Pro .15 upgrade...advice needed

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bleugt

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I know this has been discussed a lot, but my situation is a little different. I have already widened my truck with 3.3 a-arms, axles, turnbuckles and carriers. I am sick of the .15 engine and would like to upgrade. Every time I get my truck out I end up getting pissed off and then don't touch it for a year or two. My .15 engine only has roughly 15 tanks ran through it but I can never get it to run right. I have read that this is one of the worst engines to tune.

I would like a new engine for power and hopefully for ease of tuning. I have been looking at the OS .18CV-RX as I have heard that it is a direct drop in replacement. How is the power compared to the TRX 2.5r or 3.3? I realize that I would lose the EZ start, but I'm not a big fan anyways.

Since I already have most of my truck converted with 3.3 parts, should I just get new drive shafts and go with a 2.5r or 3.3?

At this point I would like the easiest engine to tune with more power than the .15. I am determined to get this thing going again...its been too long.

Any help is greatly appreciated!
 
the 3.3 and os are both great motors... os engines can be really picky to tune.. i prefer the trx 3.3 to the os 18 and have run both engines.. avoid the 2.5r
 
If you like a Traxxas mill over an OS, there's something wrong with the OS. OS engines are built to tighter tolerances and are overall higher quality engines.
 
The only reason i prefer the traxxas mill is for ease of tuning.. the os's can be EXTREMELY picky.. and the OP directly stated he wanted an easy to tune motor
 
I've had experience with 6-7 Traxxas mills, all fairly easy to tune. And the OS makes them seem like rocket science. Hands down, the OS holds a tune better and is easy to dial. Traxxas engines are known for being finicky.
 
Thanks for the help guys. I've been researching the OS 18CV-RX and I am hearing nothing but good things. I think I'm going to pick one up real soon.

Will I need to convert my tranny to forward only with this engine?
Can I use my current exhaust off the .15 with the .18?
Also, I need a new gas tank - will one from a 3.3 fit mine?

I appreciate the help!
 
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You'll definitely want to foc your tranny. It'll be a lot smoother and stronger. You'll want to pick up a header and exhaust that is matched to your engine. I think all versions of the Maxx use the same mounting patterns for the tank.
 
Hi, I just noticed the OS .18CV-RX on sale from towerhobbies.com today ($139). I have one in my original T-Maxx, and it was easy to install, although I did have to make a new throttle link as I opted for the rotary carb version.

I don't like how the new link goes over the spur so I've ordered a slide carb and associated parts, but haven't set that up yet.
 
wow dude you sound like you are going thru the same damn thing i am. I also am upgrading my .15 pro and was set on the 2.5, but found a os 18 today at the hobby shop for $130. Plus i need a new tank....lol
 
The only thing about os motors is that if you want a pull start its like 35-40 bucks
 
ya thats true. It comes in handy some times but some times its a pain to carry around
 
Dynamite makes a direct fit for the tmax---http://www.dynamiterc.com/Products/Default.aspx?ProdID=DYN0700
 
DO not waste your time on a 2.5 or 3.3 you'll be plenty happy with the os motor....like most ppl with experience say...Traxxas motors are garbage they never hold a tune for long at all......but its all on what you want to spend
 
Thanks for all the help! I think I am sold on the O.S. 18 CV-RX.

Is it true that I need two 3.3 rear center axles for both the front and rear of my .15 truck?
Can someone confirm if this is the correct FOC kit I would need? http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXCNA8&P=7

Please let me know if there is anything else you guys would recommend I do while my truck is torn apart. I'm trying to gather a list so I can order everything at once.

Thanks again!
 
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Before you blow money on that engine, you might wanna look into the pro .15 to 2.5 conversion kit, (side exhaust to rear exhaust). It converts your maxx to accept a rear exhaust engine, of which there are tons of choices! Comes with a pipe and manifold too. Rear exhaust engines make more power than a side exit.

Traxxas mills are decent, they just need more lovin than other engines.....Get a OS, you'll be glad you did.
 
Before you blow money on that engine, you might wanna look into the pro .15 to 2.5 conversion kit, (side exhaust to rear exhaust). It converts your maxx to accept a rear exhaust engine, of which there are tons of choices! Comes with a pipe and manifold too. Rear exhaust engines make more power than a side exit.

Traxxas mills are decent, they just need more lovin than other engines.....Get a OS, you'll be glad you did.
I was actually going to buy the conversion kit anyways since I want a slide carb. I was planning on the OS 18 CV-RX slide carb version.

What engine would you recommend?
 
I was actually going to buy the conversion kit anyways since I want a slide carb. I was planning on the OS 18 CV-RX slide carb version.

What engine would you recommend?

That'll do! Anything more and you'll be poppin' alot of driveline parts. That engine will be reliable and should make a good bit more power than the pro 15.
 

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