Our take on the classic 4 to 1 Miata header! The most bang for your buck, with all the features you need in an all stainless steel header.
Manufactured entirely from 304-stainless steel with thick flanges that will not warp like other stamped or cast flanges. Large 1.7" primaries collecting to a 2.375" OD tube via a smooth 4:1 merge. O2 sensor bung included after the merge.
Manual transmission only. EGR compatible.
Gasket included. Comes with plugs loosely installed in the oxygen sensor bungs.
Now updated with a SECOND o2 bung down near the outlet flange, which you can use it to add an auxiliary wideband sensor, or use it when you go to the dyno for the o2 sensor that's hooked up to the dyno, etc. All without having to weld in an extra bung later.
Note that adding any header results in an increase in the exhaust sound level on your Miata.
Note there is an INTENTIONAL small dent in one of the primary tubes for clearance to the steering rod.
Manual Transmission Only.
SORRY, WE CANNOT SHIP TO CALIFORNIA CUSTOMERS!
Brian's Application Notes: Year after year our top choice was the Racing Beat and year after year they ran out of stock because the batches of CAST flanges would be too warped to use and then they would be out of stock for months trying to get a good batch. We got tired of that, customers were tired of that, so we did our own that avoids the use of the problematic cast flanges and otherwise is similar for pipe size and length and all stainless construction. We think it is the best header you can get for the money and as a result our warranty is lifetime, which you will not get on ANY other choice!
Awesome piece of kit! Great upgrade over the stock exhaust manifold. Good relocation of the oxygen sensor. The EGR pipe (engine side) did require some pulling/pressure to line up the nut with the new header. Definitely get a new gasket and some nuts and washers. Exhaust sound is more distinct and has a sharper sound to it. Also running an FM catback and it sounds great!
Pro tip: get some heat reflective tape for the outlet hose on the cabin heater and the lower radiator hose. They are both close to the header and will see more heat than before.
Other than my nerves while removing the stock 25 yr old headers. The new header install was ease enough. Paired that with a Resonated cat delete from ISR and the Manzo cat back and shes a screamer.