Got myself a traxxas Revo 2.5!!

[bearster18]

Been out the Rc world for quite a few years. Let's just say it was when a .21 conversion on the tmaxx was all a custom type install. Like no chassis was available so I took my ofna hyper .21 and made it custom. Then of course the super maxx stuff started coming out and I jumped on one of those!

Just picked up a used revo 2.5 this weekend for only $180 with remote and all. Has been used pretty good but overall in good shape! The 2.5 is a bit tired however. So I've been searching around you guys forums, which are awesome by the way, and trying to find a good drop in replacement.

I thought about trying to do the traxxas upgrade to power to the 3.3 engine but I hate the tuning issues I had with my old traxxas stuff. Then upon research ran across the picco .26 drop in replacement though now I see that was is discontinued.

Now I've been a fan of ofna issues has my hyper .21 was a breeze to tune and reliable. So I'm come across this ofna .28 MAX. I'm seeing mixed reviews if it drops in or not without a lot of upgrades.

Would I need to upgrade a lot with the ofna .28 max or not? Would the driveline hold it? I do know it needs motor mounts to install.

Don't mean to come on here possibility asking a beating to death question but just want a sure thing answer. Thank you guys and look forward my time here on your board!


Thanks,
Dan

 

[hulkmaxx]

The Ofna .28 is a beast! I would recommend the new Picco .21 maxx. More RPM better quality. I am still running the older Picco maxx .21 engine and it carries more speed than my buddies maxx running the Picco JL red dot .26. Heres a pic of the new Picco maxx .21

View attachment 13308

 

[bearster18]

Pretty awesome specs on that .21 p-max! Does that bolt on to existing engine mounts?

 

[hulkmaxx]

You would use the same mount as the Ofna .28 maxx engine. Pretty sure all the Ofna and Picco maxx upgrade engines use's that mount. I am running the Ofna Picco in my old 2.5 Revo. I also am running one in an old beater #4910 short chassis maxx. My buddies running the new .28 ofna in his #4907 maxx and my old .21 can overtake him at top speed. I am still on the old style black trans also so he has better gearing than I also.

 

[bearster18]

How is your driveline holding up?

 

[hulkmaxx]

Well the stocker 2.5 diffs held up pretty good, but I do a complete tear down and clean and inspect and shim my diffs about every 7 or 8 runs. I was running the stock 2.5 axles and drive shafts for about 4 runs first WFO bash session I exploded the rear and front drive shafts. When I tore it down I also noticed the rear axles were twisting like a pretzel LOL! On my revo 2.5 running the Maxx .21 I have been running the stock driveline forever with little problem's. I would recommend a good set of steel CVD's with any after market engine making more UMPHH LOL!

 

[bearster18]

Thinking about ordering up some center CVDs as well for a cheap insurance as well. Only problem is this, I highly doubt the 2.5 and 3.3 revo chassis has the same center shafts. Hate to continue being a pain but do you know of a place to get the centers for a 2.5?

Also planning on ordering the 17t clutch bell as well. Was thinking of the 36t spur gear but all I can find is a plastic one. I found a 37t steel spur would that be adequate for just bashing around?

 

[Snook Man]

THS makes a good set of Center cvd’s for the 2.5 Revo.
Stick with the plastic spur; it is more than adequate for any engine you can install on a revo. If you strip a plastic spur, there is a reason other than engine power as to why.

 

[bearster18]

Excellent thank you!

Are the 2.5 revo and 3.3 revo CVD axles the same length in the event I need to get some cvds?

 

[Snook Man]

Wheel axles are the same. Only the front center shaft is longer on the 3.3 compared to the 2.5

 

[bearster18]

Thank you Gentlemen! Pretty friendly board you guys have around here.

 

[bearster18]

well here's some parts I ordered today for it-
Ofna JL .28 Max 1
Ofna Engine Mount
Traxxas Clutch Bell 17T 1
Traxxas Spur Gear 36T
Duratrax LR3 Glow Plugs
STRC Clutch Shoes/Flywheel Set

Ended up going with the .28 ofna since its a reasonably priced engine and seems to get good reviews.

 

[Snook Man]

If the tranny still has reverse, dont forget the FOC. You will need it eventually. RRP would be even better.

 

[bearster18]

the RRP steel gears? does that retain reverse or is it an FOC too?

 

[Snook Man]

I don’t think RRP has reverse gears for the Revo, unless you’re physically handicapped and need it you will become a better driver quicker without reverse.

 

[bearster18]

edited

 

[bearster18]

Went ahead to cover my bases. Just ordered some THS CVDS all around, centers and sides. Along with a RR steel FOC.
I remember tearing crap to pieces in my .21 maxx so I guess just bracing myself.

Can't wait to get all this installed!

.28 ofna engine
ofna engine mount
STRC aluminum 3 shoe clutch setup
traxxas 17t clutch bell
traxxas 36t spur
RR steel FOC
THS hardened steel center and side CVDS

Should be setup for some fun bashing around!

 

[bearster18]

Got the engine and all installed. Well the pull start doesn't want to pull back In on the Jl .28 ofna engine sooo. Back to square one with irritations with this hobby. Hopefully ofna gets back with me soon.

 

[Nitrotrout]

Could it be the screws attaching the pullstart to the back plate are too tight?
Try backing the screws off a bit. If it frees up, use some blue Loctite on the screws
and let them cure.

 

[bearster18]

Sending p/s unit back to ofna for warrantying out. I firmly believe its the one way bearing. The ps unit seems to be super smooth in operation off engine but the one way makes me curious though. Guess we'll see when I get my new parts!