Oddball TH400 idea

[CTX-SLPR]

Howdy,

we all know that the vaccum modulator is the big sticking point for those who want a TH400 and automatic shifts. There is the diesel cable modulator option and the full manual valve body option as definate alternatives. There is also the check valve and pinhole leak method to keep vaccum from being trapped in the modulator on a quick rise to boost. My thought was what about an emission solenoid type approach to the leak. Tie a 0psi hobbes switch to trigger a canister purge or simular solenoid to vent the modulator under boost and use the checkvalve as quicker reacting protection for the modulator diaphram. Atmospheric pressure would send the trans to full mod pressure wouldn't it since its 0 vaccum?

Critque if you will,

 

[charlief1]

The diesels had a vac pump on them if I remember right. No cable adaptation. I may be wrong cause it's been a few years since I've been under the hood of one.

 

[Alky V6]

You're correct Charlie.

Any type of system that would supply atm pressure to the modulator when the engine goes to boost would work fine.

 

[CTX-SLPR]

Cool, a 0psi hobbes switch I'm sure is cheaper than the cable modulators. Trying to limit the new parts I have to buy to add the turbo that won't eventually be useful with my 4L80E.

Thanks,