I have a heavily modded 383 in my 89 Camaro. I'm getting a Vortech SQ-trim blower and wanted to know if someone out there is running without an FMU? I have a custom chip from TPIS and can get it reprogrammed. I'm running #24 injectors right now but will step up to may be #36. I know my friend with a mustang is doing this right now. Is it possible? Thanks

 

To run without an fmu you need to use either aftermarket, or factory ecm that uses a 2bar map. The sy ty ecm is one example of factory. However if you're like me, and stuck with a factory one bar map ecm due to smog checks......then it's an fmu....just make sure you use a wideband to safely tune.

 

Thanks. I have hear of the 1 bar & 2 bar Map, what exactly is that, and what's the difference? I have an aftermarket TPIS chip, with the stock 89 ECM.

 

1 bar= reads from -1 bar to 0
2 bar= reads from -1 bar to +1 bar

If you want the ECM to know when youre under boost (over 0 bar) you would have to have a 2 bar sensor, but this is nothing you just change you need to modify more to make it work, specially on a MAF car.

Ways to go (search and check out the sticky)

- Change to 808 code and use a 2bar MAP and compress "all" the tables.

- Change to a GM730 ECM and do the same thing

- Change to a GM749 ECM (typhoon) This one is made for boosted application.

/N.

Do a search and read and post your questions.....

 

Thanks, I'll check into it.

 

There's another thread running right now about this.
Also, searching for info on 749 will get you volumes of good info..