ECU Crystal mod with Dyno Results

Hi,

I own a 1995 Eunos Roadster 1.8L (Mazda Mx-5). Engine is unmodified except a cold air intake and different exhaust. This Swedish winter I have worked on improving the engine, and had the opportunity to also the to get bottom of this Crystal ECU mod. Here we go...

Last summer, I changed the crystal in the ECU, to raise the rev limiter by 5,75%. It worked good, but alot of discussion where whether it also gave some performance gain. Today I got results from dyno run with and without the crystal mod.

• I have two ECUs,
• The first one is an unmodified ECU from Japan (orginal in the car).
• The Second one I bought on ebay for ~€10. It from a 1995 Mx-5 sold in UK.
• I ran both without modification on the road, without any difference in feel what so ever.
• I replaced the original 8MHz crystal for a 8.47MHz crystal in the UK ECU.

Original ECU (Japan) dyno run

Crystal Modified (UK ) dyno run

As you can see, the result is quite clear, I did get more power. 

The only uncertainty in this test is that we didn't test this with the same ECU hardware, but the software in the ECU was checked and is identical. 

Conclusion

Either the hardware is different (unlikely) or the Crystal mod does work both for raising the revlimiter and give you some extra horse power, almost for free.

References

• http://forum.miata.net/vb/showthread.php?t=145076 
• http://www.mx5racingclub.se/forum/viewtopic.php?f=5&t=2071 (Swedish)

Note

If you liked this article, follow my blog or youtube channel. Have fun modding and racing!

Big thanks to Claus Aichberger at http://www.turbocenter.se/