What's the Difference between Tmaxx 2.5 engine & trx 2.5 R

The TRX2.5R has just slightly different porting, and the blue machined cooling head. Thats about it. More power between the 2.5 and 2.5r? Maybe a little, but not noticeable to me. The 3.3 on the other hand, does have some more power. You can jump on ebay and upgrade to the 3.3 diffs, axles, bulkheads, etc if needed for pretty cheap.

u can put a 3.3 in the truck but u need to cange the spur gear to a 52 tooth in sted of a 72 tooth. the diffrence between a 2.5 and a 2.5 r is that the 2.5r is a race engin and the 2.5 is not. the diffrence between a 3.3 and a 2.5r is not much but u do not need to change the sure gear on a 2.5r.

2.5r is a ported version of the 2.5 and it has that blue head

tano14 said:

u can put a 3.3 in the truck but u need to cange the spur gear to a 52 tooth in sted of a 72 tooth. the diffrence between a 2.5 and a 2.5 r is that the 2.5r is a race engin and the 2.5 is not. the diffrence between a 3.3 and a 2.5r is not much but u do not need to change the sure gear on a 2.5r.

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Um, this is not necessary. I actually went to a RRP 73 tooth SG and a 20 tooth CB after putting a 3.3 in my 2.5 maxx. It's a great combo.

Hey I just installed like 2 weeks ago and ran about a 1/3 - 1/2 gallon of fuel through my 3.3 engine on my 2.5R truck. i have no problem running with the stock 72 tooth gear. why do you say go down to the 52? wouldn't that just kill your acceleration and give you a higher top speed?
as for the original poster the 3.3 does have more kick. after i broke in the engine and i was giving it more and more gas i had enough power to filp the truck over onto its back on grass.
I still have everything stock with the drive system and its still in good condition, just has wear and tear from 2 years of driving. replacements of the stock plastic drive shafts are like $7. Though like .21Rc10GT said, you can get the stronger drive shafts and such for pretty cheep. I would recommend rcsuperstore.com, towerhobbis.com and ebay
also i got the 3.3 on ebay for $100

Interesting. ... i went to my hobby shop for a 3.3 piston and sleeve and i saw that the 2.5r had the same part #.

---------- Post added at 8:40 PM ---------- Previous post was at 8:34 PM ----------

Never mind i just checked. 5230X is the 2.5r and the 5230 is the 2.5
There must be a big difference though.

I had a 2.5 and swapped it with the 2.5r and there is a noticable diff in speed between the two. I was gonna go 3.3 but the dude at LHS was explaining the diff between the 2.5r and 3.3. 3.3 has more torque and less high end , 2.5r more highend speed less torque just my 2 cents