ok, i have a 20b front clip (so stock ecu etc) and from my reading of old posts and asking questions i had the understanding that it is not possible to use the stock ECU and run a 5 speed transmission. now i know that it would be silly to not use an aftermarket ECU but i just want to get one thing clear. i stumbled onto this old post -> https://www.rx7club.com/forum/showth...hreadid=198702 in which a person with a 20b cosmo installed a 5speed gearbox with no problem using the stock ecu. so my question is -> is it, or is it not possible (without major modifications) to run the stock cosmo ecu, without the automatic transmission? if the answer is that it is not possible... what would prevent the engine from running on its own with the transmission not connected? thanks to all the knoledgeable 20b forum readers.

 

Without the correct signals from the auto trans computer & all the other sensors you are going to detach.

You are going to be in "limp mode" & not know how to get out unless you electrically simulate all the missing inputs.

There is a guy in NZ with a company called "Gizmo electronics" Try him at www.gizmoelectronics.co.nz at a guess, not sure.

He can modify the stock ECU to "re-boot" & ignore all missing inputs thus allowing it to run correctly. Much easier I'd say, Good thing about the NZ Peso is how cheapit would appear to the average guy in the US.

REgards

 

It is possible to run the stock ecu with a manual trani,
i have tried it and the motor seems to run fine with the
auto trani control box not connected, you may have to
keep some of the speed sensors connected to the wiring
or put resistors in their place but it can be done.
Now is it worth it? since i have the stock ecu running
the 20b in a 88 rx7 (with the auto trani) I know how
much work is involved and i would say its not worth it.
someone else to ask about the stock computer is the
guy who built the delorian 3 rotor car he is running
a 6 speed with the stock cosmo computer.
there are a few secrets you need to know to
make it work but not that many.
I still think its not worth it , i intend on going after market
as soon as i get the computer and my new motor
built.
matt

 

we have a stock ecu 20b running in an 87 b2600, and so far its happy with the manual. its bascially a dont ask dont tell deal for us

mike

 

thanks very much guys!! i appreciate all the info! untill now i had heard that it was not possible. well now that i know it is doable, the question that Now brings up is "is it worth it" ..... well probably not. im trying to figure out who would be the most qualified to tune a stand-alone ecu (and which one) in my area. hey mike: what are you running and are you/did you do the tuning yourself? heath

 

I have the JC Cosmo here in NZ with a 5 speed and factory ECU, no issues, just diconnected the Auto ECU and away we went.

Gizzmo even said there should be no problems which to me contidicts what was said about Lance Warrend HB Cosmo conversion.
But it works.

 

i'm switching from an e6k to an e11 right now, paul (from k2rd) and i are gonna tune it, actually if i'm lucky the map in the e11 might be close enough i dont have to do much

mike

 

I will be interested to hear who that goes for you,,, i am still unsure
as to what i should get the e11 or a microtech.


matt

 

i'll keep you posted

mike