ECU Speed limit removal help
 

ECU limit removal
Sorry Ive I'm repeating previous thread.
I have a 2006 Japanese RX8 MT. On the weekend I was returning from Nikko in mountains 2 hours outside Tokyo and I found the 180KM limiter, I was not impressed.
Apparently all Japanese car manufactures have this voluntary limit installed.

I would like to ask the RX8 community from experience what would you recommend to remove this? I’m happy with the power the engine is a gem just want limit removed without messing with the injection profiles.

I would appreciate your advise.
Email gturner@cisco.com

Cheers,
Garry

Since your'e in Tokyo, you can have the ECU reflashed (RE-Amemiya offers this service) to remove the speed cut. Alternatively, you can get an SLD (Speed Limit Defencer) from HKS. Good luck.

Ray

Or you can put a kill switch on the speed signal wire that inputs the pcm, your speedo will effectively read 0 when the switch is turned on however because its a manual vehicle it will allow you to keep accelerating. Essentually the ecu cant cut your speed if it has no idea how fast your going... yes its a hill billy style fix but if you dont need to exceed 186kmph very often then it is a cost effective method (switch cost me .20c) your dash wi read 0 but your car will keep accelerating to its red line rpm limit. Remember to sever the inward signal to the pcm not the out bound signal from the pcm to your dashboard. Works with my 2004 5sp model and cant see any reason it wouldnt work on a 6 spd version. Auromatics may go weird as they have computerised readings for shift points etc and i wouldnt suggest it but as for my S1 manual RX-8 it worked fine. If i found myself around the 180kmph mark i simply flick the switch and keep the pedal floored and it keeps going. I will add if you turn it back on at more than 186kmph it will shut off the engine until it drops below as per factory limits.... all because the RX-8 was sold new with shitty tires that were highway rated to 195kmph... thats their reasoning for the top end limitation and tire safety ratings is the reason most vehicles have top end limits so be sure to check your tire ratings if you wish to exceed their stock limitations for top speed. Of course this is done at your own risk and i accept no responsibility for the outcome. But it works very well and costs very little and any nav unit will show gps based speed should that actually be of importance but i find at 220kmph im watching the track/road not watching my speedo on my dash.

that was from 13 years ago and the RX8 get’s it’s speed signal from the ABS sensors so your entire post makes zero sense.

And it's all CAN based.... not sure what he's cut but wouldn't be a good idea....

Before I got into flash tuning I found a way to delete the speed limiter by just disconnecting the rear wheel speed sensors in the boot. Only problem was it also took out the ABS........................... so coming to a stop from 220km/hr for a hairpin (pukekohe old circuit) I managed to flat spot ALL my tyres . Expensive lesson!

that’s what I suspected he might have done and would be the result if so, but didn’t think anyone could be that ... :)

You're sure about that 😏

two no less ... :Eyecrazy:

Maybe they just wanted to work on improving their threshold braking skills.:dunno:

sounds like one tried and failed, the other is likely practicing fiction story writing.

plus, you can practice it with ABS active regardless, you just don’t end up with flat tires or worse screwing up

the bigger issue though is the braking system is only F/R balanced electronically. You’re pretty much guaranteed to screw up without having made modifications to mechanically balance it without that being active.

Iv done 143 on a us street why cant you🧐

Maybe because he's driving a JDM car with the 180km/hr restriction in the ECU?

The clue is in the first post......

Safest way is to flash the ECU. The wheel sensors control braking and traction control. Fine for a race track but not very safe for a street driven car.