Jump to content
SAU Community

Recommended Posts

As many of you are aware for a few years now I've been bitten by the rotary bug, they're not for everyone but I love 'em!

So quite some time ago I purchased myself a JC Cosmo with a factory 20B in it, I had the motor built by local rotary gurus 'Rotomotion' (GT4202R, dowelled, bridgeported etc.) and it made a bunch of power which was great. 2 years ago at RaceWars 2014 my tailshaft let go and I destoryed the back of my gearbox, since then the Cosmo has not been driven :( The Cosmo was in pretty poor condition and the dream ever since has been to buy an RX-8, drop the 20B in and go racing, good chassis + good engine should mean a fast car!

So last Saturday I finally got my hands on a car I wanted in my budget, picked up an un-registered RX-8 roller and thus my first proper motorsport build has begun!

As you can see I purchased the car with no engine or box so that is alread taken care of for me, I now have the car in the corner of the workshop and I'll probably start stripping it down soon.

RX-8.jpg

engine bay.jpg

  • Like 3
Link to comment
https://www.sau.com.au/forums/topic/465765-hanks-brap-brap-rx-8/
Share on other sites

1 hour ago, r32-25t said:

I thought you were building a street car with it

Nope, un-rego'd shell.

Sure I might chuck the trade plates on it but ultimately I'd like to take it to the track.

Welcome to the RX8 family.

My daughter has had a Series II RX8 for the last two years and I have spent many hours during that period servicing and upgrading it.

Dimension wise it is very close to my R33 GTR in wheelbase and track. The front and rear brake disks are also the same size as the GTR.

They are a strange animal to drive with a 50/50 weight distribution compared to our nose heavy Skylines. Braking, turn in and mid corner grip is amazing it is just the lack of power to drive out of corners like a Skyline that they lack. The installation of a 20B would go a long way to fixing the lack of punch.

In the US there are a number of kits to install a LS series motor and box from the new Corvette into the RX8 - that really gives them some punch. The kits are that detailed that they run the Corvette ECU to run the engine and then splice all of the sensors back into the Mazda ECU to run the dash and all of the systems. A friend has done this conversion in a FD RX7 and it is that seamless of a conversion that it looks like it came that way from the factory.

Subscribed to your thread to follow your progress.

13 hours ago, Victory said:

Welcome to the RX8 family.

My daughter has had a Series II RX8 for the last two years and I have spent many hours during that period servicing and upgrading it.

Dimension wise it is very close to my R33 GTR in wheelbase and track. The front and rear brake disks are also the same size as the GTR.

They are a strange animal to drive with a 50/50 weight distribution compared to our nose heavy Skylines. Braking, turn in and mid corner grip is amazing it is just the lack of power to drive out of corners like a Skyline that they lack. The installation of a 20B would go a long way to fixing the lack of punch.

In the US there are a number of kits to install a LS series motor and box from the new Corvette into the RX8 - that really gives them some punch. The kits are that detailed that they run the Corvette ECU to run the engine and then splice all of the sensors back into the Mazda ECU to run the dash and all of the systems. A friend has done this conversion in a FD RX7 and it is that seamless of a conversion that it looks like it came that way from the factory.

Subscribed to your thread to follow your progress.

Thanks Charles, from the Gong as well!

One of the reasons I wanted the RX-8 was because it has a great chassis. It's a fair bit more modern in design than an FC or an FD (or say a Skyline), lots of available aftermarket parts as they were sold locally in Japan, Australia and the USA and it should be made to be really good around corners. A nice set of coilovers, swaybars, strut braces, underbody bracing and eventually a cage should make it turn on a dime.

Luckily for me I have the ECU, wiring and Microtech out of the Cosmo, between that and what's left in the RX-8 I don't imagine it will be too difficult (in the scheme of things) to get everything running nice. And putting a rotary into a car which already had a rotary in it obviously makes things a bit simpler again.

 

  • Like 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Latest Posts

    • Given you're running a 2.8 and my 2.5 is not really like for like, I suspect there could be a bit more timing you could give it. What is the kW yield per degree you're putting through it? Here's my E85 map to give you an idea, where it was I could still get another 3~4kW per degree thrown at it.  
    • It turns out that Setrab make a fan specifically for the oil cooler which is great and I've installed it with minimal swearing. I removed my 2x 12in push fans from the front of my aircon condenser and wired them into this. My main thermo fans kick on when I use the aircon anyway and would effectively already be working as puller fans through the condensor which is infront of the rad. The push fans (understandably) didn't really do much in the config they were previously in so now they're out. Now we're on to the "Oil fan doesn't really do much either!". Yes I'll duct it next if it does nothing in heavy use which it shouldn't. But hey, the object exists and fits great and is cool. Let me have this. The car is still in the "do my fittings leak oil now? do my wheels actually rub?" phase. I did a spirited drive on them and didn't hear or feel anything. Then I got back home and noticed there were grind marks on the inside of the rims, though I couldn't see where they were touching I got out the grinder and attacked the suspects. Note: I do not know how to use a grinder. Then I realised I had dragged my new rims across my concrete driveway before I did this drive. I didn't think I had damage at that time when I briefly looked...... but remembered this occurred after I did all the angle grinding. The grinding on the wheels in some very specific spots. It's not around the whole rim for example, which lines up with dragging it across concrete more than hitting a suspension component for even 1 full rotation. So everything is currently painted and taped up and I need to test it some more to see if it really IS rubbing, but from inside the car it doesn't feel like it is. In other news I attempted to do a before and after comparison of the heads/cam upgrade thing. Dynos lie, everything is in different measurements. Here is the data from the sandown back straight. Car go faster than before. Vroom vroom.
    • Here's my base ignition. +3 correction to redline when shooting water/meth which is always on. Looking at my old ignition table, I should be able to add 1-2 degree's next time I'm on the dyno.  Let me know your thoughts. 
    • Given what I know now - same haha, but this was 12 years ago with second hand 740cc Nismo injectors in my S15 daily, I was too busy hunting elsewhere for the issue to even look at the injectors, running through some cleaner was a happy coincidence haha
    • Not a terrible idea. But if I ever had concerns that my injectors were sufficiently dirty to be causing me a problem, they would be out of the engine and onto the actual injector cleaner/testing bench.
×
×
  • Create New...