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T maxx Big block conversion

Discussion in 'Traxxas T-Maxx' started by hipluther01, Feb 9, 2009.

  1. hipluther01

    hipluther01 Well-Known Member

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    I'm looking to put an HPI k4.6 (.28) onto my T maxx. This is the first T maxx Ive had. Ive been running a rustler for a long time and its Extremly fast. A friend of mine has a BB T maxx which he bought that way with the HPI SS .25. Its super fast. The T maxx that I have has basically nothing on it. It already has the chassis for the conversion. My question is basically clutch bell and spur gear set up. For some reason I'm completely lost. I'm trying to figure gear ratio. The problem having to use the HPI clutch housing and the Traxxas spur gear and they just seem.. well.. awful I'm wanting a mid range. good torque with really descent top end. So far The best has been a 18T robinson clutch and a 56T Integy spur. The problem is that all the reviews Ive read said that wont work cause there isnt enough room. However that is on a Savage truck. Will It work with the T maxx? Has anyone on here done this conversion? Does anyone have any suggestions???
     
  2. olds97_lss

    olds97_lss Well-Known Member Supporter

    HPI savage and t-maxx spur gears are not innerchangeable.

    The old 2.5 and earlier maxx runs a 32P (tooth pitch) spur gear whereas the savage runs a standard 1M pitch, so you can't mesh them.

    However, you can buy a 1M spur for a t-maxx, but the only one I know if is offered by RC Solutions. If you do get that one, you need to get a hardened CB to match up with it. I'd suggest it though as it allows you to run a 1/8th scale clutch, which holds up way better on a 21 converted maxx than the stock Traxxas clutch.

    Here's are links to the spurs:
    http://r-cstore.com/store/product_info.php?cPath=26&products_id=92
    http://r-cstore.com/store/product_info.php?cPath=26&products_id=93

    I want to say I ran a 54 with a 16T OFNA hardened bell. I used a HPI Savage 3-shoe flywheel with teflon shoes. Worked really well. It was a few years ago though. You may want to shoot them (RCS) an email to ask for the gear ratio chart so you can order everything at once and figure out what works best for you. They have a chart that shows you the equivalent gear ratio on 1M pitch gears to the stock 32P gears. THen your not buying blindly.
     
    Last edited: Feb 9, 2009
  3. Lessen

    Lessen Super Awesome! Supporter

    Olds is correct, those gears are not compatible. I have the 52 tooth version of the rc-solutions spur gear he mentioned which I could sell you. I won't be using it. Send me a PM if you're interested.
     
  4. hipluther01

    hipluther01 Well-Known Member

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    Thanks to the both of you. With the help of the both of you and a little tech support from HPI Ive ordered the parts needed. I got a Integy 3 piece clutch, 18T CB and a 54T spur witch gives me a 3:1 drive ratio. Thats not too bad. I can always change the cb. They are just 10.99 a peice.
     
  5. olds97_lss

    olds97_lss Well-Known Member Supporter

    What CB did you buy? The OFNA hardened ones run in the $20 range.
     
  6. hipluther01

    hipluther01 Well-Known Member

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    I bought an integy racing CB. I'm looking at a Robinson on ebay. I got the Integy flywheel with alluminum shoes. I ordered the 54t from rc solutions. should give me a 3:1 ratio. should be peppy.

    After I get all these little kinks worked out I'm planning on adding a super charger and nitrous from RB Innovations. Should be interesting.. :D
     
  7. tim-rachel

    tim-rachel Well-Known Member

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    let us know how that works out fitting it in put some pics to i have a t-maxx i might be intrested in doing that
     
  8. hipluther01

    hipluther01 Well-Known Member

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    HPIM1162.JPG

    HPIM1163.JPG

    These are a couple of the befores. When I recieved the truck eveything was apart. I had to assemble the bulkheads to the chassis and connect all the servos. I'm missing a wheel but it is on the way.:hehe:
     
  9. hipluther01

    hipluther01 Well-Known Member

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    There has been another potential problem brought to my attention. I'm planning on going with a FOC 3.3 tranny. Will it hold the added power? Do they make metal gear conversion for it? And also I dont think Ill be using the AWD on it and just use 2 wheel drive. I have the metal CVD driveshafts for the driveline. Also what about the differential. In my rustler I had to use T maxx metal gears for the spur and something else. The HPI k4.6 is supposedly rated at 2.9 hp. Is it going to hold together???
     
    Last edited: Feb 11, 2009
  10. olds97_lss

    olds97_lss Well-Known Member Supporter

  11. hipluther01

    hipluther01 Well-Known Member

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    Hmm that could pose a problem. How do I tell if i have the 3.3 or the 2.5? Ive been reading through the threads and I have noticed integy parts do not hold a very high reputation. The flywheel and clutch assembly I have is from HPI. The CB is integy. Maybe I should hurry and get the Robinson CB instead. Thoughts?:\
     
  12. olds97_lss

    olds97_lss Well-Known Member Supporter

    Well, your kind of jumping back and forth. I'm not sure what your ending up with.

    If you have an HPI savage 3-shoe flywheel, you have to run a 1/8 clutch bell. The only 1/8 clutch bell I can vouch for holding up to a steel spur is the OFNA ones I mentioned earlier.

    However, then you mentioned your getting the 3.3 trans (shaped different in a gray case with a revo'esque slipper) which I don't believe will work with the RCS steel 1M spur.

    So, what are you ending up with?
    1) 3.3 trans? Yes/No?
    2) RCS 1M spur? Yes/No?
    3) 1/8 flywheel-clutch? Yes/No?

    Without knowing the answers to these, I can't really give you answers to anything else.

    The old black 2.5 trans with RRP internals holds up just fine.
    The old black 2.5 trans with the RCS spur works well.
    The HPI savage 3-shoe flywheel and teflon shoes work well with the OFNA hardened bell.
    The OFNA hardened bell wears really good with the RCS spur.

    I had that entire setup along with an alloy trans case. The trans was more or less bomb proof. However, at the time, RRP didn't make two speed steel gears for the 2.5 trans. Now they do. If I had those, then it would have been definitely bomb proof.
     
  13. hipluther01

    hipluther01 Well-Known Member

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    I have the 1/8 flywheel. (HPI recommended from their tech dept.)
    The Integy CB is 1/8 for the 4.6. (HPI said it would work also tech dept.)
    My Tranny is a black one so it must be a 2.5. I was told it was a 3.3
    RCS 1M spur= yes

    http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXPPK2&P=7 (this is the CB)
     
  14. olds97_lss

    olds97_lss Well-Known Member Supporter

    Thanks for clearing that up. I was a bit confused as to what you had.

    I wouldn't count on that CB lasting very long. Your right in what you heard, integy's stuff isn't all that great. For $11, I can't imagine it's hardened too well.

    Running 18/54 may be a bit tall of gearing. But maybe not for your engine. I just hope it fits.

    If the 18T holds up ok and lets you figure out if it's geared right, then when it comes time to replace the bell, I'd get this one:
    http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXBL96&P=7

    I don't think RRP sells a grouped kit for the 2.5 trans. You have to piece it together.

    Here's the list:
    RRP Steel FOC
    RRP Steel forward primary gear
    RRP 2 speed top shaft
    RRP First Gear
    RRP Second gear

    If you do go that route, order a few of these as well:
    2 speed top gear bearing
    Boca sells them as well, they are sealed and last quite a bit longer.

    Honestly though, the 2 speed gears hold up for quite a while as plastic. So, you could probably hold off on getting those since the list does make for a pricey upgrade. These, RRP First Gear, RRP Second gear
     
  15. hipluther01

    hipluther01 Well-Known Member

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  16. olds97_lss

    olds97_lss Well-Known Member Supporter

    That should work as well.
     
  17. hipluther01

    hipluther01 Well-Known Member

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    Good then all I have to do is play the waiting game and tap my fingers till the parts get here so I can TEAR into it and get it running. I'm going to take photos of the conversion and post them. Prolly take a video of the after break in to show all as well
     
  18. hipluther01

    hipluther01 Well-Known Member

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    Ok so I got the hpi motor in yesterday and I put it on the chassis. Its a snug fit but it goes. I'm just waiting on the CB and Flywheel to get here so I can mock it up and see what mods I'm giong to have to do. I HATE WAITING! This motor has SUPER compression. Can barely pullstart it. It also Look HUGE on the tmaxx chassis.

    HPIM1172.jpg

    HPIM1173.jpg

    HPIM1179.jpg

    The last is a pic of the new rims and tires
     
  19. olds97_lss

    olds97_lss Well-Known Member Supporter

    You will probably have to slide the engine further back on the blue mounts once you drop the trans in. I know with my XTM conversion kit, I had a bit of the nut on the bolts through the top sticking out the back of the engine mount. Otherwise the end of the crank hit the trans case.
     
  20. hipluther01

    hipluther01 Well-Known Member

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    After mocking up the tranny yesterday I did have to move the motor back. Now all I have to do is wait for the Cb and flywheel assembly to get here as well as a few other small parts. Found out that I had lost the brake parts so I had to order new ones... MORE waiting. Damn... I jsut remembered I need a set of crystals...... does the small crap EVER end???!!! I'm ready to hear this thing purr.. It will still be next weekend or so b4 I can officially start it. I have to wait on my check to order a pipe. Does anyone have a suggestion as to what is a good tuned pipe that will fit a HPI K 4.6? I ordered shocks off ebay and they were the wrong ones. I believe they are for an 1/8 scale truck. They like 2 inches from mounting up. :angry: However my friend ordered a set for his truck and I "stole" his stock ones. After changing the shock oil in his old stock shocks they work better then the new ones he recieved. I thought that was funny. They old ones are super stout. I'm also waiting on the new spur gear I ordered from rc solutions. HMM come to think about it.. it should have been here already. Guess Ill wait and see what comes in the mail. Well sorry so long. Guess I'm bored. Still need a suggestion on the pipe.
     
  21. going_fast

    going_fast Well-Known Member

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    Same Project

    Hi i am doing this same upgrade. I bought the hpi k4.6 with a JP4 pipe. I made my own chassis extension blocks. My extension measures 1 3/8 give or take 1/32. What cb, center drives, and diffs are you using?:)

    Also which motor mounts?
     
  22. hipluther01

    hipluther01 Well-Known Member

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    http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXPNK3&P=SM (center dirveshafts)
    On the dif I'm planning on putting a spool in it with robinson gears as well.

    The CB I'm using is an HPI extra hard 17T. I had planned on going with a 18T. I may get one if I dont like the outcome of the gear ratio. I also had to get a special spur gear for the tranny from rc solutions. The pitch on the HPI CB is 1M. If you look in the first couple posts on this thread Rolex posted the link to get to them. They are available in a 54 and a 52T. When you recieve it there will be a gear ratio chart included with the gear. I dont know the name of the engine mount. It cam with the chassis. However if I had to explain it I would say its the slide kind. The nuts have a slot they go in that keeps them from turning. THen you can adjust where the motor actually sits in accordance to your tranny. I felt this was very helpful in stead of having the kind that merely bolts straight down. Gives you some leway. Kinda forginving in a way. I think you can see it in one of the pics I posted.
     
  23. hipluther01

    hipluther01 Well-Known Member

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    Got more parts today. Its like christmas in Feburary! well gonna put the parts in. Hope to be running by the weekend
     
  24. olds97_lss

    olds97_lss Well-Known Member Supporter

    How are you using those center axles with an extended chassis?
     
  25. hipluther01

    hipluther01 Well-Known Member

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    I'm not. Lessen give me address for a guy who does custom driveshafts. I'm waiting to hear back from him.
     

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