T maxx Big block conversion

[hipluther01]

Im 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 Im completely lost. Im 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 Im 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???

[olds97_lss]

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_in...products_id=92
http://r-cstore.com/store/product_in...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.

[Lessen]

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.

[hipluther01]

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.

[olds97_lss]

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

[hipluther01]

I bought an integy racing CB. Im 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 Im planning on adding a super charger and nitrous from RB Innovations. Should be interesting..

[tim-rachel]

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

[hipluther01]

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. Im missing a wheel but it is on the way.

[hipluther01]

There has been another potential problem brought to my attention. Im 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???

[olds97_lss]

Yes. There is!
http://www3.towerhobbies.com/cgi-bin...&I=LXSDP9&P=ML

However, the 3.3 trans with the FOC may hold up better... I don't think the RCS spur gear bolts right on to that trans though. It was made for the 2.5 trans/slipper assembly.

[hipluther01]

Originally Posted by olds97_lss

Yes. There is!
http://www3.towerhobbies.com/cgi-bin...&I=LXSDP9&P=ML

However, the 3.3 trans with the FOC may hold up better... I don't think the RCS spur gear bolts right on to that trans though. It was made for the 2.5 trans/slipper assembly.

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?

[olds97_lss]

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.

[hipluther01]

Originally Posted by olds97_lss

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.

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...?&I=LXPPK2&P=7 (this is the CB)

[olds97_lss]

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...?&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

[hipluther01]

That what I was afraid of as far as the integy CB goes.
http://cgi.ebay.com/HPI-Savage-Extra...3A1%7C294%3A50

This was the other one I was thinking about