cerpindicular

iTrader: (1)

I have a 2.5 tmaxx and have found a bigblock conversion for a good price. My question is what clutch bell/spur gear combo do i need to pick up to make it work for my truck since the pitch is diffrent from the stock truck. If it matters it still uses the pellet style slipper clutch.

dug44

iTrader: (29)

You found a Big block conversion kit for a Traxxas T-MAXX? Could you give me that link? You have to extend the chassis? Is there even enough room to fit it?

cerpindicular

iTrader: (1)

Conversion kit includes the extended chassis. It the price wasn't what it is i would just pick up one of the mid block .21 or what ever size engines are out now and drop that in and eliminate the guess work but like i said the price is good

cerpindicular

iTrader: (1)

from what i understand i can run a mgt spur gear and a 1/8 clutch and clutch bell and it will work does anyone know if this correct?

trxnut454

I don't know about the gears, but you'll need alot more than just a bb kit.

By the time you get it reliable enough to hold that kind of torque you'll have spent alot more than just the cost of a bb kit.

tmaxx26power

iTrader: (39)

Totally agree. I highly recommend not doing the BB conversion. I did one years ago(hence my forum name) Between blown drivetrain parts all the time and the money I spent to make it bullet proof it just wasn't worth the time or $

trxnut454

I have a newer 4907 maxx with the picco 26 (technically not a big block) and it rips! I had to put about 200 bucks into it plus the engine before I had a reliable truck, and it is reliable.

However, OP, you are starting with an older 2.5 maxx.....good luck to ya.

cerpindicular

iTrader: (1)

most of my drivetrain has already been upgraded since when i upgraded to the 3.3 i kept breaking crap. If i do the conversion it will have cvd center shafts and i was thinking about keeping the revo spec axles and knuckles for a break point if needed.

tmaxx26power

iTrader: (39)

What has been done to your trans and diffs? Those are the weak points on the original 2.5 Tmaxx and most expensive to make reliable.

Check out this website.
http://www.unlimitedengineering.com/

cerpindicular

iTrader: (1)

Trans was gutted and i also added a forward only conversion haven't messed with the diffs yet but i can get some of the revo spec diffs also for fairly cheap

tmaxx26power

iTrader: (39)

Stock trans gears will not hold up to the torque of a respectable BB. Neither will the Revo diffs(been there done that). I'm definately not trying to discourage you in any way, just informing you of what your in for from my experience. You would be alot better off saving your $ and time and getting a Savage or LST2 or something along those types of monster trucks that are built from the factory and suited for BB power. You will have way more fun in the long run.

Overdriven

iTrader: (18)

IDK why everyone seems to have problems blowing the drivetrains in their Maxx trucks. I used to use stock 2.5 gears, shimmed in aluminum cases and never had any problems unless a bearing went bad. And I ran Novarossi .28 and O.S. .30, not exactly weak engines. Center CVD's and 3.3 sliders for the axles are a minimum though. A cheap diff upgrade is LST diffs and cases stuffed in between the maxx bulkheads as they can be found fairly cheap on ebay. Just google it and you'll get some how to's from TRX, rcm and other forums. Its not hard and requires no mods to the bulkheads.

For my big block conversions I used a RR double slipper on the 2.5 trans and a stock slipper on a 3.3 trans, with an Integy 3 shoe clutch. You might have to play with different collets and possibly shims to get it lined up perfectly, but it isn't a big deal. Going to a FWD only is a must in either trans, other than that I never had any issue with either under BB power. Results will vary with use, slipper setting, yada yada yada. Just my exxperience. LST is a way better truck to start with though, unless you can't help but love the Maxx trucks like me

trxnut454

Get traxxas brushless diffs, metal primary trans gears, traxxas cvd centers and revo spec plastic shafts or cvd to the wheels. The stock plastic tranny gears will hold for a little while if you convert to a good slipper and set it right. First thing would be the diffs and slipper, the traxxas brushless diffs will hold any bb.

Funny thing is, a picco 26 will stomp alot of big blocks in a maxx.
You can save the hassle of getting a chassis and bb manifold.

I've done the maxx several different ways, but never a true big block. That's what my xxl is for.

team jeremiah

iTrader: (5)

For the people that haven't figured it out the picco maxx .26 is a big block displacement with a small block crank case. Which basically means it's a big block with a shortened crankshaft.

So I guess what ever route you take make sure to have extra parts and diffs on hand or upgrade to 1/8 scale diffs. oh yeah and with a bigger motor means more fuel so you might want a bigger fuel tank too... proline makes one. Not that i'm trying to steer you away from having a big block T-Maxx.. Cause I put a big block in my T-Maxx I was fun until my second tank then it seemed like I couldn't go a tank with out some thing breaking like drive shafts, wheel hexes and rim hexes rounding out or diffs and bearing failures. And the bulkheads I kept breaking from all the crazy jumping I couldn't stop myself from doing. So after a butt load of money I wised up and realized that traxxas put a 2.5 in the T-maxx for a reason and got myself a LST. Good luck

trxnut454

[QUOTE=team jeremiah;8638732]For the people that haven't figured it out the picco maxx .26 is a big block displacement with a small block crank case.

That's pretty obvious to those of us who DO know it's not a big block. The point I was making is that he could have the same, if not more power without spending a ton of cash on a chassis or moving the trans forward.

Traxxas brushless diffs will hold anything a nitro can throw at them, and my 4907 maxx has been pretty good so far with the picco 26. I'm anticipating a burned up first gear and maybe a broken shaft (out to the wheels) from time to time but nothing else. I have a center dogbone setup that works great.