Day 2 of the Advanced Engineering Technology Conference (AETC) continued the 2011 theme of the latest advancements and developments in engine performance technology by attacking a variety of themes. Throughout the day we would hear issues discussed like, advanced airflow technology, advanced EFI strategies, tightening emissions standards, advanced filtration strategies, and NASCAR valve train design and development.
If you missed our opening day coverage you can read it here
I want to make parts that people win races with – Rick Roberts
Roberts explained to everyone how he approached designing intake manifolds, “On the surface, designing a intake is just a basic plumbing exercise.” He explained how ultimately an intake manifold is simply a way to connect the throttling device to the heads. He went on to show us how Edelbrock builds an intake manifold:
- Select basic layout (EFI or Carburetor)
- Determine cross-section area
- Determine runner length
- Determine Plenum Size
- Select area, length, and plenum to best meet the goals for the engine. (power, torque, rpm range)
When selecting the basic layout Roberts noted a interesting effect that the EFI systems have created. “EFI takes the cuffs off of us as far as the design we can use for the intake manifold. Their is a lot of possibilities there. ”
He would then go on to show the crowd just how complex and how crucial having the correct intake manifold is to your success. “We all know it’s possible to get more than 100% Volumetric efficiency. But how does that happen? The intake manifold. Think about that, we are forcing more air into the engine than if it was without the manifold and the pistons were just sitting there turning,” Explained Roberts. But just how much more? “In a race engine we have seen 110-115% volumetric efficiency.”
Roberts presentation was built around designing a intake manifold for a 565 c.i. BBC with a 4.600 bore, 4.250 stroke, and with 15/1 compression. Roberts would show how they built the intake manifold for the big block by four steps.
- Determine cross-section using a 300 ft/sec average over 180degrees fill duration.
- Determine runner length using the Engleman tuning equation and plenum size using the refined two spring model.
- Linear results yield resonant engine RPM but simulations are needed to determine the amplitude of VE increase.
- Accurate dyno experiments and on track testing provide the feedback needed to make the simulations more accurate.
Up next for the crowd was Lance Ward from Fuel Air Spark Technologies. Lance has an extensive background in computers, motorsports, and fuel injection systems. He has worked for Digital fuel injection, FP performance, and Speed-Pro Electronics before coming to FAST as their Senior System Engineer. Lance is also the lead design engineer for the FAST XFI engine management system that he discussed with the folks in attendance.
Lance began his time on the podium by explaining the different types of Superchargers, Turbos, and Nitrous Oxide Injection. Ward would lay out all the specifics, benefits, and caveats of each system. He would also touch on the different nitrous oxide injections available. He would spend a lot of time explaining all the benefits and issues with each system so that we could understand later how exactly you could tune the XFI engine management system to battle these issues.
Lance would showcase the FAST XFI engine management on screen and show us just how to use the program. The XFI has provisions for the use of power adders. There are for separate stages of power adder control. Each stage incorporates a switched output control signal to turn on a given external power adder device. Each stage also allows for changes to fueling and ignition timing using a variety of control strategies. “In order to get the boost up quicker, and avoid turbo lag, we can actually program that into the XFI to speed up the spool of the turbo.”
The XFI has different modes of traction control, one of which is the heuristic approach. operates by manipulating the timing. The XFI will monitor the driveshaft acceleration live, and as it detects wheelspin it will start to pull timing out of the engine until the wheel spin stops. “The first test we had was a 1600 hp Camaro with Drag radials. The Driver responded that it was as safe as he ever felt in the car,” explained Ward. “The other benefit is once the system is enabled it works all the time, in any condition.”
Ward would finish off his time on the podium by reminding us that traction control is still not perfect, “I truly believe no traction control is perfect, but this software allows you to at least be able to salvage a run.”
Speed is a certified lubrication specialist and spoke to the crowd on the tightening emissions standards and the impact on performance lubricants. Speed explained that since 1993 motor oil has seen some changes, “Before 1993 Zinc & Phosphorus content in the oil was unlimited, but phosphorous degrades catalytic converters. Because of this Zinc and Phosphorus now limited to max 800ppm in for 10W-30 and lower. This has caused a greater need for increased detergents, to get better emissions. “I can remember going to K-mart in Daytona with my father and buying all the Mobil-1 to run the 500 with, Those days are long gone.”
Speed explained that surface finish plays a vital role when choosing the correct oil. Smoother surface finishes delay the transition from full film to mixed film lubrication. Rougher surface finishes require higher viscosity oil to maintain full film lubrication.
The other thing to consider is your oil clearances. “If you have to much clearance with to low of viscosity, your engine bearings may not fail but your rod bearings more than likely will,” explained Speed. “A good rule of thumb is, loose clearances require higher viscosity, while tight clearances need a lower viscosity.
Like other speakers, Speed warned against just accepting common thinking, “Thinner is not always better when it comes to lubricant, some of the big blocks with large strokes seem to respond better to a higher viscosity.”
Speed closed out his speech by giving everyone the four R’s of lubrication.
The Right Oil
- Proper Viscosity and additives for application
- There is no magic molecule that prevents engine failures
- No amount of Zinc can fix bad geometry – lifters must spin
- Must be clean! 70% of machine failures are due to contamination
In The Right Place
- The best oil sitting in the oil pan doesn’t help your camshaft
- Oiling system design is critical to proper lubrication
- Look into EDM hole lifters piston oilers, valve spring oilers
In The Right Time
- On time delivery is critical
- Cold starts and dry stars account for majority of engine wear – Synthetic oils dramatically reduce cold start wear
In The Right Amount
- Proper oil flow is critical at all times
- Oil is the lifeblood of an engine
- What size is the engine?
- How much power do you plan to make and at what RPM?
- What kind of conditions (drag racing, paved track, dirt track, off-road) will the engine be used in?
- What is the service interval that the filter will be expected to live through?
Steve Williams who was Originally scheduled to speak was not able to make it so instead Devin Rickey filled in for Williams. Rickey has been with K&N for 6 months, and has an extensive background in racing engine development “I think like everyone else, I overlooked filtration,” admitted Rickey.
Rickey gave the entire crowd some great advice on how to choose the correct air filter which you can find on the right. He then gave some warnings about choosing the wrong air filter, one of which was with the issue of pressure drop. Pressure drop occurs when you try to pull more air through a smaller filter, “As far as I’m concerned pressure drop is the enemy. But if you don’t have a little bit of pressure drop you will not do a good job on the filtration of the air or oil.”
Some of the most valuable information he gave was some helpful calculations that can help battle pressure drop:
Air velocity through air filter:
- Engine Flow Rate (CFM)/ Face Area (sq. ft.) = Velocity (ft/min)
HP required to pump a given volume of air at a given pressure drop:
- Pressure drop(pascals) x Flow Rate (m3/sec)/ pump efficiency (%)= power
HP loss for a given intake depression:
- predicted HP@ ambient pressure X (actual pressure in inlet system/ambient pressure) = HP at given depression
Correcting flow for change in pressure:
- Square root of (new pressure/old pressure) X Old Flow = New Flow
Rickey explained how the pressure drop was just as big of a concern for the oil filter as well, “we want a filter that is sized correctly so we can minimize the pressure drop, and maximize horsepower. Minimizing pressure drop also minimizes HP loss.”
Finally Rickey would offer a warning to those who choose to run a bypass with the oil filter, “if the filter you are using has a bypass you should make sure that the bypass opening pressure is above the pressure drop of the filter at your intended oil flow rate. A filter that is bypassing around the element is no longer protecting the engine.”
For the final speaker of the day Josh Stewart of Roush Yates Engines spoke to crowd on NASCAR valvetrain technology and how it can be applied to your race engine. Stewart hails from the United States Military Academy at west point and even became a commissioned armor officer in the US Army. In 2009 he took a position with Roush Yates Engines within the R&D group as a valvetrain engineer.
Stewart explained the success that they have had with their FR9 within the Cup series today came with extensive NASCAR testing. “We were able to take a system approach to it, and establish performance goals while working with that engine,” explained Stewart. “People think we were looking for huge gains when testing engines but even at the cup level we were consistently just looking for .3% of a increase in HP or Torque.”
“From the beginning you have to think of the engine and vehicle as a system, and integrate the two. We can’t just hand off the engine to the team anymore and expect good results,” Stewart continued. But how can all the success that Roush-Yates Cup engines have seen really translate to the grassroots level?
Roush-yates has a 360 sprint engine that has over 50 wins and 4 championships over the past two years. But instead of accepting this as acceptable, they decided to take the Cup testing techniques and apply them with this engine in hopes of seeing increases. The thing to remember on this engine is the ASCS uses a spec head port. So the choices are extremely limited when it comes to finding additional horsepower.
While the testing is still being completed on this project they did release to us what they hoped to see by incorporating the NASCAR technology into their grassroots engine:
- Improved power: +5-10 HP @ peak, +2-3 HP average
- Improve limit speed: 9000-9200 RPM (+400-600 from current 8,600 RPM)
- Maintain drivability
- Maintain durability, and serviceability
- No cost increases
So how did they expect to accomplish this? “We wanted to reduce the system mass and inertia, all while increasing the system stiffness in hopes of optimizing the valve event.” Stewart would explain how they would use complex equations to determine that a larger ratio results in less mass seen by the valve, and by using the equation they could determine that a two point ratio change with our base engine would result in a 19%mass reduction.
They then were able to determine where their point of attack would be. “By changing to a new rocker arm design and changing from aluminum to steel we were able to see a 84% increase in stiffness, but as always that came with a couple of penalties 22% increase in moment of inertia and a 17% increase in mass, explained Stewart.
They would also incorporate a new valve, spring, and cam side component design to accomplish their goals. Unfortunately extensive testing is still being conducted to see just what type of results have been achieved by Roush-Yates. But it is very clear that they have been able to take the knowledge that they have learned in the Cup series and filter it down to the grassroots level.
Or as Stewart put it in his conclusion, “Our methodology applied to our product development, has been tested from cup cars to sprint cars.”
Make sure you check back tomorrow when the final speakers will take the podium and we’ll cover the 21st annual AETC Roundtable session with many special guests.