air fuel ratio??
#1
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air fuel ratio??
one for the fuel mapping experts, i've just fitted an innovate AFR guage, all seems to be reading correctly, taking stoic as 14.7 the readings i'm getting are as follows:
warm up: 13.5 or so,
normal idle: 15 or so
throttle planted it goes from 11.5 at first plant of throttle to 13.5 as the revs build.
off throttle it hits 21 at the instant of letting off throttle and then settles to 15.5 or so. after a bit more checking looks closer to 14.7 off throttle
do these figures sound safe? by the way my car is a 90 spec rs turbo running standard mfi, just an airtec fmic and a scorpion exhaust. any help appreciated
warm up: 13.5 or so,
normal idle: 15 or so
throttle planted it goes from 11.5 at first plant of throttle to 13.5 as the revs build.
off throttle it hits 21 at the instant of letting off throttle and then settles to 15.5 or so. after a bit more checking looks closer to 14.7 off throttle
do these figures sound safe? by the way my car is a 90 spec rs turbo running standard mfi, just an airtec fmic and a scorpion exhaust. any help appreciated
Last edited by teahan; 21-07-2011 at 09:38 AM.
#4
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cheers, i was thinking it should drop closer to 11 as it gets higher in the rev range, i haven't done any proper testing, i've too much preload on the wastegate at the moment so must back that off. all seems really good, i was just checking how close is it to correct figures
#5
*** Sierra RS Custard ***
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How much boost is it running?
Sounds a little lean if its much, as a rule of thumb I tend to go for 13 on low boost (ie half a bar) mid 12s on moderate boost (ie a bar) and then into the 11s or even lower on big boost depending on the specific car I am mapping and how the EGT's are.
Sounds a little lean if its much, as a rule of thumb I tend to go for 13 on low boost (ie half a bar) mid 12s on moderate boost (ie a bar) and then into the 11s or even lower on big boost depending on the specific car I am mapping and how the EGT's are.
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its only standard-ish boost, 0.6 bar, so the fuelling is about right going by your figures chip. i'm not looking for power gains or anything, car always starts and runs fine so i just want to keep it that way for now
#7
*** Sierra RS Custard ***
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Yes that sounds fine mate, although I wouldnt want to do something like tow a heavy trailer up a steep hill where you are flat out at high rpm for long periods on boost so it does depend a bit on use.
Richening it up is likely to lose you a bit of performance at that boost.
Richening it up is likely to lose you a bit of performance at that boost.
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#8
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Yes that sounds fine mate, although I wouldnt want to do something like tow a heavy trailer up a steep hill where you are flat out at high rpm for long periods on boost so it does depend a bit on use.
Richening it up is likely to lose you a bit of performance at that boost.
Richening it up is likely to lose you a bit of performance at that boost.
no worries about long spells of high load, i don't care for top speed testing!
and even better news, pass mot today
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I need a little help!
I've installed an AEM 30-4900 wide-band gauge in a Ford Escort RS Turbo.
I'm on EFI, OFAC.
And got this:
12.9-14.3 AFR @ idle
15-18 AFR @ low acceleration, -0.3 bar
15-13 AFR @ 0 bar
13 AFR @ full load
Is this normal??
I've installed an AEM 30-4900 wide-band gauge in a Ford Escort RS Turbo.
I'm on EFI, OFAC.
And got this:
12.9-14.3 AFR @ idle
15-18 AFR @ low acceleration, -0.3 bar
15-13 AFR @ 0 bar
13 AFR @ full load
Is this normal??
#10
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Im no expert but i think thats a little lean all round except idle.
My car runs as follows:
Idle 13.8
Off boost driving 14-14.5
Low boost (under 1bar) 14-13afr as boost builds
High boost (currently 1.2bar) 12-12.5afr
Now i think my high boost is a little lean but it goes like a train and doesnt seem to get hot and theres no hint of det, once i increase boost i plan to get a steady 11.5afr and increase the timing to try and cancel out the performance loss.
My car runs as follows:
Idle 13.8
Off boost driving 14-14.5
Low boost (under 1bar) 14-13afr as boost builds
High boost (currently 1.2bar) 12-12.5afr
Now i think my high boost is a little lean but it goes like a train and doesnt seem to get hot and theres no hint of det, once i increase boost i plan to get a steady 11.5afr and increase the timing to try and cancel out the performance loss.
#12
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Agreed with Chip.
Idle - ideally 14.7-15 but tbh what ever the car is happy at. Lots of cvh's have a really stable idle at 13.7-14.
- WOT no-low boost (2-5psi) I go from 13.5 - 12.8. 13.5 at or below peak torque and 12.8 there after.
- 10psi boost is 12-12.5
- 15 is 11.5-12
- 20 psi is 11-11.5
- any thing much above 24psi I just go really rich at 10.5 - 10.8 but it seems to bring egt down a lot and stops a lot of potential det.
I find 12.5-13 gives the highest peak hp, however you will not get close to this at high boost going from 10-11.5 afr on a cosworth at 20psi of boost is good for nearly 25bhp with the same advance.
Cruise - around 15 but lots of people go leaner with more ignition advance, however its not that easy to tune cruise on the dyno and needs some motorway driving. Autotune works really really well for cruise tuning.
Rob,
Idle - ideally 14.7-15 but tbh what ever the car is happy at. Lots of cvh's have a really stable idle at 13.7-14.
- WOT no-low boost (2-5psi) I go from 13.5 - 12.8. 13.5 at or below peak torque and 12.8 there after.
- 10psi boost is 12-12.5
- 15 is 11.5-12
- 20 psi is 11-11.5
- any thing much above 24psi I just go really rich at 10.5 - 10.8 but it seems to bring egt down a lot and stops a lot of potential det.
I find 12.5-13 gives the highest peak hp, however you will not get close to this at high boost going from 10-11.5 afr on a cosworth at 20psi of boost is good for nearly 25bhp with the same advance.
Cruise - around 15 but lots of people go leaner with more ignition advance, however its not that easy to tune cruise on the dyno and needs some motorway driving. Autotune works really really well for cruise tuning.
Rob,
Last edited by Rob_DOHC; 19-05-2013 at 10:14 PM.
#14
I've found that life I needed.. It's HERE!!
Agreed with Chip.
Idle - ideally 14.7-15 but tbh what ever the car is happy at. Lots of cvh's have a really stable idle at 13.7-14.
- WOT no-low boost (2-5psi) I go from 13.5 - 12.8. 13.5 at or below peak torque and 12.8 there after.
- 10psi boost is 12-12.5
- 15 is 11.5-12
- 20 psi is 11-11.5
- any thing much above 24psi I just go really rich at 10.5 - 10.8 but it seems to bring egt down a lot and stops a lot of potential det.
I find 12.5-13 gives the highest peak hp, however you will not get close to this at high boost going from 10-11.5 afr on a cosworth at 20psi of boost is good for nearly 25bhp with the same advance.
Cruise - around 15 but lots of people go leaner with more ignition advance, however its not that easy to tune cruise on the dyno and needs some motorway driving. Autotune works really really well for cruise tuning.
Rob,
Idle - ideally 14.7-15 but tbh what ever the car is happy at. Lots of cvh's have a really stable idle at 13.7-14.
- WOT no-low boost (2-5psi) I go from 13.5 - 12.8. 13.5 at or below peak torque and 12.8 there after.
- 10psi boost is 12-12.5
- 15 is 11.5-12
- 20 psi is 11-11.5
- any thing much above 24psi I just go really rich at 10.5 - 10.8 but it seems to bring egt down a lot and stops a lot of potential det.
I find 12.5-13 gives the highest peak hp, however you will not get close to this at high boost going from 10-11.5 afr on a cosworth at 20psi of boost is good for nearly 25bhp with the same advance.
Cruise - around 15 but lots of people go leaner with more ignition advance, however its not that easy to tune cruise on the dyno and needs some motorway driving. Autotune works really really well for cruise tuning.
Rob,
#15
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Certainly worth a shot mate, I run quite a bit more advance at cruise where possible, and get 16:1 on light cruise on a zetec.
Yes, you will be making a lot more power with a an afr of 12 compared to 10. And as long as egt's aren't excessive and you don't have any det then theres no issue with it. You might find you can run more advance too, worth giving 11.5 a go with a few degrees more. This is where dyno's really are worth the money.
Once the car is in a safe state of tune I play with the afr to find where most hp is made and do numerous power runs slowly increasing advance in one are at a time until tractive effort falls/stays the same or I get light det. Then back it off by a few degree's. Then move onto a different area of the map. You can usually gain a fair chunk of power all over the curve doing this. At low loads I just rpm hold and adjust timing and afr live, but things get a little hot and sticky if you do that at higher loads.
Rob,
Yes, you will be making a lot more power with a an afr of 12 compared to 10. And as long as egt's aren't excessive and you don't have any det then theres no issue with it. You might find you can run more advance too, worth giving 11.5 a go with a few degrees more. This is where dyno's really are worth the money.
Once the car is in a safe state of tune I play with the afr to find where most hp is made and do numerous power runs slowly increasing advance in one are at a time until tractive effort falls/stays the same or I get light det. Then back it off by a few degree's. Then move onto a different area of the map. You can usually gain a fair chunk of power all over the curve doing this. At low loads I just rpm hold and adjust timing and afr live, but things get a little hot and sticky if you do that at higher loads.
Rob,
#16
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Auto tune doesn't work at all well (and can really f*** your map up!) if:
-you have a slight misfire, even a missfire that you can't feel.
-You have accel enrichment turned on
-if your afr gauge doesn't match tuner studio's exactly (within .2 of an afr).
If the ecu thinks the afr is different to reality it will just be trying to tune to the wrong target. Its also good to tell auto tune to only tune in a specific area of the map, ie) above 2500 rpm and below 60kPa for cruse. The closer your map is to perfect the smaller the step changes in auto tune should be (ie, it can only make small changes each time and has less potential to bugger things up), you also need to press Send/Burn frequently because autotune will stop making adjustments once it hits it maximum change threshold, hitting send resets its counter.
A confident person will nearly always be better than autotune though, so if you have the luxury of getting a mate to drive then your onto a winner No good for us billy no mates tho. A good combination of autotune and real person tuning (at least supervising to make sure changes are positive) is essential.
I always tell people to use auto tune as much as possible before hitting the dyno, as long as there isn't a problem (like above) it will get afr's in low load areas pretty close and means I can spend more time playing with the fun high load areas.
Love topics like this
Rob,
Last edited by Rob_DOHC; 20-05-2013 at 01:07 PM.
#17
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Some good advice Rob, nice one!
I love topics like this too...
Im keen to get mine on a dyno once i have my boost controlled more accurately, im on a mbc atm and i get a 2-3psi spike which i don't really like. I also use my bro to map my car, he just sort of follows my target AFRs and instructions which is nice to get the map nearer there, i had planned to get him to drive the car whilst i map but he's gone and broke his arm so thats off for a while lol. But once he's back i plan to map some more advance into the "on-boost" areas of the table.
A dyno must be a god send as it gets abit hairy trying to map high revs/high boost on the road sometimes (sorry officer i was mapping) But it really is all good fun, i think its something i will never be fully happy with as i find myself going out for a random drive with the laptop then adjusting things lol!
I love topics like this too...
Im keen to get mine on a dyno once i have my boost controlled more accurately, im on a mbc atm and i get a 2-3psi spike which i don't really like. I also use my bro to map my car, he just sort of follows my target AFRs and instructions which is nice to get the map nearer there, i had planned to get him to drive the car whilst i map but he's gone and broke his arm so thats off for a while lol. But once he's back i plan to map some more advance into the "on-boost" areas of the table.
A dyno must be a god send as it gets abit hairy trying to map high revs/high boost on the road sometimes (sorry officer i was mapping) But it really is all good fun, i think its something i will never be fully happy with as i find myself going out for a random drive with the laptop then adjusting things lol!
#18
On a tangent
iTrader: (1)
Cruise is a nice place to start tuning and is usually the easiest. 5th gear and highish speeds mean the load changes are fairly slow and easy to keep up with.
Auto tune doesn't work at all well (and can really f*** your map up!) if:
-you have a slight misfire, even a missfire that you can't feel.
-You have accel enrichment turned on
-if your afr gauge doesn't match tuner studio's exactly (within .2 of an afr).
If the ecu thinks the afr is different to reality it will just be trying to tune to the wrong target. Its also good to tell auto tune to only tune in a specific area of the map, ie) above 2500 rpm and below 60kPa for cruse. The closer your map is to perfect the smaller the step changes in auto tune should be (ie, it can only make small changes each time and has less potential to bugger things up), you also need to press Send/Burn frequently because autotune will stop making adjustments once it hits it maximum change threshold, hitting send resets its counter.
A confident person will nearly always be better than autotune though, so if you have the luxury of getting a mate to drive then your onto a winner No good for us billy no mates tho. A good combination of autotune and real person tuning (at least supervising to make sure changes are positive) is essential.
I always tell people to use auto tune as much as possible before hitting the dyno, as long as there isn't a problem (like above) it will get afr's in low load areas pretty close and means I can spend more time playing with the fun high load areas.
Love topics like this
Rob,
Auto tune doesn't work at all well (and can really f*** your map up!) if:
-you have a slight misfire, even a missfire that you can't feel.
-You have accel enrichment turned on
-if your afr gauge doesn't match tuner studio's exactly (within .2 of an afr).
If the ecu thinks the afr is different to reality it will just be trying to tune to the wrong target. Its also good to tell auto tune to only tune in a specific area of the map, ie) above 2500 rpm and below 60kPa for cruse. The closer your map is to perfect the smaller the step changes in auto tune should be (ie, it can only make small changes each time and has less potential to bugger things up), you also need to press Send/Burn frequently because autotune will stop making adjustments once it hits it maximum change threshold, hitting send resets its counter.
A confident person will nearly always be better than autotune though, so if you have the luxury of getting a mate to drive then your onto a winner No good for us billy no mates tho. A good combination of autotune and real person tuning (at least supervising to make sure changes are positive) is essential.
I always tell people to use auto tune as much as possible before hitting the dyno, as long as there isn't a problem (like above) it will get afr's in low load areas pretty close and means I can spend more time playing with the fun high load areas.
Love topics like this
Rob,
Fascinating read, you explain this stuff exceptionally easily, making it very simple to understand
Shame EFI OFAC cant be worked so easily
You in the "trade" of tuning then fella...?
#19
I've found that life I needed.. It's HERE!!
Cruise is a nice place to start tuning and is usually the easiest. 5th gear and highish speeds mean the load changes are fairly slow and easy to keep up with.
Auto tune doesn't work at all well (and can really f*** your map up!) if:
-you have a slight misfire, even a missfire that you can't feel.
-You have accel enrichment turned on
-if your afr gauge doesn't match tuner studio's exactly (within .2 of an afr).
If the ecu thinks the afr is different to reality it will just be trying to tune to the wrong target. Its also good to tell auto tune to only tune in a specific area of the map, ie) above 2500 rpm and below 60kPa for cruse. The closer your map is to perfect the smaller the step changes in auto tune should be (ie, it can only make small changes each time and has less potential to bugger things up), you also need to press Send/Burn frequently because autotune will stop making adjustments once it hits it maximum change threshold, hitting send resets its counter.
A confident person will nearly always be better than autotune though, so if you have the luxury of getting a mate to drive then your onto a winner No good for us billy no mates tho. A good combination of autotune and real person tuning (at least supervising to make sure changes are positive) is essential.
I always tell people to use auto tune as much as possible before hitting the dyno, as long as there isn't a problem (like above) it will get afr's in low load areas pretty close and means I can spend more time playing with the fun high load areas.
Love topics like this
Rob,
Auto tune doesn't work at all well (and can really f*** your map up!) if:
-you have a slight misfire, even a missfire that you can't feel.
-You have accel enrichment turned on
-if your afr gauge doesn't match tuner studio's exactly (within .2 of an afr).
If the ecu thinks the afr is different to reality it will just be trying to tune to the wrong target. Its also good to tell auto tune to only tune in a specific area of the map, ie) above 2500 rpm and below 60kPa for cruse. The closer your map is to perfect the smaller the step changes in auto tune should be (ie, it can only make small changes each time and has less potential to bugger things up), you also need to press Send/Burn frequently because autotune will stop making adjustments once it hits it maximum change threshold, hitting send resets its counter.
A confident person will nearly always be better than autotune though, so if you have the luxury of getting a mate to drive then your onto a winner No good for us billy no mates tho. A good combination of autotune and real person tuning (at least supervising to make sure changes are positive) is essential.
I always tell people to use auto tune as much as possible before hitting the dyno, as long as there isn't a problem (like above) it will get afr's in low load areas pretty close and means I can spend more time playing with the fun high load areas.
Love topics like this
Rob,
#20
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No worries guys, its all good fun. Josh, you are welcome to come along to the next day and have a demo/chat or have a session. Even a power run will show up any issues pretty quickly (as long as the operator is any good!), and would give a good idea of which areas of the map could be improved.
Rob,
Rob,
#22
PassionFord Post Whore!!
iTrader: (4)
Not 100% at the moment. I generally wait until there are 3-5 people asking for it. Its a bit of a waste (ie, we loose money) for just one. But I have a few people asking for dates at the moment so probably end of June(ish). Its more fun for every one with when we have a few victims there at the same time too
There will be a skyline engined reliant scimitar there next time too for mapping on one of our ecu's which should be good to look round if you fancy popping over?
Rob,
There will be a skyline engined reliant scimitar there next time too for mapping on one of our ecu's which should be good to look round if you fancy popping over?
Rob,
#25
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My EFI ERST on OFAC:
I've adjusted the fuel pressure regulator by watching the AFR values. (got a standard MK5 1.6 CVH EFI regulator, is that the same as the FRST one?!)
Max boost is 0.5 bar.
This was before:
And this is after:
What do you think of these values?
On OFAC I can adjust AFR with the CO pot and the fuel pressure only, right?
Thanks!
I've adjusted the fuel pressure regulator by watching the AFR values. (got a standard MK5 1.6 CVH EFI regulator, is that the same as the FRST one?!)
Max boost is 0.5 bar.
This was before:
And this is after:
What do you think of these values?
On OFAC I can adjust AFR with the CO pot and the fuel pressure only, right?
Thanks!
#26
Advanced PassionFord User
Not 100% at the moment. I generally wait until there are 3-5 people asking for it. Its a bit of a waste (ie, we loose money) for just one. But I have a few people asking for dates at the moment so probably end of June(ish). Its more fun for every one with when we have a few victims there at the same time too
There will be a skyline engined reliant scimitar there next time too for mapping on one of our ecu's which should be good to look round if you fancy popping over?
Rob,
There will be a skyline engined reliant scimitar there next time too for mapping on one of our ecu's which should be good to look round if you fancy popping over?
Rob,
#34
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Haha, that sounds like an offer too good to refuse. If I had my pick of any dyno in the UK I think yours would be the one Stu. Shame your at the cold end of the country I've been meaning to give you a call about mapping northern cars on out stuff too.
Hope the new dyno is going well too.
Rob,
#39
PassionFord Post Whore!!
Can you wait a month or so, then i can join in as another megasquirt car. I only live around the corner, a power run would be good once its mapped.