Maxing out MAF & injectors?
Feb 13, 2006, 01:17 PM
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Maxing out MAF & injectors?
Today, I was able to run over 100% on the MAF fuel table. When I did this I had a wicked fuel cut or something. It was real similar to when the vacuum line blows off the regulator. I noticed that my AFR's try to go to the high 9's-low 10's in that region. So basically, what happens when the injectors hit 100% or when the MAF goes over 100%?
Is it ok to add a 105% row on the MAF fuel table?
Is it ok to add a 105% row on the MAF fuel table?
Feb 13, 2006, 01:31 PM
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Originally Posted by atlvalet
I'm assuming you have a Walbroor other fuel pump. I don't know the specific answer, but it obviously sounds like you need bigger injectors.
From a layman, my question would be how can injectors function at over 100% duty cycle?
From a layman, my question would be how can injectors function at over 100% duty cycle?
Feb 13, 2006, 01:33 PM
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Going static on the injectors wont induce any strange fuel cut. Have you measured IDC with PWM0in? Also, the 100% point on the load axis is pretty much arbitrary. We just picked a max frequency and assigned that to 100%. We could rescale MAF quite easily with a big-turbo specific firmware update. I'll talk to the software guys tonight...
shiv
shiv
Last edited by shiv@vishnu; Feb 13, 2006 at 01:37 PM.
Feb 13, 2006, 01:37 PM
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Originally Posted by shiv@vishnu
Going static on the injectors wont induce any strang fuel cut. Have you measured IDC with PWM0in?
shiv
shiv
Feb 13, 2006, 04:30 PM
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I tried adding a 105% row, but the XEDE overides it to a 128% row. Any values I put in it gets scrambled and new numbers will appear in the zero row.
Last edited by jj_008; Feb 13, 2006 at 04:34 PM.
Feb 14, 2006, 09:17 AM
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Adding the 128% row seems to have fixed the problem. Hopefully, when I turn up the boost another 4 psi this problem doesn't come back.
Shiv, have you ever seen any problems w/ the traces on the MAF map? Mine seem to be skipping 5000-5500rpm cells which is where I am stupid rich (low 10's). Everything above is 11.5-12.0 and at 4500 its 11.5.
Shiv, have you ever seen any problems w/ the traces on the MAF map? Mine seem to be skipping 5000-5500rpm cells which is where I am stupid rich (low 10's). Everything above is 11.5-12.0 and at 4500 its 11.5.
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Feb 15, 2006, 02:13 PM
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I found the limits to the injectors yesterday. I kept adding fuel (up to positive +8.0) and nothing would move the AFR's lower then 12.1-12.3 at 7000rpm at 28psi. I am ordering some 880cc injectors and sending my ECU in for a reflash Monday.
Feb 15, 2006, 02:43 PM
#9
I assume you aren't on the stock turbo....BTW....I may be interested in your 680s if the price is right.
I have been hanging out in motorsports forum. Most of those fellas recommend bigger than stock injectors for road racing.
After you get the larger injectors and XedeFlash, do you still use the same XEDE maps?
I have been hanging out in motorsports forum. Most of those fellas recommend bigger than stock injectors for road racing.
After you get the larger injectors and XedeFlash, do you still use the same XEDE maps?
Feb 15, 2006, 06:23 PM
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Originally Posted by Jeff_Jeske
I assume you aren't on the stock turbo....BTW....I may be interested in your 680s if the price is right.
I have been hanging out in motorsports forum. Most of those fellas recommend bigger than stock injectors for road racing.
After you get the larger injectors and XedeFlash, do you still use the same XEDE maps?
I have been hanging out in motorsports forum. Most of those fellas recommend bigger than stock injectors for road racing.
After you get the larger injectors and XedeFlash, do you still use the same XEDE maps?
If you do buy injectors you have to get them scaled w/ the XEDEflash and you won't be able to use the base maps. They'll need to be adjusted for the added fuel.
Feb 18, 2006, 05:42 PM
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I don't know what's going on but its starting to irritate me. I keep getting a stutter at 5000rpm and I can't get rid of it. It's running crazy rich right there, but I can't adjust it because it isn't hitting any cells in that column. Actually, I am only hitting 2 columns after 5000rpm. I'm pretty sure this is why my positive fuel adjustment w/ the smaller injectors have had no effect in the 6500-8000rpm range. Now, with my big injectors I am going to have some low AFR problems in those regions and probably an extremely rich spot at 5000rpm.
OK Vishnu, I am going to need your help on this since I have your dyno day coming up next weekend and I would like to attend w/ a functional car.
OK Vishnu, I am going to need your help on this since I have your dyno day coming up next weekend and I would like to attend w/ a functional car.
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