Mazda KL-ZE V6 Miata Swap — Budget V6 Guide

The KL-ZE swap is the best-kept secret in the Miata world. For under $4,500 in parts and a weekend of work, you can have a V6-powered Miata that sounds completely different from every other Miata at the autocross.

The KL-ZE is a 2.5L DOHC V6 that produces about 200 hp and comes from the JDM Mazda 626 and MX6 GT. It shares enough with the Miata engine family that the swap is significantly more straightforward than an LS or rotary conversion.

Sourcing: JDM KL-ZE engines run $400–900 from importers like JDM of California or SJ Japanese Auto Parts. Look for engines with under 80,000 km. The complete engine with accessory drive and exhaust manifolds is ideal.

Mount compatibility: The KL-ZE uses the same engine mount points as the Miata K8 V6 — which means it drops into the V6 Miata with minimal modification. For the more common 4-cylinder Miata, a modified crossmember is needed. Several vendors sell pre-fabricated mount kits.

Exhaust: The KL-ZE requires a custom exhaust from the headers back. Several Miata specialty shops sell stainless header kits. Full exhaust fabrication from a local shop typically costs $400–700.

ECU: The KL-ZE can run on a modified version of the stock Miata ECU with the appropriate chip, or on a MegaSquirt MS2/MS3 for proper tuning flexibility.

Result: A 200 hp Miata that weighs 2,200 lbs, sounds like a sports car, and confuses everyone who assumes it is stock. For the cost, nothing comes close.