Results 1 to 7 of 7
  1. #1
    RC poster
    Join Date
    Mar 2017
    Posts
    3

    Mods to the trx 2.5 engine for Tmaxx

    Hello everyone!
    This is my first official post on the forum, since I couldn't a thread about the specific info I was looking for. I have an old Tmaxx classic with a 2.5 engine, and I am interesting in modding it to be as close to the performance of a 3.3 while still maintaining the 2.5 crankcase. I'm not really looking to bore it out or do anything super custom, but I did want to install the RB mods crankshaft (for the 3.3/3.7 he makes, but it will fit the 2.5), losi 340 carb, and a three shoe clutch system. I'm also looking into modifying the sleeve a little bit at home. Anyway, my question is, would it be better to go for an exhaust system that is designed for the 3.3 or the ones still made for the 2.5? Will the 3.3 exhaust (whether it be traxxas resonator or ths or other performance brand) give me more performance since my 2.5 will be so modded? Where can I find a great set of lightweight bashing tires that fit the stock tmaxx classic 14mm ( I think they are 14 right? maybe 12?) mounts. Those stock wheels last forever but they're so heavy... Also, is there a way to mod the 2.5 to accept turbo glow plugs instead of regular ones? Answers to any of these questions (preferably the ones regarding the pipes) would be much appreciated. Thanks!

  2. #2
    RC Qualifier westoakmech's Avatar
    Join Date
    Dec 2011
    Posts
    915
    If you look under the engine section, I think there is a thread about modding the ports in the sleeve. I have a 2.5 that I modded the crank, and the ports in the sleeve. I am running a losi 3.4 carb, and a traxxas aluminum pipe. I think it was the same pipe that comes stock on a 2.5 jato. I did drill out the stinger a little bit, it seemed to help. I think it would come close to stock 3.3 in performace. I just don't think it is going to have the bottom end torque. I don't how much difference there is in a chamber made for a 2.5, and one for 3.3, so not sure about interchanging the pipes.
    Rusty 2.5R,T-max 2.5 & 3.3,Summit VXL Nitro 4-tec

  3. #3
    RC Competitor
    Join Date
    Feb 2017
    Posts
    88
    Above my grade on this one, but good luck to you!
    Currently moding my maxx 3.3 cause I'm just never happy with stock

  4. #4
    RC Turnbuckle Jr. Wildman4910's Avatar
    Join Date
    Jun 2009
    Location
    Cocoa Florida
    Posts
    4,909
    for all that, just drop a 3.3 in it with either a maxx resonator pipe or a THS pipe THS1045 or THS145H(Hard Coated).
    A 3.3 pipe will work fine on a 2.5.
    Nobody I know of makes a turbo plug head for these engines.
    For a lighter weight tire go with the ProLine Badlands, great tire, and get the 17mm hexs as you'll need them.
    Or the Traxxas SportTraxx tires are a good choice too.
    https://traxxas.com/products/parts/5470

    Bad Lands



    THS 145H pipe

    Last edited by Wildman4910; 03-09-2017 at 03:02 PM.
    Look out for the tree/crunch!

    LiPo? Naw NITRO!!

  5. #5
    RC Racer rustlerstein's Avatar
    Join Date
    Jan 2016
    Location
    Wisconsin
    Posts
    227
    I'd go 3.3. For 100 you can go wrong and don't have the headaches of wondering if the mods will work.

    Sent from my SM-N920R4 using Tapatalk

  6. #6
    RC poster
    Join Date
    Mar 2017
    Posts
    3
    Thanks for all the input everyone! I appreciate and understand that the 3.3 is the cheaper and higher performance choice between a modded 2.5 and a 3.3, but it's more about the fun of the modifying what I have at the moment. The idea of having a "sleeper" rc car is super fun... just imagine people seeing the 2.5 and laughing, then the surprise on their face when all they taste is my dust! Another random question that I couldn't really find specs for, is there a weight difference between the 2.5 and the 3.3 engines?

  7. #7
    RC Turnbuckle Jr. Wildman4910's Avatar
    Join Date
    Jun 2009
    Location
    Cocoa Florida
    Posts
    4,909
    Quote Originally Posted by SleepyMaxx View Post
    Another random question that I couldn't really find specs for, is there a weight difference between the 2.5 and the 3.3 engines?
    Not enough to matter.
    Look out for the tree/crunch!

    LiPo? Naw NITRO!!

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •