Tibbett's SCCA RX-7 Race Car Build/Log Thread

[Simon Tibbett]

Hello everyone.

My name is Simon and I'm new here, I figured I'd start off with a build/log thread.

The car is a 1983 Mazda RX-7. I bought it already fairly race ready so "build thread" may not mean much building other than updating/changing/updates on races.

The car was originally racing out west in Pro7 before coming to the southeast at some point. I bought it locally in June of 2012 to race with the SCCA in IT7 for now until I can't find another 12a.

I'll also post videos here: https://www.youtube.com/user/simontibb?feature=mhee

Mods:

-Header w/ full exhaust.
-Strut tower bar.
-Full roll cage.
-Tokico struts.
-Unknown springs.
-Some type of aftermarket sway bar w/adjustable end links.
-Steel braided brake lines.
-Panasport for dry/Diamond Racing wheels for wet.
-...and some other things I can't remember.

Day One:

This is the day I brought it home, it ran good, but had a stumbling issue that was known when I bought it. Previous owners cleaned the tank, new pump, you name it. Got it running better but there was still some hesitation.

Pics:

After some cleaning...I got it shined up a little better and removed the decals to make room for "my own."

After the cosmetic stuff I fixed a few small things and put a OMP blockoff plate on to pre-mix.

I decided to run an HSR event, the "Atlanta Historic Races" as a "test" to get a feel for the car. Since I don't drive it on the street it'd be my first real time behind the wheel of it. To get it ready I just did a few very minor things including new harnesses and what not.

My first session out sucked, I stuck all my Diamond Racing wheels on which I bought with fairly new Toyo unshaved tires I bought in case of rain but were in better shape than the R888s on the car, as I pulled down to grid my "crew" noticed the wheel was wobbling bad and was either loose or bent. Ended up being bent so hurried and went back to throw two Panasports on the rear.

I did get out there though with some time left. The car handled great! I was very surprised. I took it easy just getting a feel for it, biggest headache was the stumbling issue coming out of corners and sometimes on straight aways, it really limited the car. The other issue was a bad vibration above 70 or so, so I kept my speed down to around 85 tops, which sucked especially on the backstraight.

Second session went better, I went quicker and started to get more out of the car. Handling wise it felt very neutral.

Third session on Sunday was the best, because I fixed the issue. It was just the vent solenoid unplugged on the carb, plugged it in and the car ran smooth! The only downside is it "feels" slower now, not sure if it's in my head or if it really did lose some power.

In the final session I went fastest and had a blast. Car ran good, no issues engine wise.

 

[Simon Tibbett]

2012 SCCA American Road Race of Champions

The next race was the 2012 American Road Race of Champions enduro at Road Atlanta in November. I had a lot to do.

I decided to run the RA1s off the Diamonds and have the R888s as spares for the ARRC.

I went with Porterfield race pads for the ARRC.

While switching pads two days before the test day I found a brake leak. Wonderful! I ended up just rebuilding the rear calipers as that's where the leak was then the night before had more issues, the brake master went out. This was harder to find in stock and I couldn't get it until the day of the test day. Sadly I missed the test day but finished the car.

Pictures from the ARRC:

Last chance to look over the car before Sunday's qualifying and race.

Race day!

The green flag fell to a wet race.

Missing an apex. lol

Our pit stall.

Checkered flag.

Post race impound.

Well earned trophy.

The Story:

Sunday comes, qualifying at 8am. My driver will qualify the car so he can get some seat time before the race. He does three laps or so and comes in with a shifter issue. He also had trouble getting it in first to begin with but out on track he said he had problems going into forth and some other gears. I told him to try double clutching or blipping the throttle even on upshifts, he went back out for a lap, came in and said it felt better and didn't have an issue.

As the race rolled around the sky darkened and a few minutes before we went to the grid it started to rain. The five minute was given and the track was officially damp by now and it was still raining. As the cars rolled off...guess what? No first gear. It took him a minute but finally got it in gear and we were able to join the pack from the rear as they had two pace laps.

The green flag came out and we actually started moving up spots, primarily because we were on unshaved RA1s so had more grip out there, some others pitted for different tires and we could run a consistent start. I think we actually made it up to like 12th overall, we started 24th or something. As time went by the car kept turning laps, which was a good sign. I was a nervous wreck just sitting in our pit stall waiting for my stint and fuel stop.

About an hour and fifteen minutes in he came into the pits (we told him we'd call him in at an hour, but decided to play with his mind and leave him out as long as we could lol). He came in for a driver change (my turn) and fuel. He also claimed bigger transmission issues, the car would slip out of 4th gear and do some other funky things.

I fueled the car and got in.

The car felt like CRAP. Fourth gear was indeed pretty much shot, you could get it in OK, but if you let off the throttle it would slip out, and shortly after it started slipping other gears too sometimes, clutch slipping randomly, etc. It was 100% the hardest thing I've ever driven.

I literally had to drive with one hand, one hand holding it in gear. While watching my mirrors. While trying to stay on line. While trying to turn OK lap times.

Let me tell you something, one handed driving through turn 12 at Road Atlanta is no easy task, it's quite sketchy.

After around 30 minutes or so it got bad, I was losing time fumbling for gears and going into T1 I braked and downshifted as usual, but couldn't get a gear. I was still traveling quite quickly fumbling with the shifter. I am running out of road FAST, can't get back on the power to make it, I see a group of cars coming up behind me...I just open my hands and go both feet out. lol Hard off over the curb, luckily kept the car straight in the grass and didn't hit anything. I cruised up to turn 3 in the grass and sat there for a minute fumbling for a gear. Got one. Continued slowly back to the pits.

I got into the pits and decided I was done, too hard, I couldn't see out my right mirror and in multi-class endurance racing that's an issue. So I opted to put my friend in the car, who is very experienced, and told him screw the transmission get us a trophy.

He went out and got up to speed, still with the issues I had. He also had one off for the same reason, this time in the esses, and a couple of two offs but kept going strong.

Around 5:00 the checkered flag was thrown, we were ecstatic to have finished the race with a car in such bad shape. We got 1st in class, but we were the only IT7 car in class. HOWEVER, finishing alone was a huge win in my book and that's why endurance racing is awesome. We kept fighting the car, kept going, and finished on a high note. By the end the only gears being used were 3rd and 5th. lol

The car overall was great, the brake pads were AMAZING, the car handled well, the engine was just stupid strong (duh, it's a rotary) the only issue was the transmission. So it's off to rip the car apart in the next few weeks and have it ready for next season.

 

[Simon Tibbett]

Preparing for 2013

I officially start the continuation of the thread here as we prepare for the 2013 season. It looks like we will start it off in March for the SCCA ECR enduro. I plan to run all the Road Atlanta ECRs and the NASA enduros at Road Atlanta as well, one of which is a night race!

Naturally, I had a list of changes I want to do for 2013.

First up is mirrors! I couldn't see really at all at the ARRC so that was one major change. Luckily easy and cheap too. I found a good deal on small roll bar convex mirrors and had a wink mirror that I made some better mounts for.

Of course a major thing was a transmission, luckily I found one for cheap and snagged it. I plan on buying a couple more as well just to have as spares.

Another issue I've had with the car was the steering wheel. I hated the Grant wheel that was in the car and picked up this older Grant GT wheel for cheap. It's smaller and the three spoke design is what I prefer. Excuse the mess!

Added safety was next in order so I purchased a right side net and a new seat. The seat in it was a trimmed down economy Kirkey seat. I bought a Kirkey road race seat which is a HUGE difference. Very comfortable and "hugging."

I decided to "kind of" install the right side net just to get an idea. I need to re-install after the new seat is in.

With all that I also thought since I'm in the south, it gets hot! I snagged this drink bottle holder for a few bucks with a mount and bought a Longacre drink bottle with drink tube/bite valve as well.

With that, I also decided an older pit board wasn't always ideal and we needed something better. I found a killer deal on a complete radio setup including helmet harness so I snagged it. It uses Midland radios right now but can be upgraded down the road.

The helmet kit uses a NASCAR plug, I simply added some velcro to keep it out of the way when not being used.

Here's some more of the new stuff...

Contour 1080P Camera
Contour roll bar mount
Exedy clutch kit
Slave cylinder
Longacre drink bottle

I needed some more power as the car was down a bit straight line speed and found two carbs for sale. One is a Yaw tuned Nikki, the other is a 7s Only tuned Nikki. I'll probably install these down the road once I get use to everything else.

Today I started planning my seat install. The current setup is the factory rails modified with steel plates welded on for a simple flat bottom mount.

It was this, or side mounts. Since the cockpit is so small, side mounts will require cutting and banging which I'd like to prevent.

Old seat out, excuse the mess, it will be cleaned/painted before March:

The mount:

New seat and mount, simply mark and drill.

The basic idea. Not finished yet as I'll be putting in large fender type washers to spread the load if I have an impact.

So that's where I stand right now. Hoping to finish the seat install tomorrow. I recently found I need a new idler arm as well so I'll be installing that and new tie rods while I'm at it. Hopefully soon I'll be getting it into a friend's shop and do the transmission work to get it back drivable again.

I'll keep updating this thread as I move along with updates on the build and race photos/videos!

 

[Simon Tibbett]

UPDATE.

Got the new seat in. I LOVE it. I'm still debating whether to buy a cover or buy a lot of padding and sort of make it fit me. Price wise would be about the same. Either way, here it is. MUCH better than the Kirkey that was in there and MUCH more protective feeling.

 

[Simon Tibbett]

UPDATE.

After a long winter I'll finally have the car back out on track this weekend. Fingers crossed nothing happens.

We just did a LOT of work to it such as replacing the transmission, clutch, all associated items, suspension bits, and tons of just small things here and there to make the car more reliable and what not. Of course half of these simple things turned into complicated things so a simple slave cylinder job ended up taking 3 hours because of a bolt size issue, just small stuff like that.

Finally making progress:

An example of what came out of the old transmission:

New transmission ready to go:

Long nights:

We made this cool setup to add transmission fluid without causing a mess from a hand pump. We drilled a hole in the tunnel where the fill plug is, then ran tubing, a 90 degree bend, and more tubing into the transmission so you can just pour it into a funnel from the interior. Worked like a charm.

Anyway, that's it for now I'll post more later and updates through the weekend. I'll have some video as well with lap time overlay courtesy of Harry's LapTimer.

 

[magnumP5]

Not sure how I didn't see this before. Sub for more RX-7 builds on these forums. I've got a lot to learn when it comes to track prepping cars. I REALLY need to get my car back on the road so I can get back into HPDE. Also, let me know if you have any transmission questions. I've recently completed a Miata swap/rebuild in my FC and I have two spare FC gear sets. Either way, good stuff!

 

[Simon Tibbett]

Yeah I can't wait to pull apart the bad transmission and see what went wrong. I have another that's good as well as a spare but have to reseal it.

UPDATE.

Got the car on the ground, got it running, and drove it! Easier said than done though. It did not want to start, we had fuel (too much) and spark, but it just kept flooding over. We finally figured it out and got it fired up then I held my breath and went through the gears, luckily they all worked!

We got the car down and I took it for a quick test drive, I never knew these transmissions could be so smooth. After the last time I drove it this felt like slicing butter. It ran good, transmission shifted smooth, clutch feels good. We're ready to race...I hope.

The rest of the day was spent tightening up odds and ends, cleaning the car, etc. I'll take it to the track tomorrow.

 

[Simon Tibbett]

UPDATE.

What a weekend.

Before leaving the shop and going to the track I ran into a small issue, my kill switch went bad causing the car to cut on and off, luckily I caught it early, sourced a new one from a vendor at the track, and got it back together quickly.

We took the car to the track with no issues at all on the drive over, since Road Atlanta is just ten minutes down the road I drive the car there.

The first session our Saturday was damp, so I mainly took it slow and just got a feel for the car again and made sure everything was working properly. Everything felt good, the transmission was smooth, and I was ready for the session after lunch.

Session two was now completely dry and I immediately went almost two seconds faster than my previous best time in the RX-7. Still very underpowered on the straights I could make up a good amount of time in the corners. Session three was even better with another half of a second shaved off of my previous time. I was happy, the car was running good, and I was excited for Sunday.

Sunday came and so did the rain. A lot of rain. Enough to flood quite a bit in the local area specifically Flowery Branch. We arrived at the track wet and early and I knew the day would be a rain fest and I wouldn't be able to keep shaving time off. I would however get valuable experience in the wet. The first session out was soaked, there was standing water in turn one, the esses, a pond on the entry into ten, and a river running down the hill from eleven into turn twelve. It made for a very exciting session mixed with hydroplaning down the back straight and a game of throttle control and smooth steering inputs. I had a blast in all honesty, speed wasn't high but it was a lot of fun and I learned a lot.

The second session was also wet, although not as rough as the first. This was the last session of the weekend so my main goal was to just have some fun and not screw anything up. It was once again a blast sliding around in the wet and a good conclusion to a fun weekend.

Ready to go:

Donate if you can!

Last minute kill switch swap:

My Volvo played support vehicle for the weekend:

Videos: (MAKE SURE IT'S ON HD!)

Sliding in the rain:

Rain lap with Harry's LapTimer using my iPhone. Not a very fast lap but this is a great tool for anyone who sees track time.

Camaro losing it:

Mowing the grass:

Dry lap:

 

[Simon Tibbett]

Final session start:

 

[Simon Tibbett]

A few photos from last weekend:

 

[mspeedP5]

Is that an Autopower bolt-in rollcage? I'm assuming it is as the door bars look very similar to what mine will be like.

 

[Simon Tibbett]

Is that an Autopower bolt-in rollcage? I'm assuming it is as the door bars look very similar to what mine will be like.

I believe it is.

 

[Simon Tibbett]

UPDATE.

Decided to run the car this past weekend at the Chin Motorsports track day (I just ran Sunday) at Road Atlanta to get things sorted for the American Road Race of Champions in a month.

The event didn't go as well as I would have hoped. The car had a horrible sputtering issue which ended up just being a clogged fuel filter but I lost a bit of time before we found the issue. Then into the final session the radiator blew on the back straight ending the day.

All in all though I feel good that these issues occurred before a real race and I still managed to knock off another second.

The only work that was done between this event and the last one in May was wheel bearings, the airdam, and that's about it! I did put a new mirror on but...

Here are a few photos:

Radiator went bye bye.

Exit of T1.

Heading to T6.

Exit of T5.

Turning into T5.

Having issues coming out of 5.

Getting strapped in.

Heading out of 10B.

Next on the "To Do" list includes:

Change radiator.
Put new belt on.
Put new cap and rotor on.
Oil change.
Check fuel system, clean or replace filter.
Adjust seating position and steering column.
Touch up some body work.

Nothing major, I'll be racing the 2.5 hour ARRC enduro. We raced it last year with issues but finished, hoping for a trouble free year!