Full Race Twin Scroll Manifold

On the side, I’m aiming to be productive by collecting parts for future endeavors. I’ve been keen on Full Race’s FD manifold for a long time now. I do not reckon that it is the most widespread manifold in the RX-7 community, as most people opt for offerings from Rotary specific shops. Like me, initially, with my current A-Spec Short Manifold.

I took my time and consulted the owner of Full Race, Geoff, directly for his insight. After comparing other options and taking into account what Geoff had inputted about his manifold’s design, I was convinced that it would be worthwhile to switch to Full Race.

The manifold arrived in a well packaged box.

I thought the serial numbered certificate of authenticity Full Race includes was a nice touch.

More importantly, the manifold itself was absolutely beautiful to behold. The A-Spec manifold I have is great quality, but if I’m honest, Full Race’s quality is at a higher cut.

They use robotic TIG welds to ensure excellent penetration and weld quality with no bleed-thru or “sugaring” of the weld on the inside seam. This puts less heat into the metal which equates to the metal having stronger integrity because its HAZ (heat affected zone) is reduced. Usually when welding by hand, the start/stop point of a bead is a potential weak point. Robotically welding essentially negates this weakness.

I’m also a fan of the exceptionally thick 8 Gauge stainless used in the manifold’s construction.

The flanges are thick and nicely finished with the inner bores cleaned.

Full Race includes high grade studs with inconel nuts and Nordlock washers.

One concern I had with the manifold was with its placement for the wastegates. It seems counter-intuitive to have the wastegate runners come out at 90* angles rather than follow the path of the exhaust gas. As it was later explained to me, such a design was purposefully done to give turbine priority. This will ultimately help with spool and response times. Since the manifold is designed specifically to be used with dual 44mm wastegates, the surface area of the wastegates will be so large that they do not require direct flow.