How exactly does the 112mph limiter on Jap Cars work?
 

Just wondering if someone can give me a quick explanation as to how the 112mph limit on Jap cars actually works, is it all electronic?

Also, does hitting this limit cause any damage to the engine, or is it totally different from Red Lining a car?

I haven't been that fast in my car lol, only had it 2 days, but was just curious as to how its works as mine is still limited and in km/h.

i believe it is a sensor on the speedo mechanism itself, as disconnecting the speedo can cause the car to enter "limp" mode.

IIRC the converter just gears down the movement of the needle.

so my kph reading is now mph :) so 180 kph is now 180 mph

and i blacked out the kph letters with a marker pen.

Ah ok cheers for the reply. So can it cause any actual damage?

i wouldn't really know about this to be honest, but i would avoid bouncing it of the limiter. Also acts as a bit of a "licence saver!!"

if you want more speed (say for track use) then get it derestricted.

When I brought mine I was thinking about getting it derestricted but ive had it a year now and hav not bothered with it. Im use to driving it in KMH and i neva really go over a hundred anyway. Well a couple of times but I rarely do it.

I have a WRX - type-ra, took mine to 110mph but the 5th gear ratio is not going to go much faster than 115 i would think.

I've always wanted to know what happens when you hit the limit

Does it bounce like if you hit redline if that makes sense?

It did'nt redline but it was like a bounce. I backed off then down to 100.

sort of like jerks slightly and sort of misses and just dose not get and kwicker no matter how hard and how long you press throttle...can be annoying when you have a prat close and you leave them for dead and they eventually catch up and pass thinking there INIT cosra has just found 250 bhp from somewere :mad:

Mine just cuts the power for about half a second and then cuts back in again, quite off putting, doubt it does any damage as I guess it only cuts the ignition cycle for a few goes.

the speed restriction is actually done by the ecu.. it monitors speed and there is a setting within it for the speed restriction point. . hence it is an ignition cut similar to rpm lmit but softer and if you disconnect the speedo the ecu limits the rpm to 4500rpm.. or tries :)

you can derestrict by a speed converter that changes the pulses the ecu sees and therefore it doesn't see the actual speed, or if an early car alters the amount the cable into the speedo rotates.. the gearbox speedo drive feeds the speedo in the dash which then sends pulses electronically to the ecu.

Or via a remap the speed restriction rpm can be changed.

Simon

Yeah I still run in KM, licence saver. Well you can still get banned for doing 112mph but it's better than doing 150mph!

It's nice to know it cuts ignition and not fuel, I though it sounded as if the car was running lean when I hit. I just get to that point on the track and it jolts you and says I don't think so sunny :D