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Chevy, TPI, MS1 Accel Enrichment Bins

Posted: Tue Aug 10, 2010 8:11 am
by frenchsquared
Can some one point me to an article explaining the Acceleration Enrichment Bins (Ms)
I read the stuff inthe megamanual but that didnt explain this specific section.
Currently mine are all set to 5.0 and that cant be correct.
If possible can I get a few sample numbers to start from?

I dont know what TPSdot does?
Accel time I guess is the length of time these changes are made?
If it is cold I guess the cold air enrichment does something?
Cold Accel Mult is a percent so I guess it increase the full ratio by that amount.
So mine is getting increased by 130%. If that is true then under deceleration
my fuel ratio is decreasing by 90%.

This is a 350 with a very large cam. I want it tuned for power.
TPSdot = 19.922
Accel Time = .05
Cold Accel Enr = 3.0
Cold Accel Mult = 130
Decel Fuel Amount = 90

Acceleration Enrichment Bins (ms)
2 v/s = 5.0
4 v/s = 5.0
8 v/s = 5.0
15 v/s = 5.0

Re: Chevy, TPI, MS1 Accel Enrichment Bins

Posted: Tue Aug 10, 2010 9:26 am
by Bernard Fife
fs,

Did you look here: http://www.megamanual.com/mt28.htm#tl ?

There's also info here: http://www.megamanual.com/ms2/tune.htm#accel

Lance.

Re: Chevy, TPI, MS1 Accel Enrichment Bins

Posted: Tue Aug 10, 2010 10:50 am
by frenchsquared
this one helps some: http://www.megamanual.com/mt28.htm#tl ?
Thanks

Do you know any good starting numbers?

Re: Chevy, TPI, MS1 Accel Enrichment Bins

Posted: Tue Aug 10, 2010 1:10 pm
by Bernard Fife
fs,

The defaults are from my 406/460HP small block chevy (see viewtopic.php?f=31&t=38595&p=230122#p230122 to get the defaults).

However the accel parameters depend on the injector flow rate, and the method and final values of the VE and other tables, so it's hard to grab a set of values that will work from someone else. Instead the best bet is to follow the procedure from the manual.

It's not hard, and an experienced tuner can do this in several minutes (though it can be much longer if inexperienced - that's how you get experience, though!). You have to be methodical, and you may need to re-do it if you substantially change the VE table, etc..

Lance.

Re: Chevy, TPI, MS1 Accel Enrichment Bins

Posted: Tue Aug 10, 2010 1:13 pm
by frenchsquared
Thank you.
I will eventually figure this out.
I just want some numbers to look at to try to verify what I am doing.

Re: Chevy, TPI, MS1 Accel Enrichment Bins

Posted: Tue Aug 10, 2010 1:17 pm
by Bernard Fife
fs,

I just realized you have MS-I, the link for tuning accel for MS-I is here: http://www.megamanual.com/v22manual/mtune.htm#accel Those defaults aren't from my car (only MS-II is).

My MS-I values are here: http://members.shaw.ca/corvette.84/MS_TBI.html (scroll down the page)

Lance.