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TE SmartCarb

Started by retaRD, July 26, 2020, 12:48:11 PM

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teazer

I am not following that explanation.  The air passes under the slide and the dividers smooth out flow which creates a higher gas velocity and stronger signal.  I get that bit.  But what's this about at the motor side?  It doesn't much matter when the dividers stop but when they do, the airflow will still be more or less as turbulent as if they were not there at all.  Surely?

Except at WOT of course, but at small to mid sized throttle openings, if the passage open up abruptly at the slide or at the manifold, the flow will be just as turbulent won't it?  Or is the theory that flow at the discharge point ( just after the slide) needs to be laminar to also be laminar through the venturi under the slide?

I could see an argument that flow just after the slide has to be laminar, but I'm not sure if fluid dynamics works that way.  In fact using flow restrictors like the AMA used to mandate actually improved flow through the carb body.

Are you saying that the coefficient of discharge improves with dividers with a proportionate increase in airflow before the nozzle (slide)? 

Or is the theory that the reversion waves are trapped and are less disruptive to incoming flow?  Logically that might work if they are on the motor side of the venturi..


racerclam

Whats not to follow? Smaller area means higher velocity. When the dividers are full length of carb and get as close to the reeds or intake port all the more effective . It works . How about a tri power 427 corvette with 3 two barrel carbs of 350cfm each that open progressivly totaling 1050 cfm that works well butif you throw on a 1050cfm dominator carb it wont handle it with out falling on its face , BLAH! because the big venturies have low velocity. You would have to creep up on throttle opening as engine speed was able to move enough air to accept the available air . The point is to have atmospheric pressure fill the cylinder or crankcase as soon as possible while keeping the air moving . Fine line .Again the carbs WORK EXTREMELY well. I hears today from anothee vintage race customer witha 1974 yz 250 who love it , no light switch off on but linear and controlable  power.

m in sc

actually the 6 packs were about fuel distribution in the manifold before manifold technology improved.

However, using another automotive comparison, this always reminded me of the old offenhauser '360' manifolds with the split runners to keep the velocity up.   :twocents: but, its hard to have laminar flow with a slide halfway between the blades. but yes, it will improve the signal at low velocity to get it to build better so you don't stall out at the wider throttle openings.  what is the surface area in the bellmouth of the front of the blade, persay on a 34mm carb? 

the other thing i find interesting is the use of a power jet with the dividers. with the flow directed by the blades straight across, will it go lean w/out the signal going as strong across the lower part of the venturi, and therefore being made up by the power jet(s)? which, is fne, but,  just curious as to what the theory here is.

because, with what the smart carb is driving at is the 'directed' flow at the bottom of the bellmouth by their claims and pressurised fuel bowl helping with the atomization by speeding up the fuel out of the jet tube at higher belmouth pressures.

racerclam

When I instal a intela jet system with dividers the discharge nozzle is below the 3/4 divider and actually contributes to the needle adjustment which is really cool not just wot. And wrong on your tri power theory . I guess you wont really believe it works without trying . We could go on and on , if you dont believe you can ask many of my customers ,

rodneya

The idea of wing type pieces in carbs has been around for at least 50 years. The fact that the very clever people at Mikuni or keihin, or even Yamaha or any other manufacturer dont use them, and the the commercially available versions have retarded names like scary fast leads me to believe the same as them that it is a gimmick with no real benefit. Long story short, id it worked everybody would have it.

teazer

The idea of small carbs for small throttle openings is a well tried idea and is applied in two barrel carbs and of course all those Hondas with oval or figure 8 shaped bores so that at small openings, it's like having a small carb but with an oval carb you get the equivalent of a larger round carb at WOT.  We used them extensively on Honda race bikes to get better part throttle response than with an equivalent WOT Mikuni. 

You still have not explained why the airflow after the dividers doesn't create the same problem as they are supposed to avoid, but I'd like to see the results on a dyno or other objective data as to how they are better and under what operating conditions. 

But to your point, at any particular throttle opening, the area through the venturi under the slide is the same with or without dividers isn't it?

Is it just better tracking between different circuits or actually making more power at some throttle openings?

Jspooner

Quote from: rodneya on July 31, 2020, 11:46:15 PM
Long story short, id it worked everybody would have it.

Wouldn't that be true of any mod...........I guess we all must be wasting our money.
"Just quit brain fucking it and get it done"

sav0r

This thread is like an oil thread. Many people are going to have a preference and it's mostly confirmation bias. Nobody is presenting any data, it's all just anecdotes. The truth is, for the majority of people, just getting whatever carb you have to work reasonably right will mean you are doing great. There are plenty of piss poor carb setups out there.

Does the TE SmartCarb make it easier? Well, nobody here knows because not a single one of us owns one.
www.chrislivengood.net - for my projects and musings.

Jspooner

Quote from: sav0r on August 01, 2020, 12:51:20 AM
This thread is like an oil thread. Many people are going to have a preference and it's mostly confirmation bias. Nobody is presenting any data, it's all just anecdotes. The truth is, for the majority of people, just getting whatever carb you have to work reasonably right will mean you are doing great. There are plenty of piss poor carb setups out there.

Does the TE SmartCarb make it easier? Well, nobody here knows because not a single one of us owns one.

👍🏻
"Just quit brain fucking it and get it done"

m in sc

#39
direct port injection proves my point with the tri power theory.. or ls motors would have had 8 throttle bodies, not 1. I mean, sorry going  to have to disagree there 100%. also why the 440 and 340 Six pack cars didnt in reality make the power the 4bbl cars did. but the manifold tech at the time got much better . inline 6s were the same way.. look at the hyperpack slant6 for an improved intake vs multiple carbs on a traditional log intake. . but 6pack carb setuos are damn sexy to look at. :cheerleader:

regardless, theres many ways to achieve the same goal.  that's the takeaway from all this. I think the big q is, how much better is, if at all, the smart carb vs a well tuned flatslide? and is it worth the much higher price point,  or is it just the bling factor, which does have some merit.   :twocents:

racerclam

You dont have to believe it works . But as I said I have MANY customers who love them and I offer names and numbers of them If you want to grill them . Just cuz the manufactures dont have it dont mean that it dont work . So what is the after market all about ? I guess since port work on a factory machine must be ultimate also , and pipes , if the after market pipes worked then the factories would have them . This is ridiclous. I guess Smoky Unik and Bill Jenkins , Vic Edelbrock just had marketing scams .

Striker1423

Numbers speak volumes in debates like this. For the average rider like myself, what's the point? I'd be happy to be able to hop on a bike and just ride. But that's what the cruiser is for.  The RD is a simple yet highly debated machine on power output, carb setups, etc etc.

What earns the coveted cash in my pocket is what allows me to ride with less tweaking.

m in sc

i believe they work, i actually know a few people who have had it done and speak highly about the mod, for sure.

Fuel systems are like donuts. there's many flavors. Use what suits your needs.  :patriot:

pdxjim

Dyno numbers would be a lot more valuable than phone numbers.

... and I've had RB's divider plates in my TDR carbs for over ten years now.  Really couldn't tell you if they work or not as I did a lot of mods all at once.

The look cool tho  :metal:
Wasting time on 2T forums since the dawn of the internet. '89 TDR250, '13 300xcw, '19 690smcr, '56 Porsche 356A

racerclam

RB dividers are not bad but he didnt take it far enough to achieve the linear power application. Like a power now drop in does some good but not alot it does nothing to keep velocity up past the slide .