At Italianiron, and as a result of our intensive Research & Development, we have acquired a new perspective as it relates to our preference for the use of our SmartCarb Flat-Slide carbs over fuel injection for many modern and vintage motorcycle applications such as our TT 1000. The first advantage that our flat-slide carbs have proven to provide is that due to the "pressurized" float bowls of our 36 mm SmartCarbs, we get linear "injection" of the fuel mixture into our engines much like electronic fuel injection and without the need of an ECU!! Further, we have found that once we have the carbs "set", we do not have to spend additional time adjusting them based upon any atmospheric changes. Different race series internationally that allow Ducati 1000 cc two valve engines do not allow injection and with our SmartCarbs we have found that not to be a penalty but a benefit!!
Our 36 mm SmartCarbs are more than sufficient in providing the volume of fuel mixture to meet the requirements of this big 1000 cc engine that was shown on the dyno runs posted in earlier blogs. As mentioned in these earlier blog posts, the other technical benefits of the SmartCarbs are a 30% saving in fuel consumption, 6 to 14% improvement in HP, adaptability to altitude and other atmospheric changes, ease of adjustment and 80% less hydrocarbon emissions. Also, there is no need for expensive ECU's or sensors required to perform fuel management. We have found for both modern and vintage Ducati twins, that our SmartCarbs are not just equal to, but superior to injection as a complete "value proposition" when looking firstly at costs:benefits of each method. A set of SmartCarbs is less expensive than the combined expense of ECU, electronic sensors and throttle bodies with injectors.
It is widely understood throughout the automobile industry, that carburetors deliver higher horsepower and torque numbers in side by side comparisons than fuel injection. In tests where catalysts are removed, it becomes very apparent that fuel injection is neither cleaner nor more efficient when compared to carburetors. There is a reason that US Pro Stock gasoline engines still use carbs and NASCAR initially refused to use fuel injection. NASCAR ultimately adopted fuel injection as a means to control the enforcement of race class rules, not due to performance!! A self-adjusting, very finely vaporizing mechanical fuel system will improve both performance and durability without unwanted complications and expenses of fuel management systems such as fuel injection the automobile industry has determined.
It has also been proven that carbs have an intrinsic "Qualitative" advantage in their design that creates a proactive or pre-atomization of the fuel mixture into our race engines. This is an important benefit as gasoline does not burn efficiently (as discussed in the 12 Oct 19 blog post) as its energy potential is "harnessed" inside of its liquid form. As such, the benefits of carburetion over fuel injection cannot be overstated. Through the use of carburetion, our SmartCarbs have the ability to emulsify fuel with air prior to entering the engine unlike fuel injection. Please find the photo below where the atomization of the fuel mixture is almost completely vapor and that process begins significantly early before it enters the intake tract of the engine. It is therefore, mixed and ready to combust.
This is considered a "wet-flow" system where the finer vapor and shorter duration of time that the fuel mixture has before delivery into the engine creates an opportunity for cooling of both the engine and the intake tract. This process allows the fuel to vaporize even more thoroughly than if this raw liquid fuel was just injected directly into the inlet or straight into the cylinder as found in fuel injection systems. Additionally, the engine will also run cooler and quieter while achieving superior fuel economy by using carburetors as efficient as our 36 mm SmartCarbs.
As mentioned in my previous blog post (12 Oct 19), the inherent benefit of fuel injection is its ability to digitally control the amount or "Quantity" of the fuel spray as shown above but not the Quality of the fuel spray. The topic of "Quality versus Quantity" is at the heart of our discussion as to why we deem our SmartCarb system to be superior to fuel injection in the majority of applications using our Ducati engines. "Fuel components, being heavier than air, tend to cast out and away from the swirling air mass that is trying to mix with it," according to the Technology Elevated engineers as illustrated above and below. In the picture below, fuel exiting the injector remains in a very liquid, globby or "sticky" state in comparison to the photo (second photo above) of the SmartCarb where the fuel mixture is vapor and nearly completely invisible.
This visual result from an injector should not be a surprise as fuel is 600 times heavier than air by volume. Shown below is a CFD simulation of the same injection process showing the fuel mixture returning to a liquid state shortly after injection. In the previous blog post (12 Oct 19), I shared my experience at the race track after replacing the fuel delivery system (carburetors in that example) of my race bike with an even larger system. As a result, I had a miserable race day as I was literally "drowning" my engine with too much liquid fuel. This was also after numerous practice sessions where I was trying different adjustments. I can only imagine that like in the image below, my flawed theory of "bigger being better" directly resulted from my taking the Quantitative approach of "dumping" too much fuel into the engine on that race day. I learned that day the importance of taking a more Qualitiative approach of "flowing"the correct fuel:air mixture and in the optimal volume. As stated in earlier blog posts, our research has proven time and time again that the healthier the engine, the leaner the carb settings can be.
Our experience has also proven that our 36 mm SmartCarbs maintain consistent linear delivery of the fuel mixture like injection as demonstrated by our dyno runs. Further in comparing SC's with other carburetors, we have found that we can get more performance out of our flat-slide carbs in a smaller size to better match inlet size. According to the Technology Elevated engineers,"the SC’s flow more per size than our round venturi counterparts, and due to the fact that they are a single circuit, they appreciate the increased velocity that a slightly smaller throat size affords. They still make more peak power than the stock carbs, but the bottom to mid is where the real improvements are". We are getting better performance from a 36 mm SmartCarb over a 41 mm Keihin FCR for example. I will provide those direct results in a future blog post.
Current benefits of SmartCarb technology exist for a wide range of Ducati twin and single cylinder applications as a superior option to fuel injection that has been until recently a very prolific, yet now dated technology. It is also interesting that many international vintage race series are requiring the use of carbs over fuel injection. Shown below is our TT 1 with race-prepped Ducati 750 cc engine with 13:1 high compression pistons, flowed and dual plug heads that love the performance gains that our SmartCarbs provide. For more on our day at the dyno with our TT 1, please check out my 3 Nov 19 blog post.
The science and technology of the SmartCarb fuel system is leading the way to an entire new market of “Smart Carburetion” systems. Come and experience the "pinnacle of carburetor technology" at Italianiron.com and Technology Elevated.
Share this post