Cycle Weighted Emissions
Here you can see a comparison among four parts combinations; carbureted with 100-octane Street Blaze gasoline and no catalytic converters, EFI with 100-octane Street Blaze and no cats, EFI with 100-octane Street Blaze and 100 cpi converters, and EFI with E85 and 100 cpi cats. Keep in mind that no ECU recalibrations were attempted to optimize each of these combinations. Still, note that although there were slight reductions in HC and CO emissions, NOx decreases were on the order of 50 percent compared to non-catalysts versions. Future chassis dyno and on-track adjustments (as pointed out elsewhere in the story) are projected for further improvements in power and emissions reductions.
Based on Engine Dyno Tests to
Date Although additional conclusions are forthcoming, based on practical and theoretical analysis of the dyno results, following are summary points from discussions among the project's team members.
The configuration of EFI and E85 resulted in a significant horsepower and torque increase across the entire rpm span, excluding a small reduction near maximum rpm. A consistent 5-7 percent increase was produced at peak improvement rpm. This slight reduction in peak power can be compensated for by ECU recalibration, nozzle design change, or both.
Catalytic converters are defined...
Catalytic converters are defined by the number of cells inside the unit called the substrate. This honeycomb-looking interior has 100 separate cells per inch of surface hence it's designation as a 100 CPI converter. The higher the number, the more cells and, more efficiency in converting harmful exhaust to inert gases.
The 100 cpi catalysts had only small impact on overall power. In fact, using EFI, E85, and catalysts, more power was produced throughout the rpm span compared to the combination of carburetor and 100-octane Street Blaze racing gasoline.
Use of the catalysts did a good job reducing NOx (on the order of 50-60 percent) but not as well for CO and HC. A lack of O2 for peak power and durability calibrations was the cause. This deficiency will be addressed during the on-track testing portion of the project. Expectations are CO and HC will be reduced significantly during this phase of testing.
Even though the E85 fuel generated more HC emissions than the Street Blaze, a solution proposed to enable increased O2 should reduce these emissions significantly. Future, on-track emissions testing will be the proof of this solution.
The benefits derived from use of the EFI system (manifold design and greatly improved fuel atomization) that led to increased torque and horsepower suggest this combination to be very worthy for circle track applications, particularly regarding where in the engine speed range these improvements occurred.
Next Steps in Project
One of the immediate conclusions...
One of the immediate conclusions is that additional engineering is going to need to be done on the catalytic converters as they began to show signs of collapse after three days of intensive dyno testing.
As initially planned, the 2010 "Body in Yellow" Camaro is being built out as a "putting stock back into stock car racing" vehicle. In so doing, it will feature suspension components of design iterations functionally similar to the OEM components replaced. Based on these critical parts, the Camaro will be transformed into a bona fide race car capable of helping us evaluate major aspects required to span the gap between a conventional circle track package and one that addresses specific objectives of a more "green" approach to racing.
As the Camaro is being built, we will utilize a special experimental chassis that will allow easy access to the testing equipment for the initial on-track evaluations. These evaluations will include the use of an on-board ECU (controller), dual catalytic converters (as initially evaluated during the engine dyno tests at Mast Motorsports), a repeat comparison of the induction systems and fuel choices already discussed in this story, and a Sensors, Inc. PEMS to enable measurement of exhaust emissions during laps comparable to actual race conditions.
Present at the on-track sessions upcoming will be the same team already involved in this project, along with motorsports-oriented staff from the Federal Environmental Protection Agency. It's vitally important that CT readers understand that the efforts of this project are directed toward, and aligned with, assuring the future of circle track racing by providing a thought-provoking approach to advancing the sport while addressing a variety of environmental concerns. The use of sustainable fuels in motorsports is an objective CT has deliberately included in the format of this project. Over time, the blending of this approach into the core of circle track racing is a particular goal, and the project's steps thus far completed reflect that objective.