90-93 Miata Racing Beat Header (56005)
Racing Beat Miata Headers for the 1990-1993 Miata (manual transmission only) are the result of exhaustive research and engineering efforts, utilizing both chassis dynamometer and road testing. Our Racing Beat Miata headers incorporate a tuned 4-to-1 design configuration to optimize exhaust gas scavenging characteristics and power output, while improving both the exhaust note and retaining the factory catalytic converter. Hundreds of development hours and over 200 on-chassis dyno runs were undertaken in the refinement of our Miata headers. The Racing Beat Miata header has been design-tuned to provide measurable horsepower and torque improvements throughout he entire RPM range.
Manufactured entirely from 304-stainless steel for superior durability, this 4:1 Miata header will offer years of enthusiastic performance driving. Our exclusive cast stainless steel engine-to-header flange features specially designed exhaust ports which transition smoothly to the primary tubing. For the 1.6 liter Miata engine our header utilizes large diameter 1.5" OD tubing for the primary tubing, and then collects into 2.0" OD secondary tubing. All emissions control devices are retained. Each Miata header kit comes complete with installation instructions and replacement rear gasket. If needed, a header-to-engine gaskets can be ordered separately. Two gaskets are required, inner and outer.
During the summer of 2002 we undertook a significant project to upgrade our Racing Beat Miata header line. The scope of the project was to produce a 4-1 (four-into-one) type header for both the 1.6 & 1.8 liter Miatas and compare them against the power characteristics of our then current 4-2-1 (Tri-Y) type headers. These new prototype headers featured a new engine-to-header flange, collector, and outlet flange. We also took the opportunity to change construction materials from mild-steel to 304-stainless steel.
With the new 4:1 header project, our initial performance objective was to retain the mid-range performance (3,000-5,000 RPM) of the then current 4-2-1 (Tri-Y) header, and improve the top-end performance (5,000-7,000 RPM) normally associated with the 4:1 type header. Under the guidance of Jim Mederer, Racing Beat's co-founder and chief engineer, initial testing on this project took place almost entirely on the chassis dyno. A rather strange looking test header was configured that allowed us to actually change the primary and/or secondary lengths while the car was strapped to the dyno. This entire assembly was suspended over the car by a specially built frame.
Over 200 on-chassis dyno runs allowed us to determine the optimum tubing diameters and lengths for both the primary and secondary tubes. We also took the opportunity to experiment with various engine-to-header flange porting configurations and collector designs. This development allowed us to fine-tune the performance of this new header to achieve our performance requirements.
After repeated test sessions, we finally found the optimal combination that allowed us to achieve our target goal. The test results showed that the top end power of our 4:1 header had improved and the mid-range power was retained. Click here to view an article on the development of our Miata headers and dyno results.
Once the cast stainless steel engine-to-header flange the flange was completed, the prototype was assembled and our 1990 Miata headed back out to the chassis dyno for final confirmation testing. Click here to view the dyno results for the 1600cc header.
Header shown is for the 2001-05 Miata.