runx 2zzge speed cut

[captain crescent]

has anyone removed the speed cut from the runx / allex / feilder? i have a few track days coming up and i would like to remove it incase i get the chance to take it over the 180 mark. is the only way with a rsm?

[kompressor]

has anyone removed the speed cut from the runx / allex / feilder? i have a few track days coming up and i would like to remove it incase i get the chance to take it over the 180 mark. is the only way with a rsm?

I thought jdm went past 180km. I thought mine was 200km

When and where you race Im keen to race too?

[91 ZERO]

I have been wondering this myself.

I was doing 1.30 flat laps in my then stock as a rock RUNX around Manfield and just touching 178kph on the straights. Now it has an exhaust, air filter plus semi slicks etc and so wanting to dip into the 1.27ish bracket but it won't do that if I will now be hitting a 180kph speed cut!

[sergei]

I thought jdm went past 180km. I thought mine was 200km

When and where you race Im keen to race too?

most likely speedo will be inaccurate and will show you a lot higher speed than you are doing.

My AE101 would point straight down, way past 180 (one could estimate at about 200) and then hit a speed cut. GPS would show exactly 185kph when speed cut would hit.

[Mr Revhead]

Hard to find any JDM car post 90/91ish with out a 180k cut

[captain crescent]

i have a track day at manfeild cuming up on the 3rd of feb and yea have some mods so in guessing im going to hit that speed cut i am in contact with the forty one toyspeed sponser about getting the hks speed limit defencer he quoted me $201 with free postage . it is the cheapest option i have found others is the apexi rsm which i am led to beleive has the speed cut remover. the pivot speed metre will not remove the speed cut unfortunatly because it has a bunch of other cool functions like g meter.

[Malcolm]

not sure how the speed cut is done on newer Toyotas, or what the speed signal to the ECU is used for other than speed cut, but you can do a very simple mod on older Toyotas where you put a small integrated circuit chip into the speed signal input to the ECU, and it gives an output pulse once for every 2 input pulses, basically telling the ECU you're going half as fast as you are.

If you're interested in more info, I'll see if I still have it here somewhere

[captain crescent]

yea ill be very intereasted if you have somthing there if i can save a bit of money on removing such a annoying little thing i would be very pleased

[kompressor]

keep me posted if you get something sorted

[Malcolm]

Ok so here's the instructions I found. Basically this chip is placed in line with the speed signal going to the ECU, it intercepts the signal and outputs only every second pulse. You can actually configure it to output less often, if you look at the datasheet for the IC I posted below, you'll see there's pins labelled Q1-Q7. Q1 (pin 12) gives half frequency, I think Q2 gives 1/4 frequency, Q3 gives 1/8 frequency etc.

Anyway, the wire colours and numbers are for a ST205 I think, but if you have an ECU pinout you should be able to work it out.

4024 pin #
1 ----> from speed sensor (cut the purple-white wire going on pin 9 ecu E6; 22 pin connector)
2 ----> Ground
7 ----> Ground
12 ----> this is the half frequency output from chip to ecu. It's the other end of the wire from the speed sensor that you cut
14 ----> +5v source. Will need to connect to a sensor voltage supply from the ECU. The speed sensor will have a 5v source you can use for this.

Here's an appropriate chip.
http://www.jaycar.co.nz/productView.asp?ID=ZC4024

Cost is about $2

Hope that helps, let me know if it works because I haven't tried it yet.

[MAGN1T]

If you look into it a bit deeper you'll probably find that all you need to do is to cut the speed wire to the ECU. If that upsets anything then just put a switch onto it.
It works with Mitsis..... same idea behind it, the speed sensor sends the speed signal to the ECU , the ECU cuts the speed. On Mitsis there's a function where if the car is moving, the motor has a fast idle , once below a certain speed the idle drops back to the proper idle speed. Cutting the wire disables that but the function isn't needed in a race car.
All you need to do is have a play with it, it's the only way to get the right answer.
I've never seen the point in fitting a frequency divider chip.

Steve

[fivebob]

If you look into it a bit deeper you'll probably find that all you need to do is to cut the speed wire to the ECU. If that upsets anything then just put a switch onto it.
It works with Mitsis.....

Doesn't work with Toyotas though

I've never seen the point in fitting a frequency divider chip.

Perhaps to remove the speed cut from Toyotas

[captain crescent]

the main problem i have is i really dont want to try and check that i have no speed cut on the road if i lose my licence i will lose my job so yea this is why i am using my car on the track to go fast and play around.

has any one tried using this set up? is there any teoretical way of checking it works?

[fivebob]

has any one tried using this set up? is there any teoretical way of checking it works?

It works on every other Toyota it's been tried on. If you connect it and don't get an engine check light then chances are it will work on your ECU, well at least until 360km/h

[MAGN1T]

is there any teoretical way of checking it works?

Axle stands.

Steve

[sergei]

is there any teoretical way of checking it works?

Axle stands.

Steve

Don't turn the steering wheel while doing "high speed" on axle stands. Gyro is a bitch in this case.

[fivebob]

is there any teoretical way of checking it works?

Axle stands.

IMHO Advocating such a dangerous method of testing is stupid in the extreme and even surpasses some of your previous efforts

[B_giB]

is there any teoretical way of checking it works?

Dyno?

[iOnic]

Do NOT use axle stands to test it Just assume it works until you're on the track or pay for a dyno run.

[Dell'Orto]

is there any teoretical way of checking it works?

5th gear standstill burnouts hey its safer than magn1ts idea!