RX8 Build Thread



Long time viewer, first time poster here. As someone who grew up loving to read build threads, everything from Zilvia to NASIOC, and the death of most forums. I figured it was time to do my part. Please bear with me through the beginning where I am missing a lot of pictures of what I am trying to describe. After driving a local skid pad in my friends 240SX, I was hooked. A couple days later I was driving to Detroit to pick up my first “project car”.



On July 23rd, 2021, after work I left Chicago and went to Detroit, picked up the car and drove back through the night. The car is a 2005 and had 72,000 miles on it. While it drove great on the test drive, the next day after getting it back it was very apparent that there was a fueling issue. The car would stutter and hiccup when trying to drive around and wouldn’t rev past where the secondaries would kick on. I ended up ordering a DW200 as I had previously had one in my STI, and it worked well. When I opened the fuel top hat it was apparent that someone had been in there before me. There were very poorly soldered wires, and where the wires had been soldered, they were left bare, opening themselves up to a possible spark in the fuel tank. Obviously not good. After fixing the wires and putting the new fuel pump into the car ran great and I was in love with it.

Next on my list was general maintenance. New fluids and brakes were installed. The car fought me a bit with a stuck rotor screw but besides that, all went well.




After making sure the car was running right was good to drive, it was time to take it to the local skid pad for the first time. Unfortunately, I don’t have any pictures of my driving (only a couple of cell phone videos), but it is fun to look back and see how much progress has been made.


(White Castle stop after drifting)

Now, knowing that the car was pretty sorted, I had bought a ticket (and new truck) to my first ClubFR drift event at USAIR. On October 22 of 2021, I loaded the RX8 on the trailer to make the haul north. Below are some pictures of the process as well as at the track.







While I had a ton of fun at the event it was clear that the RX8 needed a few things to be what I wanted it to be. However, first on the list was some new wheels. TF-Works is local to me, and they had a set of 18x9.5 +38 Work CR Kiwami’s in stock. So, I picked those up about a week after the event. The wheels were wrapped in a 225/40 Falken RT660 up front and a 225/40 Cosmo MuchoMacho burner in the rear. I also put an inch spacer on the wheels because the +38 offset of the wheels gave a too sunken look for my preference.







Once the wheels were on, I drove up to Wisconsin to store the car for winter where my parents have a house and garage space they don’t use. While the car was in storage, I started accruing parts to install onto the car. First, one of the most important things I found at the USAIR event was the necessity of having a bucket seat. Additionally, I wanted to have some gauges, so I knew when to pull off track and let the engine cool down. I ended up going with some Tanabe VLS OLED gauges for water temp, oil temp, and oil pressure. Along the same lines (although not pictured), I installed a Koyo radiator and low temperature thermostat with new black HPS silicone hoses.







Having installed these items and with winter starting to ease up (working on a car in the dead of winter in Wisconsin without heat is not a great time), I wanted to address the lack of steering angle that stock RX8s have. I ended up purchasing cut knuckles from @RX8Knuckles on Instagram and installed them along with a set of 4 piston Wilwood calipers utilizing the bracket from Keisler automation. At the same time for peace of mind I installed new wheel bearings/hubs onto the new knuckles.





Shifting my attention to the rear of the car, I wanted to replace some of the old ball joints and add a bit more adjustment to the alignment and decided that the SPL camber and toe arms were the best solution for the RX8. This would have been a very easy install if it weren’t for a seized bolt in the subframe.







FINALLY, spring was here, and I wanted to get the car out as soon as possible. I decided I would make the hour drive north to the skid pad and test out all the new upgrades. I also included a couple pictures of a cruise a friend and I did before the skid pad day. Ignore the wheels on the back of the car, I had found a pair of CMW wheels on Facebook Marketplace for less than a pair of tires, I ended up burning off the tires and selling the wheels for a small profit.









The car drove great, and all the upgrades were doing a great job, however the added angle of the knuckles and wider wheels with a high offset meant that the inner barrel of the wheel would rub on the LCA at lock. Then on the drive home, my saga with this car started. I was cruising with a pack of friends back from the pad, went downshift to keep up with their higher horsepower cars and the engine shut off. After a bit of diag on the side of the road I determined there wasn’t anything more I could do there. So, I hopped in the passenger seat of one of their cars and went home to get my truck and trailer.

The next day, once home and not on the side of the highway, I could hear that the fuel pump was no longer priming when I turned the key. Simple fix. I ran to TF and grabbed a Walbro 255 (what they had in stock), Once I threw it in, the car fired right up like nothing happened. Thinking that was a fluke part failure, I signed up for another ClubFR drift day at USAIR. I also thought I could drive around the wheels rubbing on the lower control arm. With that I packed up and headed north.




Once again, the car did what I asked of it all weekend. However, it was clear that there was no way I would be able to drive around the wheels rubbing on the control arm. So, I picked up a set of Advan RG3s in 18x9 +28 and with the inch spacer it works out to about +4 offset. This time due to the limited tire options for that size, I went with a 215/40 Federal RSRR for the front and Accelera PHIs in the same size for the rear. Please note that I like to experiment with different rear tires so the tires would switch occasionally. I also kept the Work’s for burners. With acquiring my new wheels, it kicked off a bit of an addiction with Advan and quickly picked up a pair of 18x10 RG2 and Advan RS’s in the event I wanted to grip drive/switch up the look.





(this shows off the added angle of the knuckles now that the wheels don’t hit the LCA)

With the new wheels installed and another ClubFR event around the corner, I loaded up and went back to the track. The car ended up being so much better and I was improving my skills, so I wanted to hit another one before the season was over. Below are a few pictures from the events.



With that, it was the end of the 2022 season. Following the event I again brought the car to Wisconsin but this year with the goal of making the car look how I wanted. Thanks to the RX8 Facebook groups and a bit of luck I was able to find a real OE Mazdaspeed front bumper in Memphis and OE Mazdaspeed rear diffuser in Ann Arbor, Michigan. After securing these pieces I thought the Ings+1 side skirts would complement the kit well and ordered those up.






I wanted to try my hand at painting. I have a friend that owns a body shop so I figured if it didn’t turn out how I wanted I could drop the pieces off with him and he could respray them. I opted to not paint the rear diffuser as the colors looked good and the piece was in good shape.



Here is the first picture of the kit on the car that I took. I am still in love with it. Fortunately, I was also able to find (actually @game_blouse5 found it for me) an R-Magic lip for the trunk, however, I didn’t paint and install it until months later.




Now finally having the car look and drive like I wanted, spring was just around the corner, and it was a short wait until I started going to events. This season was largely uneventful in terms of mods, but I ended up driving a lot. The only mod I did was buy VersaTuner (I didn’t know that MazdaEdit was the software I should’ve bought) to turn the fans on earlier and inject a little more oil from the OMP at high temp/RPM to try and prolong the motor. Below are some pictures from that season.





2023 was also the year I learned never to say one more. At the last event of the season that I was going to be running on the last lap, I was driving with 2 of my friends when the lead car checked up and I didn’t have time to stop. The damage wasn’t awful, but it did hurt my soul.



I wasn’t planning on changing anything with the car for that winter but now I had to fix the damage. I dropped the bumper, rear diffuser (flames damaged the structure), and rear lip off at the body shop to get fixed and repainted. Luckily you would never be able to tell it happened.





Installed R-Magic lip as well

For the 2024 season I left the car alone and continued to drive more events. Each time the car never broke down or did anything funny. However, that spring I picked up a 1991 240SX shell because I felt I was at the maximum the car could do without adding significant power. I (very wrongly) thought that building the 240 would be more cost effective than building a Renesis for boost and turboing the car or REW swapping.

Everything was going great until it happened again. The weather was nice, and I decided to take the Mazda to work… and ended up on the side of the road. Another dead fuel pump. Now I know it isn’t a faulty part, rather something is killing these pumps. But for the time being I went to TF and threw another 255 in it.


Also bought a pair of Enkei NT03+ from Facebook Marketplace





With the new pump in the car, I drove a couple more events but haven’t touched it besides that. As it sits now (spring of 2025) the car is in storage waiting for the 2025 season to start. After looking into it more I believe I need to do the fuel hanger mod. My working theory is that the fuel is getting hot, possibly boiling, and that is working the pump so hard that it kills itself. The car has only died while on the highway while under low load cruising, never while being beat on at the track. As of now, my plan is to finish my 240 and turbo the Mazda with the Brettspeed manifold. However, things could change.

*Edit from original writing: I had to take out 10 pictures to fit the maximum requirements.

 

With the car put away in storage for the winter, I wanted to update what happened for the last year. Unfortunately I didn't get to do as much driving as I wanted to but I did drive my favorite event yet. However, back tracking, before I started the season I put in a new Delphi fuel pump assembly to try and get through the season reliably. With that done, I drove a few skid pad events to shake the car down for GridLife Summer Apex at Road America. Below is a picture of the car before the event as well as a picture of the interior that was lacking in my prior post.


With the car bolt checked and ready to go it was time to make the drive up to Wisconsin for the 3 day event. It was a blast and near unlimited seat time and the car ran great until the final day when I was getting a CEL for a lean condition. As I was pulling into my pit spot in the final hour of the final day my fuel pump died again. While it was annoying to hand winch the car onto the trailer, it couldn't have happened at a better time. Below are some pictures from the event.




Eventually decided to take the diffuser off before I destroyed it as it kept falling down because the OE mounting tabs were broken.
With the car home I installed a new fuel pump and headed north for a big entry comp at the skid pad. With a short run up I wasn't able to get the car faster than 67 MPH on entry but was able to flick it hard enough to manage to finish as one of the finalists. Overall happy with the event.

And that wrapped up the season. Apart from some street miles I didn't drive the car for the rest of the summer. As I stated earlier I wish I had drove more but focusing on other projects and my nerves about being stranded with another dead fuel pump made me refrain. This winter I think I'm going to try and pull the fuel tank and clean it as I noticed some sediment on the fuel sock and believe that could be what's killing the pumps.

 

Very cool project and I like that you've had it and enjoyed it the last few years. I've seen on other vehicles that I've worked on, metal shavings from the pump itself, get deposited in the basket and eventually collect in the filter sock. A lot of the shavings from the pump eventually get back into the pump and it kills the fuel pump. I'm curious, what brands other than Delphi have you used over the years?

 

Thanks man! You may be onto something with shavings in the basket. I think I'll be trying a new assembly when I clean the tank to try and mitigate that. As for other pumps, I've tried a deatchwerks and Walbro.