Tuning for low speed, very light throttle driving

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Tuning for low speed, very light throttle driving

Postby 73Inka2002 » Wed May 16, 2012 1:20 pm

Hi guys,

I've got my VE table pretty well sorted, but one area that I'm having trouble with is low speed (1500 - 2000 RPM) and very light throttle (1% - 5%) conditions. Think crawling through a parking lot. I can make things better by cranking in a lot of advance (40*), but then what winds up happening is that the car idles high sometimes because it gets "stuck" on the extra advance. If I keep the advance lower than the idle returns to normal idle (1050 RPM idle) much more quickly. With the extra advance it sometimes gets stuck at 2000 RPM. I've attached a tune file and recent log. Check out the 1600 and 2000 RPM cells at 0%, 1% and 3%. However, as the tune file sits today I was playing around with those areas so it may not be indicative of how I've been running it for the last few weeks.

The car is a 1973 BMW 2002 with throttlebody injection. The cam is fairly long duration at about 290*...

Any general tuning help is greatly appreciated!

Robert
Attachments
2012-05-16_13.16.46.msq
(47.51 KiB) Downloaded 37 times
2012-05-15_13.20.43.msl
(1016.48 KiB) Downloaded 20 times
Car Info:1969 MK1 Ford Escort with 2.3L Cosworth Duratec

MS Info: MS3X, firmware 1.3.0, full sequential fuel and COP.
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73Inka2002
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Re: Tuning for low speed, very light throttle driving

Postby 73Inka2002 » Fri May 18, 2012 11:19 am

Before I give up and just try to live with the poor light throttle driving, I wanted to appeal to the group one last time... Anyone have any advice?

Thanks,
Robert
Car Info:1969 MK1 Ford Escort with 2.3L Cosworth Duratec

MS Info: MS3X, firmware 1.3.0, full sequential fuel and COP.
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73Inka2002
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Re: Tuning for low speed, very light throttle driving

Postby Matt Cramer » Fri May 18, 2012 11:29 am

Any reason you're running a really old beta code? The fact that the INI file for that one is hard to find has probably discouraged responses.
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Re: Tuning for low speed, very light throttle driving

Postby 73Inka2002 » Fri May 18, 2012 2:06 pm

Hi Matt,

Thanks for the response. Is it anticipated that my issue would be resolved by using the latest code?

I've resisted the temptation to chase the latest code versions because doing so in the past has required mild to moderate retuning of tables. I guess I decided a couple years ago that the car was running and I didn't need any additional features, so I stopped there. I can upgrade to the latest code version, but I'm not looking forward to export/importing tables and trying to get my head around any new features, etc. At some point I feel like I just need to draw a line and drive the car and enjoy the fruits of my labor...

Thanks again for your response,
Robert
Car Info:1969 MK1 Ford Escort with 2.3L Cosworth Duratec

MS Info: MS3X, firmware 1.3.0, full sequential fuel and COP.
User avatar
73Inka2002
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Posts: 136
Joined: Sat Sep 18, 2004 3:21 pm

Re: Tuning for low speed, very light throttle driving

Postby Matt Cramer » Mon May 21, 2012 5:20 am

It's possible. You'd want to at least get the bug fixes when 2.0 was released.
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Re: Tuning for low speed, very light throttle driving

Postby 73Inka2002 » Tue May 22, 2012 9:09 pm

Thanks Matt,

I upgraded to the 3.2.1 code last Friday on your suggestion. I've been retuning the VE table and will repost msq and logs if the problem persists. I've also taken this opportunity to adjust my req_fuel to gain some additional granularity in the low load areas of the VE table - that might be part of the problem... I'm not using "multiply map" now because I'm doing pure alpha-n, but I may turn it on if I need additional granularity.

Thanks again,
Robert
Car Info:1969 MK1 Ford Escort with 2.3L Cosworth Duratec

MS Info: MS3X, firmware 1.3.0, full sequential fuel and COP.
User avatar
73Inka2002
Helpful MS/Extra'er
 
Posts: 136
Joined: Sat Sep 18, 2004 3:21 pm


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