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-Pete LRRS/CCS #81 - ECK Racing, TonysTrackDays
GMD Computrack Boston | Pine Motorparts/PBE Specialists | Phoenix Graphics | Woodcraft | MTag-Pirelli | OnTrack Media
The Garage: '03 Tuono | '06 SV650
You should have heard my Mom repeat the team name Mike Hawk in the Wind over and over this weekend when Peter Kates kept asking about it. Soooooo funny.
You can take the girl outta Jersey.....
USCRA #75
Street- 03 Suzuki SV650
Track- 71 Honda CB350
Hooooly shit, that's hilarious... Who deserves a high five for that name?
-Pete LRRS/CCS #81 - ECK Racing, TonysTrackDays
GMD Computrack Boston | Pine Motorparts/PBE Specialists | Phoenix Graphics | Woodcraft | MTag-Pirelli | OnTrack Media
The Garage: '03 Tuono | '06 SV650
-Christian LRRS/CCS HasBeen ECK Racing
2011 Pit Bike Race CHAMPION!
2nd gen SV is fuel injected. The compression ratio is the same as the 1st gen, but the 2nd gen has 9 ponies more. That means that the 2nd gen runs leaner and has a cam tuned for that. That's how you make more horsepower while going EFI, by shifting from a a conservative and somewhat rich calibration (carbs are dumb devices compared to EFI) to a leaner and hotter one.
2nd gen runs hotter, that's why the oil cooler was added. Removing it would be ill advised. Suzuki engineers knew what they were doing when they added it. They probably had to make their case for adding it to the corporate beancounters. It's there for a reason, don't mess with it.
If you want to save weight on your track SV - get a lithium battery and an aftermarket rear subframe, lose the tail. You'll save a lot more weight, and you will do it up top where it matters. That oil cooler is mounted low enough, it wouldn't materially affect your handling even if it were made from Lead or Depleted Uranium.
Chop half of your subframe off. Should weigh about the same, and it doesn't cool anything.
LRRS/CCS Amateur #514 / RSP Racing / Woodcraft / MTAG Pirelli / Dyno Solutions / Tony's Track Days / Sport Bike Track Gear / 434racer / Brunetto T-Shirts / Knox / GMD Computrack
Even the most sophisticated carb is a very inflexible way of metering fuel/air mixture. At the end of the day it's a mechanical device, and the only way to make it flexible is to add actuators and electronics to it. At which point you might as well do EFI. Unlike modern engine management systems, carbs don't affect your ignition advance in any way. You can dial in a carb to perform well on one dimension (say produce max power at certain RPM). But then you may get bad emissions, poor fuel economy and less than optimal power levels at other RPM ranges. So you end up compromising everywhere to get some "middle of the road" calibration. EFI allows you to dial the calibration exactly right, if you know what you are doing. There are tables for ignition advance and fueling. If you put the correct values in them, the engine will run much better than it ever did with carb.
Motorcycles, and particularly twins have some unique challenges with EFI. Because the air gets sucked in unevenly, in a pulsating fashion, measuring the amount of air accurately is difficult. We are in 2018, and this problem was solved well over a decade ago.
(not because drama, but because this just turned into a nerd discussion on an interesting topic. )
Last edited by OreoGaborio; 08-15-18 at 05:19 PM.
-Pete LRRS/CCS #81 - ECK Racing, TonysTrackDays
GMD Computrack Boston | Pine Motorparts/PBE Specialists | Phoenix Graphics | Woodcraft | MTag-Pirelli | OnTrack Media
The Garage: '03 Tuono | '06 SV650
Interestingly, most of what you've said is pretty much... wrong.
On carbs not controlling ignition advance, yup... generally speaking ignition advance is controlled by... the ignition system. You can use a TPS or other sensors to add more inputs to the ignition if you want, just the same way you do with an EFI setup. The primary difference between a carb and EFI is EFI is an indirect system, you infer what the engine is doing based on various sensors, slam that data against a predetermined base map and fire the injector based on what the final mash up guesses. After that you then observe the after effect through another series of sensors and deduce trims to try and hit ideal sensor readings. A carb is a direct system, the act of the motor drawing an intake charge operates the system, it's response determined by jets, needles, or other means.
Carbs are FAR from inflexible, or only tunable for one dimension but if your only experience with them is cost reduced mass produced untuned, likely out of sync CV carb banks from the 80s I can see where you'd get mad at them. (Just like many get mad at overly lean out of the crate Alpha-N EFI setups on many bikes.) I suggest you do some research on the topic, carbs are still being developed and improved. Also remember that 'carbs' covers multiple technologies and systems, not all work off the same principles as a needle/jet/multiple metering circuit Keihin. At the moment carbs still hold the crown for atomization quality over piston valve injectors for example. It's also hard to argue with the simplicity of them vs EFI.
At the end of the day though, unless you're up on the latest developments out there, you're better off avoiding bad blanket statements and just sticking with something more defensible and accurate, you prefer EFI. I'm a digital nerd too and geek out over the possibilities of monkeying with ECU code in EFI, but if money wasn't an object, it wouldn't be EFI I'd be engineering for my FZR to replace it's flatslides...
Controlling ignition advance alone without accurately controlling the fueling will never get you the same result as controlling both. That's why it's called an engine management system. A modern engine management system, in addition to ignition and fueling also controls how much air gets in and when (electronic throttle) and when the valves open (variable valve timing). 20-30 years ago electronics were expensive, so we had to live with horrible complex mechanical carburetion systems. Adjusting a 1970s vintage 4 barrel Solex (metric Rochester variant) is an exercise in frustration. The damn gadget is too complex and simply incapable of running right with any amount of wear. Any attempt at making a carb flexible has invariably produced overly complicated mechanical system that was ultimately unreliable. So, yeah, you can't make them flexible and reliable at the same time. Today I can buy a computer for $25 that will be the size of a pack of cigarettes and has more compute power than 1980s vintage high end mainframe.
Since NESR is a motorcycle forum, I will skip the altitude compensating aircraft carbs and other exotics. Due to weight limitations motorcycle carbs are inherently simple devices. They lack the following:
- ability to compensate for atmospheric conditions (air temp, barometric pressure, etc.)
- feedback loop adjusting the mixture based on actual objective measurements of the combustion process (oxygen sensors)
- ability to compensate for engine wear, air leaks and etc.
- ability to compensate well for engine temperature during warm-up
The idea that fuel injection is inferior because it's somehow "indirect" is ridiculous from the engineering standpoint. Engine management systems measure the outcome and react. It's called "closed loop operation". When the sensors are shot the system falls back on "open loop" strategy, which is closer to how a carb operates. The equivalent of the calibration tables in a carb is the mechanical properties of the various parts (venturis, jets, etc). So it's just like tables in the ECU, except more difficult to change and with less flexibility.
When it comes to atomization, guess how much I care? Not at all. The atomization that can be achieved with today's injectors is more than adequate. I don't care for improvement past "perfectly adequate", because there is no need for that.
What I do care about is the combination of breathing and combustion chamber design. At the end if the day, the spark-ignition internal combustion engines are knock limited when it comes to power. Being able to control spark and fuel in a flexible way enables combustion chamber designs that would never work with a carb. And that's why a 2nd gen SV makes 9 ponies more than the 1st Gen. That's also why a laundry list of 70s and 80s vintage cars make 10-20% more horsepower out of pretty much the same engine by going fuel injected. Case in point: fox body mustang. Once the clever and resourceful engineers at Ford shitcanned the carburetor and went EFI they could bump up compression from 8.4 to 9.2. basically they "found" 80 extra ponies out of the same displacement by going EFI. So, why didn't they simply bump the compression up with a carb? Because it would detonate on pump gas, that's why. The only way to make a carbureted engine run with high compression is adding TEL (tetraethyl lead) to fuel. Which by the 1980s was illegal, and for a good reason.
Again, go look at what's being done with Lectron style designs. Far fewer parts than a traditional carb, MUCH simpler tuning, AND at least one version (Smart carb) does do altitude / temperature / pressure compensation, engine wear, etc via it's direct operation. They've got variants that also can be adjusted realtime via O2 sensor feedback to further dial them in.
On the atomization front, you should care, better atomization directly translates to power and efficiency.
We're not stuck with 1950's amals any more.
Can we specify the laundry list of engines that produced 10-20% more power? I ask because 70's and 80's vehicles were notoriously choked out by the advent of the catalytic converter and those engines made 10-20% less power for a number of years. I'm curious to know if I've been misinformed this entire time
Wasn't it Honda who took an Oldsmobile V8, late 70s IIRC and put their swirly combustion chamber tech to it and got it to meet emission standards without a cat or the crazy emissions plumbing of the time? Possibly more power too, carb'd?
I remember early 80's Dodge 318s being rated for a whopping 150hp...
Holy shit! Full blown nerd battle!
LRRS/CCS Amateur #514 / RSP Racing / Woodcraft / MTAG Pirelli / Dyno Solutions / Tony's Track Days / Sport Bike Track Gear / 434racer / Brunetto T-Shirts / Knox / GMD Computrack
LRRS/CCS Expert #820 / RSP Racing / Woodcraft / MTAG Pirelli / Dyno Solutions / Tony's Track Days / Sport Bike Track Gear / GMD Computrack /
Mercedes M110 (6 cyl, 2.8L 2 valves per cylinder, DOHC). High compression no-cat Eurotrash carbed version: 160 Hp. High compression Eurotrash version with K-Jetronic (mildly retarded mechanical fuel injection system) - 185 Hp. For low compression versions for US market subtract 10-15 Hp from both figures.
BMW M30B28, Carbed version - 168 Hp, fuel injected - 181.
BMW M30B30 Carbed - 177 Hp, Injected - 197 Hp
Volvo B19A Carb - 97 Hp, B19E injected - 117 Hp (both with 8.8 compression, to be fair)
Volvo B21A Carb - 100 Hp, B21E injected - 123 Hp (both with 9.3 compression, to be fair)
It's a very long list, I am too lazy to type it all up. Lots of Euro engines from mid-70s to mid- and late-80s fall into this category. These were the last Euro car engines that were available with the carb. The later engines were only available in fuel injected form, so no comparison can be done.
Omg my brain hurts now.
None of this "smart carb" stuff is new to me. I have seen it all in the early 1980s 3-series BMWs. Basically they replaced a whole bunch of mechanical and vacuum operated regulators (like opening secondaries for instance) with electronic actuators. The "smart" carb had all the complexities of the fuel injection system, without any of its advantages. It had the same horsepower as prior "dumb" carb designs, except it could pass emissions. Fuel injection still made more horsepower on the same engine, even the dumb mechanical one (K-jetronic). The cost of "smart" carb was similar to EFI, so they only made these clunkers for a couple of years before getting rid of carbs and going all EFI.
Again, I'm not talking 80's tech (Smart Carb FYI is not a tech, it's specific brand name under the Technology Elevated umbrella, didn't exist until the 2000s) I'm talking about continued, modern development. You're operating based on outdated info, which is why I'll repeat - Do some research before making broad blanket statements.
The "smart carb" SmartCarb – Technology Elevated looks like a good ol' flatslide carb with the float chamber "pressurized" by the intake air. I don't understand what physics would enable this gimmick to match the performance of a modern engine management system. The manufacturer's site offers not explanations at to why, just states that it's awesome. This carb seems remarkably similar to the technology available in 1940s. What is the physics that makes it work?