How to make a 2 BAR MAP work with a GM 8D #1227727 ECM?
 

Hi Folks,

First post. I tried searching and goggling for help on this but my extensive efforts were not fruitful.

I have a L98 350 TPI from a 90 Vette running the stock vette 8D ECM with a Procharger 600b. I am a novice tuner so please take that into consideration when you explain this to me.

I was advised that I could get a better tune if I used a 2 BAR MAP instead of the stock 1 BAR MAP. I purchased a 2 BAR MAP for a 87 Buick GNX, and cut the key ways so I could plug the MAP into the stock connector.

Some of the posts I found said others have switched to 2 BAR maps in "similar" GM ECM's by just halving the VE to MAP table. I tried cutting my current VE to MAP table by 1/2 but the car will not start or run when I install the 2 BAR MAP. So I assume there are more changes needed. It kind of shuddered. Reinstalling the stock 1 bar MAP and the car runs good.

I was hoping someone could guide me on how to get the #1227727 ECM to work with a 2 BAR MAP.

Or is it impossible?

Thank you in advance.

Re: How to make a 2 BAR MAP work with a GM 8D #1227727 ECM?
 

Have you been over to WWW.thirdgen.org

Re: How to make a 2 BAR MAP work with a GM 8D #1227727 ECM?
 

Antoine's got a good point.
I'd try the DIY PROM forum there.

Lou

Re: How to make a 2 BAR MAP work with a GM 8D #1227727 ECM?
 

Somebody rewrote a code for boost with 8D but I've never seen it completed or used. it was never given out to the public.

To use a 2 or 3 bar map on GM ecm, you would want to use the 730 or 749 ecm's and run Code $59 from turbo trucks. Code59.org I believe you can find all the information. Thats what I use in my 401 twin turbo. 800+ hp on motor on the old setup.