NA6 Chassis and Boosted MZR 2.5 motor
 

Thanks to an intervention from 2 Americans, the current 204 RWHP naturally aspirated MX5 NA6 (BP motor) will be retired at the end on 2020. In its place will be a build that conforms to World Time Attack clubsprint rules, essentially putting a boosted Mazda 2.5 ltr motor into the NA6 chassis.

Why the NA6 chassis, weight! The rules set the weight for a NA6 at 893, NB at 1,012 and the NC at 1,055 (KG's of course).

The current plan is to run the naturally aspirated car for the rest of 2020 then start testing the new build in 2021. Will update the forum as stuff starts.

Ordering a dry sump and sourcing a gearbox so the engine/driveline can be installed. NB subframes will be used for the small advantage in track and more rear suspension travel.

The current wiring powered by a Racepak Smartwire and the Haltech PS1000 will be transplanted, all that will be required is a new engine loom!

The motor that will be used for mock up. Will be interesting as being RH drive the exhaust, turbo and steering will be all on the one side. The car does not run a brake booster so this is one thing less to worry about.
https://cimg1.ibsrv.net/gimg/www.mia...1a83c4db34.jpg

The shell that will be used to fit everything into
https://cimg2.ibsrv.net/gimg/www.mia...3be606574c.jpg

Car being retired :(
https://cimg3.ibsrv.net/gimg/www.mia...101decdc74.jpg
https://cimg4.ibsrv.net/gimg/www.mia...5e5ac23644.jpg

Mariner blue never looked so nice (yes it is my car)...
https://cimg5.ibsrv.net/gimg/www.mia...2a934cef93.jpg


One of the people responsible for the decision to go down this well trod path...
https://cimg2.ibsrv.net/gimg/www.mia...6b3f0968f6.jpg

Wow, a 121kg weight break for the NA is a no brainer. I must be missing something there as to me the NB is essentially the same car, especially at the build level you are aiming for. Will be keeping tabs on this for sure. Lots of luck!

Sounds like a really cool project, eager to see more!

In for results, sounds awesome!

This is beyond exciting! Seeing these 2.5 swaps into the NC has made me want to see one boosted in a NA!

This is a swap that has neither rhyme nor reason. Its more costly and WAY more work than a 99+ swap. Its additionally a similar sum or more work and most likely cash as the honda swap with significantly less to pick up. It could bode well on the off chance that you were in a hustling class that solitary let motor swaps from a similar producer in, yet that is about it.

Oh boy.

you being a negative Nancy has no rhyme or reason

I think this swap has alot of potential if it is simple to execute. These engines are dirt cheap and make decent power turbocharged.

Man that car looks sick. IN4 Results.

The rules do not allow a K swap so that is off the cards, unless the car moves to open class (WTAC rules). Rumor is that this swap has already been done once or twice in the states anyway so not new...

To add fuel to the fire, it will more than likely be converted from RHD to LHD for a few reasons.

1. No need to fit the steering column in between the exhaust plumbing. The exhaust is now on the right side...
2. Between weight distribution options, especially for anti-clockwise tracks.
3. Rules do not prohibit the swap :)

Only real concern at the moment will be the NC 6 speed gearbox, if this proves to be a weak link then there is the local option to graft a T5 gearbox in.