Project [Rotary] FD RX-7: Part 6 – V-Mount Cooling System (Overview and Intercooler)


And here we have the rear brackets welded to the intercooler core and bolted to the cross-tube. This mounting system has exceeded my expectations for stiffness and may have been overkill. The front bracket was designed to be more flexible than the rear brackets to provide some allowance for thermal expansion and chassis flex, but it may not be enough.
Both intercooler end tanks needed holes cut in them before welding on the Vibrant cast aluminum elbows. The first hole for the inlet of the intercooler was far from perfect because it was cut using a hole saw mounted to a hand drill with the end tank in a bench vise. The second hole went much better since it was cut on the mill.
We sanded down the hose retention bead on the Vibrant elbow and test fit it into the end tank. The intercooler outlet location is locked in so we can start mocking up cold-side tubing.
One last mockup of everything before beginning to weld it all together.
Many hours and way too many tungsten regrinds later we have a finished intercooler. Having never welded end tanks to an intercooler core before, this was definitely a trial by fire. Things could have gone better here and there, but overall it turned out pretty good. Now let's just hope it fits…fingers crossed.


    1. Hope…yes. How much? Not a lot for something soon. Long story short, I moved 2 years ago and the car was in a storage unit in a different state until 2 months ago. Finally have it with me, but currently have very little time to work. The project is still alive, just no where near the top of the priority list at the moment. Keep checking back and you’ll see something eventually :).

  1. Hi There,

    Very nice Build!

    I was wondering if you intercooler set up was going to be made available for purchase? or if I was able to purchase some cooler end caps from you.



  2. KISS. What are you building the car to do. looks like you have too much time and money, making the car
    look flash but never driving it. looks like you don’t understand the RX-7.Sure there are shortfalls but all with much more cost effective solutions. and yes i do know what i’m talking about. Over 20,000 racing km’s beating factory backed Porsches. NO D.N.F.

  3. I agree with KISS typically, but a 13B-REW sequential turbo probably isn’t going to be competitive in modern day time attack racing, which is what the car was originally being built for. Trying to keep a 450-500hp 13B happy without significant changes to the cooling system (oil, air, and water) is going to be very tough.

  4. Sorry , Not trying to put you down, The car looked more like a show and dyno car. My experience is 450 hp tarmac rally car with competition from Germany backed Porsche 993 turbo 996 turbo . You are right you will have to
    modify a few things and if you are serious about time attack maybe not the right place to discuss. i had to develop the car from scratch and was selling parts to mazdaspeed japan at one point and made quite a few mistakes along the way as well , I can see a few things that could help done different. I’m in Australia and no longer race these cars but will defend their underestimated ability i will shut up now . This is your project,

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