Help me tune! - Third Generation F-Body Message Boards

sylgeist · 09-13-2009, 11:46 PM

There is a wealth of information on this site, so I apologize if there is a thread right in front of me that I'm missing.

I need some help tuning my Ramjet 350/4L60E. I had a number of issues with the MEFI setup and in a moment of frustration called Howell and got a computer from them. It's a 7427 which from my reading seems like a decent PCM. Last week I bought the Moates Burn 2, and adapter so I can make some adjustments. The 7427 is already miles ahead of the MEFI setup as far as drivability, but it still has some things I'd like to change.

Here are my questions:

1. I'm using TunerPro because I can compare the MEFI cal easily. I'm very confused on the spark advance bias values. Different XDF's ($0D) show different amounts in the spark table and I'm not sure which is correct or what the purpose is. For example, in one the highest spark value shows as 31, and another 41, but they both have the spark bias set to 10 degrees. The cal that came on the Ramjet is super simple, but has significantly more advance than the Howell unit or a stock cal. Is there a reason they chopped it back so far that I'm not seeing? I'm read a lot of threads, but haven't seen a consistent way to go about tuning the advance. I never show any knock counts (which may mean my sensor isn't picking it up) so I'm not sure how close I am to maxing it out.

2. I live at ~6000ft - is there anything that should be altered while I'm customizing that would make it run better at this altitude, or does it matter?

3. As I mentioned before I live at higher altitude and the Ramjet is in a Jeep so I know it's not going to be as fast as a car. I did a baseline dyno when I got the 7427 and pulled 190HP/245TQ at the wheels corrected for altitude. Even with drivetrain losses that seems far from the advertised engine specs. Am I crazy thinking there should be more power in this motor?

Thanks for any help that might be out there!

webcat · 09-14-2009, 01:05 AM

[quote=sylgeist; I never show any knock counts (which may mean my sensor isn't picking it up) so I'm not sure how close I am to maxing it out.

[/quote]
If your sensor was'nt picking it up i would think that you would have a check engine light!!

Ronny · 09-14-2009, 03:25 PM

Try rapping on the block with a small hammer to force a KC. I am surprised your logs do not register a K on startup. I always do. 100-200 counts.

Six_Shooter · 09-14-2009, 05:21 PM

Quote:

Originally Posted by Ronny

Try rapping on the block with a small hammer to force a KC. I am surprised your logs do not register a K on startup. I always do. 100-200 counts.

I don't get KR at start-up, but will most often get LOTS at shut down.