Cleverfrog's 89 RX-7 GXL Restoration/ Build

Got the clutch bled and started breaking it in this weekend. As I was cruising on the highway I noticed my oil pressure gauge dropping scary low. Pulled it out of gear and gave it a blip of the throttle and it raised a little but, it wouldn't hold. So, I started doing some searching and read that it could be a failed o-ring behind the front cover or a failed sending unit. The pressure was fine after the rebuild however, that doesn't mean that the o-ring hasn't failed still. Step one is going to be putting a mechanical gauge on it and getting an accurate reading. I will just buy the o-ring in the mean time though just so I can have it if it is in fact that. I'm pulling for it to be the sending unit but, I think it will end up being that o-ring.

you can change the front timing cover seal at that time as well.

Is this pressure drop occurring after driving for awhile? What weight of oil do you run?

In reply to wvumtnbkr:

At start up it rises to 45ish then after a few minutes it starts to dwindle. It showed this symptom with 10w30 and right now it has 20w50 in it.

I went ahead and got an oil pressure gauge. Installed it to double verify. Turned the car on, pressure rose to 45ish psi then the longer it ran the lower the pressure went. Shut it off when it hit about 20psi roughly. Err... Oh well, I had a sneaking suspicion that it was that o-ring so, I went through and bout all the seals and gaskets it takes to replace that o-ring. Too bad I have to take the water pump off. Especially after finally bleeding the system completely of air. I get to use the polycarb cover I have over my radio hole though. Finally, putting that to use.

Yep... I knew before I opened it. Confirmation feels relieving though.

Did you read the writeup from mazdatrix on how to seal it correctly?

http://www.mazdatrix.com/faq/oring.htm

Sorry I didn't link that earlier.

In reply to wvumtnbkr:

Sure did but, thanks for linking it!

Autocross was fantastically successful this weekend. Not only did I have enough time Friday to get the front cover o-ring fixed, I also had enough time to cut out a flange and weld on a tube to make an adapter for my Apexi cone filter. Of course I didn't take a picture of it. My welds didn't suck too much this time. Practice makes perfect. It was very evident at the autocross that I really need more seat time. Thankfully, I've finished every mod that I had a goal set for done already. Now, there is nothing I want to change for this season. It is all down to learning the car and getting seat time in. Overall, I'm happy with how everything is going this year. Failed front o-ring and all.

Sloppier run

Fastest Run

Driving tips always welcome.

Soooooo.....errrrr.....

Somehow I lost a suspension bolt sometime between the last autocross and this past monday...........

Picture from mazdatrix but, that is the bolt that is missing.

That is a weird one to lose!

It's definitely fixed now. Pretty sure it wasn't in when I autocrossed last...................... The car is very tail happy now and it makes me smile. Reminiscent of gran turismo racing now lol. Now, I need get it to idle. I've adjusted the TPS perfectly but, I think it's actually the throttle cable being too long. Deleting all the stuff of the throttle body is biting me at this moment. The idle air screw on top allows for finer adjustments but, I need to adjust the throttle cable first. We will see. It's really a non-issue but worth mentioning I think. Mainly for a reminder for myself though.

Autocross was...weird. Unorganized region. It seemed like safety was not really taken seriously and the course layout was terrible.

Hoosier challenge this weekend was exciting and terribly frustrating at the same time. The more I drive the better my car feels but, I still don't get close to the s2000s or m3s. Watching my videos I can see so many mistakes and places to improve. Hopefully, I can work in changes in my driving to get faster times. Also, wider 245 tires and 200 tread wear would be so much better than 225 wide 300 tread pilot super sports would be great.

Day 1 Run 1 Didn't capture fastest since my gopro died. Luckily I brought a battery pack to recharge it for the next day

Day 2 Run 2 Fastest run

Love watching videos of myself driving it really does point out your flaws.

Car is looking sweet though!

Awesome thread. Looking forward to future updates.

Sunday's autocross went fairly well. Considering the factual lack of grip of a 300 tread vs a 200, being 1.5 seconds behind second isn't too bad. Next year I'll have better rubber. If I don't have everything I need to start and finish the turbo engine build, I will probably hold off until I do.

The runs

Finally got some action shots of racing

Looking good!

Well, I stepped up in the world I think. Got me a new daily to replace my focus.

Iv always liked those Focus's should make for a good reliable, reasonable, daily...

Just kidding! Killer WRX they make amazing daily performance cars!

Well, I found my vacuum leak.



I also found my water leak. The barb on the rear iron I capped with a rubber bypass cap just split and has been causing me to lose lots of water. Good news though. Wasn't internal to the engine. I tore that apart since I am installing the megasquirt and turbo parts. Irons, housings, everything looked perfect. For my first rotary rebuild to look that nice after 2 years of hard thrashing, I am very pleased.

Now I need to clean up my garage floor.....

And as it turns out there was more of a failure to the rear iron. I'm thinking a little piece of that has been blown out for a while now. Explains a few things. At least I'm not reusing it.

So, I guess my thread will become another one of those "Hey, I'm looking for 300-350 Hp to the wheels" threads. I will try to be more mythological and methodical than some. My plan here is to have my s5 turbo front and rear irons lapped with the s5 NA iron (as the NA and TII irons are identical according to my limited research). I will be reusing the eccentric shaft from my NA engine, purchasing either FD or FC rotors (they are also the same), doing a custom exhaust and turbo manifold, I will be doing a bumper delete sort of and a center exit exhaust, 750 secondary and 550 primary RC engineering high impedance injectors with a walboro 255 pump, custom fuel rails and lines, TII intake manifold, try my luck with deleting the BAC (I know it's nice for idle if you don't know how to tune for it), BorgWarner S360 turbo, not sure yet if I want to do a v-mount or a front, all ready have been working on the megasquirt ms3x, raspberry pi digital dash, I would also like to get everything rebalanced (perhaps to go above 9k rpm for future endeavors), probably more stuff I can't remember at the moment however, that's most of it. There's still a lot of researching and purchasing to be done. I also am working on my own custom engineered dual element rear wing. I've put a lot of time into flow analysis and have a great profile ready to be shaped with carbon fiber. This is purely a fun weekend/autocross car. The goal is to have a relatively quick turbo response time so I'm not blowing the tires off when boost hits. All of my research is showing that the s360 should be the perfect size and cost for my goals, same with the injectors. Is there a better way to achieve what I want? Probably. It's all about the knowledge and learning experience for me though. I am a very DIY oriented person. Loads and loads of work and updates are coming.

I made 333 whp on a TII with a streetport, t3/t4, Bosch 044 fuel pump, and a Syclone water to air IC. No real issues with traction but then again it wasn't in an RX7 either.

At one point I was thinking about doing an NA engine build for my old FC and researched a lot of mods for getting them to live better at high rpm. One of the main issues of going faster is the eccentric shaft flexing, causing rotor tips to touch the irons. Extra tip clearance helps there.

Some oil mods you might consider are replacing the eccentric shaft oil jets with webber carb jets. Also, external oil supply to the main bearings is often done with oil lines run from a block at the stock filter area, maybe combined with a remote oil filter. This helps give a more consistent oil supply to those bearings. Also, you can drill and tap the front iron for an oil cooler feed and block off the passage to the front cover, where that o-ring failed on yours. Use straight threads and o-ring fittings on the irons, as NPT are tapered and can cause cracking.

Something else to research and consider.