5-Speed to Auto Conversion

fastsc92

Registered User
I see a lot of posts about converting an auto to a 5-speed, but not the other way around.

Just built myself a nasty C4 (billet aluminum high and forward drums, lightened input shell, fully rollerized, etc, etc. $4400!!!) that I plan to drop into my project car which is currently a 5-speed. The swap seems pretty straight-forward but what would I need to get this done? I will be using a reverse pattern gate shifter and not the factory shift console if that matters.

Here's my list of assumptions:

  • Auto Brake Pedal Assy - I assume everything is just plug and play here? Any jumpers, harnesses or bypass plugs required?
  • Transmission Harness - I can use/modify my 5-speed harness but perhaps it's easier to get one from an auto? All i really need is the speed sensor and the neutral/reverse I'll be splicing anyhow....
  • Clutch Master Firewall Blank-Off - Does such a thing exist? Are auto cars just not drilled to accept a clutch master?
  • Any ignition jumpers or harness plugs needed?- I'm guessing there must be something for a neutral safety switch or something?


The mechanical side is all figured out, just have questions on the above. Any input would be great guys!
 
Last edited:
I see a lot of posts about converting an auto to a 5-speed, but not the other way around.

Just built myself a nasty C4 (billet aluminum high and forward drums, lightened input shell, fully rollerized, etc, etc. $4400!!!) that I plan to drop into my project car which is currently a 5-speed. The swap seems pretty straight-forward but what would I need to get this done? I will be using a reverse pattern gate shifter and not the factory shift console if that matters.

Here's my list of assumptions:

  • Auto Brake Pedal Assy - I assume everything is just plug and play here? Any jumpers, harnesses or bypass plugs required?
  • Transmission Harness - I can use/modify my 5-speed harness but perhaps it's easier to get one from an auto? All i really need is the speed sensor and the neutral/reverse I'll be splicing anyhow....
  • Clutch Master Firewall Blank-Off - Does such a thing exist? Are auto cars just not drilled to accept a clutch master?
  • Any ignition jumpers or harness plugs needed?- I'm guessing there must be something for a neutral safety switch or something?


The mechanical side is all figured out, just have questions on the above. Any input would be great guys!


Here are some thoughts
* Auto brake pedal assy & transmission harness: since manual cars are much more rare than automatics, I'm sure you can sell these parts off and get the auto versions for a song.
* Clutch master firewall blank: auto cars are just not drilled for the pedal mount and the master. Just fabricate your own plate to cover the holes and screw/weld it in to seal off the honles. Seal it off so any fumes/flames from your engine bay dont come through into the cabin. That won't be fun.

-g
 
looking at the master wiring diagram, it looks like there is a clutch position jumper plug/harness. It's primarily for the starting circuit but it also feeds information into the ECU. Should I be adding this to my shopping list as well?
 
That's the other thing - you may need to swap the ECU, or get it tuned, to swap the manual dependencies to the automatic dependencies.

This is a question for someone like LaSota or our dechipha (and a boatload of others who know what the differences in the tunes are! I don't, it just seems like there'll be a difference in the tune ...)

RwP
 
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