AFR Lean on 90% E85 mix??? - E85Performance.net

turbohemi6 · 03-06-2010, 07:26 PM

Question:
I am having issues with not enough fuel up top wth my E85 carby turbo set up. Apperently the fuel pump and carby are plenty big enough but no matter how big or small I jet the carby down th AFR does not seem to change??? Th car seems t be running fine though.

I have done tests on the fuel which I am getting out of a pump here and it is reading 90% ethanol. Is this the problem???
If I add more gasoline to the mix to bring it down to the 85 % mix will this read the AFR differently?

rancherort · 03-06-2010, 09:58 PM

What carb are you using? I'll assume it's a holley 4bbl. Depending on your setup you may need some jet extensions in the secondary bowl. You also need to have 6psi more fuel pressure over the max boost your turbo makes with a blow thru setup. I say no more than 10psi boost your carb cannot handle air that dense on a blow thru. If it's under 10psi your ok but than that points to a fuel supply problem. 90% ethanol will cause a leaner condition but you'll see it across the board not at full throttle only!!! good luck

turbohemi6 · 03-07-2010, 02:59 AM

The carb is a 4bbarrl Holley built proffeionally by CSU to suit E85. Base pressure is 7 psi and rises 1:1 with boost.

Stangfireman · 03-07-2010, 07:35 PM

What fuel pump are you running and line size?

turbohemi6 · 03-07-2010, 10:14 PM

A1000 pump and reg, -10 feed, -8 return, twin -6 feed as per aeromotive recomendation.

corey872 · 03-08-2010, 08:54 AM

Quote:

Originally Posted by turbohemi6

...no matter how big or small I jet the carby down th AFR does not seem to change??? ...

Well, there is your problem. What are you using to measure AFR? It sounds like it's broken. What is the actual number?

turbohemi6 · 03-09-2010, 02:06 AM

No, I used a hand held Innovate LM1 and also the dyno had one and were both reading the same. Its not the air fuel meters.

89shortbox · 03-12-2010, 02:48 AM

if possible start the car with the return line unhooked and see if there is a difference in your base pressure. If its more than 1 or 2 psi different than its possible that your return line being smaller than the feed line is causing your base pressure to be artificially high then when you get into boost the fuel pressure is to low.

03-06-2010, 07:26 PM	#1
turbohemi6 Junior Member Join Date: Jan 2010 Posts: 23	AFR Lean on 90% E85 mix??? Question: I am having issues with not enough fuel up top wth my E85 carby turbo set up. Apperently the fuel pump and carby are plenty big enough but no matter how big or small I jet the carby down th AFR does not seem to change??? Th car seems t be running fine though. I have done tests on the fuel which I am getting out of a pump here and it is reading 90% ethanol. Is this the problem??? If I add more gasoline to the mix to bring it down to the 85 % mix will this read the AFR differently?

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03-06-2010, 09:58 PM	#2
rancherort Member Join Date: May 2008 Posts: 35	What carb are you using? I'll assume it's a holley 4bbl. Depending on your setup you may need some jet extensions in the secondary bowl. You also need to have 6psi more fuel pressure over the max boost your turbo makes with a blow thru setup. I say no more than 10psi boost your carb cannot handle air that dense on a blow thru. If it's under 10psi your ok but than that points to a fuel supply problem. 90% ethanol will cause a leaner condition but you'll see it across the board not at full throttle only!!! good luck

03-07-2010, 02:59 AM	#3
turbohemi6 Junior Member Join Date: Jan 2010 Posts: 23	The carb is a 4bbarrl Holley built proffeionally by CSU to suit E85. Base pressure is 7 psi and rises 1:1 with boost.

03-07-2010, 07:35 PM	#4
Stangfireman Junior Member Join Date: Dec 2009 Location: Choctaw, Oklahoma Posts: 21	What fuel pump are you running and line size?

03-07-2010, 10:14 PM	#5
turbohemi6 Junior Member Join Date: Jan 2010 Posts: 23	A1000 pump and reg, -10 feed, -8 return, twin -6 feed as per aeromotive recomendation.

03-09-2010, 02:06 AM	#7
turbohemi6 Junior Member Join Date: Jan 2010 Posts: 23	No, I used a hand held Innovate LM1 and also the dyno had one and were both reading the same. Its not the air fuel meters.

03-12-2010, 02:48 AM	#8
89shortbox Senior Member Join Date: Jan 2008 Posts: 113	if possible start the car with the return line unhooked and see if there is a difference in your base pressure. If its more than 1 or 2 psi different than its possible that your return line being smaller than the feed line is causing your base pressure to be artificially high then when you get into boost the fuel pressure is to low.