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3.0 or .21 conversion

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J

jmcgary

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looking for advise need new engine should i go with 3.0 sirio or .21 conversion any advise would be helpful and greatly appreciated
 
Conversions

The Sirio 3.0 conversion is the simplest way to go as it's a bolt-in replacement for the TRX 2.5 (assuming you do have a MAXX TRX 2.5)
The TRX 2.5 engine mountings, EZ-Start, flywheel and clutch bell all bolt on to the Sirio making it a fairly easy upgrade too.
The kit I got comes with a header, carb and linkages, I also invested in the Sirio big bore pipe, although the standard TRX 2.5 pipe can be used once the stinger has been modified with a 1/4" drill.
The TRX 2.5 makes +- 1.33HP (According to the RCRM Dyno) and Sirio claim their .18 makes 1.99 HP, so technically it's a bolt-on solution offering about 30% more power.

As for a .21 (or bigger) conversion, I havent undertaken one, so I cannot comment.
I am sure Members who have done big block conversion will share their knowledge.
 
The .21 conversion will reek havoc on a stock drivetrain, so unless you have upgraded all that already, I'd go with the Sirio 3.0...
 
Originally posted by ImBroken
The .21 conversion will reek havoc on a stock drivetrain, so unless you have upgraded all that already, I'd go with the Sirio 3.0...
Click to expand...

I have a Sirio .18 myself, winter is kicking in, so I haven't quite found the motivation to install it. Bottom line, I'm in hibernation/lazy assed mode!:sleeping:

I've heard nothing but good things about the Sirio upgrade and some MAXXers claim their Sirio .18 powerplanted MAXXes can hold their own against .21 big bore versions. Of course this depends on what .21 motor you use!
That was the deciding factor that made me buy a Sirio.
 
I've got the Sirio in my Maxx and it rocks. I go out and bash with my buddies about once a week, and every time they are all still impressed with it. One time a guy said "damn that thing is quick", and I just kind of chuckled because I hadn't even cracked 5/8 throttle yet because it was still warming up.
But, I'm sure with a .21 conversion and a strong big block, the Sirio would be no match. Some .21's have close to 3hp nowadays, but to be able to utilize all of that power you've got to upgrade quite a bit to handle it all.
Either of your choices you'll be happy with I'm sure. The .21 conversion will cost you more, will be MUCH more labor intensive (ever replaced your chassis?), and you'll have more power. The Sirio is cheaper and easier.
In the end it just depends on how much you have/want to spend, how much work you want to do, and what you want your end result to be. Good luck, I'm sure you'll be happy with whatever you choose!
 
3.0

thanks for all the advise will probably go with the 3.0 sirio next question is wheres the best place to purchase one (sirio 3.0 )
 
If budget is in the plan, don't even think .21. Sure, it can be done, but how reliable will it be? It might last forever, or it might not.

If I had time to go over, I think I would have just stuck a 3.0 in, instead of converting. I would have waited to convert later on.
 
IMO the best place to get the engine you want is your LHS. I'm all about keeping the business close to home. If you LHS doesn't carry it, is more expensive than they need to be, or if you just don't like your LHS there are a couple of other options. You can go to an online hobby store, you can go mail order (maybe from an ad in a magazine), or you can go E-Bay. You take your obvious risks online. TowerHobbies normally has very competitive prices and I hear there service is excellent.
 
Originally posted by GilBeQuick
IMO the best place to get the engine you want is your LHS. I'm all about keeping the business close to home. If you LHS doesn't carry it, is more expensive than they need to be, or if you just don't like your LHS there are a couple of other options. You can go to an online hobby store, you can go mail order (maybe from an ad in a magazine), or you can go E-Bay. You take your obvious risks online.
Click to expand...

I couldn't find a Sirio motor or pipe here in the UK.
When I found an EBay seller who wanted $185 for the Sirio, he did not ship outside the U.S.!
Fortunately an amigo of mine in Camarillo helped me out and sourced an exhaust. I had the motor shipped from CT to CA and Kevin the owner of BLiND Batteries then re-shipped to stuff to me here in the UK.

At +- $230 (UK£145) it was a bargain as they ask £125 for a standard TRX 2.5 on this side of the ocean.

Most EBay e-tailers are cool, just avoid any with negative feedback.
 

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