FD RX-7 Project Developments

For those of you who have been following our FD RX-7 project build, we thought it was time we made a post to cover our recent developments. There’s still a lot more work to do, and more updates to come, but keep reading if you want to get caught up with our recent progress..For those of you who have been following our FD RX-7 project build, we thought it was time we made a post to cover our recent developments. There’s still a lot more work to do, and more updates to come, but keep reading if you want to get caught up with our recent progress..

Being based in Queenstown (along with being super fussy), it can be difficult for us to get good high quality fabrication work completed. A while back Vinny Fab in Christchurch reached out and expressed an interest in becoming involved in the project. Looking at their previous work, and the fact that they’re FD RX-7 experts, we were understandably interested. Long story short, we liked what we saw and got them on board.

To provide you with an overview, the car is fitted with a full Turblown turbo kit which consists of a BorgWarner EFR 8474 which sits on the Turblown investment cast stainless steel exhaust manifold. The investment casting process allows a lot more flexibility in the manifold design compared to fabricating the manifold. Case in point is the tapered runners which allows seamless port matching from the large exhaust port on the 13B, to the entrance of the twin scroll housing for the EFR 8474 T4 flange. The manifold also houses a pair of 40 millimetre Turbosmart external wastegates, and Turblown have been very careful with the way the wastegates integrate to the manifold to ensure good flow and solid boost control.

While the turbo kit is remarkably thorough, including everything you need for the installation, there was still some fabrication work required to plumb up the new turbo system. First up was the need for an intercooler to suit, and we initially got our hands on a front mount intercooler kit. There’s no doubt this FMIC would have done the job, however with limited space in the front of the FD3S, fitting it would require cutting the front bumper. As our RX-7 is pristine, we wanted to keep it looking 100% stock and cutting the bumper wasn’t an option. Instead, a V mount configuration was what we decided on and Vinny Fab made us a custom built kit to suit our exact requirements. If you look at the engine bay photo, you’ll see the intercooler on top with the radiator tucked away underneath. 

Next up we have the new intercooler plumbing from the intercooler to the GReddy elbow that comes off the factory throttle body. Of course, the last thing you want on a possible personal best pass down a drag strip (or at any time for that matter) is for an intercooler hose to come off, so silicone joiners weren’t for us. Instead we’ve chosen to go with a set of Plazmaman Plasmaclamps, which are a wiggins-style clam shell clamp that virtually eliminate any chance of a failure. 

Although these clamps can be a lifesaver, they do have a downside, which is that they’re limited in the amount of movement they allow. To combat this, it’s important to consider the type of engine mounts that will be used and in our case we’ve replaced the factory rubber mounts with a heavy duty nolathane material. This will reduce the movement although not eliminate it. Solid mounting the engine would ensure zero movement, however this also transfers a lot of vibration into the chassis and isn’t ideal for a street driven car.

Another aspect that Vinny Fab dealt with was the intake system. Particularly with mainstream V-mount kits such as the popular GReddy option, it can be difficult to get a cold air supply straight into the turbocharger. The common solution with the GReddy kit is to mount the air filter in the engine bay which isn’t ideal as it’ll be sucking in hot air. Heat is not our friend when it comes to power since hot air is less dense containing less oxygen, which means we make less power. Instead, Vinny Fab installed the intake pipe in front of the intercooler and radiator where it can get a supply of cool fresh air. Using pie cuts on the 4” intake pipe allowed the flexibility to achieve the tight radius needed to reach where it needs to go.

While all of this was going on Vinny Fab also removed the compressor cover from the turbocharger to allow the Plazmaman Plazmaclamps to be installed on the compressor inlet and outlet. 

Next on the list was mounting our IGN1A ignition coils which we wanted to locate under the inlet manifold. Vinny Fab made a flat mounting plate that bolts to the top of the rotor housings to mount these coils. We put a bit of thought into the best location for the coils and decided that this gave a neat mounting solution. There are kits available that mount them in the corner of the engine bay however that won’t work in our case since this is a RHD model which has the ABS pump is in that exact spot. 

We love data, so while Vinny Fab still had the tig out we got them to add some weld bosses to the underside of the intercooler end tanks. These will be used to mount a pressure sensor and an air temperature sensor pre and post intercooler. All of this will be data logged into our Adaptronic ECU to provide data around the efficiency and effectiveness of the intercooler. 

So as you can see, there have been lots of exciting developments with our FD RX-7 recently. There is plenty more to come, so watch this space!