rich carb

vic guilmino · 09-04-2019, 03:52 PM

holley carb go fat at start and low gear in high gear is is about 12.7
need help

Hacksaw · 09-04-2019, 04:19 PM

Using a power valve in primary side?

Ralph A Powell · 09-04-2019, 07:51 PM

Dripping Bosters?

vic guilmino · 09-06-2019, 07:41 PM

yes power valve no dripping

RJ Sledge · 09-06-2019, 08:36 PM

Vic
I’d be looking real hard at the idle circuit.
If your going off a 2-step, wot, it will be rich.
Footbraking you might play around with squirter size, most Holleys are around a 28 Stock I have run as high as a 43.
How fat is it down low ?

RJ

vic guilmino · 09-07-2019, 09:38 AM

10.6 afr

RJ Sledge · 09-07-2019, 07:22 PM

If your O2 is in your collector, and it is within 12” from the end, you will not get a “clear” read, it will always show rich until you bring up rpms as in making a pass down the track then it will read correctly.
You can slip on an 18” extension to the end of collector and tune it for lower rpms (2 step leave or foot brake leave). Then take off extension. It’s is sucking air back up past the O2 sensor and it will show rich until you get rpms up and going down track.

Good luck
RJ

Darrel Goheen · 09-07-2019, 09:14 PM

Quote:

Originally Posted by RJ Sledge

If your O2 is in your collector, and it is within 12” from the end, you will not get a “clear” read, it will always show rich until you bring up rpms as in making a pass down the track then it will read correctly.
You can slip on an 18” extension to the end of collector and tune it for lower rpms (2 step leave or foot brake leave). Then take off extension. It’s is sucking air back up past the O2 sensor and it will show rich until you get rpms up and going down track.

Good luck
RJ

Actually it'll show lean.

Glenn Briglio · 09-08-2019, 08:37 AM

Put O2 sensor in primary pipe.

RJ Sledge · 09-08-2019, 08:51 AM

In my experience on a carb combo it showed rich when staging with 2 step at 3000 rpms or so. Moving O2 or extending collector will correct that.

On an efi combo putting an extension on allowed us to tune it so it did not search and go lean/rich while in 2 step staging. Like the computer couldn’t make up its mind up from due to O2 not getting clean data. That was with a BS3 system but believe it to be the same with all.

Believe Vic’s combo is 780 Holley but maybe not.

RJ

09-04-2019, 03:52 PM	#1
vic guilmino Senior Member Join Date: Dec 2001 Location: wv Posts: 884 Likes: 42 Liked 56 Times in 21 Posts	rich carb holley carb go fat at start and low gear in high gear is is about 12.7 need help __________________ Vic Guilmino 1129 STK

09-04-2019, 04:19 PM	#2
Hacksaw Senior Member Join Date: Sep 2016 Posts: 889 Likes: 211 Liked 314 Times in 177 Posts	Re: rich carb Using a power valve in primary side?

09-04-2019, 07:51 PM	#3
Ralph A Powell Member Join Date: Oct 2017 Location: Bay City Texas Posts: 393 Likes: 2 Liked 227 Times in 138 Posts	Re: rich carb Dripping Bosters?

09-06-2019, 07:41 PM	#4
vic guilmino Senior Member Join Date: Dec 2001 Location: wv Posts: 884 Likes: 42 Liked 56 Times in 21 Posts	Re: rich carb yes power valve no dripping __________________ Vic Guilmino 1129 STK

09-06-2019, 08:36 PM	#5
RJ Sledge Senior Member Join Date: Jun 2007 Posts: 792 Likes: 507 Liked 294 Times in 93 Posts	Re: rich carb Vic I’d be looking real hard at the idle circuit. If your going off a 2-step, wot, it will be rich. Footbraking you might play around with squirter size, most Holleys are around a 28 Stock I have run as high as a 43. How fat is it down low ? RJ

09-07-2019, 09:38 AM	#6
vic guilmino Senior Member Join Date: Dec 2001 Location: wv Posts: 884 Likes: 42 Liked 56 Times in 21 Posts	Re: rich carb 10.6 afr __________________ Vic Guilmino 1129 STK

09-07-2019, 07:22 PM	#7
RJ Sledge Senior Member Join Date: Jun 2007 Posts: 792 Likes: 507 Liked 294 Times in 93 Posts	Re: rich carb If your O2 is in your collector, and it is within 12” from the end, you will not get a “clear” read, it will always show rich until you bring up rpms as in making a pass down the track then it will read correctly. You can slip on an 18” extension to the end of collector and tune it for lower rpms (2 step leave or foot brake leave). Then take off extension. It’s is sucking air back up past the O2 sensor and it will show rich until you get rpms up and going down track. Good luck RJ

09-08-2019, 08:37 AM	#9
Glenn Briglio VIP Member Join Date: Nov 2002 Location: Massapequa Park,NY Posts: 1,290 Likes: 1,914 Liked 977 Times in 312 Posts	Re: rich carb Put O2 sensor in primary pipe. __________________ 1989 Camaro Iroc-Z I/SA B&B Auto Machine Shop.

09-08-2019, 08:51 AM	#10
RJ Sledge Senior Member Join Date: Jun 2007 Posts: 792 Likes: 507 Liked 294 Times in 93 Posts	Re: rich carb In my experience on a carb combo it showed rich when staging with 2 step at 3000 rpms or so. Moving O2 or extending collector will correct that. On an efi combo putting an extension on allowed us to tune it so it did not search and go lean/rich while in 2 step staging. Like the computer couldn’t make up its mind up from due to O2 not getting clean data. That was with a BS3 system but believe it to be the same with all. Believe Vic’s combo is 780 Holley but maybe not. RJ

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