Innovate AFR Test
Discussion
Evening chaps.
Love to hear your thoughts on what you can see from the XD-16 gauge and wideband sensor.
I have my thoughts but I wanna see what you think. Especially the engine builders/tuners amongst you.
Cheers
Lucks
http://www.youtube.com/watch?v=hEDRuY-OUMs
Love to hear your thoughts on what you can see from the XD-16 gauge and wideband sensor.
I have my thoughts but I wanna see what you think. Especially the engine builders/tuners amongst you.
Cheers
Lucks
http://www.youtube.com/watch?v=hEDRuY-OUMs
I believe you fitted the Holly HP series carb.
If so then it would appear to be doing just what I would expect giving you max power capability under any situation regardless of load.
This is OK unless you also wanted economy in which case the HP carb was not for you.
11 & 12 is right where you will make most power.
This is where EFI comes into its own. It is unlikely to produce more power but should respond really well to light loads and throttle so a gentle cruise will lean right out for economy.
Steve
If so then it would appear to be doing just what I would expect giving you max power capability under any situation regardless of load.
This is OK unless you also wanted economy in which case the HP carb was not for you.
11 & 12 is right where you will make most power.
This is where EFI comes into its own. It is unlikely to produce more power but should respond really well to light loads and throttle so a gentle cruise will lean right out for economy.
Steve
running into the 11s is not where you make best power, that's turbo rich and way over fuelled for a NA road engine. fortunately its in the 12s/high 12s occasionally 13s most of the time which is still too rich on light cruise but will certainly be smooth and the mixture easy to ignite. I'm guessing though that economy wasn't high on your agenda when you specced this motor? it does look ike a carb fed AFR trait, or if it's injection the mapper wants shooting!
Ha!! You are all right!
Steve knows this motor, but yes I should have said:
It's a Holley HP with a brief for high power!!
I'm led to believe that this comes at 12.8-13.2 but you are right, this is running rich nearly all the time. No wonder I am filling up every trip out!!
By showing idle and constant throttle (ie. cruising) I was hoping to get some insight into how to achieve a 14 point cruise without affecting the acceleration 12 point something.
Is this a case of not being able to have my cake or can a compromise be had which won't give me bogged corner exits on track?
Steve knows this motor, but yes I should have said:
It's a Holley HP with a brief for high power!!
I'm led to believe that this comes at 12.8-13.2 but you are right, this is running rich nearly all the time. No wonder I am filling up every trip out!!
By showing idle and constant throttle (ie. cruising) I was hoping to get some insight into how to achieve a 14 point cruise without affecting the acceleration 12 point something.
Is this a case of not being able to have my cake or can a compromise be had which won't give me bogged corner exits on track?
Hi Pete
Looks to me like it could come down a jet size or two. Like the others say it's a bit too rich for a NA motor. Like Stevie says it goes a bit week on initial acceleration. The accleration squirter could do with being a size or so bigger. If it were me I would experiment with some different jet sizes on a dyno. It wouldn't take long to get it bang on the money. You may be looking for max power but there's no point in wasting fuel. It's nearly there Pete!
Hope to see you Sunday!
Regards Dave
Looks to me like it could come down a jet size or two. Like the others say it's a bit too rich for a NA motor. Like Stevie says it goes a bit week on initial acceleration. The accleration squirter could do with being a size or so bigger. If it were me I would experiment with some different jet sizes on a dyno. It wouldn't take long to get it bang on the money. You may be looking for max power but there's no point in wasting fuel. It's nearly there Pete!
Hope to see you Sunday!
Regards Dave
My fault for posting the equivalent to 'what's the meaning of life?' so late in the evening.
Gail (A/S) has just seen this and replied to me. The cam I am running (the 720 factory cam) has moosiff overlap, and it is very difficult to get it to run to 14 on cruise.
I spec'd trackday tool and I that's what I got!! Can't wait to get it on the tarmac!!
Gail (A/S) has just seen this and replied to me. The cam I am running (the 720 factory cam) has moosiff overlap, and it is very difficult to get it to run to 14 on cruise.
I spec'd trackday tool and I that's what I got!! Can't wait to get it on the tarmac!!
Very intersting video. Whats good about it unlike datalogging, is that we can hear the engine - so we understand what you were doing at the time.
As others have said, its rich - i did see 10:1 at one point!. The leaness when you put your foot in it, is the accell squirters which need to be bigger.
Cruise / low load wants to be around 13.5:1 (I'm avoiding saying 14: or lower for safety)
High load / acceleration wants to be ~ 12.5 - 13 really (still safe to cover yourself) - which is an improvement over the 10-11-12's i was seeing. What you set the fueling at depends if you are after fit and forget (go rich for safety) or leaner if you keep your eye on it. This is why the suppliers always set them rich.
I'm more of an edelbrock man, so cant offer advise on the holley jetting. But you need to come down in both power mode and cruise mode (edelbrocks have two distinct circuits to tune each area, Im pretty sure the holleys are similar)
In the efi world, you work out what the percentage reduction in fueling you need to come down a particular AFR, in theory you should be able to work out the % reduction in jet size to acheive the same thing.
As others have said, its rich - i did see 10:1 at one point!. The leaness when you put your foot in it, is the accell squirters which need to be bigger.
Cruise / low load wants to be around 13.5:1 (I'm avoiding saying 14: or lower for safety)
High load / acceleration wants to be ~ 12.5 - 13 really (still safe to cover yourself) - which is an improvement over the 10-11-12's i was seeing. What you set the fueling at depends if you are after fit and forget (go rich for safety) or leaner if you keep your eye on it. This is why the suppliers always set them rich.
I'm more of an edelbrock man, so cant offer advise on the holley jetting. But you need to come down in both power mode and cruise mode (edelbrocks have two distinct circuits to tune each area, Im pretty sure the holleys are similar)
In the efi world, you work out what the percentage reduction in fueling you need to come down a particular AFR, in theory you should be able to work out the % reduction in jet size to acheive the same thing.
Lucky,
Charles can sort all this. The low figures under acceleration can be corrected by changing the accelerator pump cam.
this shows the cam rates
Explained in this
http://www.stockcarracing.com/techarticles/scrp_06...
Charles can sort all this. The low figures under acceleration can be corrected by changing the accelerator pump cam.
this shows the cam rates
Explained in this
http://www.stockcarracing.com/techarticles/scrp_06...
Good spot that, Guy.
Will have to see how she performs around the bends. See if she hesitates or not.
Now I know why Charles likes to go to the track with his new builds, he spent a lot of time with Crazy's changing these pump cams to get smooth acceleration. I think mine is matched to his, but this can only be a datum as things are different in my engine, and my driving characteristics may also be different to Crazy's.
Will have to see how she performs around the bends. See if she hesitates or not.
Now I know why Charles likes to go to the track with his new builds, he spent a lot of time with Crazy's changing these pump cams to get smooth acceleration. I think mine is matched to his, but this can only be a datum as things are different in my engine, and my driving characteristics may also be different to Crazy's.
Yes you can see the cam as it is on the lowest part of the carb.
Think this is the sheet you need for your carb but if it is wrong go back to the source of the link and find the correct pdf for your carb model.
In there you will find pics of where the cam is and notes about tuning it.
http://www.holley.com/data/Products/Technical/199R...
Steve
Think this is the sheet you need for your carb but if it is wrong go back to the source of the link and find the correct pdf for your carb model.
In there you will find pics of where the cam is and notes about tuning it.
http://www.holley.com/data/Products/Technical/199R...
Steve
Carbs in the year of 2008 ? 
A complete 950 Commander efi is only a couple of grand and those nice people at Abbey motorsport just up the road from you can map it to perfection on their hub dyno.
The carb can then assume its proper function of propping open the greenhouse door ......
Think how much grief and aggro that will save (and fuel !!!)
A complete 950 Commander efi is only a couple of grand and those nice people at Abbey motorsport just up the road from you can map it to perfection on their hub dyno.
The carb can then assume its proper function of propping open the greenhouse door ......
Think how much grief and aggro that will save (and fuel !!!)
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