zener diod mod

[shred is not dead]

Instead of the gps mod, is it possible that you could use the "old" zenerdiod(4,3V) mod for removing the restriction in 6th AND this mod keeps the mapping and timing of all the other gears original(N12345 (6becomes5,because of diod))?

Anyone tried this (before i start measuring the voltage of the GPSswitch)on the busa2? any success?

 

[High-Gain Busa]

Shred

The mod would have to be done physically in the switch for something like that to work and the switch is not designed to come apart which is why most hackers are making the TRE's. The Busa uses a laser trimmed carbon resistive gear position sensor much like the TPS. The further the distance the higher the resistance. We just got 6" of snow today so I am going to do some work at the ECM where the wires come in. It would be a much easier mod to do it there.

BTW: Diode is the correct spelling

 

[Draco1340]

Actually the Gear position sensor on the 08 Busa uses descrete through hole resistors and provides 6 discrete values of
1st = .56k
2nd = .8k
3rd = 1.5k
4th = 2.7k
5th = 6.8k
6th = 15k
It is not a continuious film resistor. Just to be 100% accurate...It is identical in construction to that of earlier models. The TRE just has the single resistor value.

Smithabusa does the mod correctly, and does it for short money. And they are a board sponsor that turns stuff around fast.

 

[Tybalt71]

Say what? lol

 

[shred is not dead]

I think you misunderstood me;
The diodemod is not tre(=resistor) related; the diode also disables the speedlimiter in 6 BUT KEEPS stock timing,gear indicator and control for all gears (except:6>5).
The tre thinks 5( 6,8kohm) in all gears and you loose the gearindicator(which i do not want;i just want to get rid of the speedrestriction in 6 and want to keep timing and mapping of the other gears)
You just put the zenerdiode between the pink and black wire.(GPS>ECU)
Here is a link to the mod:

http://www.hayabusaclubbelgie.be/begrenzing.htm

it is written in dutch, but the pics will say enough.


The voltages measured(busa1) are:

1 - 1,80V
2 - 2,26V
3 - 2,99V
4 - 3,68V
5 - 4,38V
6 - 4,70V

So if you put a zenerdiode 4,3V then the voltage above 4,3V will be blocked off,but lower voltages still flow (that's the function of a zener)
It works on the busa1, so I'll try it on the busa2.
This very cheap mod "dissapeared" with the arrival of the tre,but if you JUST want to get rid of the speedrestriction,it is (maybe) the solution.
This mod was suggested by a friend(chief busaclub Belgium) and apparently this kind of mod is not very known ?.

 

[Draco1340]

Shred,
The diode mod does work the same way as changing the sensor resistor. V=4.3 for 5th and 6th. Same system as GenI.

 

[BusaWizard]

Interesting, very interesting.

 

[Italian Trev]

how often would you get the chance of go flat out in 6th?

 

[Got-Busa?]

how often would you get the chance of go flat out in 6th?

This from the guy with the AUTOBAHN in his backyard...

 

[bacharles]

 

[shred is not dead]

Shred,
The diode mod does work the same way as changing the sensor resistor.  V=4.3 for 5th and 6th.  Same system as GenI.

If that's the case,then i know enough.
I'll just measure the voltage in 5th and 6th gear again,cause my buddy claims that he measured different values compared to the values measured by you USguys .

 

[High-Gain Busa]

Just measured them last night and 5th is 4.39 with engine running and 4.72 on 6th. I did that because another site posted those voltages as the voltage dropped when in fact it is the voltage remaining.

That circuit is know as a pull down circuit and has 5v on it. The higher the resistance, the less the circuit is pulled down which is why the higher gears have a higher resistance value in the GP switch.

You have the zener diode operation backwards though. The reverse bias voltage of a zener diode is what must be reached before current will flow through it esseciantially backwards and there is a significant voltage drop in reverse bias equal to the reverse bias value. Zener diodes also have a forward bias voltage drop just like silicon or germanium diodes.

 

[shred is not dead]

OK ,high gain busa; thanks for the effort to measure again. I'll check the values of my euro busa(ecu europe is not the same as US ecu), but i am pretty damn sure the values will be the same.If so, then a 4,3V zener will be installed and  

 will be the result

 

[High-Gain Busa]

Let me know your results...

According to the pic below, the zener diode is in reverse bias with the pink 5v GP switch wire and connects to ground. When the voltage on the pink wire starts to excede 4.3v which it will in 6th the zener diode will be reverse biased and the circuit will be pulled low.

The question is what gear will be displayed?

A rev de-limiter can be made to be placed in series with the GP switch connector that will allow 1N23455 to be displayed. Easier to get at then the GP switch itself.

If this works ok, 4.3v zener diodes are 5 cents each.

 

[EarlyBird]

Good work!!! I am following you both on this post. I like to see your results with something installed in series with the GP switch. Instead of the whole removal of the clutch to get the gear position switch to swap it out or to do the mod itself to the switch.

 

[shred is not dead]

Someone here in Belgium, tried the zener mod and claims that it works: gearindicator still functions and shows: 1N23455 so the speedrestriction is gone !
Tuesday I'll buy my zenerdiode and will confirm if everything is ok...

 

[TulBusa]

nerds!!!!

........I have no idea what ya'll er talkin bout.

 

[V8Pinto]

how often would you get the chance of go flat out in 6th?  

one weekend a month for 7 months of the year plus one week at Bonneville. Just the Bonneville portion ends up being about 50 miles of WOT in 6th gear

 

[EarlyBird]

 

[shred is not dead]

OK, the zenermod works perfect!!

installing a 4,3V zenerdiode gives you:

1N(green light)23444 !perfect without any hassles !

No more speedrestriction in 6 !