Getting more power out of you 3.3

[bluesilver]

G'Day, This might be an old one but then again it could be new. I haven't heard of it before untill somone told me that they have done it.

You take out the original carby and install a .26 size carby like the Force .26 carby.

This really makes the engine come alive. Heaps of bottom end and the top end is just crazy compared to the standard 3.3.
Even makes the modified 3.3 or the modified O.S. motors look tame.

The .26 carby lets more air flow in therfore more power. The temps stay at about the same as they normally are as well. Just drill out the exhust a little more to help the extra flow. It dosn't appear to drink that much more fuel either.

[fjv23]

have you done this?

[bluesilver]

Yes I have. This acually works, I could post some pics if you really want.
I have in the past been running big blocks in my Jato, But after this I wouldn't even go back to them. It makes that much of a difference.

[Desert JATO]

sounds good news ! show us your project,
what is the exact part No. of this carb to make it easer for us ordering it.
is it a direct fit ?

[arceeguy]

This sounds like an interesting modification. Yes, we'd like to see pictures!

I'm suprised that a larger carb made a difference in bottom end. Usually going with a larger bore carb will increase top end breathing, but the bottom and mid-range can suffer because of the "over carburation". A while back I had Chevy with a 350 V8 engine and I did some mods to the engine and bolted a 750 CFM carb to the intake. The engine was really powerful at high rpm, but low and mid range power stunk. A smaller 550 CFM carb greatly improved low and mid end, and didn't take too much off the top end. Sometimes bigger is not always better.

[Desert JATO]

The stock Jato's performance is incredibale,
how about if it became much aggressive ?

i have a new DRZ dirt bike, many advises me to upgrade with a larger carb.
maybe the same thing could work in this case ?

anxiously waiting to see bluesilver's project details.

[rustler.21]

If that is the case then why wouldint Traxxas just put bigger carbs on the 3.3???

[n3.3d_for_sp33d]

Does it really make that big of a difference?

[I know pi!]

can you post a link to the carb you used?

[Desert JATO]

If that is the case then why wouldint Traxxas just put bigger carbs on the 3.3???

in my opinion, Traxxas's engineers knows that more than the stock power of the current jato with it's weight leads only to an uncontrolled RC truck.. maybe in addtion to production plans.

i do believe that those working at Traxxas can easily build an ultra super truck.. but it isn't their goal at least in the time been.

[KyLeader7]

pictues plz. this is kinda the same idea about tx cranks and such..
PICTURES PLEASE

[triton5150]

you can drill out your existing carb, taper the inlet and polish it. i cant remember the drill size but you can only go so far, due to the timing on the crank and porting.

[bluesilver]

Ok here is the photo of the carb.
It is a Force .26 carb. I haven't got any links onwhere you can get them from as I got this one from ebay.

But yes it really doese make a difference.
It is a direct drop in. Just pull the old one out and this ones just goes stright in with no modifications at all.

[Desert JATO]

That's a great job bluesilver
go ahead ...
i wish that anyone would help to tell if it's can be sold on any hobby megastore online. i did search on it at towerhobbies with key word of 26 Force carbuerator but didn't get it.

[FastGT94]

GOOGLE:

Ofna Part 52131
Factory Part 21131(7mm)
CARBURETOR COMPLETE, 7mm 61.95
http://www.ofna.com/pdf/eng-force25-26.pdf
http://www.nitrohouse.com/eng,_force_25_parts.htm

I too would be nervous about bottom end suffering from an overly rich condition brought on by the larger carb... but maybe this one is the ticket and traxxas "de-tuned" the 3.3 for sake of control and durability.

[Desert JATO]

Many thanks fastg94, actualy i did some search by google with key word of Force 26 carb.
maybe twin pipe would be a match for the larger carb.

[FastGT94]

I'd be interested to hear more results before I go spending $50-60 on this. Sounds promising though.

[mIRCmAN]

thats one dirty jato lol

Edited for language

[Desert JATO]

I'd be interested to hear more results before I go spending $50-60 on this. Sounds promising though.

bluesilver already confirm getting good result out his project..
he would also give more comments about it .
for me i'm gonna wait to hear even more. Thanks again for you and offcourse to Bluesilver.

[NOLA JATO]

it only is common sence, a larger carb. is required for a larger engine, the 2.5 and the 3.3 share the same carb and header, if the engine is larger it needs more air flow, every engine is a air pump. in a 1 to 1 car you use a larger carb. and a better flowing exhaust system, these are production engines, it is a cost production reason. in real life 1 to 1 engines a larger engine turning the same rpm's will need a larger carb. and a better flowing ehhaust system to get the full potential out of the larger engine.

[FastGT94]

Correct Nola, however we must also keep in mind that too big a carb (too much fuel or air) can also be detremental to performance if the engine cannot take it all in. For real world, a carb ment for a 454 V8 stuffed onto a 350 won't work too well. (or for you Ford fans, 460 vs 351) lol

Same example here. the 3.3 is about .201 cu in and the carb you're putting on is for an engine rated at .260 cu in, an engine that is 22-23% larger than the 3.3.

Unless the carb for the .26 is too small for the .26 to begin with instead of perfectly matched, the potential risk of installing a carb that is too large for the 3.3 is present. Like I said, its possible this works great but I'd have to hear more positive outcomes first.

[Desert JATO]

if bluesilver would .. he can show us a short video clearing everything here.
the difference in perfromance should be noticed.

[FastGT94]

True, would also like to see a side-by-side with a stock 3.3 jato for a true comparison. Who knows if that is possible though, would have to have a second Jato.

[als_burnout]

3.3 and 2.5 share the same carb right? woud this be some to try on a 2.5?

[arceeguy]

Correct Nola, however we must also keep in mind that too big a carb (too much fuel or air) can also be detremental to performance if the engine cannot take it all in. For real world, a carb ment for a 454 V8 stuffed onto a 350 won't work too well. (or for you Ford fans, 460 vs 351) lol.....

This is the point I was trying to make earlier.

While I didn't have problems tuning the 2.5, many have reported that the 3.3 is much easier for them to tune than the 2.5. The theory is that the 2.5 was a bit over-carbureted with the big bore carb, and that it was a better match for a larger displacement engine. So while this .26 carb physically fits in the 3.3, it *may* introduce low-mid range problems at the expense of top end power. But then again, maybe not because we have at least one happy user. You never know, he may be on to something!

[KyLeader7]

ide need a video before i buy it..
video plz!

[bluesilver]

The jato is a tad dirty as it is used on a clay track and it is a bit wet at the moment.

You are right about the two carbs being the same for the 2.5 and 3.3. So I figured that the carb on the 3.3 is a bit restricive.
The .26 carb seams to be matched pretty good for the 3.3.

I am only runing 25% nitro with about 14% oil and the bottom end performance is roughly 1/4 or a tad bit more punch than the stock carby gives
I haven't had the chance to open it right up to full throttle yet.
I am going to but a larger manifold on it over the weekend to see if it improves it any more.

Sorry I can't post some videos as I am not sure how to go about it plus I will have to find a video camera.

But if you find one going chaep on ebay it is worth trying out. There was one on there but ended 2-3 days ago.

[Desert JATO]

Thanks 4 the addtional info. if u got the chance one day
use a mobile phone video cam... no need to buy a Video camera.. goodluck.

[FastGT94]

FYI, the PICCO .26 carb is a different size (9mm)

[Desert JATO]

i don't have that much exp. in that field, but as long as he
mentioned that it's a direct fit , so may be he's reffering to the
same part or an equivalent to the 1 you posted up.

[FastGT94]

He's definitely referring to the .26 FORCE carb but I wanted to point out that Ofna also makes another .26 enging called the PICO and I wanted to point it out that the PICO carb is a different size (even larger)

[bluesilver]

Good point there. Didn't even know they had a different size carb.

The base of the one that I used is the exact same size base as the Traxxas carby.

Fits in there just as well as the original one doese.
Tunes well. Will stay on idle happly. Holds a tune well.
Can't really say much else except I tried the larger mainfold last night and wouldn't fit the 3.3 motor exhust. So for now I am just going to leave it with the Dual chamber pipe that has the stinger drilled out a bit.

[Desert JATO]

no one advised for this before , but you might think of it one day..

http://www.rdlogics.com/cgi-bin/cate...egory=Exhausts

[Brent Davis]

Great find and mod bluesilver but will advise "ALL" of you with the stock 3.3 engines, your stock rod will not last too long as they are very thin up top near the piston. Don't ask me how I know this.

RBmods.net has the rod fix for that as they custom make a lighter billet rod that has the beef up top where the stock Traxxas rod doesn't. Buyin this rod fixed my broken rod issues. I will go and get one of these carburetors and test it on my complete RBmodded 3.3 that has already been 90 MPH in a 4-tec with the stock carb. WOW am I excited to try this out.

Here's the link to the RB rod.

https://rbmods.net/rbshop/product_in...d0845c54682fb6

[Desert JATO]

thanks Brent for that new info, but the $$ of it is beyond anything.

[Brent Davis]

thanks Brent for that new info, but the $$ of it is beyond anything.

Yeah uh hugh, like a new engine I guess ? I assume that you are speaking for yourself though as some may find it interesting to do no matter the cost.

It's just a heads up. If you get more power out of that little 3.3, then you are also asking the rod to be up to the task as well.

[arceeguy]

Great find and mod bluesilver but will advise "ALL" of you with the stock 3.3 engines, your stock rod will not last too long as they are very thin up top near the piston. Don't ask me how I know this.....[/url]

The majority of drivers do not have any problems with the connecting rod. I have had them last many gallons of fuel without any problems, and others I know have had the same experiences. Many times, when someone posts pictures of a broken conrod, you can see that the failure was due to abuse. (blackened and burnt rod ends, piston skirts, etc.)

Traxxas does recommend that the rod be inspected periodically and replaced when necessary, most people do not do this, which could explain some of the failures.

[Brent Davis]

LOL.

GUYS! The point about the rod is this thread is telling you how to get more power from your 3.3 engine. Due to it making more power/torque, the stock rod is in jeopardy. "BEEN THERE, DONE THAT"!

Traxxas does recommend the inspection..............for your "STOCK" 3.3 with the "STOCK" carburetor. This topic is about putting a bigger carb on it for what?????? MORE HORSEPOWER.

I'm not here to argue at all. I just wanted to point out what I did with 2 different 3.3 engines before figuring out that the stock rod was the culprit both times up top. Both engines were modified with ported sleeves and ported crankshafts with the silicone insert. My 4-tec went from stock 3.3 engine 68-70 MPH to 88-90 MPH with the engine modded, THS header but a big block Fusion pipe with the baffle taken out. Once the RBmods.net rod went it, I ran it as hard as I could and the rod never let go again.

Good luck to all and I will report back when I get a .26 carburetor for my 3.3 engine.

BTW, arceeguy, "your signature speaks "VERY" loud about this issue"

[bluesilver]

Thanks for the info on the rod.
Must look at mine now that you have mentioned it.
Thanks.

[arceeguy]

I'm not here to argue either, but telling everyone they need a $225 connecting rod for a $150 engine is a little over the top. I run my engines stock, but know a few who have modded 3.3's with stock internals and no problem.