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Thread Topic: Megasquirt and ITB's, are you using SD or Alpha-N? Threaded

   
Date: 3-28-08 08:48
From: beast02er in B'Ham View user's profile Send e-mail
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 View user's profile
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..
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Prep the jet car for city driving



Date: 3-29-08 02:32
From: johnhup in San Francisco, CA View user's profile
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.
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