AFR adjustment
The IPW in open loop is based mainly on load which looks up the AFR map and uses injector size to reach a final value.
Using the IPW and RPM you can then calculate the IDC. The injectors won't introduce more fuel once you get beyond about 95% IDC because they have no time to close.
The "real" size of the injector doesn't matter here, it is only the electrical duty cycle of the injector drivers.
Using the IPW and RPM you can then calculate the IDC. The injectors won't introduce more fuel once you get beyond about 95% IDC because they have no time to close.
The "real" size of the injector doesn't matter here, it is only the electrical duty cycle of the injector drivers.
What can cause this (AFRMAP value different from map value) anyhow?
.
.
I run less boost than that on Methanol injection
Last edited by C6C6CH3vo; Feb 6, 2007 at 05:06 AM.
Evolved Member
Joined: May 2006
Posts: 2,399
Likes: 6
From: UK
I believe that the AFRMAP logged value is a post-processed AFR value from the fuel map AFTER lean spool modifications have been applied.
Remember this is active on US cars as well and seems to lean out the mixture 1 AFR approx from the fuel map value until 7000 RPM.
Remember this is active on US cars as well and seems to lean out the mixture 1 AFR approx from the fuel map value until 7000 RPM.
Evolved Member
Joined: May 2006
Posts: 2,399
Likes: 6
From: UK
I increased my fuel pressure from 3.0 to 3.6 bar by modifying the OEM regulator. I prefer this to a new reg for stealth and reliability.
Now I can run 23-24 PSI (depends on atmospheric pressure mainly it seems) at 6000 RPM with 11 degrees timing at lambda 0.78 with 90% IDC whereas before I was at 100%. I get the odd knock sum of up to 3 or 4 scattered about, usually in the lower gears.
Here is my timing map with the 10% methanol:
http://john824.fotopic.net/p38418308.html
Now I can run 23-24 PSI (depends on atmospheric pressure mainly it seems) at 6000 RPM with 11 degrees timing at lambda 0.78 with 90% IDC whereas before I was at 100%. I get the odd knock sum of up to 3 or 4 scattered about, usually in the lower gears.
Here is my timing map with the 10% methanol:
http://john824.fotopic.net/p38418308.html
I increased my fuel pressure from 3.0 to 3.6 bar by modifying the OEM regulator. I prefer this to a new reg for stealth and reliability.
Now I can run 23-24 PSI (depends on atmospheric pressure mainly it seems) at 6000 RPM with 11 degrees timing at lambda 0.78 with 90% IDC whereas before I was at 100%. I get the odd knock sum of up to 3 or 4 scattered about, usually in the lower gears.
Here is my timing map with the 10% methanol:
http://john824.fotopic.net/p38418308.html
Now I can run 23-24 PSI (depends on atmospheric pressure mainly it seems) at 6000 RPM with 11 degrees timing at lambda 0.78 with 90% IDC whereas before I was at 100%. I get the odd knock sum of up to 3 or 4 scattered about, usually in the lower gears.
Here is my timing map with the 10% methanol:
http://john824.fotopic.net/p38418308.html
....BTW, with regard to your airbox modification, have you found that putting the hole on the side of the lid to be beneficial? I have a lid with just the top cut and will be doing back to back comparisons. Thanks for your help.
Sorry for my unclear question. I have the lid cut out on the top, but don't have the side cut out. Do you think there is a benefit of having the side open as well as the top ? Someone speculated that the side hole helped flow, but I can't understand why other than more of an open filter. Thanks again.
Evolved Member
Joined: May 2006
Posts: 2,399
Likes: 6
From: UK
The whole lid off would flow slightly better but I feel it would draw too much hot air, hence I did the coldest side I could and stopped when I saw the pressure drop getting near to an induction kit's performance. Result: free and should outperform induction kit in hot conditions.
The whole lid off would flow slightly better but I feel it would draw too much hot air, hence I did the coldest side I could and stopped when I saw the pressure drop getting near to an induction kit's performance. Result: free and should outperform induction kit in hot conditions.
Unrelated topic...I am about to put on an O2 Housing (ebay SS autochrome / Megan Racing) and am wondering whether I should send the part to Swain for coating. Any thoughts on this and/or the exhaust manifold -- is it worth the expense / time to do, or should I just slap the new O2 housing on? Thanks
Thread
Thread Starter
Forum
Replies
Last Post
Shaun@AWDMotorsports
Vendor Announcements
131
Jun 14, 2016 10:34 AM
SwiftEVO
General Engine Management / Tuning Forum
17
Jun 22, 2005 11:20 AM
