Engine Management Forum Use this area for discussing Haltech, Wolf 3D, Power FC, AEM and any other aftermarket ECU upgrades. Help/Questions/Tuning

Tunning A/F question

Old May 8, 2003 | 02:15 PM
  #1  
KNONFS's Avatar
Thread Starter
B O R I C U A
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (14)
 
Joined: Mar 2001
Posts: 5,482
Likes: 36
From: VA
Question Tunning A/F question

Hey Guys,

I really don't know jack about tunning, so I ask for help! I've heard about tunning A/F's on the street because of load, what exactly do people mean by load?

Another question is, what the perfect A/F's? And I don't mean the numbers, but should the numbers be linear vs the rpm's? or should the increase\decrese vs rpm's?

I would appreciate any info, if not anybody knows books that my answer my questions?
Reply
Old May 8, 2003 | 03:01 PM
  #2  
eViLRotor's Avatar
Brother of the Rotary
Tenured Member: 20 Years
iTrader: (2)
 
Joined: Jun 2001
Posts: 5,781
Likes: 2
From: Arkham Asylum
Some people prefer to tune on the street because there is more rolling resistance placed on the car compared to a dyno. This means more accurate tuning.

Some dyno's (ie DynoDynamics and Mustang Dyno's) 'LOAD' up the car to simulate that resistance.

Load in terms of tuning an EMS, is the amount of manifold vacuum or boost you see.

For instance, 100% load on my car is 15 psi, since I'm wastegate limited to that.

Your desired air fuel ratio is dependent on load and rpm.
You will definitely need lees fuel at 5000rpm while cruising than at 5000rpm under boost.

The more load, the more fuel...
Reply
Old May 9, 2003 | 06:13 AM
  #3  
KNONFS's Avatar
Thread Starter
B O R I C U A
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (14)
 
Joined: Mar 2001
Posts: 5,482
Likes: 36
From: VA
Originally posted by eViLRotor
Some people prefer to tune on the street because there is more rolling resistance placed on the car compared to a dyno. This means more accurate tuning.

Some dyno's (ie DynoDynamics and Mustang Dyno's) 'LOAD' up the car to simulate that resistance.

Load in terms of tuning an EMS, is the amount of manifold vacuum or boost you see.

For instance, 100% load on my car is 15 psi, since I'm wastegate limited to that.

Your desired air fuel ratio is dependent on load and rpm.
You will definitely need lees fuel at 5000rpm while cruising than at 5000rpm under boost.

The more load, the more fuel...
Hmm, I see. This is actually more complicated than what I thought So how do you tune for cruising vs boost in say a halltec\microtec? Do they have special functions for this? Or is just "practical" to tune for "under boost" and use this map all the time?

Thanks for your response!

Anybody else want to chime in?

TIA!
Reply
Old May 9, 2003 | 09:39 AM
  #4  
Cosmo Donk's Avatar
Queer
Tenured Member 10 Years
 
Joined: Mar 2001
Posts: 742
Likes: 0
From: Formerly in the Ass end of the pacific.
Cruising should be close to 14.7

Full boost should be around 11.5-12.0

You just need to tweak until you get it. No easy way.

Sorry, it's early in the morning Hop onto Haltech's page and DL a demo of the software. It will give the inside look of how to tune things.
Reply
Old May 9, 2003 | 02:05 PM
  #5  
fatboy7's Avatar
Got Boost?
Tenured Member 15 Years
 
Joined: Feb 2002
Posts: 1,066
Likes: 1
From: Watertown, MA
Hmm, I see. This is actually more complicated than what I thought So how do you tune for cruising vs boost in say a halltec\microtec? Do they have special functions for this? Or is just "practical" to tune for "under boost" and use this map all the time?
You can tune for both...... there are usually hundreds of points at which you can tune. Usually there are 15+ load points from heavy vacuum (engine braking) to full boost, that can be tuned for at many different rpms. So like on a map when you are finding a city, which has coordinances (D-2 for instance) EMS's have a "map" that they use to detirmine the amount of fuel to add. (15psi - 4500rpm), is an example of the coordinances that would be used.

So you have to tune everywhere, not just under boost.
Reply
Old May 9, 2003 | 08:08 PM
  #6  
KNONFS's Avatar
Thread Starter
B O R I C U A
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (14)
 
Joined: Mar 2001
Posts: 5,482
Likes: 36
From: VA
Originally posted by fatboy7
You can tune for both...... there are usually hundreds of points at which you can tune. Usually there are 15+ load points from heavy vacuum (engine braking) to full boost, that can be tuned for at many different rpms. So like on a map when you are finding a city, which has coordinances (D-2 for instance) EMS's have a "map" that they use to detirmine the amount of fuel to add. (15psi - 4500rpm), is an example of the coordinances that would be used.

So you have to tune everywhere, not just under boost.
Sorry man, but I didn't undertand what you were trying to say

I guesss I need to pick a good book in FI!
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
_Tones_
Adaptronic Engine Mgmt - AUS
10
May 25, 2021 05:37 AM
t-von
3rd Generation Specific (1993-2002)
9
Sep 10, 2015 01:56 PM
Nosferatu
2nd Generation Specific (1986-1992)
7
Sep 5, 2015 02:13 PM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 06:49 PM.