K20 mx5

**madjak** · 28-03-2014 02:39 PM

Originally Posted by PHO

K20a3 is a potato.

What about these killer vtech builds? Putting the exhaust rocker on the intake to remove the vtech and using a2 cams. They seam to get 200hp out of a a3 pretty easy. Though there are a few that have grenaded by the sounds of it.

**dorikin** · 28-03-2014 03:01 PM

Here you go

http://www.k20a.org/forum/showthread.php?t=112309

**RenzokukenJ** · 28-03-2014 05:11 PM

Subbed for Perth and kswap feel

**chez00** · 28-03-2014 05:42 PM

The gearboxes are actually pretty good strength-wise - their main downfall is the (single) synchros causing crunches, particularly 3rd. This comes down to driver sympathy though - there are fixes but can be fairly expensive. I reckon you'll be fine with a natural K in front of it. There are lots of final drive options available too for the MX5 which are shared with the s2000. Go for it!

**lilthug** · 28-03-2014 06:50 PM

Originally Posted by u mad?

k20a3 are fukin shit. might be ok while you source/build another engine though. not worth trying to get power out of.

Those mx5 6 speed are the same as the rx8 gearbox if im not mistaken, seem to be good for around 400 or so hp.

from what ive been told

same as 6 speed s15 200sx boxes

please correct me if this info is wrong

**chez00** · 29-03-2014 07:36 AM

Yeah the 6 speeds are pretty similar between the mx5, silvia and rx8. The OP would have a 5 speed in the na though I think.

**plohl** · 29-03-2014 08:04 PM

You have to get a rhd sub frame from v8 roadster and fab up engine mounts yourself as the subframes magic will be selling are lhd specfic.

The difference is the steering rack mounts are located different laterally between lhd and rhd.

Using an s2k manifold will be much cheaper than itbs.

You'll need a custom exhaust made to clear the steering rack.

I did a lot of research into this when the k20a thread first popped up. It was looking close to 15k for the conversion with myself doing the labour but paying for the required fabrication.

good luck with it man!

There is an nb mx5 being done by byp at the moment as far as I know.