Now that the suspension was done, it was time to move on to getting the car back to a drivable state.

That meant finally finishing the exhaust. The 20-valve manifold has a completely different flange and sits at a different angle than the stock part. To fit the flange, I made two cuts in the downpipe to allow me to spread the “Y” portion wider, then welded the seams back up.

I used the same “slice/bend/re-weld” method to alter the angle of the downpipe.

For more content like this, check out Daily Downshift

Advertisement

Here’s the downpipe painted and wrapped. Unfortunately shortly after I took this picture I realized I forgot to add the O2 sensor flange, so it all had to come right back off. Oh well.

Finished downpipe pre-wrap, this time with the O2 sensor flange mounted.

Advertisement

Once the downpipe was mounted to the manifold, I was able to weld up the new flex pipe to complete the exhaust.

Before I ran the car too much I went ahead and changed the oil and filter. It seems like 10w40 is the preferred weight for track use with the 4A-GE, so that’s what I went with.

Advertisement

Time for a test drive. The Miata wheels that came with the car wouldn’t clear the upgraded front brakes, so the track wheels were used. I ordered spacers for the front that evening.

Advertisement

Looks pretty sharp. However on the test drive there was some immediately apparent issues. The power steering pump was making quite a bit of noise, the clutch engagement point was far too high, the gas pedal was a little too close to the brake, and the alignment was terrible. How terrible? Enough toe-in that the front tires were squealing over 15mph, and the car was almost uncontrollable. Once warmed up, the idle would surge over and over as well, which was very irritating.

For more content like this, check out Daily Downshift

Advertisement

Back on jackstands it went. The gas and clutch pedals were re-modified and front wheel spacers added. As for the toe-in, when I went to adjust it enough to limp the car to work, I found the outer and inner tie rods seized on one side. Rather than cut them off and replace them, I decided to remove the steering rack and use the vice to help separate them. Then, while it was out of the car, I could de-power the whole thing properly.

After reading some guides online for de-powering racks in Miatas and RX7s, I felt comfortable enough to tackle it myself. After disassembling the rack, I removed the rotary valve from the pinion and welded the shaft solid. I also removed the rack itself from the housing and cut off the internal seal. This will allow for less internal friction and less effort behind the wheel. 

Advertisement

Here’s the rack reassembled, re-greased, and all the ports blocked off. The effort behind the wheel is totally acceptable and is actually less effort than my MR2 with it’s quick ratio rack and smaller aftermarket steering wheel.

Advertisement

This is all the stuff I was able to remove by ditching power steering. Due to the way the belt and tensioner are routed, I couldn’t remove the AC compressor without also removing the power steering pump. Both of these heavy accessories and brackets are on the very front side of the engine, in the worst spot for weight balance in the car. It also frees up the engine with less things to turn. The only belt left on the motor is for the water pump and alternator. Like Colin Chapman once said - “simplify, then add lightness”.

 

Advertisement

Once the toe was reset using my very scientific ‘eyeball’ method, I was finally able to take the car to work to get a much needed proper alignment. Hopefully soon I’ll be able to figure out the surging idle, clean the car up a little, and have it ready for it’s first autocross event this coming weekend! Stay tuned, she’s not quite done yet!

For more content like this, check out Daily Downshift