90 degree turn up which hits the mag carb. You can cut, re-clock, and re-weld from say the 1 o clock position to the 11 o clock position just like how scott did his in the picture he posted but getting a tig torch between the fitting and the side bulkhead plate is TIGHT!

I found a tight radius "J" shaped hose that worked pretty good by just cutting the 90 degree bend (making it a straight outlet) then just welding around the fitting to build up a lip to clamp/seal against making plenty of clearance with minimal work.

 

[sno*jet]

sexy pipes!
wonder if that one expansion chamber running close to the cylinders will mess with the cooling on the two closest.
I know some people stagger jetting for those reasons, but I never did on my triples even when recommended. They say put a fatter jet in a cylinder that gets more heat, but to me it seems like you would want to go leaner as the extra heat would make those cylinders more sluggish... i over think things a bit

 

[Idcatman3]

It's not like you'll really notice the loss of bottom end from the exhaust valves!

It almost looks like if you were willing to cut into them, you could tighten up the curve on that center pipe and get a bit more clearance, but I'm not sure what that would do on the hood side.

It was definitely fun re-welding that fitting. The one in the picture above is actually a 570 fan bulkhead, with a custom cooler put in it, specifically to avoid that problem.

 

[mattymac]

By cutting the mag pipe and turning it to get more power valve clearance it only puts it's further into the hood which I already had to cut for the mag pipe and for the center pipe... The correct fix is getting a taller hood.

I did trim the hood just to see what it would take to work and it's more than I was hoping but it's totally runnable... I don't run a hood when I don't have to and since cat puts a notch in their hood hinges other than the one electrical plug and speedo cable (which I'm not running) u can take the hood off or on in a matter of seconds!

 

[Idcatman3]

On ours we ran the electrical plugs out the speedometer hole. Then you can unplug and pull the hood off really quick.

 

[joshkoltes]

ditch the hood hindge and use four straps instead, with no electrics in hood to and have full access

 

[mattymac]

ditch the hood hindge and use four straps instead, with no electrics in hood to and have full access

On my 1200 WC's thats how I have em setup. I think ive only ridden maybe a couple times with the hood on. Getting that heat out makes these big triples run so much better, plus covering up these monsters is criminal in my mind!

I just am seeing what it takes to run this setup and give people the idea of what the end result is, Im certain there wont be many miles with a hood on when riding this build. When its over the hood powder ill just fire up the apex... maybe! depending on how this thing actually runs when its all dialed!!!

Mtn fit is still making the 2" taller hoods so thats always an option.

 

[Idcatman3]

how bout a picture of the crank?
are you going to have the catman send you a recoil adapter for the m8 style?

Not his crank, but our spare:

One of these days I'll get a ZRT 600 case/crank and take a comparison picture. We don't have a T-cat one handy.

 

[sno*jet]

id go hood on but remove everything from it including windshield and hinges. a bit less decibels and the belt wont slip everytime you hit a drift. motor will be happier in a roll over too.

 

[mattymac]

ran into a snag in the ignition, but I think I found a pretty good fix that will address two issues with running a TCAT flywheel that should make this setup a bolt on and go deal. Also brainstorming with scott we think we may have a solution to running the twin electronics for the ignition. So for someone who wants to build one of these there are more options to make putting one together that much easier and can save some money doing it!

Just doing more test fitting, and working on some of the pluming, nothing really else to show other than its starting to look more like an actual finished sled! Work gets in the way of having fun! Ill have more updates soon!

 

[Zrt1200]

Nice Build. Just curious. Do you have a 1 piece plate under the engine to help keep the cases tied together??

 

[mattymac]

yeah, 3/8ths aluminum plate bolted to the bottom!

 

[Zrt1200]

yeah, 3/8ths aluminum plate bolted to the bottom!

Smart Move. I have seen some 4 cylinder T-cat's that were welded together and the cases cracked because they did not have a plate on the bottom.

Oh Ya, Just a FYI if running two springs per tab. Either make up or buy some extra tabs from Jaws. On our Prostock & Nitrous outlaw sleds we probably replaced those tabs 2 times a year running two springs per tab. We ended up just running one spring per tab.

 

[mattymac]

Smart Move. I have seen some 4 cylinder T-cat's that were welded together and the cases cracked because they did not have a plate on the bottom.

Oh Ya, Just a FYI if running two springs per tab. Either make up or buy some extra tabs from Jaws. On our Prostock & Nitrous outlaw sleds we probably replaced those tabs 2 times a year running two springs per tab. We ended up just running one spring per tab.

Interesting?!?!?

On my crankshop, and SLP's, Ive always run two springs and never had a problem with tabs, the Jaws tabs dont look any weaker?

 

[Zrt1200]

Interesting?!?!?

On my crankshop, and SLP's, Ive always run two springs and never had a problem with tabs, the Jaws tabs dont look any weaker?

The new tabs may not be weaker but 8 years ago we broke a lot of them.

 

[mattymac]

heres my fix for the ignition issue using the twin welded case...

By doing what I did I:

wont sheer flywheel keys
can run either twin or triple cdi boxes (different timing curves)
no case mods on the mag housing
bolt on and run after this mod

The twin CDI box has a hot timing curve in the mid range making cruising down the trail or steady half throttle or so really heat up the exhaust temp... DETONATION!!!

Back in the day, the tcats all responded well with a timing key, not the twins to much timing in the mid range! 2-3 degrees on the tcats made a noticeable difference! they had a milder timing advance in the mid range so the extra 2-3 degrees throughout didnt seem to want to detonate in the mid range if you were cruising down the trail but gave you the extra advance at 8000+rpm's for longer legs. The 2000 and newer tcat cdi has a 13 degree advance at 8000 rpm, the 900 mtn twins have 12.5. with the extra 2-3 degree advance puts you at at 15-16 final degrees of timing advace BTDC. Dynotech has had numerous tcats in all sorts of configurations with around 16 degrees final timing which netted some impressive gains! all without the dangerously hot mid range. There is obviously some variables here and its not like this for every motor.


Lots of measuring, even more so when these flywheels are off farther than people would think, mainly the hub center isnt dead center in the flywheel so it basically has a wobble in it. Trying to get it within .0001 on the edm machine makes it more difficult than it should have been and people wonder why one sled runs better than others out of the box...

Tcat flywheel on the left, notice the keyway without the sharpie mark in relation to the timing trigger, compare that to the twin 900 flywheel on the right, no tirgger where the keyway is.



Now when I rotate the tcat flywheel, the triggers are in the same position in relation to the keyway, this is where the timing sensor/pickup is located in the stock CARBED twin case... approx the 10 o clock position. On the tcat case its around the 11:30 position. So by re-clocking the flywheel it essentially doesnt know the difference. Just rotating the flywheel trigger to where the twin pickup is.



Heres the retapered hub, it measured around .002 off from the twin to the tcat flywheel taper, close enough to run with some locktite or even a tack weld but most will end up sheering a keyway and leave you stranded.

 

[Zrt1200]

Nice Work. I take the T-cat flywheel is off a 98 or newer NOI with 6 magnets VS the NCI with 4 magnets?? You are correct about the T-cats gaining big top end with the timing around 15-16 degree's. They just Sing on top end with that timing.

So what Stator plate are you going to use. I take a T-cat stator??

 

[mattymac]

Nice Work. I take the T-cat flywheel is off a 98 or newer NOI with 6 magnets VS the NCI with 4 magnets?? You are correct about the T-cats gaining big top end with the timing around 15-16 degree's. They just Sing on top end with that timing.

So what Stator plate are you going to use. I take a T-cat stator??

Yes, 2001 tcat ignition with TPS sensor on the CDI, 6 magnet flywheel.

on this setup the twin stator plate is used, tcat stator, and CDI


Scott is working on the twin (reprogram-able) CDI with altering the timing in the box itself to not have to mod the flywheel or the case itself moving the timing pickup sensor, if going this route you will have to run the twin stator as the plugs are different compared to the tcat setup.

 

[kiliki]

your love for the 1200 wc has you looking for big power...and the cat is the next step. Keep up the good work. you could have just gone with the 900-1000 triple as this has already proven the way to big power.

 

[mattymac]

your love for the 1200 wc has you looking for big power...and the cat is the next step. Keep up the good work. you could have just gone with the 900-1000 triple as this has already proven the way to big power.

That big naturally asperated big power/torque has a place in my sled trailer for sure! I love my turbos ive had over the years but our wet HEAVY west coast snow the torque of these motors make em shine in that stuff! This is just the cat version of the polaris WC... Polaris just has the cases to do it! The power over the cat 900 twin vs the 800 VES polaris is pretty significant IMO, when you add that 3rd cyl magic happens!!!

Without being on a dyno with this motor, I think 275 is pretty conservative, I think its right around 300hp, rideable/trailable HP if done right!

I had some really good friends who had a D&D prostock 1000 tcat motor that had everything money could do to it, it made 264 on the dyno... It was in a purpose built grass drag chassis! Ran well but isnt anywhere near the monster this motor is! Since it is 50% bigger displacement!!!!!!