1987 Mazda Rx7 Build 3.0

Thanks to GRM peer pressure, I made the questionable decision to buy surfshibby07's old RX7 Challenge car, with a plan of getting it put back together in time for the 2024 Challenge. Given that I truly have no idea what I'm doing, I'm depending on many, many others who have far greater knowledge than I do. Still, we have a long way to go and a short time to get there. 

The car first competed in 2020, and incredibly well and finishing 5th overall. It was running an LS motor and TH400 transmission, with a big shot of nitrous.

It then came back in 2021 with a turbo set up and did not fare as well (27th place). Build thread here. For sale thread here.

PimpM3 bought it at the end of 2021 and dropped an LT1 and T56 in it. Build thread here.

In 08/23, he listed it for sale. First with an engine and parts car, then with no engine, selling it as a roller here. I happened to sit next to him at the GRM holiday get together in central Florida and agreed to buy it. He was so happy to get rid of it that he even delivered it to Gainesville for me!

It sat for a while at a buddy's shop until I finally dragged it home. Stampie and Dusterbd-13 helped me procure a 5.3L Chevy truck motor along with a 4L60e transmission, and 03panther was hugely helpful by grabbing the engine in NC and meeting me in middle GA so I could bring it home.

Since then, we've tackled the fuel cell (it was inside the hatch - we moved it to below the car) and got the brakes bled. We've also been wrestling with the engine, attempting to get it into the car several times, finally succeeding (somewhat), only to pull it again so we can try to get the last exhaust manifold stud out of the block (a few broke, but we managed to get them all out but this one).

At this point, there is still so much that needs to be done, not the least of which is get the engine fully seated in the car. There are a few parts we could use, if anyone happens to have them laying around. One is a LS style intake manifold to replace the truck manifold. Another is an F-body oil pan. The truck oil pan *mostly* clears the steering rack but an F-body pan would be much better.

Many thanks to Stampie and MrJoshua, both of whom have put a bunch of hours in with me so far, as well as several of my local car buddies, all of whom are experiencing a Challenge build for the first time!

Here are some pictures:

This is going to be good

Well now that I guess I've been released from my NDA I gotta say this has been fun.

When this was first mentioned as being for sale at the Challenge a few years ago a few people asked me to look at it.  I liked what I saw for the price.  When dyingtorace text me this fall about it I was supportive.  I had actually been within 15 feet of it the week before but I avoided going to look at it closer to keep the temptation down.

The biggest thing I've enjoyed about the process is dyingtorace learning new things.  He's learned NHRA safety rules, learned how to run a hot metal glue gun, and how to remove exhaust bolts without breaking them.  The engine came with three broken in typical LS fashion and he removed all the rest intact with just a little instruction.

BTW ... I have another idea to get that last broken exhaust bolt out.  Now I wish I had taken pictures but someone told me there wouldn't be a build thread.

In reply to Stampie :

I figured I might as well let the cat out of the bag! 

Weld a nut on the broken studs. Works every time on the ls exhaust bolts. 

In reply to Dusterbd13-michael :

Not every time.  Don't ask us how we know.

I can help with chassis knowledge!  I Raced a 2nd gen for like 15 years.  Owned about 13 fc rx7s.

If you have fc questions, I can help!

I've also been known to dabble in engine swapping rx7s and rx8s.  However, the only 5.3 experience I have is with my atock 2016 truck and I don't touch it.

Good luck.  We are all counting on you!

Edit to add...  I have a bunch of brake parts for these that I can bring to the challenge for you.

Good to see this resurfacing. 

This car really should be named Phoenix, each time rising from the dead with a different drivetrain.

wvumtnbkr said:

I can help with chassis knowledge!  I Raced a 2nd gen for like 15 years.  Owned about 13 fc rx7s.

If you have fc questions, I can help!

I've also been known to dabble in engine swapping rx7s and rx8s.  However, the only 5.3 experience I have is with my atock 2016 truck and I don't touch it.

Good luck.  We are all counting on you!

Edit to add...  I have a bunch of brake parts for these that I can bring to the challenge for you.

We could use some suspension help. The car came with "ebay coil overs in the rear and some k sport ones up front". Watching the video from 2020 and seeing the cuts in the tires, the front fenders are definitely rubbing the tires. Seems like it needs more stiffness up front?

fender rubbing tire is a symptom, but of what?  tires too big?  body roll too much?  driver too heavy?

or my favorite, wheel arch too low.  sawzall FTW

All of the above?

The car came with an uninstalled big front swaybar. But Jonathan noted in a post in 09/21 that the turbo set up he installed mean no front bar.

"3rd motor is in the car, and the hotside is hooked up. Down side is i has to remove the front sway bar... and lost the ability to go power steering."

I ran a stock swaybar, 245 40 15 tires (with flares).  Spring rate doesn't need to be obnoxious.  400 to 500# from springs and 300 to 400# rear springs should do it.  

Ride height was set just high enough so that the tires wouldn't rub the fenders.

2.75 to 3 degree front camber.  All of the caster.  Like all of it.

1/8inch front toe out.

1/8 inch rear toe in and whatever the camber does, it does.

wvumtnbkr said:

I ran a stock swaybar, 245 40 15 tires (with flares).  Spring rate doesn't need to be obnoxious.  400 to 500# from springs and 300 to 400# rear springs should do it.  

Ride height was set just high enough so that the tires wouldn't rub the fenders.

2.75 to 3 degree front camber.  All of the caster.  Like all of it.

1/8inch front toe out.

1/8 inch rear toe in and whatever the camber does, it does.

Thanks for the input. Once we get the engine in and the weight back on the front end, we'll see how the alignment looks.

Another work today. It felt like good progress, but there is still so much to do. I asked Stampie if this is destined to be the PLB this year!

We got the engine cleaned, the last remaining exhaust manifold stud tapped, the lexan hatch fully polished, the interior cleaned, the u-joint burned off the yoke, and more.

In reply to dyintorace :

I'm glad to see the Hogtown Speed Shop sled dog team had what it takes to make that plan work. Where's Bob when you need him!