z 34 speedlimiter

[Reimer]

how do you disconnct the speed l;imiter on a 92 z 34. right now it cuts out a 210 kph and the car has soooo much more speed potential

[The Burning Rom]

You have to modify the Memcal inside the ECM. There is no mechanical part to "disconnect".

[hoosier1]

Originally Posted by Reimer

how do you disconnct the speed l;imiter on a 92 z 34. right now it cuts out a 210 kph and the car has soooo much more speed potential

The engineers detuned the 3.4 engine from roughly 280 HP to 210 for the 5 speed and 200 HP for the automatic because the transmissions available ( (at that time )would not take the big horsepower. The only transmission available in 1989 was the old hydramatic THM 440-T4.
The old THM 440-T4 was reworked and called the THM 4T60E
They detuned the 3.4 DOC by limiting fuel delivery and spark advance curves. The rev limiter under load was set at 6500 RPMS and 3000 free rev RPM`s. The top gear shift point is roughly 6,250. The engine control Module does all this stuff.
Even if you were able to eliminate the rev limiter the engine would not develop its originally designed HP because the fuel delivery and spark advance would be beyond design parameters.
There are speed chips available for this engine, I believe. There is also a programmable transmission shifter that allows you to tweak the shift points and line pressures.
I believe a supercharger or turbo would be fun to try on this engine.
Bob

[The Burning Rom]

Originally Posted by hoosier1

I believe a supercharger or turbo would be fun to try on this engine.

It's been done already.... http://www.brian89gp.com/

And I think there was more to detuning it than just fuel and spark. I think they made some mechanical adjustments as well (cam grinds, combustion chamber size, compression, etc)