Date: 3-28-08 08:48 From: beast02er in B'Ham Subject: Megasquirt and ITB's, are you using SD or Alpha-N?
I am in the beginning phases of tuning my car now that I have gotten it running. I have started off trying to tune with Alpha-N as I am using the ITB's and it is recommended to use due to the MAP signal issues.
So my question is, if you are running the ITB's, are you:
1. Using standard Speed density and are dampening the MAP signal with something like a little fuel filter.
2. Using megatune and running Alpha-N
3. Using MSNS-extra and running Alpha-N
I have been trying to use megatune to run Alpha-N, but am getting the feeling MSNS-extra is better suited to Alpha-N. I don't want to make the switch unless I am sure because I have to change some of the jumpers on the board.
Let me know, I am interested to hear (and get my car driving!)
Thanks,
Bryan
red73
Date: 3-28-08 09:45 From: nv02 in Lake Tahoe Subject: Re: Megasquirt and ITB's, are you using SD or Alpha-N?
Although I use a Haltech F9 system, I run ITBs with a 304 cam that wouldn't give a strong vacuum signal at the MAP sensor. I tried the fuel filter thing, re-routing the vacuum lines, different MAP sensor, all to no avail. Life improved significantly when I switched to Alpha-N.
One thing i noticed about the crusty DOS based Haltech display is that it was set up for Speed density and adjusting the maps in Alpha-N was touchy at best. In my setup, the map values change very little between RPM and TPS values and very sensitive to minor dips and bumps. I ended up writing a smoothing program that would apply a simple bilinear filter.
So, I would use whatever setup is best targeted at the values for Alpha-N and has a smoothing function. A good 3D graphical display with a zoom option would be beneficial too.
I assume you have a WB02 to monitor the AFR. I now have an in-town driveable car that runs great at the track. It wouldn't have easily happened if I tried to map it using speed-density (not without some serious mods).
Hope that helps a little,
Dave.. _________________ Prep the jet car for city driving
Date: 3-29-08 02:32 From: johnhup in San Francisco, CA Subject: Re: Megasquirt and ITB's, are you using SD or Alpha-N?
Check out my blog (click my sig). I am running SD with a 278 degree cam. Works like a charm. _________________