[nigelmac]

Hi folks,

I converted an automatic 4age 20v silvertop to manual but I'm still using the auto ECU. Recently did a dyno run and we noticed that the engine generally runs very rich above 3800rpm. (regularly spits flames out the back).
I'm thinking this is down to the auto ecu and may change to the manual ECU (though I'll have to change the harness as well).

The dyno plot also shows max. power at 7400 rpm, it seems to be missing a large chunk of mid-range power due to the fuel richness

Is my thinking correct? Anyone else encounter this problem?

 

[REN69]

You won't have to change the harness and a lot of people I've heard of running 20V motors have run manual cars with auto ECUs. But yeah.. Auto 20V = 140hp, 5spd 20V = 160hp so who knows. :dunno:

 

[nigelmac]

I'm afraid the harness will have to change ..... the pinouts for manual and uto are different and the ECU connectors are also mildly different.

Any body else have any thoughts?

 

[mr220v]

Output wise, there isn't much difference between a 20v auto or mt ecu.

The pinouts are different for the silvertop At and Mt ecu's. It's pretty easy to repin. I actually make an adapter harness for this.

 

[94_Rolla_Guy]

you have resistors in for the shift solenoids? anyone i have ever talked to says you have to do this??

 

[mr220v]

you have resistors in for the shift solenoids? anyone i have ever talked to says you have to do this??

Nope, you don't have to do this. I've switched blacktop ecu's back to back. Driveability wise, there is no difference. Power wise, a customer of mine dynoed 151hp hp on a dynojet, and another 137hp on dynodynamics (one high reading dyno one low).

No adjustments need to be made for the AT ecu.