How to tune IAT and ECT
02-24-2009, 08:26 PM
#1
1.5 BAR
Thread Starter
Join Date: Jun 2005
Posts: 875
How to tune IAT and ECT
I've been datalogging and the IAT and ECT temps seems to change over a range where I can't figure out a way to tune them. IAT and ect are ambient when I first start the car, of course. Then they start to rise, and then settle at a temp, then kinda heat soak, then go down when I'm moving. This can all be datalogged.
So tuning afrs. You can tune the map all day. but in theory the afr should change with temp. I assume entire map would be for a give temp. so you could tune the map as long as you in that temp. everything outside of that you'd use the iat enrichment?? I can't think of a good step by step way to tune so the afr is ideal at an ambient temp/IAT .........
So tuning afrs. You can tune the map all day. but in theory the afr should change with temp. I assume entire map would be for a give temp. so you could tune the map as long as you in that temp. everything outside of that you'd use the iat enrichment?? I can't think of a good step by step way to tune so the afr is ideal at an ambient temp/IAT .........
02-24-2009, 08:38 PM
#3
3.0 BAR
Join Date: Oct 2006
Posts: 2,330
Re: How to tune IAT and ECT
Originally Posted by cloud
I've been datalogging and the IAT and ECT temps seems to change over a range where I can't figure out a way to tune them. IAT and ect are ambient when I first start the car, of course. Then they start to rise, and then settle at a temp, then kinda heat soak, then go down when I'm moving. This can all be datalogged.
So tuning afrs. You can tune the map all day. but in theory the afr should change with temp. I assume entire map would be for a give temp. so you could tune the map as long as you in that temp. everything outside of that you'd use the iat enrichment?? I can't think of a good step by step way to tune so the afr is ideal at an ambient temp/IAT .........
So tuning afrs. You can tune the map all day. but in theory the afr should change with temp. I assume entire map would be for a give temp. so you could tune the map as long as you in that temp. everything outside of that you'd use the iat enrichment?? I can't think of a good step by step way to tune so the afr is ideal at an ambient temp/IAT .........
02-24-2009, 10:17 PM
#5
0.5 BAR
Join Date: Jun 2008
Posts: 100
Re: How to tune IAT and ECT
you could probably leave IAT alone, since the way air density changes vs temp is universal regardless of your setup.
Log your IATs while driving around after everythings warmed up. At those temps the multiplier should be set to 1, for lower temps make it slightly >1 so your AFRs become slightly richer than usual.
Same thing for ECT. Just use values slightly > 1 for ECT temps under 160. The goal is to have the engine run rich while cold so the fuel is easier to ignite.
The stock curves work well, but you can tweek them where you feel appropriate. Just remember its OK to run rich when its 40*
Log your IATs while driving around after everythings warmed up. At those temps the multiplier should be set to 1, for lower temps make it slightly >1 so your AFRs become slightly richer than usual.
Same thing for ECT. Just use values slightly > 1 for ECT temps under 160. The goal is to have the engine run rich while cold so the fuel is easier to ignite.
The stock curves work well, but you can tweek them where you feel appropriate. Just remember its OK to run rich when its 40*
02-24-2009, 11:19 PM
#7
0.5 BAR
Join Date: Jun 2008
Posts: 100
Re: How to tune IAT and ECT
This a honda? Rad fan kicks on at 190*
You should set the ECT multiplier to be 1 when the car is at operating temp, (160*-200*)(if it isnt already) That way you know the ECT corrections will not conflict with IAT corrections while the car is at temp.
Then find the IATs the car runs at when its at operating temp (takes a bit more driving for the whole bay to heat up). Set the IAT multiplier close to 1 in these temps. Higher mult for lower temps and lower mult for higher temps.
My IAT table looks like
Temp *F _____-22___-17____14.4_____41.7_____78.6____151.5____284
Multiplier______1.21___1.21___1.08_____1.06____1.0 0______.94_____.94
That way IAT corrections wont interfere with other things at normal temp.
You should set the ECT multiplier to be 1 when the car is at operating temp, (160*-200*)(if it isnt already) That way you know the ECT corrections will not conflict with IAT corrections while the car is at temp.
Then find the IATs the car runs at when its at operating temp (takes a bit more driving for the whole bay to heat up). Set the IAT multiplier close to 1 in these temps. Higher mult for lower temps and lower mult for higher temps.
My IAT table looks like
Temp *F _____-22___-17____14.4_____41.7_____78.6____151.5____284
Multiplier______1.21___1.21___1.08_____1.06____1.0 0______.94_____.94
That way IAT corrections wont interfere with other things at normal temp.
02-25-2009, 01:19 AM
#8
1.5 BAR
Thread Starter
Join Date: Jun 2005
Posts: 875
Re: How to tune IAT and ECT
The IAT 1.0 multiplier covers a wide range of temps. If that's correct IAT doesn't make that much of a difference and they don't really need to be tuned until your reach the extreme of ether side. Can you even get IAT's in the 40's boosted..... Even when its freezing outside. 28-32 My IAT's get up to 78.6.
By the way that looks like the stock p28 IAT compensation. Did you not make any changes to it?
By the way that looks like the stock p28 IAT compensation. Did you not make any changes to it?
02-26-2009, 03:20 PM
#10
0.0 BAR
Join Date: Jun 2005
Location: WA
Posts: 0
Re: How to tune IAT and ECT
Originally Posted by cloud
The IAT 1.0 multiplier covers a wide range of temps. If that's correct IAT doesn't make that much of a difference and they don't really need to be tuned until your reach the extreme of ether side. Can you even get IAT's in the 40's boosted..... Even when its freezing outside. 28-32 My IAT's get up to 78.6.
By the way that looks like the stock p28 IAT compensation. Did you not make any changes to it?
By the way that looks like the stock p28 IAT compensation. Did you not make any changes to it?
